Journal articles: 'Copper welds'

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Neidel, A., S. Riesenbeck, and M. Giller. "Liquid Metal Embrittlement in Narrow Gap Welds." Practical Metallography 59, no. 2 (February 1, 2022): 92–101. http://dx.doi.org/10.1515/pm-2022-0009.

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Abstract Failure analysts are sometimes surprised to find well-known metallurgical failure mechanisms at work in completely unexpected places. This contribution is an eloquent example for just such an incidental convergence of well-known failure mechanism and fabrication process where it was not reported to have previously occurred. Liquid Metal Embrittlement (LME) was observed in Narrow Gap Welds (NGW) produced for Welding Procedure Qualification (WPQ). The embrittling liquid metal was copper in this case. It is believed to have originated from copper backing used for weld pool protection. It was recommended to replace copper backing with ceramic weld pool protection.

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Leal, Rui M., Carlos Leitão, Altino Loureiro, Dulce Maria Rodrigues, and Pedro Vilaça. "Microstructure and Hardness of Friction Stir Welds in Pure Copper." Materials Science Forum 636-637 (January 2010): 637–42. http://dx.doi.org/10.4028/www.scientific.net/msf.636-637.637.

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The aim of present research was to study the effect of the position of the tool relative to the support backing plate of the FSW machine on the formation of defects and on alterations of the microstructure and mechanical properties of friction stir welds in phosphorus-deoxidised copper (Cu-DHP) thin sheets of 1 mm thick. The welds were carried out using position control conditions; distances between the tool and the backing plate of 0.1 mm, 0.075 mm and 0.05 mm were used. The formation of defects like continuous voids along the weld is very influenced by the tool position, though the heat-input plays an important role in the process. Large grain refinement was observed in the nugget of the welds; the change of the relative tool position has little effect on this grain refinement. Substantial hardening was observed in the thermomechanically affected zone (TMAZ) of the welds. The welds exempt of defects, such as continuous voids, attained a little tensile strength overmatch condition.

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Will, Thomas, Jannis Kohl, Claudio Hoelbling, Lars Müller, and Michael Schmidt. "Laser welding of different pure copper materials under consideration of shielding gas influence and impact on quality relevant surface topographical features." Journal of Laser Applications 35, no. 1 (February 2023): 012013. http://dx.doi.org/10.2351/7.0000891.

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The high demand for electronic products increases the need for high-quality welds of copper. Laser welding can be applied but may result in undesired weld characteristics such as humping or spatter. Process control is needed to identify defective welds in the production line. Surface topographical features can be used to identify different weld characteristics by optical coherence tomography (OCT). The resulting surface topography of a weld can be influenced by process parameters like its material properties or the application of process gas. In this work, we investigate the influence of different pure copper materials and process gas on weld seam surface features for the classification of quality-relevant weld characteristics. First, the resulting changes in weld depth and metallographic cross sections are qualitatively and quantitively characterized for different pure copper materials under the consideration of weld categories such as melt ejection, deep penetration welding, humping, and heat conduction welding with and without the application of shielding gas. Afterward, a qualitative and quantitative analysis of weld surface features is performed for the beforementioned categories under consideration of the copper material and shielding gas. As a result, an influence on the achievable weld depth could be identified for pure copper with residual phosphor content. No significant changes in surface topographical features could be identified for different material properties of copper. The influence of shielding gas and pure copper material is found to be negligible on surface topographical characteristics for process control.

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Imani, Yousef, M. K. Besharati Givi, and Michel Guillot. "Improving Friction Stir Welding between Copper and 304L Stainless Steel." Advanced Materials Research 409 (November 2011): 263–68. http://dx.doi.org/10.4028/www.scientific.net/amr.409.263.

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As a solid-state welding technology, friction stir welding (FSW) can join dissimilar materials with good mechanical properties. In this paper, friction stir welding between 304L stainless steel and commercially pure copper plates with thicknesses of 3 mm was performed. A number of FSW experiments were carried out to obtain the optimum mechanical properties by adjusting the rotational speed to 1000 rpm and welding speed in the range of 14-112 mm/min and with an adjustable offset of the pin location with respect to the butt line. Microstructural analyses have been done to check the weld quality. Cross-sectioning of the welds for metallographic analysis in planes perpendicular to the welding direction and parallel to the weld crown was also performed. The mechanical properties of the welds were determined using a combination of conventional microhardness and tensile testing. From this investigation it is found that the offset of the pin is an essential factor in producing defect free welds in friction stir welding of copper and steel.

