Journal articles: 'Varying temperature hardness'

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Joshua, T. O., O. S. I. Fayomi, F. H. Olatuja, and A. O. Inegbenebor. "Hardness and Microstructural Behavior of Normalized Steel-Welded Joint under Varying Temperature." Procedia Manufacturing 35 (2019): 1375–82. http://dx.doi.org/10.1016/j.promfg.2019.09.006.

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Pazur, Richard J., and T. Mengistu. "ACTIVATION ENERGIES OF THERMO-OXIDIZED NITRILE RUBBER COMPOUNDS OF VARYING ACRYLONITRILE CONTENT." Rubber Chemistry and Technology 92, no. 1 (January 1, 2019): 129–51. http://dx.doi.org/10.5254/rct.18.82592.

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ABSTRACT The thermo-oxidative behavior of carbon black–reinforced sulfur-cured nitrile rubber compounds with varying acrylonitrile (ACN) content (18–49 wt%) was investigated. Accelerated heat aging was carried out from 40 °C to 115 °C for various aging times. Ambient aging was also included. Samples were tested for hardness, 10% tensile stress, tensile strength, elongation at break, network chain density by equilibrium solvent swell, and toluene-soluble fraction. Diffusion-limited oxidation affected data at high temperatures and was eliminated for time-temperature superposition. Linear Arrhenius kinetic behavior was confirmed throughout the whole temperature range, and calculated activation energies varied from 75 to 93 kJ/mol. Activation energies calculated through the hardness data were found to increase steadily with ACN concentration, whereas the other test responses showed less direct correlation, likely because of the influence of the underlying NBR microstructure, which changes as a function of ACN content. The high-temperature thermo-oxidative process consists of both oxidative crosslinking and chain scission reactions. Sulfur reversion and alkyl radical recombination reactions are likely prevalent at low temperatures during the buildup of hydroperoxides up to 60 °C. The shelf life of nitrile rubbers strongly depends on their ACN level, with lower ACN nitriles being more susceptible to degradation, leading to shorter shelf lives, than higher ACN-containing nitriles.

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Mahathanabodee, S., Tippaban Palathai, S. Raadnui, Ruangdaj Tongsri, and Narongrit Sombatsompop. "Effect of h-BN Content on the Sintering of SS316L/h-BN Composites." Advanced Materials Research 410 (November 2011): 216–19. http://dx.doi.org/10.4028/www.scientific.net/amr.410.216.

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In this work, the three compositions of hexagonal boron nitride (10, 15 and 20 vol. %)-embedded 316L stainless steel (SS316L/h-BN) composites were prepared by a conventional powder metallurgy technique and then sintered at varying temperatures of 1100 to 1250°C for 60 min in H2 atmosphere. The h-BN content and sintering temperature were found to affect the microstructure and hardness of the composites. The hardness decreased with increasing h-BN content and was improved by increasing the sintering temperature. Microstructure results revealed that the boride phase was formed at the grain boundary at the sintering temperature higher than 1150°C and the boride phase formation was observed to transform the h-BN in the composites.

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Gurumurthy, B. M., Sathya Shankar Sharma, and U. Achutha Kini. "Ferrite-Martensite Dual Phase Treatment of AISI 1040 Steel and Mechanical Characterization." Key Engineering Materials 748 (August 2017): 280–83. http://dx.doi.org/10.4028/www.scientific.net/kem.748.280.

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The present work is focused on the characteristics of dual phase (Ferrite-Martensite) medium carbon steel (AISI1040) austenized at different inter critical temperatures (750,770, and 790°C). AISI1040 is plain carbon steel with moderate strength and hardness. The machinability of the steel depends upon the balanced properties obtained by preferential control of phases (wt. % and type) by altering the room temperature structure. In this view, the dual phase is obtained by varying wt. % of ferrite and martensite structure in the steel and then subjected to bulk mechanical property (tensile, hardness, impact resistance and microstructure) analysis. As bought steel is subjected to normalizing treatment which is taken as datum for analysis. The dual phase structure obtained is then tempered to enhance the balanced properties. It was observed that hardness and tensile strength increases with low temperature tempering (260°C) compared to high temperature tempering (425°C) and impact resistance is excellent in high tempering temperature.

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Landgraf, Pierre, Peter Birnbaum, Enrique Meza-García, Thomas Grund, Verena Kräusel, and Thomas Lampke. "Jominy End Quench Test of Martensitic Stainless Steel X30Cr13." Metals 11, no. 7 (July 3, 2021): 1071. http://dx.doi.org/10.3390/met11071071.

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In this study, the influence of thermal treatments on the properties of the martensitic stainless steel X30Cr13 (EN 10088-3: 1.4028) were investigated. These steels are characterized by a high hardness as well as corrosion resistance and can be specifically adjusted by heat treatment. In particular, the austenitizing temperature ϑA and cooling rate T˙ affect the hardness and corrosion properties of martensitic stainless steels. In order to investigate these influences, the Jominy end quench tests were performed at varying austenitizing temperatures. The aim is to determine the hardness and corrosion properties as a function of the austenitizing temperature and the cooling rate. The austenitizing temperature strongly influences the solubility of alloying elements within the austenitic lattice as well as the grain size, and thus affects both precipitation and phase transformation kinetics. In consequence, different austenitizing temperatures lead to different macroscopic material properties, like hardness and pitting corrosion potential. The heat treatment was simulated using finite element (FE) method and compared with time-temperature sequences measured at different locations of the Jominy end quench sample using thermocouples. That allows determining the cooling rate T˙ between 800 ∘C and 500 ∘C and to assign it to each location of the Jominy end quench sample. The numerical estimations were in close conformity with the experimental values. By assigning the hardness and pitting corrosion potentials to the respective cooling rates as a function of the austenitizing temperature, it is possible to determine optimum process windows for the required properties.

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Rotich, Sammy Kiplangat, Ngetich Gilbert Kipkirui, Tzu-Tang Lin, and Shih-Hsun Chen. "Effect of Varying Plasma Powers on High-Temperature Applications of Plasma-Sprayed Al0.5CoCrFeNi2Ti0.5 Coatings." Materials 15, no. 20 (October 15, 2022): 7198. http://dx.doi.org/10.3390/ma15207198.

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In this work, the microstructure and mechanical properties of atmospheric plasma-sprayed coatings of Al0.5CoCrFeNi2Ti0.5, prepared using gas-atomized powders at varying spray powers, are studied in as-sprayed and heat-treated conditions. Gas-atomized powders had spherical shapes and uniform element distributions, with major FCC phases and metastable BCC phases. The metastable BCC phase transformed to ordered and disordered BCC phases when sufficient energy was applied during the plasma-spraying process. During the heat treatment process for 2 hrs, disordered BCCs transformed into ordered BCCs, while the intensity of the FCC peaks increased. Spraying power plays a significant role in the microstructure and mechanical properties of plasma sprayed because at a high power, coatings exhibit better mechanical properties due to their dense microstructures resulting in less defects. As the plasma current was increased from 500 A to 700 A, the coatings’ hardness increased by approximately 21%, which is directly proportional to the decreased wear rate of the coatings at high spraying powers. As the coatings experienced heat treatments, the coatings sprayed with a higher spraying power showed higher hardness and wear resistances. Precipitation strengthening played a significant role in the hardness and wear resistances of the coatings due to the addition of the titanium element.

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Ren, Junzhao, Hongyan Wu, Lu Wang, Zhehang Fan, Yanzhao Qiu, Lu Yu, and Enxi Shi. "Molecular Dynamics Simulation of Nanoindentation of Nb-Zr Alloys with Different Zr Content." Metals 12, no. 11 (October 27, 2022): 1820. http://dx.doi.org/10.3390/met12111820.

