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Madhusudan, S., M. M. M. Sarcar, and N. R. M. R. Bhargava. "Fabrication and characterization of aluminium–copper composites." Journal of Alloys and Compounds 471, no. 1-2 (2009): 116–18. http://dx.doi.org/10.1016/j.jallcom.2008.04.025.
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Soda, H., C. K. Jen, G. Motoyasu, S. Okumura, A. Ohno, and A. McLean. "Fabrication and characterisation of aluminium clad aluminium–copper alloy cored rod." Materials Science and Technology 11, no. 11 (1995): 1174–79. http://dx.doi.org/10.1179/mst.1995.11.11.1174.
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O'Sullivan, Eugene J., Cristina T. Camagong, Ria Paranjape, Marinus Hopstaken, and Christian Lavoie. "An Investigation of Tin Electroless Deposition." ECS Meeting Abstracts MA2022-02, no. 23 (2022): 958. http://dx.doi.org/10.1149/ma2022-0223958mtgabs.
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Electroless metal/alloy deposition can be an efficient process in certain areas of microelectronic fabrication. In fact, it is often easier to obtain coatings of uniform thickness and composition using electroless deposition than with electrodeposition, since one does not have the current density uniformity problem of the latter. For example, we were able to develop a Ni(P) process as a replacement for the final aluminum interconnect level, significantly decreasing wafer processing cycle time, by selectively depositing a Ni(P) capping layer on the Cu bitline wiring level. In STTM MRAM, we successfully employed this Ni(P) capping process to enable the evaluation of memory state retention via functional testing in an air atmosphere at elevated temperatures (1). However, there is a need to explore materials + deposition methods for rapidly developing fields, such as Quantum computing, e.g., materials with superconducting properties. Conventional electroless metal deposition, utilizing a separate reducing agent, can deposit materials with unique and useful properties, such as phosphorus-containing alloys in the case of hypophosphite reducing agents. This talk discusses work we have carried out on electroless tin deposition, including aspects of electroless solution preparation and stability, copper substrate surface preparation and catalyzation, and the mechanisms of electroless deposition and solution decomposition. Electroless processes can deposit a limited number of materials, especially pure metals. This is in part due to conventional electroless processes requiring catalytically active surfaces both to initiate the deposition reaction and to sustain it, the heterogeneous oxidation of the reducing agent being a kinetically hindered process, often with multiple reaction pathways (2). Though not possessing good catalytic activity due to its Periodic Table related, p -block element status, pure Sn, an environmentally robust, superconducting metal, can be electrolessly deposited through a disproportionation reaction involving stannous ions (3) in an alkaline aqueous medium. We achieved electroless Sn deposition rates of up to 8 – 9 μm/hr for tartrate-citrate complexed electroless Sn solutions in the temperature range 80 – 85 ⁰C with sodium and potassium hydroxides to adjust alkalinity. We found that either in-house formulated, or commercially available, immersion Sn solutions deposited a uniform Sn catalyst layer (≤ 0.5 μm) to initiate the electroless Sn deposition reaction on copper; however, improperly formulated immersion Sn solutions rapidly developed precipitates due to tin ion hydrolysis. The biggest technical challenge was minimizing unwanted electroless deposition of tin in bulk solution, i.e., deposition not associated with the catalytically active substrate surface. Tin oxide (SnO) is known to be metastable at ambient conditions and to decompose at temperatures above 300 ⁰C with “noticeable rate” into Sn and SnO2 (4). Thus, removal of filterable hydrolysis products of Sn(II) following solution preparation was important, but not always sufficient, for obtaining solutions that were viable for several days of use. The reasons for, and mechanisms of, electroless Sn solution decomposition do not appear to have been adequately addressed in the literature. We will show SIMS analysis of both immersion and electroless Sn layers along with synchrotron X-Ray analysis results of immersion Sn catalyst films on Cu to determine the extent of Sn-Cu intermetallic formation following their formation. We will discuss the current understanding of the mechanism of electroless Sn deposition including that of concomitant H2 gas evolution. We will conclude with contrasting the Ni(P) and Sn electroless processes in terms of ease of operation and reliability for routine processing. † Present address: Solvay, 1937 West Main Street, Stamford 06902, CT. ‡ Quantum intern at the IBM TJ Watson Research Center, Summer 2019, 2020 and 2021. [1]. E. J. O'Sullivan, C. Camagong et al., 2019 Meet. Abstr. MA2019-02 916; https://doi.org/10.1149/MA2019-02/15/916. [2]. E. J. O'Sullivan, Ch 5, Advances in Electrochemical Science and Engineering, Volume 7, https://doi.org/10.1002/3527600264.ch5. [3]. A. Molenaar and J. W. G. de Bakker, 1989, J. Electrochem. Soc. 136, 378 and refs therein; H. Koyano, M. Kato, and M. Uchida, 1991, Plating and Surface Finishing, 78, 68-74 and refs therein. [4]. H. Giefers et al, 2005, Solid State Ionics, 176, 199-207; https://doi.org/10.1016/j.ssi.2004.06.006. Acknowledgements The authors gratefully acknowledge the efforts of the staff of the Microelectronics Research Laboratory (MRL) at the IBM T. J. Watson Research Center, where some of the fabrication work described in this talk was carried out.
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Mamalis, A. G., N. M. Vaxevanidis, A. Szalay, and J. Prohaszka. "Fabrication of aluminium/copper bimetallics by explosive cladding and rolling." Journal of Materials Processing Technology 44, no. 1-2 (1994): 99–117. http://dx.doi.org/10.1016/0924-0136(94)90042-6.
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Loganathan, Arulmurugan, and Ilangkumaran Mani. "Experimental investigations on Thermal Performance of Copper with Aluminium Based Finned Heat sinks for Electronics Cooling System." JOURNAL OF ADVANCES IN CHEMISTRY 12, no. 12 (2016): 4582–87. http://dx.doi.org/10.24297/jac.v12i12.787.
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An Experimental investigation on the thermal performance of copper with aluminium based finned heat sinks for electronics cooling system was studied. The heat sinks have different material proportions containing major constituent of aluminium and minor constituent of copper. Considered with straight finned heat sink for the experiments for its easiness in fabrication and efficient heat transfer properties. The observational results for aluminium with copper alloy are compared with pure aluminium heat sink. Heat sink geometry, fin pitch and its height were taken from the commercially available heat sinks. In this research work best heat sink geometry is chosen and cooked up with different volume of copper added with aluminium. Selected four different spots of heat sinks and the temperature raising characteristics were measured for natural convection. also the temperature is raised to a fixed temperature and the temperature lowering characteristics were measured in forced convection as the air circulation takes more heat to keep the heat sink temperature within the desired level.
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Kawashima, Satoshi, та Kazutaka Tajima. "Advanced Chemical Processes for Semi-additive PWB fabrication for Fine Line Formation Targeting Line and Space=5μm/5μm". International Symposium on Microelectronics 2015, № 1 (2015): 1–4. http://dx.doi.org/10.4071/isom-2015-tha22.
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Demand of powerful & fast computing requires the packaging configured with finer lines. The current requirement for Line and Space (L/S) is around 10μm/10μm, it will go down to less than that and 5 μm/5 μm is industry's target in our site. To achieve this miniaturization, a number of improvements are ongoing in equipment, material and chemical for surface finishing process. It seems there is a threshold which requires non-contiguous improvement for the miniaturization. The improvement in surface finishing process requires finer surface roughening for Dielectric material, selective dissolution of metals, or same metal made by different method such as Electroless copper and Electroplated copper, which never exist in the industry. In this paper, advanced chemical processes for semi-additive process (SAP) to fabricate PWB with fine line formation targeting L/S =5μm/5μm are reported. The series of improvements of chemical process enables confidence to manufacture fine lines which L/S=5μm/5μm using finer surface roughening of Electroless copper seed for better Dry Film Resist (DFR) formation, better stripping of the DFR, selective dissolution of Electroless copper seed, finer surface roughening for Solder Mask application, etc.
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Chung, C. ‐K, C. Y. Yang, M. W. Liao, and S. L. Li. "Fabrication of copper nanowires using overpotential electrodeposition and anodic aluminium oxide template." Micro & Nano Letters 8, no. 10 (2013): 579–81. http://dx.doi.org/10.1049/mnl.2013.0269.
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Thompson, George E. "The Role of Alloying Elements on the Surface Treatment and Finishing of Aluminium." Materials Science Forum 519-521 (July 2006): 615–20. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.615.
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The influence of alloying elements, deliberate or otherwise, and material processing on the performance of aluminium during surface treatment and finishing are considered. Thus, with a significant focus on copper, but with consideration of other elemental additions, the behaviour of aluminium during growth of oxide at ambient temperature, etching or pickling, conversion coating and anodizing, essential processes for generation of fit-for-purpose products, is highlighted. Further, such processes generate, modify or transform the initially present air-formed alumina film. Consequently, with knowledge of the phenomena proceeding at the alloy/film and film/environment interfaces and those within anodic or other films, the possibility of controlling features of nanoscale dimensions for improved performance arises. For example, deliberate selection of alloying elements enables control of nanotextures formed at treated surfaces, and formation of compositionally and morphologically modified films as well as generation of nanoparticles with various functional properties.