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Schmidt, Hans Christian, Christoph Ebbert, Dmytro Rodman, Werner Homberg, Guido Grundmeier, and Hans Jurgen Maier. "Investigation of Cold Pressure Welding: Cohesion Coefficient of Copper." Key Engineering Materials 651-653 (July 2015): 1421–26. http://dx.doi.org/10.4028/www.scientific.net/kem.651-653.1421.

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Joining materials by forming is an interesting approach to the manufacture of hybrid (multi material) parts. By establishing a cold pressure weld between metallic surfaces, high quality joints with superior properties can be achieved. Reliable cold welding conditions are difficult to set up, however, since the weld initiation requires extraordinary clean, virtually sheer surfaces. Until today such conditions could only be achieved under a high vacuum conditions. Various studies on cold pressure welding reported that under vacuum welds can be established at significantly lower deformation than in a normal atmosphere. Since adverse deformation is currently needed in industrial cold pressure welding processes like the cold roll cladding of metal bands, a new process with in-line electrochemical surface treatment, is investigated. The ECUF process is intended to supply clean and thereby highly activated surfaces to the cold pressure welding process.This paper presents first results on the weld-ability of copper specimens with regard to the influence of the welding environment: air, argon and KCl solution. Butt welds were made by pressure welding of previously fractured specimens.

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Porter, Nancy C., James J. Russell, Christopher Conrardy, Lee G. Kvidahl, Nicholas J. Evans, Harold A. Sadler, David J. Barton, and Brian G. Baughman. "High-Speed Tandem Submerged Arc Welding of Thin Steel Panels." Journal of Ship Production 23, no. 03 (August 1, 2007): 125–34. http://dx.doi.org/10.5957/jsp.2007.23.3.125.

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For thin steel, high-speed tandem, narrow groove submerged arc welding procedures were developed with improved flux copper backing using advanced waveform power supplies and controlled weld joint root openings. Preferred parameters produced welds that met Navy mechanical property requirements, improved weld bead quality, and doubled/tripled welding productivity.

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Faes, Koen, Irene Kwee, and Wim De Waele. "Electromagnetic Pulse Welding of Tubular Products: Influence of Process Parameters and Workpiece Geometry on the Joint Characteristics and Investigation of Suitable Support Systems for the Target Tube." Metals 9, no. 5 (May 1, 2019): 514. http://dx.doi.org/10.3390/met9050514.

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In this experimental research, copper to steel tubular joints were produced by electromagnetic pulse welding. In a first phase, non-supported target tubes were used in order to investigate the influence of the workpiece geometry on the weld formation and joint characteristics. For this purpose, different joint configurations were used, more specific the tube-to-rod and the tube-to-tube configurations, with target workpieces with different diameters and wall thicknesses. Also, some preliminary investigations were performed to examine a support method for the target tubes. In a second phase, suitable support systems for the target tubes were identified. The resulting welds were evaluated in terms of their leak tightness, weld length and deformation of the target tube. It can be concluded that polyurethane (PU), polymethylmethacrylaat (PMMA), polyamide (PA6.6) and steel rods can be considered as valuable internal supports leading to high-quality welds and a sufficient cross-sectional area after welding. Welds with a steel bar support exhibit the highest cross-sectional area after welding, but at the same time the obtained weld quality is lower compared to welds with a PA6.6 or PMMA support. In contrast, welds with a PA6.6 or PU support show the highest weld quality, but also have a lower cross-sectional area after welding compared to steel internal supports.

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Leal, Rui M., Carlos Leitão, Altino Loureiro, and Dulce M. Rodrigues. "Imaging characterization of friction stir welds in the AA 5182-H111 aluminium alloy." Microscopy and Microanalysis 15, S3 (July 2009): 81–82. http://dx.doi.org/10.1017/s1431927609990869.