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To understand the nanomechanical behaviors of the Nb-based alloys with Zr addition at room/high temperature, the molecular dynamics simulations of nanoindentation are conducted. In this work, the load-unload displacement curve, hardness, and dislocation characteristics of Nb-Zr alloys with varying Zr content ranging from 0 to 5 wt.% are studied. The simulation results are found to closely agree with the experimental one at 1 wt.%, therefore showing the reliability of the simulation. Moreover, considering distinct responses of alloys to different service temperature, the high-temperature nanoindentation are performed. The effects of Zr addition on the mechanical deformation under both temperatures are compared. The same phenomenon is found such that the optimum concentration range yielding the greatest hardness is 1–3 wt.%. The elastic modulus of NbZr alloy improves with elevated concentration at room temperature, while the hardness at higher temperature exhibits the opposite trend. This is attributed to the higher amplitude of atomic vibrations at high temperatures, which is more likely to deviate atoms from their equilibrium positions and weaken the pinning effect under external loading. Therefore, we believe that our studies on the nanomechanical mechanisms of materials at room/high temperature will provide an effective way for the alloying optimization design.

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Cai, Gang Yi, Xiao Ting Huang, and Peng Hui Deng. "Effects of Thermomechanical Treatment Process on the Microstructure and Properties of AZ80 Magnesium Alloy." Advanced Materials Research 179-180 (January 2011): 354–58. http://dx.doi.org/10.4028/www.scientific.net/amr.179-180.354.

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Thermomechanical treatment was adopted to improve the comprehensive performance of AZ80 magnesium alloys in this paper. The influence of varying the thermal processing parameters and deformation on the microstructure and mechanical properties of AZ80 magnesium alloy was studied, and the optimal process of themomechanical treatment was obtained. The experimental results show that the hardness increased with the increasing of deformation and the hardness is up to the peak value with 30% deformation. After aging, the hardness measurements and microstructure analysis results show that the hardness increased with increasing aging temperature, and reached the peak value at temperature 170°C, while the hardness decreased sharply when the temperature goes beyond 170°C. After thermomechanical treatment, the grains of AZ80 magnesium alloy became uniform and fine. The roles of both deformation strengthening and dispersion strengthening were to improve the mechanical property of AZ80 magnesium alloy.

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Huang, Xiao Ting, Gang Yi Cai, and Wen Biao Qiu. "Effects of Hot Deformation Process on the Microstructure and Hardness of AZ80 Magnesium Alloy." Advanced Materials Research 476-478 (February 2012): 46–49. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.46.

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AZ80 magnesium alloys were deformed at different temperature (270°C, 300°Cand 330°C)with different deformation ratio from 10% to 50%. The influence of varying the deformation temperature and ratio on the microstructure and hardness of AZ80 magnesium alloy was studied. The experimental results show that the hardness increased with the increasing of deformation and the hardness is up to the peak value with 40% deformation at 300°C. The microstructure was homogeneous and the grain was refined after hot deformation.The roles of both deformation strengthening and dispersition strengthening were to im prove the mechanical property of AZ80 magnesium alloy.

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Oktadinata, Herry, M. Sa'ban Dafi, and Djoko Hadi Prajitno. "Microstructure Evolution and Hardness Properties of Nodular Cast Iron for Varying Tempering Time." Key Engineering Materials 935 (November 30, 2022): 3–9. http://dx.doi.org/10.4028/p-h1ao57.

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Nodular cast iron is usually used for components that require good mechanical properties such as strength, toughness, and ductility. Heat treatment is applied to the components made from the nodular cast iron to improve their mechanical properties. This study aimed to investigate the influence of tempering time on the microstructure, hardness, and wear rate of nodular cast iron. The heat treatment was performed by austenitizing to 850 °C with a holding time of 1 hour and quenched in the oil medium. After quenching, it was tempered at a temperature of 450 °C by varying the tempering time to 15, 30, 45, and 60 min. The investigation consists of microstructure observation, hardness, and wear rate measurements. The results show that the highest hardness was 55.3 HRC at a tempering time of 15 min, and the lowest hardness was 54 HRC at a tempering time of 60 min. The lowest wear rate was 0.00476 g/min at a tempering time of 15 min, and the highest wear rate was 0.00574 g/min at a tempering time of 60 min. It can be concluded that the longer the holding time of tempering, the lower the hardness and the higher the wear rate.

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Zakaria, Marwan, Siti Rodiah Karim, and Nur Azam Badarulzaman. "XRD Analysis of Al-6vol%SnPb Composites Fabricated by Cold Forging Process with Various Sintering Temperatures." Advanced Materials Research 1087 (February 2015): 420–23. http://dx.doi.org/10.4028/www.scientific.net/amr.1087.420.

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This paper focused on fabrication of Al-6vol%SnPb from recycled Aluminium and recycled solder and its characterization in different sintering temperature. Al-20SnPb was fabricated by using cold forging process of flakes chip raw materials. Constant pressure (56.4 MPa) was used to implement cold forging process. Various sintering temperature (200 0C, 250 0C, 300 0C and 3500C) was studied to obtain the optimum hardness properties. The diffraction pattern of X-Ray diffraction (XRD) reveals the influence of varying sintering temperature of Al-6vol%SnPb. Vickers hardness result also support that, optimum result obtained is at sintering temperature 300 °C.

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S, Manivannan, Senthil Kumaran S, Srinivasan Narayanan, Kathiravan Srinivasan, and Alex Noel Joseph Raj. "Sensor-Assisted Assessment of the Tribological Behavioral Patterns of Al–SiCp Composites under Various Environmental Temperature Conditions." Materials 12, no. 23 (December 2, 2019): 4004. http://dx.doi.org/10.3390/ma12234004.

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Currently, the use of sensors and supporting technologies has become indispensable in the assessment of tribological behavioral patterns of composites. Furthermore, the current investigation focused on the assessment of the tribological behavior of the Al–SiCp composite for high-temperature applications. Moreover, the Al–SiCp composite was fabricated by adapting the liquid metallurgy route with varying weight percentages of SiCp (x = 3, 6, and 9). Density, hardness, and high-temperature wear tests were performed to evaluate the hardness and tribological characteristics and properties of modern-day advanced composites. Moreover, the inclusion of SiCp enhanced the advanced composite materials hardness from 60 HV to 110 HV due to a high degree of refinement of the α-phase. Subsequently, the fabricated samples’ wear behavior was assessed by varying the wear parameter viz. the applied load (20 N and 30 N) and sliding distance (250 m, 500 m, 750 m, and 1000 m) with the constant sliding velocity (0.45 m/s) for various temperatures (40 °C, 150 °C, and 250 °C). Moreover, the results revealed that the enhancement in the reinforcement percentage improves the wear resistance. Consequently, the wear rate decreased at 250 °C, possibly owing to the development of the oxide layers. Therefore, the occurrence of delamination and plastic deformation were evidenced in the wear-out surface, thereby depicting the prevalence of delamination and the abrasive wear-mechanism.

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Fudger, Sean J., Thomas L. Luckenbaugh, Anthony J. Roberts, Chris D. Haines, and Kris A. Darling. "Tying Processing Parameters to the Microstructure and Mechanical Properties of Nanostructured FeNiZr Consolidated via the Field Assisted Sintering Technique." Metals 9, no. 4 (April 13, 2019): 436. http://dx.doi.org/10.3390/met9040436.

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An oxide-dispersion-strengthened (ODS) nanostructured FeNiZr alloy was fabricated via high energy mechanical alloying, and subsequently consolidated by the field assisted sintering technique (FAST). A range of input parameters: Temperature, hold time and pressure were evaluated in an effort to optimize the mechanical response of the material. Improvements in density, up to 98.6% of theoretical, were observed with increasing consolidation temperature and hold time at the cost of decreasing hardness values resulting from microstructural coarsening. Hardness values decreased from 650 to 275 HV by increasing processing temperatures from 750 to 1100 °C. The relationships between the varied processing parameters, microstructure and the experimentally measured yield and ultimate tensile strengths are discussed. Specifically, the effect of varying the temperature and hold time on the resulting porosity, as observed via scanning electron microscopy (SEM) in tensile and compression samples, is emphasized.