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Lin, Jia-Horng, Bing-Chiuan Shiu, Ching-Wen Lou, and Yuan-Jen Chang. "Design and Fabrication of Smart Diapers with Antibacterial Yarn." Journal of Healthcare Engineering 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/8046134.
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In this study, intelligent eco-diapers are made by combining antibacterial yarns coated with quaternary ammonium salts with conductive yarns to improve caretaking for urinary incontinence. The combination of conductive yarns and sensors can detect the moisture content in eco-diapers, and an alarm is sent when moisture is significant. A wireless module is used to send detected signals to a smartphone or tablet PC via the Internet. This concept is used for a scenario in which nurses do not randomly check on patients in a long-term care institution. When used offline, eco-diapers can send caregivers an alarm for the need to change diapers via cell phones. The diameters of the copper and silver-plated copper fibers are 0.08 and 0.10 mm, respectively. Cotton yarns are twisted with copper and silver-plated copper fibers to form the conductive yarns, which are 0.12 mm in diameter. Moreover, 30-count cotton and 150 D nylon yarns are coated with quaternary ammonium salt via dyeing and finishing processes to form antibacterial yarns. In the current study, intelligent eco-diapers are tested for their electrical and antibacterial properties as specified by AATC and JISL test standards.
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Vedrtnam, Ajitanshu, and Anuj Kumar. "Fabrication and wear characterization of silicon carbide and copper reinforced aluminium matrix composite." Materials Discovery 9 (September 2017): 16–22. http://dx.doi.org/10.1016/j.md.2018.01.002.
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Ghane, Mohammad, and Ehsan Ghorbani. "Investigation into the UV-Protection of Woven Fabrics Composed of Metallic Weft Yarns." Autex Research Journal 16, no. 3 (2016): 154–59. http://dx.doi.org/10.1515/aut-2015-0021.
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Abstract The destructive effects of sun UV radiation on human skins are now very clear to everyone. Most of the present studies were focused on the fabrics’ structural parameters such as density, warp and weft yarns finenesses, fabric pattern and printing or finishing treatments applied to the fabrics. The aim of this work is achieving a technique through which the produced fabrics possess a higher UV-protection ability. For this purpose, two different metals including aluminium and copper yarns were employed in fabrics production process and their effects on UV-protection ability of the produced fabrics were investigated. Six different fabric samples comprised of either cotton/polyester, nylon yarns as the warp yarns as well as either aluminium or copper yarns as the weft yarns were produced. Using the spectrophotometer technique, which is known as one of the UPF measuring method, the absorbency and reflectivity of fabrics within the specified range of electromagnetic waves (specially the UV radiation) were determined. The results illustrated that the higher UV absorbency was related to the fabric possessing the copper yarns in their structures. It was concluded that the absorption ability of nylon fabrics is higher than that of the cotton/polyester samples.
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Mohammed, Ali Musa, Yi Wang, Talal Skaik, Sheng Li, and Moataz Attallah. "Conductivity measurement using 3D printed re-entrant cavity resonator." Measurement Science and Technology 33, no. 5 (2022): 055017. http://dx.doi.org/10.1088/1361-6501/ac5134.
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Abstract A technique for measuring effective conductivity of conductor materials using 3D printed re-entrant cavity resonator is proposed. An analytical formula for the extraction of the effective conductivity has been derived in relation to energy stored in the volume of the cavity geometry. A method of resonant cavity characterisation of material based on microwave losses is utilised for the measurements. The approach offers a simplified analytical method and also supports the measurements of sample with arbitrary thickness. Samples produced from three different manufacturing processes of computer numerical control (CNC) and 3D printing, made of aluminium, copper and stainless steel were measured to demonstrate the method. The 3D printed and copper coated polymer sample is considered as reference material for the measurements. The measured results have shown that the copper coated polymer sample have similar conductivity with that CNC copper. This signifies the good finishing, low surface roughness and quality of copper coating used in 3D printed polymer device.
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Waqar, Tayyab, and Sezgin Ersoy. "Design and Analysis Comparison of Surface Acoustic Wave-Based Sensors for Fabrication Using Additive Manufacturing." Journal of Nanomaterials 2021 (June 12, 2021): 1–12. http://dx.doi.org/10.1155/2021/5598347.
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Sensors have become an integral part of our everyday lives by helping us converting packets of data to make important decisions. Due to this reason, researches are done constantly to improve the fabrication processes of sensors by making them more user-friendly, less time-consuming, and more cost-effective. The application of any fabrication solution that offers those advantages will have a major impact on the manufacturing of modern sensors. To address this issue, a 3D printed Surface Acoustic Wave (SAW) temperature sensor is presented in this paper. The modelling and analysis of such a sensor have been performed for both aluminium and copper electrodes using COMSOL software. In total, 4 different sensing structures, 2 each for both aluminium and copper electrodes based one-port resonators, are designed and analysed for their application in temperature sensing. The resulting responses of those sensors are approximately 2.19 MHz and 424.01 MHz frequency ranges. The novelty lies in the possibility of mass-producing such a sensor using additive manufacturing will have a direct impact in the areas where conventional electronics cannot be utilized.
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Gu, Feng, Chorng Haur Sow, Guo Qin Xu, and Siau Gek Ang. "Fabrication and Field Emission Properties of Poly-CuTAPc Nanowires and Nanotubes." Australian Journal of Chemistry 62, no. 9 (2009): 1007. http://dx.doi.org/10.1071/ch09233.
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Poly-copper tetraaminophthalocyanine (CuTAPc) nanowires and nanotubes were successfully fabricated on porous anodic aluminium oxide (AAO) templates by electropolymerization and characterized. The product of electropolymerization, whether as nanowires or nanotubes, is a function of the monomer concentration and template pore size. The morphology and field emission properties of these nanostructures were studied for investigation of potential application as field emitters. They show interesting turn-on field, maximum current density and enhancement factor, comparable to many other organic nanomaterials.
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Yasuda, Hideyuki, Itsuo Ohnaka, B. K. Dhindaw, et al. "Fabrication of Porous Aluminium and Copper Media by Using Monotectic Solidification under a Magnetic Field." Materials Science Forum 512 (April 2006): 289–94. http://dx.doi.org/10.4028/www.scientific.net/msf.512.289.
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Unidirectional solidification of Al-In, Cu-Pb and Cu-Pb-Al monotectic alloys was performed under static magnetic fields up to 10T for formation of the regularly aligned-rod structure. mThe imposition of static magnetic fields exceeding 4T suppressed movement of the In liquid droplets at the Al solidifying front and enhanced the engulfment of the In droplets into the front. As a result, the eutectic-like structure was obtained in the Al-10 and 15at%In hypermonotectic alloys. The micro X-ray tomography indicated that the continuous In rods with diameters of 10-20 µm were aligned parallel to each other. In the case of the Cu-Pb and the Cu-Pb-Al alloys, the imposition of static magnetic fields also enhanced the formation of the aligned Pb rods. The electrochemical etching by using a 10% HNO3 solution successfully removed the minor phase, and the porous aluminum and copper with deep pores were fabricated.
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Guedes, Mafalda, José Maria F. Ferreira, and Alberto C. Ferro. "A Study on CuO-Al2O3 Infiltration by Aluminium." Materials Science Forum 636-637 (January 2010): 571–77. http://dx.doi.org/10.4028/www.scientific.net/msf.636-637.571.
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This paper reports preliminary studies regarding a new fabrication process for aluminium alloy matrix particulate reinforced composites, which uses ceramic preforms with alumina and tailored amounts of reactive copper oxide, CuO. An Al2O3-CuO mixture with 75 mol% CuO was selected, aiming at a 10-40vol% reinforcement phase fraction in the final composite, after aluminium infiltration. Molten aluminium infiltration progress was studied as a function of ceramic’s composition, doping, and infiltration time. The resulting microstructures were investigated by OM, SEM, FESEM and EDS in order to establish the liquid aluminium infiltration profile at the metal/ceramic interface. Infiltration experiments showed that the 3CuO (s) + 2Al (l) → 3Cu (l) + Al2O3 (s) redox reaction is triggered at the experimental conditions used, but the infiltration process is slow and does not go to completion. The use of NaOH as a doping agent promotes effective infiltration of molten aluminium upon the ceramic green mixture.
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Guimarães, Marcos de Aguiar, Givanildo Alves dos Santos, Mauricio S. Nascimento, et al. "Study on the Wear of Cutting-Tools Used in Dry Machining of Cu-10wt%Al-5wt%Ni-5wt%Fe Alloy." Defect and Diffusion Forum 413 (December 17, 2021): 194–200. http://dx.doi.org/10.4028/www.scientific.net/ddf.413.194.