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AbstractThe environmentally friendly friction stir welding (FSW) process is being increasingly used in joining similar and dissimilar aluminium and copper alloys and other soft materials. In this process a rotating tool promotes significant shear strain and frictional heating of the base materials, in order to stir them into a highly plasticized weld region, at the trailing side of the tool. Due to the intense plastic deformation, complex material flow patterns, such as vortices, swirls and whorls occur during welding. In dissimilar welds, these patterns are readily revealed by differential etching and the respective microstructures characterized. However, in similar welds, such as the welds between plates of AA 5182-H111 aluminium alloy, it is hard to distinguish the different features in the welds and characterize their microstructures. Fig. 1 illustrates optical and TEM micrographs of a weld in this alloy. In the optical image of the weld, at the top of the image, it is possible to distinguish three main areas signalized by numbers: the weld nugget (1), with a very fine grain structure with 2.8 um mean grain size, and a transition region (2) between the nugget and the base material (3), which is usually called the Thermomechanical Affected Zone (TMAZ).

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Park, Hwa Soon, Byung Woo Lee, Taichi Murakami, Kazuhiro Nakata, and Masao Ushio. "Friction Stir Welding of Oxygen Free Copper and 60%Cu-40%Zn Copper Alloy." Materials Science Forum 580-582 (June 2008): 447–50. http://dx.doi.org/10.4028/www.scientific.net/msf.580-582.447.

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The mechanical properties of the friction stir welds of the oxygen free copper (OFC) and 60%Cu-40%Zn copper alloy(60/40 brass) were investigated. The defect-free welds were obtained in a relatively wide range of welding conditions; the tool rotation speed had rpm of 1000 to 2000 in the OFC and 1000 to 1500 in the 60/40 brass, with the welding speed of 500 to 2000 mm/min. The SZ hardness values of the OFC welds were almost the same or slightly lower than those of the base metal. However, the SZ hardness values of the 60/40 brass in all welding conditions were much higher than those of the base metal. The SZ hardness values of both metals increase with a decrease in heat input. The tensile properties of the all-SZ showed relative correspondence to the variation of the SZ hardness values.

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Matarneh, Mohammad E., Nabeel S. Gharaibeh, Valeriy V. Chigarev, and Havrysh Pavlo Anatoliiovych. "Reduction of Copper to Steel Weld Ductility for Parts in Metallurgical Equipment." Journal of Mechanical Engineering 17, no. 1 (April 1, 2020): 103–14. http://dx.doi.org/10.24191/jmeche.v17i1.15222.

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Despite being challenging, the welding of the dissimilar metals copper and steel is an essential process that is required for improving quality of equipment manufacturing in the fields of metallurgy, machine construction, and chemical industry. Restricted solubility of iron in copper leads to the formation of a supersaturated solid solution of iron and other chemical elements in the weld pool. Investigations have found the possibility of enhancing the process of welding copper with steel. In the case of using a flux-cored welding wire and an improved welding technique, the number of dendritic inclusions is reduced, and the weld ductility is improved. Studying the microstructure of a copper to steel weld confirmed the ability to enhance the outcome of the welding process of the dissimilar metals. The implementation of recommended preparation techniques of parts before welding, and optimization of the welding technique will increase the strength of the welds and, increases the operational reliability of metallurgical equipment.

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Li, Yi Nan, and Zi Long Peng. "The Effect of Element Ag and P in Dissolving Action and Mechanical Performance of the Welds during Weld Brazing of Copper." Advanced Materials Research 472-475 (February 2012): 1151–54. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.1151.

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Dissolving action of Ag and P during weld brazing of thick copper plates without preheating was investigated and the mechanical performance of the weld of copper was analyzed. The difference of dissolving action between Ag and P is that Ag-Cu binary alloys dissolve base metals in form of body dissolution, while P diffuse into grain boundary first and reach the limit solid solubility gradually then the surface layer of base metal begins to dissolving. The stirring function of arc is important for dissolving action of P but has little effect on dissolving action of Ag. P in form of rigid and brittle Cu3P increases the micro-hardness of welds.