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Timelli, Giulio, Alberto Fabrizi, Simone Vezzù, and Alessandro De Mori. "Design of Wear-Resistant Diecast AlSi9Cu3(Fe) Alloys for High-Temperature Components." Metals 10, no. 1 (December 28, 2019): 55. http://dx.doi.org/10.3390/met10010055.

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Type AlSi9Cu3(Fe) alloy has been modified by alloying with iron, manganese, and chromium elements to develop wear-resistant diecast hypoeutectic Al–Si–Cu alloys that can be applied for high-temperature applications. Several alloys have been produced by varying iron, manganese, and chromium levels (0.80, 1.00, 1.20 wt.% for Fe; 0.25, 0.40, 0.55 wt.% for Mn, and 0.06, 0.10 wt.% for Cr). Brinell hardness measurements and pin-on-disk wear tests have been conducted from room temperature up to 200 °C. The microstructural changes that occurred with the different alloying levels have been quantitatively examined by metallographic and image analysis techniques. The results showed how the increasing content of the Fe, Mn, and Cr promoted the precipitation of both primary and secondary Fe-enriched particles, mainly with polyhedral, blocky, and star-like morphologies. These compounds showed high hardness that is not affected by chemical composition and morphology variation. At high temperatures, the diecast alloys always showed lower average hardness and wear resistance, especially at 200 °C; however, a greater amount of Fe-rich particles can compensate the alloy softening.

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Azeez, T. M., Lateef O. Mudashiru, T. B. Asafa, A. A. Adeleke, and Peter Pelumi Ikubanni. "Mechanical Properties of Al 6063 Processed with Equal Channel Angular Extrusion under Varying Process Parameters." International Journal of Engineering Research in Africa 54 (June 2021): 23–32. http://dx.doi.org/10.4028/www.scientific.net/jera.54.23.

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Mechanical properties of extruded aluminum are known to significantly depend on the process parameters such as temperature, numbers of extrusion pass and extrusion load among others. This implies that these properties can be influenced by tuning the process parameters. Herein, the effects of these parameters on the tensile strength and hardness of aluminum 6063 series were investigated by using equal channel angular extrusion (ECAE). Experiments were designed using Design Expert software. Analysis of variance (ANOVA) was then used to investigate the main and interactions effects of the process parameters. An empirical mathematical model was generated that shows the relationship between the input and output variables using response surface methodology. Temperature was found to be the most significant factor while extrusion load was the least factor that influenced the hardness and tensile strength which were the output factors. There was a significant increase in tensile strength and hardness after extrusion at different mix of factors. The optimum input variable was discovered at 1020.58 kN, 489.67°C and 3 numbers of extrusion passes.

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Aravinda, T., and H. B. Niranjan. "Characterization of Joints Produced by Diffusion Bonding." Journal of Mines, Metals and Fuels 70, no. 5 (July 22, 2022): 258. http://dx.doi.org/10.18311/jmmf/2022/30330.

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The present study reports on the preparation of diffusion joint of Al 2024 sheets with and without hematite interlayer. Parameters like holding time, temperature and pressure were considered for producing the joint. Samples were prepared at a temperature of 400 °C while varying load (90 and 110 kN). The time duration of applying load was selected as 25 and 35 min. Microstructural characterization using scanning electron microscopy was carried out for analyzing microstructure of the joint. EDS spectrum was used to analyze the elemental composition of the joint. Hardness tests were employed to find the micro-hardness of the prepared joint using Vickers hardness tester.

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Nahvi, Hamdan Gowhar. "Study for Improvement in the Surface Properties and Wear Behavior of Mild Steel." International Journal for Research in Applied Science and Engineering Technology 9, no. 10 (October 31, 2021): 938–48. http://dx.doi.org/10.22214/ijraset.2021.38538.

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Abstract: Surface of a material can be improved by depositing the filler metal for the enhancement of various properties. Surface should be harder than substrate material for surface improvement. This surface improvement is also known as surfacing. In present research Mild steel specimens of size 140×35×40 were used to deposit surfacing layers and study the feasibility of iron/aluminum with varying compositions on low carbon steel deposited by GTAW process. Specimens for hardness and oxidation resistance were prepared. While studying oxidation of surfaced and un-coated area (base material), oxidation test resulted that the oxidation occurred on surface of base metal (un-coated area) after heating at different temperatures and time intervals. Specimens kept at 500˚C, 700˚C temperatures for 3, 6, 9 hours to get oxidized from un-coated surface but no mark of oxidation and pitting was visible at surfaced area but pitting of un-coated area occurred at 700˚C temperature. Oxidation had no effect to surfaced area. Low temperature oxidation test specimens gave only weight loss from un-coated portion but high temperature oxidation gave high amount of weight reduction due to pitting occurred on un-coated portion. The amount of weight loss of specimens increased with increase in furnace holding time at constant temperature. With increase in temperature oxidation of un-coated area of specimens also increased and pitting action occurred on un-coated area of specimens at high temperature. Further, for the various wear tests the cylindrical pins of 8 mm diameter with spherical tip 4 mm radius was made. Wear tests were carried out on pin on disc sliding wear testing machine. The comparison of wear rate loss was studied with constant sliding distance, varying load and sliding velocity of different compositions of iron/aluminum surfacing and substrate material. Hardness and wear resistance of composition were increased with increase in percentage of Fe element in composition. Composition C1 (Fe:Al/70:30) had high hardness and high wear resistance as compared to composition C2 (Fe:Al/30:70) and C3 (Fe:Al/50:50). Composition C3 (Fe:Al/50:50) had better hardness and wear resistance as compared composition C2 (Fe:Al/70:30). Keywords: Surface improvement, Fe-Al intermetallic, GTAW process, Sliding wear.

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Ivanov, Alexander M., Anton V. Sadokhin, Nikita B. Strokan, Alexander A. Lebedev, and Vitalii V. Kozlovski. "Radiation Hardness of Wide-Bandgap Materials as Exemplified by SiC Nuclear Radiation Detectors." Materials Science Forum 717-720 (May 2012): 549–52. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.549.

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Polarization effect characteristically occurs in detectors based on wide-bandgap materials at considerable concentrations of radiation defects. The appearance of an electromotive force in the bulk of a detector is due to the long-term capture of carriers at deep levels related to radiation centers. The kinetics and strength of the polarization field have been determined. The capture can be controlled by varying the detector temperature, with a compromise reached at the "optimal" temperature between the generation current and the position of the deepest of the levels whose contribution to the loss of charge via capture is negligible. It has been found that the depth of a level (related to the energy gap width) is close to 1/3, irrespective of a material. The optimal temperatures are strictly individual for materials.

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Teldekov, V. A., and L. M. Gurevich. "RESEARCH OF LOW TEMPERATURE NITROCARBURIZING TECHNOLOGY FOR COMPLEX HARDENING OF MACHINE PARTS." IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, no. 10(257) (October 25, 2021): 64–68. http://dx.doi.org/10.35211/1990-5297-2021-10-257-64-68.

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The study of changes in the microstructure, thickness of the ε-phase and the hardness of diffusion coatings obtained by varying the temperature in the process of low-temperature nitrocarburizing was carried out. Studies have shown the possibility, through the use of low-temperature nitrocarburizing technology, to reduce the labor intensity of technological operations, shorten the processing time and reduce energy consumption.

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Rahman, W., Shamsul Baharin Jamaludin, and Mohd Noor Mazlee. "Microwave Sintering of Pure Iron with Addition of Stearic Acid as Binder." Advanced Materials Research 576 (October 2012): 166–69. http://dx.doi.org/10.4028/www.scientific.net/amr.576.166.