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Aluminium bronze alloys are special copper alloys that have a machinability rate from 20 to 40% compared to free cutting brasses, so the cutting parameters and type of tools suitable for machining of these materials may be very different for other copper alloys. Also, due to the relative high costs of the raw material, the absence of contamination of the chips by cutting fluids improve its intrinsic resales value and encourage the use of machining process without coolant. The aim of this work is to evaluate the tool wear mechanisms in the finishing machining of the Cu-10wt%Al-5wt%Ni-5wt%Fe aluminium-bronze alloy with carbide and cermet inserts at different cutting speeds under dry machining condition. The turning of material showed lower surface roughness in higher speed conditions and better dimensional stability at lower speeds. It was observed the formation of continuous chips, but of little volume occupied. The scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of tool wear show the adhesion as the main tool wear mechanism, followed by abrasion. At the lower cutting speed, the adhesion wears affected significantly the surface finish, reducing the tool life in comparison to the higher speeds.
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Fang, Lijia, Jing Huang, Yi Liu, Botao Zhang, and Hua Li. "Cored-wire arc spray fabrication of novel aluminium-copper coatings for anti-corrosion/fouling hybrid performances." Surface and Coatings Technology 357 (January 2019): 794–801. http://dx.doi.org/10.1016/j.surfcoat.2018.10.094.
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Dixit, Nitesh Kumar, Rajeev Srivastava, and Rakesh Narain. "Improving surface roughness of the 3D printed part using electroless plating." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, no. 5 (2017): 942–54. http://dx.doi.org/10.1177/1464420717719920.
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The effect of electroless metallic coating on 3D printed acrylonitrile–butadiene–styrene plastic parts surface has been studied. Owing to its excellent toughness, good-dimensional reliability, good-process capability, chemical resistance and cost-effectiveness, acrylonitrile–butadiene–styrene is used for fabrication of parts using a 3D open source printer. These parts are further metallic coated using electroless copper deposition technique. Two different surface preparation processes, namely aluminium paint paste and aluminium epoxy paste have been used for electroless coating. After the surface conditioning of parts using these methods, copper is deposited electrolessly using acidic solution, containing 12.5 wt% copper sulphate with 7.5 wt% of sulphuric acid. Deposition of copper, for two different methods, has been carried out using different temperature conditions and different time of deposition. In the first case, the temperature of the solution is initially kept at 45±2 ℃ and is allowed to come to the room temperature as the deposition is completed. In the second case, the temperature of the solution is maintained at room temperature throughout the process. Further, copper-deposited 3D printed parts were characterized based on their surface roughness measurement, electrical conductivity measurement, scanning electron microscopy, energy dispersive spectroscopy and adhesion evaluation test. It has been found that both the methods used for coating show better electrical performance and more uniform copper deposition. Adhesion between copper layers and 3D printed acrylonitrile–butadiene–styrene substrates is found to have good strength for Al-Epoxy-coated parts.
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Veselovsky, A. A., V. V. Erofeev, and I. P. Troyanovskaya. "Improving the Quality of Friction Surface by Applying Antifriction Materials to Them." IOP Conference Series: Earth and Environmental Science 949, no. 1 (2022): 012133. http://dx.doi.org/10.1088/1755-1315/949/1/012133.
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Abstract The article investigated the process of applying antifriction coatings to the surface of hardened cast iron gear wheels. The diffusion coating of cast iron wheels with vanadium greatly strengthened the surface and increased its wear resistance. Aluminium, tin bronze and copper were used as antifriction materials. The coating was applied with metal brushes. The brushes tore off individual fragments of anti-friction metal particles and smeared them over the surface of the coated product. Research results have confirmed the acceptability of this method instead of expensive finishing operations that cannot be applied to diffusion-hardened gears due to the shallow depth of the vanadium coating. The proposed method is universal for all types of metal products operating under sliding friction conditions. Results are presented as spatial histograms.
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H. Mustafa, N., N. N. A. Basir, R. E. Ibrahim, et al. "Characterization of in Situ Zirconium Diboride (Zrb2) Reinforced by Aluminium-Copper (Al-Cu) Metal Matrix Composites." International Journal of Engineering & Technology 7, no. 4.14 (2019): 406. http://dx.doi.org/10.14419/ijet.v7i4.14.27694.
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Aluminium matrix composites by way of in-situ reaction has arisen as a preference conducive to knock out imperfections and defects exiting within ex situ MMC. In the present work, Al-Cu-ZrB2 have been develop through in situ reaction which boost mechanical properties over dispersion strengthening together with grain refinement obtained by the existence of each particulates inside the melt all along solidification. Al-Cu reinforced among different proportion of ZrB2 (0, 3 and 6 wt. %) synthesized using in situ fabrication at 800 °C of molten aluminum-copper alloys by inorganic salts K2ZrF6 together with KBF4. The amalgam were specified using XRD, FESEM together with mechanical test on appropriately sectioned and metallographically prepared surface to examine and inspect phase distribution, hardness together with tensile properties. From result acquired, raised ZrB2 amount will increase rate of tensile and hardness characteristics of Al-Cu alloy. XRD patterns exposed development of ZrB2 particulates without existence of unspecified other compounds. Most of ZrB2 granular were located near grain boundaries of Al dendrites. Microstructural analysis exposed the homogeneous and consistent allocation of second phase particles, clean interface and favorable bonding. It is support that ZrB2 molecules are predominantly in nano size among hexagonal either tetragonal shape, yet minor molecules in micron size are also noticed. For that reason, composite synthesized using in situ techniques exhibit homogeneous distribution of reinforcing tend to be superlative associated within clean interface along the metallic matrix. In order to accomplish better mechanical features, it is necessary to regulate and control phase arrangement all along fabrication of Al-Cu with higher contents of ZrB2.
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Imai, Ken, Toshi Taka Ikeshoji, Kazuya Nakamura, Motonori Nishida, Yuji Sugitani, and Hideki Kyogoku. "Fabrication of Cu-Al-Ni Shape Memory Alloy by Selective Laser Melting Process." Materials Science Forum 941 (December 2018): 1570–73. http://dx.doi.org/10.4028/www.scientific.net/msf.941.1570.
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Additive manufacturing (AM) is a prominent technology in the industrial fields such as aerospace, medical, automotive and so on. Especially, selective laser melting (SLM) process is available to create three-dimensional complicated structures of various alloys such as stainless steel, titanium alloy, aluminium alloy, nickel-based superalloy and so on. And also, copper and copper alloys are used as a material for products with complicated shape, electrical components, and a heat exchanger because of having the high electrical conductivity and the high thermal conductivity. It is known that copper alloys show a good shape memory behaviour by adding Al, Ni and Zn. Especially, Cu-Al-Ni alloy shows a good shape memory properties at high temperature. However, it is difficult to fabricate high-density Cu-Al-Ni alloy by the SLM process. This is mainly because Cu-Al-Ni alloy has high elastic anisotropy and brittleness in polycrystalline state. In this research, the optimum fabrication condition of Cu-Al-Ni alloy by SLM process was investigated. The optimum laser power and scan speed were able to be found by evaluating the surface morphology, density and microstructure of the as-build specimens.The maximum density of the as-built specimen was 99.47%.
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Wilson, Keith, Cristian A. Marocico, Esteban Pedrueza-Villalmanzo, Christopher Smith, Calin Hrelescu, and A. Louise Bradley. "Plasmonic Colour Printing by Light Trapping in Two-Metal Nanostructures." Nanomaterials 9, no. 7 (2019): 963. http://dx.doi.org/10.3390/nano9070963.
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Structural colour generation by nanoscale plasmonic structures is of major interest for non-bleaching colour printing, anti-counterfeit measures and decoration applications. We explore the physics of a two-metal plasmonic nanostructure consisting of metallic nanodiscs separated from a metallic back-reflector by a uniform thin polymer film and investigate the potential for vibrant structural colour in reflection. We demonstrate that light trapping within the nanostructures is the primary mechanism for colour generation. The use of planar back-reflector and polymer layers allows for less complex fabrication requirements and robust structures, but most significantly allows for the easy incorporation of two different metals for the back-reflector and the nanodiscs. The simplicity of the structure is also suitable for scalability. Combinations of gold, silver, aluminium and copper are considered, with wide colour gamuts observed as a function of the polymer layer thickness. The structural colours are also shown to be insensitive to the viewing angle. Structures of copper nanodiscs with an aluminium back-reflector produce the widest colour gamut.
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Nakajima, Hideo, Takuya Ide, and Song Youl Kim. "Fabrication of Porous Metals with Directional Pores through Solidification of Gas-Dissolved Melt." Materials Science Forum 620-622 (April 2009): 785–90. http://dx.doi.org/10.4028/www.scientific.net/msf.620-622.785.