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Kim, Jisun, Jeawoong Kim, and Inju Kim. "Analysis of welding properties using various horn-tip patterns in the ultrasonic metal welding process." Mechanics & Industry 21, no. 1 (2020): 102. http://dx.doi.org/10.1051/meca/2019078.

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The present study was conducted to investigate how the characteristics of welds are affected by the horn-tip pattern shape, in order to assess how to efficiently transfer the vibration energy to a base material through the horn. Energy transfer was evaluated using the indentation marks. The experiment was carried out with aluminum and copper by combining the conditions from four horn-tip patterns, six pressure values, and ten welding time values. The aspect ratio of the indentation marks on the weld surfaces was measured. The effects of the applied pressure, welding time, and horn-tip pattern shape on the aspect ratio were analyzed, and it was found that the horn-tip pattern shape affects the aspect ratio significantly. The aspect ratio was suggested as an analytical reference, and its correlations with the shear strength and the hardness of the welds were verified. In addition, the experiment performed with aluminum and copper, which have different mechanical properties, under the same welding conditions showed that the aspect ratio was dependent on the mechanical properties of the materials. In conclusion, as the density of the horn-tip pattern is decreased, less of the vibration energy was lost, increasing the strength of the welds. Experimental results showed that shear strength of copper was nearly 400 N when the aspect ratio was close to the value of 1. The highest peak of horn-tip pattern forms the lowest aspect ratio of the indentation mark, which can be indicated that the decrease of the aspect ratio effect to the improvement of welds strength. Aspect ratio of horn-tip pattern D, which dimensions are pitch 1.5 mm, height 0.75 mm and stub tooth 0.7 mm was closely to the value of 1 compared to the other patterns.

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Sahul, Miroslav, Martin Sahul, Milan Turňa, and Paulína Zacková. "Disk Laser Welding of Copper to Stainless Steel." Advanced Materials Research 1077 (December 2014): 76–81. http://dx.doi.org/10.4028/www.scientific.net/amr.1077.76.

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The paper concerns with welding of copper to stainless steel. Technically pure Cu and AISI 304 austenitic stainless steel with the thickness of 2.0 mm were suggested as experimental metals. TruDisk 8002 laser with the wavelength of 1.03 μm and a maximum power of 8.0 kW was used for production of dissimilar metal welds. Laser power from the range of 2.3 to 2.9 kW and welding speed from 35 to 50 mm/s were used for welding dissimilar metals. Focal position was direct on the surface of welded metals. Helium with flow rate of 17 l/min was used for shielding of molten weld metal. Light microscopy, EDX microanalysis and micro hardness measurements across copper - fusion zone - stainless steel interface were performed in order to study the properties of the weld joints.

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Lee, R. N., M. K. Norr, O. J. Jacobus, B. J. Little, R. I. Ray, and P. A. v. "Composition Variations in Copper-Nickel Butt Welds." CORROSION 47, no. 8 (August 1991): 645–52. http://dx.doi.org/10.5006/1.3585302.

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Porto, J. V., and J. M. Parpia. "Diffusion welds between copper and silver alloys." Physica B: Condensed Matter 194-196 (February 1994): 857–58. http://dx.doi.org/10.1016/0921-4526(94)90758-7.

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Panteikov, S. P. "Development of welded structure of 5-nozzle lance heads in converter shop of PJSC “Dneprovsky metallurgical combine”." Izvestiya. Ferrous Metallurgy 63, no. 10 (December 10, 2020): 815–22. http://dx.doi.org/10.17073/0368-0797-2020-10-815-822.