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The purpose of this study is to investigate the effect of the stearic acid as binder in sintering pure iron using a microwave furnace. The study was focused in mechanical properties such as porosity, density and micro-hardness of sintered product. The experiment was done by varying weight percentages of stearic acid and controlling the sintering parameters such as sintering temperature and sintering time. Increasing the percentage of stearic acid resulted in higher porosity and lower bulk density. Hardness has increased by increasing sintering temperature and sintering time. The optimum material properties were found at 1300 °C sintering temperature with addition 2 % stearic acid within 30 minutes sintering time.

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Motsai, Tebogo, Elizabeth Makhatha, Sigqibo Camagu, Chris Machio, Pfarelo Daswa, Precious Radingoana, and Glenda Motsi. "The effect of vanadium and nickel on the microstructure and transformation temperatures of Ti₅₀Pt₅₀ alloy." MATEC Web of Conferences 370 (2022): 03004. http://dx.doi.org/10.1051/matecconf/202237003004.

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Significant research has been done to produce shape memory alloys that have good shape memory properties and high martensitic transformation temperatures. The Ti50Pt50 alloys have been found to have high transformation temperature of around 1050℃ however, they exhibit negligible shape memory properties. The solid solution strengthening, and improved shape memory properties could be enhanced by ternary alloying. Therefore, this work investigates the effect of varying V and Ni contents, in the range of 6.25 to 12.5at%, on the austenitic and martensitic transformation temperatures, and hardness of the equi-atomic Ti50Pt50 alloy. Arc melting followed by casting and solution heat treatment was carried out to produce the alloys. As-produced alloys were characterized by using scanning electron microscopy, differential scanning calorimetry and hardness testing. The microstructures showed high volume fraction of second phases formed in the TiPtV alloy compared with Ti50Pt50 and TiPtNi alloys. The multiple phases formed in the TiPtV alloys could be the cause of high hardness values observed in these alloys as compared withTi50Pt50 and TiPtNi alloys. Thermal transformation studies revealed that TiPtV alloys exhibit transformation temperature close to Ti50Pt50 alloy, in contrast with TiPtNi alloys. TiPtNi alloys thermal behaviour was improved by solution heat treatment.

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Chaus, Alexander S., Róbert Sobota, and Viktor Tittel. "Characterisation of the Microstructure of Plain Carbon Steel Formed during Isothermal and Continuous Cooling Following Austenitisation." Defect and Diffusion Forum 413 (December 17, 2021): 167–73. http://dx.doi.org/10.4028/www.scientific.net/ddf.413.167.

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The present study has been undertaken to compare the microstructure of the plain carbon steel, containing 0.65 carbon, which was formed during varying isothermal and continuous cooling conditions following austenitisation at the same temperature and soaking time. After austenitisation, one set of samples was subjected to isothermal treatment which was carried out at a temperature varying in the range of 650–400 °C, and the other one was continuously cooled to ambient temperature using different cooling rates ranging from 500 to 1.4 °Cs–1. The metallographic examination of the samples was fulfilled using light and TEM microscopy. Additionally, Vickers hardness measurements were performed.

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Misra, A., and R. G. Hoagland. "Effects of Elevated Temperature Annealing on the Structure and Hardness of Copper/niobium Nanolayered Films." Journal of Materials Research 20, no. 8 (August 1, 2005): 2046–54. http://dx.doi.org/10.1557/jmr.2005.0250.

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We investigated the effects of elevated temperature vacuum annealing on the morphological stability and hardness of self-supported, textured, polycrystalline Cu–Nb nanolayered films with individual layer thickness varying from 15 to 75 nm. Films with layer thickness greater than approximately 35 nm are found to resist layer pinch-off and spheroidization even after long annealing times at 700 °C, while films with layer thickness ∼15 nm exhibit layer pinch-off and evolve into an equiaxed grain microstructure. Nanoindentation measurements indicate almost no change in hardness after annealing for films that retain the layered morphology, in spite of the increase of in-plane grain dimensions. Significant decreases in hardness are noted for films that develop a coarsened equiaxed grain microstructure after annealing. The mechanism that leads to the development of a thermally stable nanolayered structure is analyzed. Also, the relative effects of in-plane grain size and layer thickness on the multilayer hardness are discussed.

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Kahyaoglu, T., S. Kaya, and A. Kaya. "Effects of Fat Reduction and Curd Dipping Temperature on Viscoelasticity, Texture and Appearance of Gaziantep Cheese." Food Science and Technology International 11, no. 3 (June 2005): 191–98. http://dx.doi.org/10.1177/1082013205055002.

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The effects of varying fat content (from 13.5 to 50.4% w/w) and curd dipping temperatures (75, 85 and 95°C) on changes in viscoelastic properties, texture and appearance of Gaziantep cheese were examined. Viscoelastic properties of cheeses were studied using creep and recovery tests. Creep measurements showed that fat reduction from 50.4% (w/w) to 13.5% (w/w) decreased viscoelasticity while dipping into hot whey increased that of low-fat cheeses. Textural characteristics (hardness, gumminess, cohesiveness, springiness) were determined by texture profile analysis (TPA). Hardness, gumminess, cohesiveness and springiness values increased with decreasing fat content (P < 0.05). The application of curd dipping also increased hardness, gumminess, cohesiveness and springiness. Textural parameters were correlated with each others, except cohesiveness. Fat in dry matter correlated only with hardness and springiness, however curd dipping process correlated with all TPA parameters considered in this study. Colour of the cheese samples was affected by fat content as L value and b value decreased with decreasing fat content (P < 0.05). The decrease in curd dipping temperature increased the L value (P < 0.05) and decreased the b value.

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Kilic, Mehmet, Dervis Ozkan, Mustafa Sabri Gok, and Abdullah Cahit Karaoglanli. "Room- and high temperature Wear Resistance of MCrAlY Coatings Deposited by Detonation Gun (D-gun) and Supersonic Plasma Spraying (SSPS) Techniques." Coatings 10, no. 11 (November 19, 2020): 1107. http://dx.doi.org/10.3390/coatings10111107.

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In this study, CoNiCrAlY metallic coatings were deposited on an Inconel 718 nickel-based superalloy substrate material using the detonation gun (D-gun) and supersonic plasma spraying (SSPS) techniques. The microstructural and mechanical properties in addition to their room and high temperature wear behavior of the produced coatings were evaluated. The wear tests were performed at room temperature (rt), 250 and 500 °C using 2N and X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) analyses of the worn coatings were performed to assess their wear performance. The coatings produced with D-gun process exhibited higher hardness and lower porosity (550 ± 50 HV0.25 hardness and 1.2 ± 1.0% porosity) than SSPS coatings (with 380 ± 30 HV0.25 hardness and 1.5 ± 1.0% porosity) which resulted in better room- and high temperature wear performance for D-gun coatings. The worn surfaces of both coatings exhibited formation of tribological layers and superficial microstructural changes by varying temperature and load conditions. Increasing load and temperature resulted in increased wear loss whereas increasing temperature resulted in reduced COF values for both coatings.

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Liu, Jing Qing, Wei Jiang, Jian Min Wu, and Cong Li. "The Influence of Total Hardness on Chlorine Decay in Water Distribution Systems." Applied Mechanics and Materials 535 (February 2014): 776–84. http://dx.doi.org/10.4028/www.scientific.net/amm.535.776.

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Free chlorine decay is a main issue in drinking water treatment since free chlorine concentration is a common indicator in drinking water security. The current view of free chlorine decay is that the process is mainly affected by the natural organic matter in water, temperature and initial chlorine concentration, on which temperature has the most evidently effect. As is generally accepted, total hardness has no effect on it. This paper investigated the impact of water hardness on the chlorine decay. The influence of varying metal ions concentrations which contribute to water hardness on effective chlorine decay constants was assessed. The results implied that total hardness had an evidently influences on the chlorine decay in tap water or DI water. For the range of metal ions concentration in this experiment effective chlorine decay constants ranged from an increase by +182% to +349% from the different concentration of metal ions.