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Porous metals with long cylindrical pores aligned in one direction were fabricated by unidirectional solidification using pressurized gas (hydrogen) method (PGM) and thermal decomposition method (TDM). The pores are evolved from insoluble gas when the molten metal dissolving the gas is solidified. In the conventional PGM, the hydrogen pressurized in a high-pressure chamber is used as the dissolving gas. However, the use of high-pressure hydrogen is not desirable because of inflammable and explosive gas, in particular, for scaling up to mass production of lotus metals. In order to overcome this shortcoming, the thermal decomposition method was developed as an alternative simple fabrication method. Gas-forming compounds were added into the molten metal to fabricate lotus metals. The porosity and pore size were controlled by the amount of gas-forming compounds. TDM was applied to fabricate porous copper and aluminium
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Klarić, Štefanija, Zlatko Botak, Damien J. Hill, Matthew Harbidge, and Rebecca Murray. "Application of a Cold Spray Based 3D Printing Process in the Production of EDM Electrodes." Tehnički glasnik 14, no. 1 (2020): 27–31. http://dx.doi.org/10.31803/tg-20190719094329.
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Cold spray process principles allow the production of near-net-shape metal parts with a fast layer deposition by using 3D printing techniques via supersonic 3D deposition (SP3D). This innovative additive manufacturing process allows an easy and quick production of copper and aluminium parts with future possibilities to expand materials and alloys. The speed and materials enable the application of this cold spray based 3D printing process for the production of tools. In this paper, Electrical Discharge Machining (EDM) electrodes were fabricated by using SP3D to investigate its application in tool production. Requirements for the materials of electrodes and some existing solutions for the production of EDM electrodes with additive manufacturing methods are described first. The fabrication and experimental results are then presented for 3D printed copper EDM electrodes that were tested by using St 37-2 (DIN 17100) steel as the workpiece.
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Nakajima, Hideo. "Fabrication of Porous Metals with Directional Pores through Unidirectional Solidification of Gas-Dissolved Melt." Materials Science Forum 654-656 (June 2010): 1452–55. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.1452.
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Lotus-type porous metals with long cylindrical pores aligned in one direction are fabricated by unidirectional solidification through thermal decomposition method (TDM). The pores are evolved from insoluble gas when the molten metal dissolving the gas is solidified. In the conventional pressurized gas method, hydrogen pressurized in a high-pressure chamber is used to dissolve hydrogen in the melt. However, the use of high-pressure hydrogen is not desirable because of its inflammability and explosive nature. This is particularly true when scaling up to mass production of lotus/Gasar metals. In order to overcome this shortcoming, the thermal decomposition method was developed. Gas-forming compounds such as hydrides were added into the molten metal to fabricate lotus/Gasar metals. The porosity and pore size were controlled by the amount of gas-forming compounds, solidification rate, atmospheric pressure, etc. TDM method is applied to fabricate lotus copper, aluminium and iron.
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Pal, Vijay Kumar, and Anuj Kumar Sharma. "Complex shaped micro-channels generation using tools fabricated by AWJ milling process." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 236, no. 1 (2021): 194–201. http://dx.doi.org/10.1177/09544089211053684.
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Fabrication of complex shape micro-channels is a major challenge for manufacturing industries. Currently in commercial applications, lithography and non-conventional machining processes like lasers, electro-discharge machining (EDM) and chemical etching are commonly used for fabrication of these channels. In the present work, a novel Abrasive water jet (AWJ) milling based tool fabrication strategy has been proposed and implemented to make micro-tools (die/ electrode). The path strategy for jet movement is considered in a manner to selectively remove metal from a piece of material such that the resulting three-dimensional features become the required die shape that can be used as tool for the texturing process. Micro-tool of complex shape as fabricated on hard material (EN 31) sheet of 12 mm thickness and its geometry were analysed by controlling the step over (SO) distance. Hydraulic control based hard press contact texturing setup was developed to analyse the performance of such fabricated tools. Experiments were conducted on soft materials like, PMMA, Copper, Brass, aluminium and Nylon. Taper along the depth of the channels was observed because of the taper of the tool during fabrication. During fabrication, width of the tool less than 200 μ m was found wavi in nature as there was not enough backing material present to bear the side wise jet pressure of impinging jet. Buckling on the tools was observed with tool height greater than 1 mm.
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Jahnes, Christopher, Eric Huenger, and Scott Kisting. "Evaluation of Low Stress Photo-Sensitive Spin On Dielectric Layers for Through Silicon Via (TSV) Copper Redistribution Layers." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, DPC (2011): 000666–98. http://dx.doi.org/10.4071/2011dpc-ta32.
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To increase performance of semiconductor devices advances in packaging such as chip stacking (3D) and silicon carrier technologies (SoC) are being developed. Adaptation of these packaging fabrication methods offers the ability to incorporate functionality as well as provide memory and power distribution on one IC with increased signal bandwidth. An enabling element in both the stacking and silicon carrier technologies is through silicon vias (TSV) which electrically connect dies to a silicon carrier or via stacked chips (1). Creation of TSV involves via fabrication, wafer thinning and back side wafer finishing, to name a few, some of which are relatively new to semiconductor processing. Furthermore, because the wafer backside is accessible it can now be utilized to route wiring to further increase package density. The focus of this research was to evaluate photo-sensitive spin on dielectric materials (SOD) that can be used as the backside wiring levels, commonly referred to as redistribution layers (RDL) in TSV technologies. The two materials evaluated are; the epoxy based Dow INTERVIA™ 8023 Dielectric and the Benzocyclobutene (BCB) polymer, Dow CYCLOTENE™ 4000 product series. These dielectric materials have low stress and provide good planarization (2). Test vehicles with a chip size of 3.7 cm x 2.26 cm were fabricated with a 6 um wide copper RDL layer using the SOD materials of interest as well as conventional PECVD SiO2/SiN dielectric layers. The large chip size accommodated parallel Cu lines running 1.8 cm long with a spacing of 3 m and represented an aggressive shorting test for the SOD materials. It also enhances chip distortion after thinning and is evaluated for all three test vehicles. Chips were then electrically tested through simulated 260° C reflow cycles (for flip chip joining) and accelerated thermal reliability tests from −55° C to 125° C for 1000 cycles.
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Somov, Pavel A., Eugene S. Statnik, Yuliya V. Malakhova, et al. "On the Grain Microstructure–Mechanical Properties Relationships in Aluminium Alloy Parts Fabricated by Laser Powder Bed Fusion." Metals 11, no. 8 (2021): 1175. http://dx.doi.org/10.3390/met11081175.
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Recent years witnessed progressive broadening of the practical use of 3D-printed aluminium alloy parts, in particular for specific aerospace applications where weight saving is of great importance. Selective laser melting (SLM) is an intrinsically multi-parametric fabrication technology that offers multiple means of controlling mechanical properties (elastic moduli, yield strength, and ductility) through the control over grains size, shape, and orientation. Targeted control over mechanical properties is achieved through the tuning of 3D-printing parameters and may even obviate the need of heat treatment or mechanical post-processing. Systematic studies of grain structure for different printing orientations with the help of EBSD techniques in combination with mechanical testing at different dimensional levels are the necessary first steps to implement this agenda. Samples of 3D-printable Al-Mg-Si RS-333 alloy were fabricated in three orientations with respect to the principal build direction and the fast laser beam scanning direction. Sample structure and proper-ties were investigated using a number of techniques, including EBSD, in situ SEM tensile testing, roughness measurements, and nanoindentation. The as-printed samples were found to display strong variation in Young’s modulus values from nanoindentation (from 43 to 66 GPa) and tensile tests (from 54 to 75 GPa), yield stress and ultimate tensile strength (100–195 and 130–220 MPa) in different printing orientations, and almost constant hardness of about 0.8 GPa. A further preliminary study was conducted to assess the effect of surface finishing on the mechanical performance. Surface polishing was seen to reduce Young’s modulus and yield strength but improves ductility, whereas the influence of sandblasting was found to be more controversial. The experimental results are discussed in connection with the grain morphology and orientation.
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Althuwayb, Ayman A., Mohammad Alibakhshikenari, Bal S. Virdee, Harry Benetatos, Francisco Falcone, and Ernesto Limiti. "Antenna on Chip (AoC) Design Using Metasurface and SIW Technologies for THz Wireless Applications." Electronics 10, no. 9 (2021): 1120. http://dx.doi.org/10.3390/electronics10091120.