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For the upper blasting lances of 250-tons oxygen converters at PJSC «DMС» (Kamenskoe, Ukraine) the author has proposed a number of welded structures of 5-nozzle lance heads with increased resistance. A set of industrial studies of their operation made it possible to establish that the devices which provide cooling of the areas back from the nozzle zone of the tip have the highest resistance. Measures to increase the values of the average cooler speeds in welded structures of the lance heads and their rigidity also turned out to be quite effective. The transfer of copper welds holding the nozzle inserts in the copper tip from its outer surface to the inner proved to be ineffective from the point of increasing resistance of the lance head (the average resistance of the heads increased by only 7 heats – from 78 to 85 heats). This allows us to assert the need for complete elimination of copper welds in the head (both external, exposed to high-temperature and mechanical stresses, and internal) that hold nozzle inserts in the holes of the welded tip and lance head collector. Thus, in spite of all the measures taken to transfer the welds from the outer surface of the tip to its inner surface, to improve cooling of the tip and its back from the nozzle zones, which also include sections of copper welds around the nozzles, as well as to increase the rigidity of the blast welded structure heads, this led, although to positive, but still to relatively low results. The data obtained indicate that welds made of copper around the nozzle inserts, which are held by this in the tip (also in the collector) of the head, are the limiting link that does not significantly increase the resistance of welded lance heads, and it is urgently necessary to back off its use.

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Chen, Ping, Zhong Ning Guo, and Bing Hua Mo. "Optimization on Resistance Microwelding Procedure of Fine Copper Wire Based on Orthogonal Experiment Design." Advanced Materials Research 418-420 (December 2011): 1448–51. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.1448.

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In this paper, an orthogonal experiment design method has been used to optimize the resistance microwelding (RMW) parameters for the fine copper wire and SUS304 stainless steel thin sheet welds. A L25(56) orthogonal array for three factors (welding current, weld time and electrode force) with five levels was used. Joint breaking force (JBF) and surface appearance were selected as the index of evaluation. The results show that welding current was the most influencing parameter on both joint strength and surface appearance, and weld time had the next most significant effect. The orthogonal experiment design method was proved to be a promising technique to obtain the optimum conditions for RMW of fine copper wire.

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Leal, Rui M., Carlos Leitão, Altino Loureiro, and Dulce M. Rodrigues. "Defect formation and microstructural changes in friction stir welds between pure copper and a brass alloy." Microscopy and Microanalysis 15, S3 (July 2009): 79–80. http://dx.doi.org/10.1017/s1431927609990857.

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AbstractSeveral attempts have been made in the last few years for joining similar pure copper and brass alloys using the solid state friction stir welding (FSW) process. For both material types, all the works performed reported that the production of defect free welds is largely dependent on the correct choice of process parameters. It was also observed that, despite grain refinement occurred in the centre of all the welds, the welds in copper showed a slight reduction in strength, when compared to that of the base material, as opposed to welds in brass alloys, for which an increase in strength was observed. Regardless of the encouraging results obtained in similar FWS of these materials, in the knowledge of the authors, few reports exist concerning dissimilar joints between them. In his work, dissimilar welds between Cu DHP cooper plates and Cu-Zn 37 brass plates, both of 1 mm thickness, with the brass plate positioned in the advancing side of the tool, were analysed. Welds were carried out with a solid tool made of high speed steel. Tool geometry was characterized by a tool shoulder of 10 mm in diameter, containing a conical cavity of 6 degrees, and a threaded probe of 3 mm in diameter. Welds were done in a milling machine, in position control, using the working parameters indicated in table 1.

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Galvão, Ivan, Carlos Leitão, Altino Loureiro, and Dulce Rodrigues. "Friction Stir Welding of very thin plates." Soldagem & Inspeção 17, no. 1 (March 2012): 02–10. http://dx.doi.org/10.1590/s0104-92242012000100002.

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The results obtained in present research, relative to friction stir welding of 1 mm thick plates of aluminium, copper, copper-zinc and zinc alloys, prove that the application of the process in the joining of very thin plates is feasible and desirable. In fact, independently of the base material, the welds produced presented very good morphological characteristics and significant grain refinement in the nugget. Tensile and hardness tests proved that all the welds were at least in even-match relative to the base material properties. Based on the AA 5182 aluminium alloy results it was also possible to conclude that augmenting the welding speed, which improves process productivity, increases grain refinement in the nugget, improving the mechanical properties of the welds.

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Eslami, Nima, Yannik Hischer, Alexander Harms, Dennis Lauterbach, and Stefan Böhm. "Influence of Copper-Sided Tin Coating on the Weldability and Formation of Friction Stir Welded Aluminum-Copper-Joints." Metals 9, no. 2 (February 2, 2019): 179. http://dx.doi.org/10.3390/met9020179.