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Mu, Si Guo, Jiao Yan Dai, Yong Ru Wang, Guo Hui Chao, Xi Ping Hong, and Yu Chang Su. "Study on Microstructure and Properties of CuZn37Mn3Al2FeSi Alloy." Advanced Materials Research 287-290 (July 2011): 868–74. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.868.

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The microstructure of Cu-37%Zn-2%Mn-1.6%Al-0.7%Fe-0.7%Si (mass fraction)alloy was studied by scan electron microscopy, X-ray and optical microscopy. The α phase ratio and micro-hardness of this alloy after aging treatment were investigated. The results show that three kinds of phases, such as α phase, β phase and hexagonal club-shape Mn5Si3 phase were observed. The needle α phase ratio increases with aging temperature under 420°C and reach peak value 25 percent after aging at 420°C×1h. The α phase ratio begin decreases when the aging temperature over 420°C. The micro-hardness varying with aging temperature is the opposite.

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Navas, R. Kaja Bantha, A. John Rajan, Udit R. Topno, and Sindiri Chaitanya. "Optimizing the Coating Parameters for Coated Aluminium Alloy 2024 T351 by Using Factor Analysis Method ." Applied Mechanics and Materials 813-814 (November 2015): 608–12. http://dx.doi.org/10.4028/www.scientific.net/amm.813-814.608.

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This paper presents a novel approach for the optimization of input parameters on coated aluminum alloy 2024 T351 with Factor analysis method. These Experiments are conducted by varying the input parameters related to surface hardness and surface roughness. In this study, input parameters like coating thickness, substrate temperature and deposition rate are optimized with the considerations of multi responses such as surface hardness and surface roughness. L4 orthogonal array was taken to conduct the experiments. The method shows a good convergence with the experimental and the optimum coating parameters where the maximum surface hardness and the minimum surface finish are obtained.

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Puspasari, Vinda, Mukhlis Agung Prasetyo, Januarius Velix Ta’an Halab, Moch Syaiful Anwar, Efendi Mabruri, and Satrio Herbirowo. "Pengaruh Annealing terhadap Sifat Keras dan Struktur Mikro Baja Tahan Karat AISI 410-3Mo-3Ni." Metalurgi 35, no. 2 (October 27, 2020): 75. http://dx.doi.org/10.14203/metalurgi.v35i2.560.

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AISI 410-3Mo-3Ni stainless steel is a martensitic steel which limited in using when compared to austenitic and ferritic stainless steels. Martensitic steel has an essential role in specific components due to a combination of strength, toughness and excellent corrosion resistance. However, martensitic steel tends to undergo decreasing in mechanical properties and microstructure after the forging process. In this study, mechanical properties and microstructure of the forged AISI 410 after receiving annealing heat treatment will be studied. Annealing aims to reduce material hardness and increase grain refinement of material. Annealing heat treatment is carried out by varying the annealing temperature and time. Annealing temperature variations are 7000, 7600, and 8000C. The annealing time variation is 3 hours and 6 hours. The effect of annealing time and temperature will be studied on the hardness and microstructure of the AISI 410 modified material. The optimum hardness of 35.9 HRC in sample with annealing treatment in 760°C for 6 hours. The microstructure shows delta ferrite, martensite, austenite, and carbide phases which affect hardness value of annealed samples.

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Emmrich, Robin, and Ulrich Krupp. "On the Impact of the Intermetallic Fe2Nb Laves Phase on the Mechanical Properties of Fe-6 Al-1.25 Nb-X W/Mo Fully Ferritic Light-Weight Steels." Metals 11, no. 11 (October 24, 2021): 1693. http://dx.doi.org/10.3390/met11111693.

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The present study aims at the development of precipitation hardening fully ferritic steels with increased aluminum and niobium content for application at elevated temperatures. The first and second material batch were alloyed with tungsten or molybdenum, respectively. To analyze the influence of these elements on the thermally induced precipitation of the intermetallic Fe2Nb Laves phase and thus on the mechanical properties, aging treatments with varying temperature and holding time are performed followed by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) including elemental contrast based particle analysis as well as hardness measurements and tensile tests at room temperature and at 500 °C. The incorporation of molybdenum into the Laves phase sets in at an earlier stage of aging than the incorporation of tungsten, which leads to faster growth and coarsening of the Laves phase in the molybdenum-alloyed steel. Nevertheless, both concepts show a fast and massive increase in hardness (280 HV10) due to precipitation of Laves phase during aging at 650 °C. After 4 h aging, the yield strength increase at room temperature is 100 MPa, which stays stable at operation temperatures up to 500 °C.

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Zaheruddin, Kasmuin Mohd, Sri Asliza Md Amin, Azmi B. Rahmat, Shamsul Baharin Jamaludin, and R. A. Khairel. "Sintering Effects on Mechanical Properties of Co-Ha Composite Prepared by Modified Electroless Deposition." Key Engineering Materials 594-595 (December 2013): 255–59. http://dx.doi.org/10.4028/www.scientific.net/kem.594-595.255.

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Co-HA composite produced using electroless deposition without conventional sensitization and activation treatment was studied with varying sintering temperature (1100°C, 1200°C and 1250°C). The particles size, bulk density, porosity, hardness measurements and the flexural strength are performed in order to find the optimum sintering temperature. After the electroless process for 1 H, the particle size of HA increase to 3.9% and finally the value bulk density percentage of 93.08%, percentage porosity of 6.89%, hardness value of 291.8HV and flexural strength value of 42.4MPa have been achieved after pressing and sintering Co-HA composite at 1250°C. Observations were supporting the idea that Co-HA produced by modified electroless method was improving the mechanical properties with increasing the sintering temperature.

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Alisha, S., T. Venkateswaran, M. Amruth, P. Chakravarthy, and D. Sivakumar. "Effect of Heat Treatment on the Mechanical Properties of Copper-Beryllium Alloy (C17200)." Materials Science Forum 830-831 (September 2015): 168–71. http://dx.doi.org/10.4028/www.scientific.net/msf.830-831.168.

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Owing to high elastic modulus and good strength, copper beryllium alloys are widely used in many engineering applications. The addition of beryllium to copper makes the alloy respond to aging treatment and thus develops very high strength. Conventional heat treatment cycles are available for copper-beryllium to obtain peak ageing hardness condition. Present study has focused on developing a heat treatment cycle to obtain synergetic combination of moderate strength and good toughness for the C17200 copper-beryllium alloy. Ageing curves have been generated for varying temperature and time. Detailed mechanical properties (hardness, impact, tensile) evaluation at room temperature and sub-zero temperatures have been carried out for the selected samples. Modified heat treatment cycle resulted in higher toughness with adequate strength. Optical microscope (OM) and transmission electron microscope (TEM) analysis were carried out to understand the precipitation behavior. Also, measurements of coefficient of thermal expansion (CTE) and thermal conductivity were carried out on the aged samples.

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Acharya, Palaksha, Ajit Kumar, and Ravishankar Bhat. "Microstructure and wear behavior of austempered high carbon high silicon steel." MATEC Web of Conferences 144 (2018): 02013. http://dx.doi.org/10.1051/matecconf/201814402013.

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In the present investigation, the influence of austempering temperature and time on the microstructure and dry sliding wear behavior of high silicon steel was studied. The test specimens were initially austenitised at 900°C for 30 minutes, thereafter austempered at various temperatures 280°C, 360°C and 400°C, for varying duration from 30 to 120 minutes. These samples after austempering heat treatment were subsequently air cooled to room temperature, to generate typical ausferritic microstructures and then correlated with the wear property. The test outcomes demonstrate the slight increase in specific wear rate with increase in both austempering temperature and time. Specific wear rate was found to be minimum at an austempering temperature of 280°C, that exhibits lower bainite microstructure with high hardness, on the other hand specific wear rate was found to be slightly high at increased austempering temperatures at 360°C and 400°C, due to the upper bainite structure that offered lower hardness to the matrix. The sample austempered at 280°C for 30 minutes offered superior wear resistance when compared to other austempering conditions, mainly due to the presence of fine acicular bainitic ferrite along with stabilized retained austenite and also some martensite in the microstructure.