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This paper presents the design of a high-performance 0.45–0.50 THz antenna on chip (AoC) for fabrication on a 100-micron GaAs substrate. The antenna is based on metasurface and substrate-integrated waveguide (SIW) technologies. It is constituted from seven stacked layers consisting of copper patch–silicon oxide–feedline–silicon oxide–aluminium–GaAs–copper ground. The top layer consists of a 2 × 4 array of rectangular metallic patches with a row of subwavelength circular slots to transform the array into a metasurface. This essentially enlarges the effective aperture area of the antenna. The antenna is excited using a coplanar waveguide feedline that is sandwiched between the two silicon oxide layers below the patch layer. The proposed antenna structure reduces substrate loss and surface waves. The AoC has dimensions of 0.8 × 0.8 × 0.13 mm3. The results show that the proposed structure greatly enhances the antenna’s gain and radiation efficiency, and this is achieved without compromising its physical size. The antenna exhibits an average gain and efficiency of 6.5 dBi and 65%, respectively, which makes it a promising candidate for emerging terahertz applications.
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Perez-Rodriguez, Jose Luis, Antonio Albardonedo, Maria Dolores Robador, and Adrian Duran. "Spanish and Portuguese Gilding Threads: Characterization Using Microscopic Techniques." Microscopy and Microanalysis 24, no. 5 (2018): 574–90. http://dx.doi.org/10.1017/s1431927618015167.
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AbstractGilding threads collected from Spanish and Portuguese palaces and from the embroideries and adornments of sculptures of the Virgin and Christ that form part of Sevillian Holy Week were analyzed and compared (20 artifacts were evaluated). The study covered a broad time period with examples from the 13th to 14th centuries, 18th to 20th centuries, and also including modern embroideries. A combination of scanning electron microscopy and energy-dispersive X-ray spectroscopy was used. The knowledge of the layered structures of the threads has provided very valuable information regarding the manufacturing techniques. The different metal threads found in the embroidery studied consisted of gold, silver, copper, and alloys of these metals and aluminium. The fabrication procedures often differed in the different workshops and changed with time. In the modern embroideries, a decrease of precious metal concentration was detected. The threads were wound around a core of silk threads.
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Ručman, Stefan, Winita Punyodom, Jaroon Jakmunee, and Pisith Singjai. "Inducing Crystallinity of Metal Thin Films with Weak Magnetic Fields without Thermal Annealing." Crystals 8, no. 9 (2018): 362. http://dx.doi.org/10.3390/cryst8090362.
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Since the discovery of thin films, it has been known that higher crystallinity demands higher temperatures, making the process inadequate for energy-efficient and environmentally friendly methods of thin film fabrication. We resolved this problem by sparking metal wires in a 0.4 Tesla magnetic field at ambient conditions under ultra-pure nitrogen flow to replace the annealing of thin films, and thus designed an environmentally friendly and energy-efficient thin film fabrication method. We employed grazing incidence X-Ray Diffraction spectroscopy to characterize crystallinity of Iron, Nickel, Copper and Tungsten thin films prepared by a sparking discharge process in the presence of 0.4 T magnetic field at an ambient temperature of 25 °C. Control experiment was conducted by sparking without a magnetic field present and using ultra-pure nitrogen flow and ambient air containing oxygen. The Iron thin film prepared in ultra-pure nitrogen flow preserved crystallinity even after one year of ageing. Nickel exhibited higher crystallinity when sparked in nitrogen gas flow than when sparked in atmospheric air and was the only element to crystalize under atmospheric air. Tungsten successfully crystalized after just 40 min of sparking and aluminium failed to crystalize at all, even after 12 h of sparking under nitrogen flow.
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Butt, Javaid, and Raghunath Bhaskar. "Investigating the Effects of Annealing on the Mechanical Properties of FFF-Printed Thermoplastics." Journal of Manufacturing and Materials Processing 4, no. 2 (2020): 38. http://dx.doi.org/10.3390/jmmp4020038.
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Fused filament fabrication (FFF) is a cost-effective additive manufacturing method that makes use of thermoplastics to produce customised products. However, there are several limitations associated with FFF that are adversely affecting its growth including variety of materials, rough surface finish and poor mechanical properties. This has resulted in the development of metal-infused thermoplastics that can provide better properties. Furthermore, FFF-printed parts can be subjected to post-processes to improve their surface finish and mechanical properties. This work takes into consideration two commonly used polymeric materials, i.e., ABS (acrylonitrile butadiene styrene) and PLA (polylactic acid) and compares the results with two metal-infused thermoplastics i.e., copper-enhanced PLA and aluminium-enhanced ASA (acrylonitrile styrene acrylate). The four different materials were subjected to a post-process called annealing to enhance their mechanical properties. The effect of annealing on these four materials was investigated through dimensional analysis, ultrasonic testing, tensile testing, microstructural analysis and hardness testing. The results showed that annealing affects the materials differently. However, a correlation among ultrasonic testing, tensile testing and microstructural analysis was observed for all the materials based on their crystallinity. It was found that the semi-crystalline materials (i.e., PLA and copper enhanced PLA) showed a considerable increase in tensile strength post-annealing. However, the amorphous materials (ABS and aluminium-enhanced ASA) showed a comparatively lower increase in tensile strength, demonstrating that they were less receptive to annealing. These results were supported by higher transmission times and a high percentage of voids in the amorphous materials. The highest hardness values were observed for the ASA material and the lowest for the ABS material. This work provides a good comparison for the metal-infused thermoplastics and their applicability with the commonly used PLA and ABS materials.
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BÉG, O. ANWAR, M. FERDOWS, S. SHAMIMA, and M. NAZRUL ISLAM. "NUMERICAL SIMULATION OF MARANGONI MAGNETOHYDRODYNAMIC BIO-NANOFLUID CONVECTION FROM A NON-ISOTHERMAL SURFACE WITH MAGNETIC INDUCTION EFFECTS: A BIO-NANOMATERIAL MANUFACTURING TRANSPORT MODEL." Journal of Mechanics in Medicine and Biology 14, no. 03 (2014): 1450039. http://dx.doi.org/10.1142/s0219519414500390.
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Laminar magnetohydrodynamic Marangoni-forced convection boundary layer flow of a water-based biopolymer nanofluid containing nanoparticles from a non-isothermal plate is studied. Magnetic induction effects are incorporated. A variety of nanoparticles are studied, specifically, silver, copper, aluminium oxide and titanium oxide. The Tiwari–Das model is utilized for simulating nanofluid effects. The normalized ordinary differential boundary layer equations (mass, magnetic field continuity, momentum, induced magnetic field and energy conservation) are solved subject to appropriate boundary conditions using Maple shooting quadrature. The influence of Prandtl number (Pr), magnetohydrodynamic body force parameter (β), reciprocal of magnetic Prandtl number (α) and nanofluid solid volume fraction (φ) on velocity, temperature and magnetic stream function distributions is investigated in the presence of strong Marangoni effects (ξ i.e., Marangoni parameter is set as unity). Magnetic stream function is accentuated with body force parameter. The flow is considerably decelerated as is magnetic stream function gradient, with increasing nanofluid solid volume fraction, whereas temperatures are significantly enhanced. Interesting features in the flow regime are explored. The study finds applications in the fabrication of complex biomedical nanofluids, biopolymers, etc.
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Suzuki, Kenta, Shinji Kumai, Kenji Tokuda, et al. "Solidification Structure and Casting Defect in a High-Speed Twin-Roll Cast A6022 Aluminium Alloy with Various Fe Contents." Materials Science Forum 519-521 (July 2006): 1821–26. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.1821.
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Closed-loop recycling should be promoted for wrought aluminum alloy scraps including impurity iron in order to use natural resources effectively. Fabrication of the alloy strip using a high rate of cooling is a promising method for reducing the detrimental effects of impurity iron. In the present study, strips of A6022 aluminum alloy with various Fe contents of up to 1.5 mass% were fabricated by a vertical-type, high-speed, twin-roll caster. The caster used in the study was equipped with a pair of water-cooled, pure copper rolls, and a cooling slope upstream of the rolls. The strips exhibited a common microstructural feature. Columnar grains grew from both surfaces of the strip, and they were gradually replaced by equiaxed grains. In the mid-central region, a band of fine grains was observed. Such fine grains seemed to originate from the crystallized α-Al dendrites on the cooling slope or the roll surfaces. Internal cracks were observed in the A6022 alloy strip that was subjected to the highest cooling rate. The cracks were located between equiaxed grains and fine grains at the mid-central region. The cracks were reduced with increasing Fe content. No cracks were observed for the alloy strips with 1.0 mass% Fe or greater. It was found that both a slight reduction in the cooling rate and addition of Fe were effective for obtaining sound A6022 strips.
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HAASE, ANJA, ELKE KRAKER, JOACHIM KRENN, et al. "ORGANIC PHOTODIODES ON PRINTED ITO COATINGS." International Journal of High Speed Electronics and Systems 20, no. 04 (2011): 787–99. http://dx.doi.org/10.1142/s0129156411007057.