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Although the joining of aluminum and copper is a difficult task, several studies have shown that friction stir welding (FSW) is capable of producing aluminum-copper-joints with excellent performance. Therefore, it is desirable to use this joining technique for the production of cost- and weight-reduced conductors for the automotive sector. The exposed copper contact spots in automobiles are usually coated with tin for design reasons and in order to improve their corrosion resistance. In this context, it is possible to perform the weld at first and to coat afterwards, or to weld already coated copper workpieces. Taking this into account, this paper presents results on the influence of copper-sided tinning on the joint formation as well as the achievable mechanical and electrical properties of friction stir butt welded aluminum-copper joints. Two variants were considered. The first variant included copper blanks with a tinned surface. For the second variant the surface and the abutting edge of the copper were coated. The best welds achieved excellent electrical properties and their tensile strength was only slightly reduced compared to the aluminum base material. Thus, it was shown that if these tensile strength losses are acceptable, FSW of aluminum to tin coated copper is applicable.

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Winarto, W., M. Anis, and B. Eka Febryansyah. "Mechanical and Microstructural Properties of Friction Stir Welded Dissimilar Aluminum Alloys and Pure Copper Joints." MATEC Web of Conferences 269 (2019): 01001. http://dx.doi.org/10.1051/matecconf/201926901001.

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Joining dissimilar metal alloys such as aluminum and copper is very difficult to be done because of alterations in chemical, metallurgical and physical behavior. Friction Stir Welding (FSW) is a solid-state welding technique which is one of the new methods used for joining the dissimilar metal. The material used is aluminum alloy 5052 and pure copper plates. The welding parameters were carried out with variable geometry shape of pin tools: taper and threaded cylindrical pin tools. Also preheating were performed on the part of copper plates with temperatures at both 25°C and 200°C. The friction stir welding of dissimilar joints was carried out at the rotary tool speed of 2800 rpm with the angle of 1 degree and the welding travel speed of 2 mm/sec. All welds were then carried out to several mechanical testing and microscopic observation. The results show that the variable geometry shape of pin tools and pre-heating on the copper part affect the microstructure grain size and the formation of Al-Cu inter-metallic phases. The creation of different structures influences the mechanical properties of the friction stir welds. The hardness of welds using threaded pin tools is higher than the tapper one. However, the tensile strength of dissimilar welds using the threaded cylindrical pin tools is lower than the tapper one. The fracture location commonly occurs at the part of aluminum plates having a brittle intermetallic phase.

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Li, Yi Nan, Z. L. Peng, and J. C. Yan. "GTA Welding of Copper Thick Plates by Using ERCuTi Welding Materials." Materials Science Forum 697-698 (September 2011): 409–13. http://dx.doi.org/10.4028/www.scientific.net/msf.697-698.409.

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The new welding material – ERCuTi alloys filler metals were developed specially for gas tungsten arc welding (GTAW) of copper. The hot cracking in welding copper is inhibited completely as the addition of de-oxidant element Ti in copper welding material. The degree of addition of Ti (2-4wt%) is critical when the susceptibility of cracking is to be suppressed. If the level is allowed to exceed 4wt%, more low-melting point eutectics (β-TiCu4and TiCu2) will be formed in the welds, and cracking susceptibility will be increased again. Results of mechanical properties tests show that although adding Ti increases the hardness and strength of the weld compared to the base metal, the impact ductility and the plastic properties are not decreased significantly.

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Bouarroudj, E., Wahiba Bouzidi, O. Menchi, and S. Abdi. "Effects of Copper Powder Insert Layer on the Properties of Friction Welded Joints Between AlCu and AISI 4140 Structural Steel." Defect and Diffusion Forum 283-286 (March 2009): 166–70. http://dx.doi.org/10.4028/www.scientific.net/ddf.283-286.166.