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RUKKUN, Jariyaporn, Kamon AIEMPANAKIT, Pimchanok REAKAUKOT, Witthawat WONGPISAN, Kirati WAREE, and Montri AIEMPANAKIT. "Investigation of deposition parameters on the structural properties and hardness of TiAlN films deposited via reactive pulsed DC magnetron sputteringInvestigation of deposition parameters on structural properties and hardness of TiAlN films deposited by reactive pulsed DC magnetron sputtering." Journal of Metals, Materials and Minerals 31, no. 2 (June 27, 2021): 118–22. http://dx.doi.org/10.55713/jmmm.v31i2.1083.

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In this work, titanium aluminum nitride (TiAlN) films were deposited on a silicon substrate via reactive pulsed DC magnetron sputtering. The effect of deposition parameters such as nitrogen gas flow rate, substrate temperature, and bias voltage on the structural and mechanical properties of TiAlN films was investigated. The crystal structure, morphology, and hardness of TiAlN films were characterized via X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM, and nanoindentation. An improved crystallinity of TiAlN films was obtained by varying the substrate temperature and bias voltage. The morphology of the TiAlN film exhibited a columnar structure, and the morphology gradually changed with the increase in bias voltage. The films thickness decreased upon increasing the nitrogen gas flow rate, substrate temperature, and bias voltage. In addition, the hardness of the TiAlN film was enhanced by adjusting the nitrogen gas flow rate, substrate temperature, and bias voltage, and a suitable elemental component ratio was obtained. A maximum hardness of approximately 28.9 GPa was obtained for the TiAlN film with a nitrogen gas flow rate of 4 sccm, substrate temperature of 500ºC, bias voltage of 100 V, and an elemental composition Al/(Al + Ti) of approximately 34.35%.

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Adebayo, Abdullahi, Olawale Ajibola, Oluwasegun Falodun, Sunday Borisade, Adebayo Owa, Oluwole Adigun, Akinlabi Oyetunji, and Kenneth Alaneme. "Effects of aluminium addition and austempering temperatures on Al-alloyed ductile iron microstructure and mechanical properties." Acta Metallurgica Slovaca 28, no. 4 (December 13, 2022): 181–87. http://dx.doi.org/10.36547/ams.28.4.1598.

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The research investigates the effect of varying amounts of aluminium (1.05, 1.575, 2.29, 3.02 and 3.74 wt.%) addition and heat treatment (austempering at 300, 350, 400 oC) on the microstructure and mechanical properties of ductile cast iron alloys. The graphitizing effects of the Al alloy and varied austempering temperatures on hardness, tensile strength, and impact toughness of the ductile cast iron (DCI) were evaluated. The results of the influences of Al addition and heat treatment on the properties of the DCI determined were presented as graphical data while the microstructures were done by using a scanning electron microscope (SEM). The microstructures revealed that the addition of Al into the matrix brings about the precipitation of ferrite around the graphite nodules. The combined effects of the increase Al content and austempering temperatures produced greater hardness values on the Al-alloyed DCI samples than the as-cast sample. The hardness value for the entire sample ranged between 27.25 to 57.03 BHN. Tensile strength increased with an increase in Al content and lower austempering temperatures, whereas, the impact toughness increased with an increase in Al content and higher austempering temperature.

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Fazily, Piemaan, Jaehyeong Yu, and Chang-Whan Lee. "Characterization of Sheared Edges in Warm Blanking of Magnesium Alloy AZ31B." Materials 12, no. 7 (March 28, 2019): 1023. http://dx.doi.org/10.3390/ma12071023.

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This research aims to characterize damage at the sheared edge caused by the blanking operation of magnesium alloy AZ31B sheets. Shearing tests were carried out on an in-house blanking die-set and mechanical press (universal testing machine) by varying punch–die clearance and temperature. Edge damage was distinguished by the geometrical features of the sheared edge and by the distribution of the edge strain hardening (ESH) index. In this account, optical microscopy and scanning electron microscopy were applied to examine the characteristic dimensions of the sheared edge, fracture profile, and sheared edge quality, while the Vickers hardness test was applied to observe the surface micro-hardness in the shear zone (SZ) and the shear affected zone (SAZ). It was concluded that the blanking of magnesium alloy sheets at room temperature results in sheared edge defects, due to premature fracture, referred to here as micro-cracks, loose particles, and a jagged-plus-curved fracture profile. However, such deformities were completely suppressed with the rise in temperature. In addition, based on optical morphology, micro-hardness tests, and microstructure evolution, the recommendation regarding blanking temperature for the magnesium alloy AZ31B has was proposed.

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Kaulfuss, Frank, Volker Weihnacht, Martin Zawischa, Lars Lorenz, Stefan Makowski, Falko Hofmann, and Andreas Leson. "Effect of Energy and Temperature on Tetrahedral Amorphous Carbon Coatings Deposited by Filtered Laser-Arc." Materials 14, no. 9 (April 23, 2021): 2176. http://dx.doi.org/10.3390/ma14092176.

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In this study, both the plasma process of filtered laser-arc evaporation and the resulting properties of tetrahedral amorphous carbon coatings are investigated. The energy distribution of the plasma species and the arc spot dynamics during the arc evaporation are described. Different ta-C coatings are synthesized by varying the bias pulse time and temperature during deposition. An increase in hardness was observed with the increased overlapping of the bias and arc pulse times. External heating resulted in a significant loss of hardness. A strong discrepancy between the in-plane properties and the properties in the film normal direction was detected specifically for a medium temperature of 120 °C during deposition. Investigations using electron microscopy revealed that this strong anisotropy can be explained by the formation of nanocrystalline graphite areas and their orientation toward the film’s normal direction. This novel coating type differs from standard amorphous a-C and ta-C coatings and offers new possibilities for superior mechanical behavior due to its combination of a high hardness and low in-plane Young’s Modulus.

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38

Ahmad, Fareed, Mohammed Al Awadh, Muhammad Abas, Sahar Noor, and Asad Hameed. "Optimization of Carbon Fiber Reinforced Plastic Curing Parameters for Aerospace Application." Applied Sciences 12, no. 9 (April 24, 2022): 4307. http://dx.doi.org/10.3390/app12094307.

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The use of carbon fiber reinforced plastic (CFRP) is increasing in engineering applications such as aerospace, automobiles, defense, and construction. Excellent strength-to-weight ratio, high impact toughness, and corrosion resistance make CFRP highly suitable for aerospace applications. Curing temperature, curing time, and autoclave pressure are among the most important curing parameters affecting the properties of CFRP. Tensile strength, impact toughness, and hardness of CFRP were selected as desirable properties for optimization. A 23 full factorial design of experiment (DOE) was employed by varying curing temperature (120 and 140 °C), curing time (90 and 120 min), and autoclave pressure (3 and 7 bar) while keeping the number of experiments to a minimum level. The cured samples were subjected to tensile strength, impact toughness, and hardness tests at room temperature as per relevant ASTM standards. Analysis of variance (ANOVA) was used, and it was found that tensile strength, impact toughness, and hardness were influenced most significantly by temperature and time. The maximum tensile strength and hardness were achieved for curing cycle parameters of 140 °C, 120 min, and 7 bar, and impact toughness was maximized for 140 °C, 120 min, and 3 bar. A concept of composite desirability function was used to achieve simultaneous optimization of conflicting tensile strength and impact toughness properties for the specific application of aircraft skin.