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We describe the fabrication and characterization of organic photodiodes on solution cast ITO (tin doped indium oxide) bottom electrodes. ITO coatings were produced by gravure printing process on PET and PEN substrates. The sheet resistance could be decreased by heat treatment at 120°C under forming gas atmosphere ( N 2/ H 2) to 1.5 kΩ. The transmission of the ITO coated PET and PEN substrates is more than 80% in the visible range. The printed films were hardened under UV-irradiation at low temperatures (< 130°C) and used as the bottom electrode of an organic photodiode (OPD), consisting of a stacked layer of copper phthalocyanine ( p -type material), perylene tetracarboxylic bisbenzimidazole ( n -type material) and Aluminium tris(8-hydroxyquinoline). The performance of the photodiodes with printed ITO on plastic substrates could be improved by adding a smoothing layer of PEDOT/PSS (Baytron® P) on the ITO coated films and was then similar to the performance of photodiodes with semi-transparent gold as anode. These results demonstrate the suitability of the printed ITO layers as bottom electrode for organic photodiodes. Furthermore the influence of different treatments (forming gas and oxygen plasma treatment) of the ITO bottom electrode on the current-voltage characteristics of the OPDs was studied.
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Singhal, L. K., and P. Poojary. "Development of 216L for Conservation of Nickel & Molybdenum and its Application in Sugar Refinery Instead of 316L." Advanced Materials Research 794 (September 2013): 741–48. http://dx.doi.org/10.4028/www.scientific.net/amr.794.741.
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Development of an austenitic Fe-Cr-Mn-Ni-Mo-Cu-N alloy 216L to substitute AISI 316L for saving a part of expensive nickel and molybdenum is described. Nickel content is reduced by 40% and molybdenum by 25% with the help of nitrogen, manganese and copper additions. Corrosion tests in boiling solutions in a variety of acidic media including oxalic, nitric, phosphoric, sulfuric and chromic acids and polarization curves in acidic and chloride environment indicate similar behaviour of both grades. There is also striking similarity in pitting corrosion resistance and inter-granular corrosion resistance of the two alloys as per ASTM G-48 and ASTM A262 respectively. Both alloys exhibit excellent resistance to any staining in prolonged salt spray test. Produced by conventional EAF-AOD-CC-Steckel Mill route, the alloy exhibits surface quality comparable to AISI 316L in both hot and cold rolled conditions. Like 316L, it is equally amenable to fabrication and welding. Higher yield strength of 216L confers potential for material saving in use as compared to 316L. In the process of extracting refined sugar from raw sugar a number of chemicals are used. Accumulated scale from the equipments is periodically removed by using hot solutions containing caustic soda and soda ash followed by rinsing in solutions containing dilute hydrochloric acid and finishing with water rinse. The steel generally used is 316L and based on comparative performance of 216L this new alloy was successfully used in sugar refinery columns where it is subjected to periodic cleaning by hot salt & caustic soda solution and hot dilute hydrochloric acid.. Key words: nickel conservation, 216L austenitic stainless steel; corrosion resistance, sugar refinery
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Manandhar, Amar B., Durga B. Karanjit, Govinda Tiwari, et al. "Experiences in Improving Efficiency of Energy and Other Resources in Metal Industries in Nepal." Journal of the Institute of Engineering 15, no. 3 (2020): 227–33. http://dx.doi.org/10.3126/jie.v15i3.32186.
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The construction sector uses various metals like steel (for frames, reinforced concrete), iron (wrought iron for beams, trusses, girders), aluminium (ceiling and walls, window frames, HVAC systems etc.) and copper (cladding, electrical wiring, oil & gas lines). Due to increasing pressure on various resources like energy, chemicals and raw materials, economic edge can be sustained only through high resource efficiency. Adopting resource efficient cleaner production (RECP) measures will improve economic and environmental performance, including reducing greenhouse gas emissions; in turn, this will make them less vulnerable to changes in external conditions and more competitive. With co-funding from the EU SWITCH-Asia Programme, the project METABUILD (www.metabuild-southasia.org) aims at implementing sustainable production processes and practices in 400 SMEs across Bangladesh, Nepal and Sri Lanka besides creating a conducive environment for further adoption of sustainable production processes in the metal products supply chain for the building and construction sector. In Nepal, the project has already engaged with 82 metal industries. These cover different sectors such as fabrication, wire drawing, electrical cables, re-rolling, galvanizing/electroplating, casting etc. and are in multiple locations viz. Kathmandu, Lalitpur, Morang, Sunsari, Rupandehi, Bara, Parsa, Kaski districts. RECP measures such as use of daylight, replacement of inefficient lights by LED lights, power factor improvement, furnace modification, waste heat recovery, insulation etc. have been implemented. These have led to savings in energy and raw materials, at the same time reducing generation of wastes from these participating industries and improvement of occupational health and safety (OHS). This paper will explain the mode of engagement with industries, details of the resource efficiency measures implemented and estimated saving.
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Pinto, Raquel, André Cardoso, Sara Ribeiro, et al. "Application of SU-8 photoresist as a multi-functional structural dielectric layer in FOWLP." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2017, DPC (2017): 1–19. http://dx.doi.org/10.4071/2017dpc-tp2_presentation3.
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Microelectromechanical Systems (MEMS) are a fast growing technology for sensor and actuator miniaturization finding more and more commercial opportunities by having an important role in the field of Internet of Things (IoT). On the same note, Fan-out Wafer Level Packaging (FOWLP), namely WLFO technology of NANIUM, which is based on Infineon/ Intel eWLB technology, is also finding further applications, not only due to its high performance, low cost, high flexibility, but also due to its versatility to allow the integration of different types of components in the same small form-factor package. Despite its great potential it is still off limits to the more sensitive components as micro-mechanical devices and some type of sensors, which are vulnerable to temperature and pressure. In the interest of increasing FOWLP versatility and enabling the integration of MEMS, new methods of assembling and processing are continuously searched for. Dielectrics currently used for redistribution layer construction need to be cured at temperatures above 200°C, making it one of the major boundary for low temperature processing. In addition, in order to accomplish a wide range of dielectric thicknesses in the same package it is often necessary to stack very different types of dielectrics with impact on bill of materials complexity and cost. In this work, done in cooperation with the International Iberian Nanotechnology Laboratory (INL), we describe the implementation of commercially available SU-8 photoresist as a structural material in FOWLP, allowing lower processing temperature and reduced internal package stress, thus enabling the integration of components such as MEMS/MOEMS, magneto-resistive devices and micro-batteries. While SU-8 photoresist was first designed for the microelectronics industry, it is currently highly used in the fabrication of microfluidics as well as microelectromechanical systems (MEMS) and BIO-MEMS due to its high biocompatibility and wide range of available thicknesses in the same product family. Its good thermal and chemical resistance and also mechanical and rheological properties, make it suitable to be used as a structural material, and moreover it cures at 150°C, which is key for the applications targeted. Unprecedentedly, SU-8 photoresist is tested in this work as a structural dielectric for the redistribution layers on 300mm fan-out wafers. Main concerns during the evaluation of the new WLFO dielectric focused on processability quality; adhesion to multi-material substrate and metals (copper, aluminium, gold, ¦); between layers of very different thicknesses; and overall reliability. During preliminary runs, processability on 300 mm fan-out wafers was evaluated by testing different coating and soft bake conditions, exposure settings, post-exposure parameters, up to developing setup. The outputs are not only on process conditions and results but also on WLFO design rules. For the first time, a set of conditions has been defined that allows processing SU-8 on WLFO, with thickness values ranging from 1 um to 150 um. The introduction of SU-8 in WLFO is a breakthrough in this fast-growing advanced packaging technology platform as it opens vast opportunities for sensor integration in WLP technology.
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"Fabrication and Characterization of Spin Coating Deposited Thin Film Aluminium/BaTiO3 and Pelletized Copper, MnO2/BaTiO3 Capacitor." International Journal of Innovative Technology and Exploring Engineering 9, no. 4 (2020): 2223–31. http://dx.doi.org/10.35940/ijitee.f4595.049620.
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Thin film capacitor using Aluminium (Dielectric-Barium Titanate) and pelletized Copper, MnO2 (Dielectric-BaTiO3 ) capacitors as substrates were constructed. The objective of this research was to develop a capacitor having high capacitance and dielectric strength. The attention was focused on the high dielectric strength of BaTiO3 and high capacitance of MnO2 , so that we can develop a good capacitor. The dependence of stacked and single forms of above capacitors with respect to various electrical parameters were analysed using LCR meter. On the basis of graphs plotted for various electrical parameters such as impedance, quality factor, dissipation factor, conductance, series and parallel capacitance were analysed from the above graphs. By analysing the comparison between Aluminium (Dielectric-Barium Titanate) single and stacked forms the conclusion that I arrived was that stacked form is more preferable over single forms. Taking consideration of copper, MnO2 (Dielectric-BaTiO3 ) capacitor stacked forms were found to be better than single forms. Thus it was clear that the stacked form of Aluminum (Dielectric-Barium Titanate) and stacked forms of copper, MnO2 (Dielectric-BaTiO3 ) capacitor is more preferable while using as capacitors. Although a variety of renewable energy technologies as well as new storage devices have been developed, they have not reached wide spread use. Therefore, there is a strong need of development of improved methods for storing energy when it is available and retrieving when it is needed. The ability to store energy when it is produced is an essential waypoint on the road to turning alternative energy into regular energy. This problem of storage can be solved by supercapacitor. It is an emerging technology in the field of electrical energy storage and its use along with battery or fuel cell is viewed as a solution in many portable systems.