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Ahmad, Fareed, Mohammed Al Awadh, Muhammad Abas, Sahar Noor, and Asad Hameed. "Optimization of Carbon Fiber Reinforced Plastic Curing Parameters for Aerospace Application." Applied Sciences 12, no. 9 (April 24, 2022): 4307. http://dx.doi.org/10.3390/app12094307.

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The use of carbon fiber reinforced plastic (CFRP) is increasing in engineering applications such as aerospace, automobiles, defense, and construction. Excellent strength-to-weight ratio, high impact toughness, and corrosion resistance make CFRP highly suitable for aerospace applications. Curing temperature, curing time, and autoclave pressure are among the most important curing parameters affecting the properties of CFRP. Tensile strength, impact toughness, and hardness of CFRP were selected as desirable properties for optimization. A 23 full factorial design of experiment (DOE) was employed by varying curing temperature (120 and 140 °C), curing time (90 and 120 min), and autoclave pressure (3 and 7 bar) while keeping the number of experiments to a minimum level. The cured samples were subjected to tensile strength, impact toughness, and hardness tests at room temperature as per relevant ASTM standards. Analysis of variance (ANOVA) was used, and it was found that tensile strength, impact toughness, and hardness were influenced most significantly by temperature and time. The maximum tensile strength and hardness were achieved for curing cycle parameters of 140 °C, 120 min, and 7 bar, and impact toughness was maximized for 140 °C, 120 min, and 3 bar. A concept of composite desirability function was used to achieve simultaneous optimization of conflicting tensile strength and impact toughness properties for the specific application of aircraft skin.

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N, Lokesh. "Study on Mechanical Properties of hBN Reinforced Al-7075 Metal Matrix Composite." International Journal for Research in Applied Science and Engineering Technology 10, no. 7 (July 31, 2022): 3121–30. http://dx.doi.org/10.22214/ijraset.2022.45693.

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Abstract: Nickel-coated hBN particulate reinforced Al7075 matrix composites were developed using the stir casting technique. Al7075 – hBN composites were subjected to tensile test and heat treatment by solutionizing at a temperature of 550 ℃ for a span of 2 hr and then quenched in water at room temperature. Hardness was measured before starting the aging process and further, compacts were artificially aged in the furnace at temperatures of 100, 150, and 200 ℃ for intervals of 60 min. Results have revealed that nickel-coated hBN particles are uniformly distributed throughout the matrix alloy. Microhardness of Al6061- hBN composites increases with an increase in the percentage of reinforcement. Heat-treated Al-7075+4.5% nickel-coated hBN possesses higher hardness when compared with the Al-7075 alloy composites. Also, the hybrid reinforced composites exhibit excellent tensile properties; as compared with base metal (Al7075) and Al7075+4.5% nickel coated hBN show high Breaking Load and Ultimate Tensile Strength. The current studies focused on strength by varying aged harden treatment for Al7075+4.5% nickel coated hBN and their tensile strength.

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Syed Akbar Ali and B.S Motgi. "A Study on Mechanical Properties of Al7068 Based Metal Matrix Composite Reinforced with Rice Husk Ash (RHA) and Silicon Carbide (SiC)." September 2021 7, no. 09 (September 27, 2021): 71–78. http://dx.doi.org/10.46501/10.46501/ijmtst0709012.

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This paper deals with the fabrication of Al-7068 composites manufactured by powder metallurgy route reinforced with different weight percentages of rice husk ash (RHA) and SiC. A low pressure of 400mpa was applied for compacting the composites and sintered at a temperature of 720°C for three hour. SEM and EDX analysis was done to study the micro-structural behavior. Hardness and compression test were carried out. The hardness has been improved by adding the weight percentage of SiC but seems to be crash by adding the weight percentage of Rice Husk Ash (RHA). The compressive strength was found to be varying.

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Drygaś, Mariusz, Katarzyna Lejda, Jerzy F. Janik, Bogdan Musielak, Stanisław Gierlotka, Svitlana Stelmakh, and Bogdan Pałosz. "Composite Nitride Nanoceramics in the System Titanium Nitride (TiN)-Aluminum Nitride (AlN) through High Pressure and High Temperature Sintering of Synthesis-Mixed Nanocrystalline Powders." Materials 14, no. 3 (January 27, 2021): 588. http://dx.doi.org/10.3390/ma14030588.

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Presented is a study on the original preparation of individual and in situ intimately mixed composite nanocrystalline powders in the titanium nitride-aluminum nitride system, Ti:Al = 1:1 (at.), which were used in high pressure (7.7 GPa) and high temperature (650 and 1200 °C) sintering with no binding additives for diverse individual and composite nanoceramics. First, variations in precursor processing pathways and final nitridation temperatures, 800 and 1100 °C, afforded a pool of mixed in the nanosized regime cubic TiN (c-TiN) and hexagonal AlN (h-AlN) composite nanopowders both with varying average crystallite sizes. Second, the sintering temperatures were selected either to preserve initial powder nanocrystallinity (650 °C was lower than both nitridation temperatures) or promote crystal growth and recrystallization (1200 °C was higher than both nitridation temperatures). Potential equilibration towards bimetallic compounds upon solution mixing of the organometallic precursors to nanopowders, monomeric Ti[N(CH3)2]4 and dimeric {Al[N(CH3)2]3}2, was studied with 1H and 13C NMR in C6D6 solution. The powders and nanoceramics, both of the composites and individual nitrides, were characterized if applicable by powder XRD, FT-IR, SEM/EDX, Vicker’s hardness, and helium density. The Vicker’s hardness tests confirmed many of the composite and individual nanoceramics having high hardnesses comparable with those of the reference h-AlN and c-TiN ceramics. This is despite extended phase segregation and, frequently, closed microsized pore formation linked mainly to the AlN component. No evidence was found for metastable alloying of the two crystallographically different nitrides under the applied synthesis and sintering conditions. The high pressure and high temperature sintering of the individual and in situ synthesis-mixed composite nanopowders of TiN-AlN was demonstrated to yield robust nanoceramics.

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Fikry, Mohammad, Ibrahim Khalifa, Rokkaya Sami, Ebtihal Khojah, Khadiga Ahmed Ismail, and Mokhtar Dabbour. "Optimization of the Frying Temperature and Time for Preparation of Healthy Falafel Using Air Frying Technology." Foods 10, no. 11 (October 25, 2021): 2567. http://dx.doi.org/10.3390/foods10112567.

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Air-frying is an innovative technique for food frying that uses hot air circulation to prepare healthy products. The objectives of this study were to establish simplified models to reflect the efficacy of the air frying process at varying temperatures and times on the quality attributes of falafel, and to optimize the frying conditions for producing air-fried falafel. Moisture content, color, fat content, hardness, and sensory evaluation of the fried falafel were analyzed under varied temperatures (140 °C, 170 °C, and 200 °C) and time periods (5 min, 10 min, and 15 min). Statistical analysis was then applied to obtain the best fit model that can describe the properties of fried falafel. Results indicated that moisture content, fat content, and L*-value of air-fried falafel were adversely related to the frying temperature and time, but the hardness and ΔE of fried falafel were increased as the frying temperature and time increased. Moreover, an increase followed by a decrease was shown for the appearance, aroma, crispness, taste, and overall preference scores with the increase in frying temperature and time. The regression analysis showed that the proposed models could be properly used for predicting the properties of the fried falafel. In addition, the overlaid plots resulted in the optimum frying temperature of 178.8 °C and time of 11.1 min. Interestingly, the fat content of the air-fried falafel reduced by 45% at optimal frying conditions compared with that for the deep-fat fried one at 180 °C for 7 min (control). In comparison, the air-fried falafel was lower in fat content, higher in hardness with more acceptable appearance and crispness scores than deep-fat fried falafel. Such information could be beneficial to the manufacturers of the falafel to produce an optimal and healthy product.

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Amir, Adibah, and Othman Mamat. "Effects of SiO₂ Particles in Mechanical Properties of Iron Composite." Applied Mechanics and Materials 465-466 (December 2013): 886–90. http://dx.doi.org/10.4028/www.scientific.net/amm.465-466.886.

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Tronohs raw sand was converted into fine silica particles via a series of milling process. Addition of these fine particles into iron composite was found to modify its mechanical properties. The composite was prepared using powder metallurgy technique with varying percentage of silica particles; 5, 10, 15, 20 and 25wt%. The composites were sintered at three different temperatures; 1000° C, 1100° C and 1200° C to find the most suitable sintering temperature. Changes in density and hardness were observed. The results showed that composite consist of 20wt% silica particles and sintered at 1100° C exhibits best improvement.

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Moosa, Jaafar M., Haider G. Abdulzahraa, Shihab A. Zaidan, and Hafidh Y. Abed. "Reinforcing Glaze Layer of Restorative Dental Zirconia by Adding Nano Alumina Ceramics." NeuroQuantology 19, no. 6 (July 14, 2021): 73–78. http://dx.doi.org/10.14704/nq.2021.19.6.nq21071.

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The objective of this work is to study the effect of adding varying ratios of Nano Alumina to the glazing powder on glazing layer of restorative dental ceramic. The effect of addition is examined by applying Vickers hardness and surface roughness tests on the glazing layer. The specimens have been cut in a cubic form. The specimens were placed in the furnace for sintering up to temperature of 1450 oC. One specimen is glazed with glazing materials and the remaining three specimens are glazed with glazing materials but supported with varying ratios of Nano Alumina (10, 15 and 25 wt%) and all these specimens sintered at 850 oC. It was found that Vickers hardness is increased with increasing the ratios of Nano Alumina but the surface roughness decreased with increasing the ratios of Nano Alumina. Weibull modulus increased with Alumina additive increases for glass coating layer.

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Prasetya, Angga Yunis, Darmanto Darmanto, and Muhammad Dzulfikar. "The Effect of Plasma Nitridation on Surface Hardness of Titanium Alloy (Ti-6Al-4V) for Artificial Knee Joint Applications." Journal of Biomedical Science and Bioengineering 1, no. 2 (January 3, 2022): 49–53. http://dx.doi.org/10.14710/jbiomes.2021.v1i2.49-53.

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Nitriding has been carried out using plasma nitriding techniques for surface treatment of Titanium as a biomaterial component. The purpose of this study was to determine the effect of plasma nitriding on surface hardness that occurs in titanium. The material used is Titanium Alloy (Ti-6Al-4V) Grade 5 which is processed by plasma nitriding by varying nitrogen (N2) and argon (Ar) gases of (100% N2/0% Ar), (95% N2/5% Ar), (90% N2/10% Ar), (85% N2/15% Ar), (80% N2/20% Ar), and (75% N2/25% Ar), and temperature 400ºC, time 5 hours and a pressure of 1.6 bar. The test results show that the optimum hardness is found in the gas composition with a ratio of 95% N2: 5% Ar. Obtained a hardness of 371 HV/VHN or an increase of 159% of the raw material with hardness value of 143 HV/VHN

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Suresh, T., P. Sures, and M. Prabu. "Influences of Ag+LiAlO2 on mechanical and high temperature wear behavior of magnesium hybrid composites." Digest Journal of Nanomaterials and Biostructures 17, no. 3 (June 2022): 731–40. http://dx.doi.org/10.15251/djnb.2022.173.731.

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The objective of this research is to analyze the mechanical such as porosity; hardness and high temperature wear behavior of Magnesium (MgZE41A) hybrid composites reinforced with Silver (Ag) and Lithium Aluminate (LiAlO2). The various wt. % such as Ag (1.0 & 1.5) and LiAlO2 (1.0 & 1.5) was reinforced in MgZE41A using Powder Metallurgy (P/M) technique. The sintered composites were characterized using Scanning Electron Microscope (SEM) coupled with Energy Dispersive Spectroscopy (EDS) line mapping Technique. The porosity and Vicker’s hardness of the samples were assessed. Further, the high temperature wear behavior of the composites was evaluated using tribometer with heater setup by varying the heat inputs such as 30°C, 50°C, 100°C, 150°C and 200°C. The results revealed that increasing the wt. % of Ag and LiAlO2 led to decrease the porosity from 0.11 % to 0.09 % due to high compacting pressure and sintering temperature. High temperature Wear rate of the composites was reduced from 2.15 * 10-4 to 0.83 * 10-4 because of wt. % of reinforcement, high compacting pressure and better sintering temperature.

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48

Muniandy, Suresh, Ananthan Soosai, and Teow Hsien Loong. "Effect of Sintering Temperature to the Mechanical Properties of Different Filler Loading of Zirconia Powder in Hydroxyapatite Composites." Materials Science Forum 1030 (May 2021): 27–34. http://dx.doi.org/10.4028/www.scientific.net/msf.1030.27.

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Hydroxyapatite (HA)-Zirconia (ZrO2) composite with varying zirconia composition ranging from 1 to 10 wt% was investigated for biomedical applications in order to produce high compressive strength. Precipitation method was used to prepare both hydroxyapatite and zirconia powders. To find the ideal composition, mixture-containing 1, 3, 5 and 10 wt% ZrO2 powder was added. Each mixture was sintered for 4 hours at 750oC, 1050oC and 1250oC. Hardness and compressive strength test were used for evaluation. It was found that with 1 wt% of ZrO2 sintered at 1250oC showed the greatest structural strength as its volume fraction porosity is the lowest. The hardness and compressive strength of this sample were found to be 2.75 GPa and 72.0 MPa respectively. This can be useful for biomedical applications especially in promoting osteo-integration.

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Mallikarjun Nagagonda and B.S Motgi. "Investigation of Microstructure and Mechanical Properties of Hybrid Composite Aluminum 7075 Reinforced with Sugar Cane Husk Ash (SCHA) and Silicon Carbide (SiC) by Powder Metallurgy." September 2021 7, no. 09 (September 27, 2021): 102–9. http://dx.doi.org/10.46501/ijmtst0709017.

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This paper deals with the fabrication of Al-7075 composites manufactured by powder metallurgy route reinforced with different weight percentages of Sugar Cane Husk Ash (SCHA) and Silicon Carbide (SiC) A low pressure of 400 MPa was applied for compacting the composites and sintered at a temperature of 720oC for three hour. SEM and EDX analysis was done to study the micro-structural behavior. Hardness and compression test were carried out. The hardness has been improved by adding the weight percentage of Silicon Carbide (SiC) but seems to be crash by adding the weight percentage of Sugar Cane Husk Ash (SCHA). The compressive strength was found to be varying.

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Zhang, Lin, Yuhang Hou, Xiao Guo, Zhaolong Xiang, and Engang Wang. "Effect of Electromagnetic Stirring on the Microstructure and Properties of Fe-Cr-Co Steel." Materials 11, no. 8 (August 14, 2018): 1437. http://dx.doi.org/10.3390/ma11081437.

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High chromium steel has been synthesized by an induction furnace adopting electromagnetic stirring (EMS). Varying amounts of cobalt was added to obtain 3, 6, and 12% Co in the steel. The melt was allowed to solidify with or without EMS in a rotary magnetic field. The effects of the varying cobalt content and the stirring have been characterized by the microstructural evolution and the consequent improvement in mechanical properties. The application of a rotary EMS during solidification has shown a significant effect on the grain refining, the reduction of element segregation, the promotion of eutectic volume fraction, and the consequent improvement of mechanical properties, including hardness and high-temperature strength. The formation mechanism of the eutectic structure and the precipitation of M7C3 and M23C6 carbides was discussed according to the calculated phase diagram. The increment of cobalt content improved the eutectic volume fraction. Cobalt addition also enhanced the hardness and the yield tensile strength, provided that the ingot structure was homogenized by the EMS.

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Journal articles on the topic 'Varying temperature hardness'

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