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"Characterisation of Aluminium Alloy (Lm6) Metal Matrix Composite Reinforced With Copper Slag/Ferro Sand." VOLUME-8 ISSUE-10, AUGUST 2019, REGULAR ISSUE 8, no. 10 (2019): 3579–83. http://dx.doi.org/10.35940/ijitee.j9749.0881019.
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Metal matrix composites are found to be one of the promising materials for advanced engineering application. It now has been produced commercially. Recent researches have shown an increased affinity towards the usage of agricultural waste as well as industrial waste as a reinforcement in the composite production which will have a momentous impact on the cost effectiveness of the composite manufacturing. This also will help in sustainable waste management. One of such industrial waste is Copper slag (CS), huge quantity of waste is left as land fill, the compositions of the CS is commensurable to the composition of the fly ash. This entailed using CS as the reinforcement in this composite Fabrication. In this work Aluminium alloy is reinforced with CS to produce a metal matrix composite using stir casting process, as it is one of the cost effective and efficient method of making ALMMC. All the samples are prepared as per ASTM standards and the properties such as Tensile strength, Elongation, Micro Hardness, Specific wear rate, Wear rate and microstructures are examined.
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Boban, Jibin, and Afzaal Ahmed. "Finishing the surface micro-layer of additively manufactured TiAl alloy using electro-thermal discharge assisted post-processing." Journal of Micromanufacturing, February 7, 2023, 251659842311517. http://dx.doi.org/10.1177/25165984231151745.
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Selective laser melting (SLM) of titanium–aluminium (TiAl) alloy components has gained significant attention in the modern industrial world. The flexibility of the SLM process in producing complex shapes with minimum utilization of material and energy makes it dominant over other manufacturing techniques. As aerospace and biomedical industries demand complex-shaped TiAl alloy components, part fabrication using SLM becomes the ultimate solution. However, the unacceptable level of surface integrity and anisotropic behavior of SLM components demand post processing operations such as laser polishing, chemical polishing, and conventional polishing methods. In this study, a recently developed polishing method called wire electrical discharge polishing (WEDP) is performed on TiAl alloys for obtaining a smooth and defect-free surface. This study aims to investigate the micro-layer modification occurring to the WEDP-processed surface in detail. The experimental results establish the effectiveness of WEDP method in terms of improved surface integrity. The surface finish (Sa) got enhanced by ~88% after WEDP processing. In addition, the thickness of recast layer formed by WEDP was found to be minimum. Moreover, post-processing of TiAl alloy resulted in better surface morphology specifically at lower settings of peak current. It is noteworthy that the migration of wire material was minimum with zinc-coated brass electrode compared to the normal brass electrode. Hence, coated wire electrodes are recommended for WEDP process. In short, an excellent surface integrity can be achieved using WEDP process through favorable surface modification aided by lower peak current and coated wire electrodes. Furthermore, less electrode wear observed in WEDP process enables the deployment of lower feed rates leading to minimal electrode consumption.
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Pokuri, Rajeswari, Durga Prasad Tadi, Sunil Tripuraneni, Hemchand Surapaneni, Sri Harsha Babu Vadapalli, and Aiswarya Suggala. "Comparison of Flexural Strength and Surface Hardness of Polymethyl Methacrylate Resin Reinforced with Silanised Aluminium Oxide Nanoparticles- An In-vitro Study." JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH, 2021. http://dx.doi.org/10.7860/jcdr/2021/49788.15421.
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Introduction: In complete denture fabrication, the common denture base material used is heat activated Polymethyl Methacrylate (PMMA). Considering various advantages, still there are some disadvantages like poor flexural strength and poor wear resistance. The flexural strength of any material reflects its potential to resist catastrophic fracture under a flexural load. Another property that influences the surface characteristics of acrylic resins is the surface hardness, which indicates the ease of finishing a material and its resistance to in-service scratching during cleaning procedures and exposure to various oral fluids. Thus an ideal denture base material should exhibit greater flexural strength and high surface hardness for the longevity of the dentures. Aim: To evaluate the effects of adding different percentages of silanised aluminium oxide (Al2O3) nanoparticles on the flexural strength and surface hardness of a conventional heat-polymerised acrylic resin. Materials and Methods: The in-vitro experimental study was conducted between October 2020 to Janaury 2021 at Drs. Sudha and Nageswara Rao Siddhartha Institute of Dental Sciences, Vijayawada, Andhra Pradesh, India. A total of 120 samples were fabricated and were grouped into four groups coded A to D (n=30). Group A was the control group (without adding Al2O3). Specimens in the other three groups (B to D) were reinforced with silanised Al2O3 at loadings of 1%, 2.5% and 5% w/w. Flexural strength was assessed with a three-point bending test using a universal testing machine. Surface hardness test was conducted using a Vickers Hardness (VH) tester. Data was analysed using Analysis of Variance (ANOVA) and Tukey’s post-hoc test. Results: Among all the reinforced groups highest flexural strength value was seen in Group C- PMMA+2.5% w/w silanised aluminium oxide nanoparticles reinforced group (88.33 Mpa) and highest surface hardness value was seen in the Group D- PMMA+5% w/w silanised Aluminium oxide nanoparticles reinforced group (29.44 VH). Conclusion: Reinforcement of the conventional heat cured acrylic resin with 2.5% w/w silanised Al2O3 nanoparticles significantly increased its flexural strength and hardness.
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Steinhoff, Lukas, Rico Ottermann, Folke Dencker, and Marc Christopher Wurz. "Detailed characterisation of batch-manufactured flexible micro-grinding tools for electrochemical assisted grinding of copper surfaces." International Journal of Advanced Manufacturing Technology, August 5, 2023. http://dx.doi.org/10.1007/s00170-023-11876-2.
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AbstractPrecision machining is becoming more and more important with the increasing demands on surface quality for various components. This applies, for example, to mirror components in micro-optics or cooling components in microelectronics. Copper is a frequently used material for this purpose, but its mechanical properties make it difficult to machine. In this study, a process strategy for finishing copper surfaces with batch-manufactured micro-grinding tools in an electrochemically assisted grinding process is demonstrated. The tool heads are manufactured from a polyimide-abrasive-suspension and silicon as a carrier substrate using microsystems technology. The matching shafts are milled from aluminium. The tools are then used on pure copper and oxidised copper surfaces. By using finer abrasives grains (1.6–2.4 µm instead of 4–6 µm) than previously, similar surface roughness values could be achieved (Ra = 0.09 ± 0.02 µm, Rz = 1.94 ± 0.73 µm) with the same grinding process. An optimised grinding process that combines the use of rough and fine tools, on the other hand, achieves significantly better surface finishes in just four grinding iterations (Ra = 0.02 ± 0.01 µm, Rz = 0.83 ± 0.21 µm). In order to achieve a further increase in surface quality, this optimised grinding process is combined with the anodic oxidation of the copper workpieces. The surface modification is done to increase the machinability of the surface by creating an oxide layer. This is confirmed by the results of scratch tests carried out, which showed less force acting on the tool during machining with the oxide layer than with a pure copper surface. To realise this within the machine tool, an electrochemical cell is shown that can be integrated into the machine so that the oxidation can be carried out immediately before the grinding process. The copper layers produced inside the electrochemical cell in the machine tool show similar characteristics to the samples produced outside. Processing the oxidised samples with the optimised grinding process led to a further reduction of about 17% in the Rz values (Ra = 0.03 ± 0.01 µm, Rz = 0.69 ± 0.20 µm). The combination of the shown grinding process and the integration of anodic oxidation within the machine tool for the surface modification of copper workpieces seems to be promising to achieve high surface finishes.
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KUMAR, Vijee, Kempaiah Ujjaini NAGEGOWDA, Satish Babu BOPPANA, Ramesh SENGOTTUVELU, and Palanikumar KAYAROGANAM. "Wear behavior of Aluminium 6061 alloy reinforced with coated/uncoated multiwalled carbon nanotube and graphene." Journal of Metals, Materials and Minerals 31, no. 1 (2021). http://dx.doi.org/10.55713/jmmm.v31i1.917.
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The current study deals with the fabrication and investigation of wear characteristics of Aluminium 6061(Al6061) hybrid metal matrix composites (MMCs) processed through powder metallurgy technique. Al6061 hybrid MMCs involving fixed 2 wt% of coated/uncoated multiwalled carbon nanotubes (MWCNTs) and varying weight percentages of graphene were fabricated through ball milling procedure. To enhance the scattering of MWCNTs in the matrix, MWCNTs were coated by means of copper through electroless deposition method. Dry sliding wear conduct of Al6061 MMCs was investigated using a pin-on-disc wear testing machine. It was found that at lower load, composites exhibited lower wear resistance than base alloy however at higher load, nanocomposites showed higher wear resistance. The research tried to find the effect of higher loads on the wear resistance. The composites were evaluated if they could give out reinforcements at higher loads during wear tests. The wear morphologies were reported using Scanning Electron Microscopy (SEM) and it was noticed that lower load abrasion was superior for the composites and base alloy although at higher loads adhesion was considered to be main reason for the wear of composites.
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"Potentiodynamic Corrosion Characterization of Hybrid Aluminium Composites for Advanced Engineering Applications." International Journal of Engineering and Advanced Technology 9, no. 3 (2020): 1434–37. http://dx.doi.org/10.35940/ijeat.c5025.029320.
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Corrosion characterization of Aluminium composites is a significant study planned for assessing the capability of utilizing the materials for aviation and automobile parts. Aluminium 5083 is a particular class of alloys which is known for its corrosion resistance in extraordinary conditions and is utilized in aerospace components. However, the experimentations on impact of reinforcements, for example, the effect of Silicon carbide and Flyash on corrosion properties of Aluminium 5083 alloys is still in its incipient stage and not much literature is available outlining the corrosion attributes. The present work includes the fabrication of Aluminium 5083 – Silicon carbide – Flyash composites and investigation of the corrosion conduct of these composites. The composites are fabricated by stir casting procedure, considering silicon carbide particulates varied in the scope of 3 wt.% to 9 wt.% at an intermittent intervals of 2 wt.%. The composition of fly ash in the present work is limited to 5 wt. % for restricting the porosity after conducting preliminary trials. The composite materials considered in this research are assessed for corrosion by Potentio-dynamic test, which is accomplished utilizing a test arrangement comprising of five mouth jar with calomel electrode and a working cathode (comprising of the specimen held rigidly with a copper wire and secured with Teflon tape notwithstanding a region of one square centimeter exposed to the electrolyte). The anodic and cathodic potentio-dynamic polarization estimations are acquired as tafel plots in the PC that is interfaced with the test arrangement. The outcomes reveal that the corrosion current (Icorr) increases with the increase in the weight percentage of Silicon carbide in the metal matrix. The electrolyte considered for the potentio-dynamic test is and 1 M HCl (acidic) medium.
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Palanivel, Ramaswamy. "A CONTEMPORARY REVIEW OF THE ADVANCEMENTS IN JOINING TECHNOLOGIES FOR BATTERY APPLICATIONS." Materiali in Tehnologije 57, no. 3 (2023). http://dx.doi.org/10.17222/mit.2023.797.
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The joining of multilayered foils to a conductive tab necessitates a joining process in the battery, which is an important storage device in renewable-energy sectors. Cell, module, and pack are the three levels of pouch cell joining in a battery pack. The joining of multi-layered dissimilar conductive materials is necessary for battery-pack fabrication. Mostly copper (Cu) and aluminium (Al) are used in battery-pack applications. The Cu and Al are characterized as high thermally and electrically conductive materials. However, obtaining a quality Cu-Al weld using conventional methods is hard and the durability of the weldments is uncertain. In general, the development of intermetallic compounds (IMCs) during welding is a major challenge for the joining of dissimilar materials due to the differences in the chemical and physical properties. This review addresses the battery packs and challenges involved in joining the conductive tabs. In addition, this review provides an insight into the suitability of various joining processes and explores their suitability for the joining of battery packs.
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ansari, mahamood, and Imtiaz Ali Khan. "Investigation on the Performance of Wire Electrical Discharge Machining (WEDM) using Aluminium Matrix Composites (AMCs) micro-channel." Engineering Research Express, August 31, 2023. http://dx.doi.org/10.1088/2631-8695/acf5ca.
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Abstract This study focuses on microchannel fabrication of Al-10% SiC composite using Wire-EDM process with the applications of single variable and multi variable, optimization. This work was targeted keeping in considerations the wider scope of microchannel applications in the fields such as medical, aerospace, automobile, etc. In this research work, the experiment was conducted to achieve high precision and quality surface finish in terms of minimum surface roughness (SR), high material removal rate (MRR), low tool wear rate (TWR) and optimum spark gap (SG). The used experiments were design on the basis of Taguchi design of experiment approach. Four input process parameters were considered namely, pulse on time (Ton), sparking voltage (SV), wire tension (WT), and wire feed rate (WFR). For the experimentation task, the workpeice (Aluminum and silicon carbide (10% Wt SiCmicro)) material, in a desired shape was fabricated through stir casting process. The tool electrode applied for the experiment purpose had specification as, 0.25mm diameter brass alloy wire (copper 63 percent and zinc 37 percent). For single variable optimization ANOVA (analysis of variance) was applied while as, for multi variables optimization, grey relational analysis (GRA) was applied. The results of the study indicated that, on the basis of single variable optimization, the highest contribution of Ton resulted in case of the performance measures, MRR and SR while as, for TWR and SG, the highest contribution of sparking voltage, observed. Furthermore, the findings of the study indicated that, on the basis of multi variables optimization, the optimal combination of input process parameters is, pulse on time 125 µs, sparking voltage 10 volt, wire tension 12 kgf, and wire feed rate 4 m/min. These results also get support from the previous research works. The findings of this study be useful for microchannel manufacturing and other related industrial applications.
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Saxena, Pragya, Arunkumar Bongale, Satish Kumar, and Priya Sachin Jadhav. "Microstructural and sensor data analysis of friction stir processing in fabricating Al6061 surface composites." Engineering Research Express, March 3, 2023. http://dx.doi.org/10.1088/2631-8695/acc158.
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Abstract Aluminium alloys, having high strength, ductility, and toughness, are useful structural materials. Composites of these with ceramic reinforcements improve the hardness and wear resistance, making them suitable for use in the aerospace and automobile industries. Since surface properties play a crucial role for most applications, the manufacturing of surface composites of aluminium alloys is recommended. For this purpose, Friction stir processing&#xD;(FSP) is being utilized nowadays. It refines the microstructure with a homogeneous dispersion of reinforcements into the matrix and improves physical properties like surface hardness, wear resistance, strength, etc., while retaining the properties of remaining volume.&#xD;The study aims to investigate and compare the temperature and vibration sensor data while manufacturing Al6061 alloy-based surface hybrid composites by using two different FSP tools. The FSP method is used for the fabrication of Al6061 alloy based composites with the copper and graphite powders mixture (1:1), reinforced into the matrix surface by using two&#xD;H13 tools with two different pin profiles - threaded cylindrical and plain cylindrical. Holes of different diameters and depths are drilled on the Al6061 matrix for reinforcement addition.&#xD;This FSP process is investigated using a thermal gun and a Cross-Domain Development kit for temperature and vibration measurement. It is verified that both the temperature and vibration values are lower in the composites fabricated by FSP tool with threaded pin profile than that by FSP tool with plain pin profile. The processed samples are later investigated for the microstructure by Field Emission Scanning Electron Microscope and Energy-Dispersive&#xD;X-Ray Spectroscopy tests. The reinforcements are dispersed more uniformly by the FSP tool with threaded cylindrical profile. This research can be used to further monitor and control properties like temperature, vibration, force, current, etc., to obtain a uniform reinforcement dispersion with improved mechanical properties during the surface composite preparation by FSP.&#xD;
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Singh, Vaibhav, P. Raja, Jitendra Kumar Katiyar, and P. Ramkumar. "Effect of friction modifiers compositions on tribological properties of Cu-Sn alloy/Al2O3 brake composite material." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, November 17, 2020, 135065012097413. http://dx.doi.org/10.1177/1350650120974132.
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Brakes are very important component in any vehicle, used to stop the motion of it either by applying mechanical or hydraulic pressure on brake pads. By engaging and disengaging of braking action, the surface of brake components (or) materials is ruined after some time. Therefore, it is important to study and develop a new composition of brake materials which provides optimum coefficient of friction along with increasing wear resistance to the materials. Hence, new combination has been formulated for fabrication of brake composite material using powder metallurgy method which consist of copper-tin alloy mixed with silicon carbide as a base materials, aluminium oxide as an abrasive material with varying volume percentage of graphite and talc powder as a friction modifiers. The pin-on-disc test was performed on brake composite material to analyse their tribological properties namely friction and wear. From tribo-test, it was observed that all composites give the friction coefficient in the range of ∼0.33–0.51 and the loss of materials in the range of ∼79–131 mg. Further, the mechanical, thermal stability and surface characterization were also carried out on brake composites using universal testing machine, vicker’s hardness tester, thermogravimetric analyser and scanning electron microscope respectively. These results reveal a very marginal change in hardness, increase in compressive strength by increase of talc concentration to the matrix, uniform distribution of reinforcement into the matrix and multi stage degradation of material loss in thermograph.