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The present investigation attempts to understand the friction welding characteristics of Aluminum alloy AlCu and steel AISI 4140. In spite, many trials were applied to achieve the sound weld zone of direct bonding between Aluminum and steel. The formation of intermetallic phase and crack in the near weld zone resulted in a lower tensile strength of joints relative to those of other welding technique. Therefore, to prevent intermetallic phase and crack formation at the interface, pure copper was used as insert powders for stress relief buffer layer. This study also envisages the influence of process parameters which include resident preform densities, friction pressure, upset pressure, and burn-off length on microstructure and mechanical properties of the welds. This work consolidates information on the aspects of diffusion joining of steel, copper and Aluminum component with wrought materials for practical execution. In the view point of tensile strength, the highest tensile strength between AlCu and AISI 4140 was acquired by using pure copper as insert powder.

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Zubairuddin, M., S. K. Albert, M. Vasudevan, V. Chaudhari, and V. K. Suri. "Finite Element Simulation of Weld Bead Geometry and Temperature Distribution during GTA Welding of Modified 9Cr-1Mo Steel and Experimental Validation." Journal for Manufacturing Science and Production 14, no. 4 (December 19, 2014): 195–207. http://dx.doi.org/10.1515/jmsp-2014-0006.

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AbstractThe thermal analysis of Modified 9Cr-1Mo steel plate during GTA welding is carried out using finite element method employing SYSWELD software. First, the simulation of bead on plate welds for 16 varying process parameter conditions by employing a double ellipsoidal heat source was carried out. Simulated bead on plate weld bead dimensions for the 16 welds were compared with the actual bead dimensions obtained experimentally. Then the simulation of GTA welding of square butt joint on 3 mm thick plates of dimensions 300 × 125 × 3 mm was carried out. The simulated thermal profiles were validated using thermocouple measurements. There was good agreement between the predicted and measured weld bead profiles and thermal cycles for square butt joint. The investigation on the effect of copper back up plate on the peak temperature and the cooling rate has revealed that the peak temperature decreased by 147 °C and the cooling rate increased by 35%.

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Carvalho, G. H. S. F. L., I. Galvão, R. Mendes, R. M. Leal, and A. Loureiro. "Influence of base material properties on copper and aluminium–copper explosive welds." Science and Technology of Welding and Joining 23, no. 6 (December 27, 2017): 501–7. http://dx.doi.org/10.1080/13621718.2017.1417783.

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Giridharan, K., P. Sevvel, R. Ramadoss, and B. Stalin. "Friction stir processing of nanofiller assisted AISI 1010 steel-CDA 101 copper dissimilar welds: a strength factor approach." Metallurgical Research & Technology 119, no. 5 (2022): 505. http://dx.doi.org/10.1051/metal/2022065.

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In this research study the effects of adding nano fillers such as SiO2, graphene nanoplatelets (Gnps) and biochar on to the weld pool of dissimilar AISI-SAE 1010 Steel- CDA 101 copper were investigated. The main aim of this research study was to investigate the effect of adding ceramic and carbon rich secondary reinforcements on to the friction stir weld (FSW) pool of dissimilar metals and its relative outcomes. The mechanical properties such as tensile strength, yield strength, % of elongation, hardness and fatigue strength were investigated in the form of the strength factor approach. According to the results, the highest strength factor of 98 was obtained for welds made using Gnps of about 1.0 wt.% with constant axial load of 5 kN, traverse speed of 30 mm/min, rotational speed of 900 rpm, dwell time of 5 s and plunging depth of 0.2 mm. The highest tensile strength of 225 MPa and a fatigue strength of 168 MPa was noted for the weld using 2 wt.% Gnps in the weld pool. However, the biochar addition of 2.0 wt.% on to the weld bead positioned the second highest strength factor of 88 due to its solid lubricity. In all the welding processes, large doses of fillers produced undesirable strength factor values. The microstructure of both the weld and tool shows desirable effects for nanoparticle assisted welds. The HAZ and TMAZ grains were refined due to the inclusion of the nanoparticles. The result shows that naturally acquired biochar nanoparticles have the potential of replacing high cost nanofillers in joining metals with more than 85% close to the high cost fillers for the same output. These properties improved dissimilar copper-steel welded plate joints that could be used in automotive, defence, aerospace and structural applications.

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Joshi, Gaurang R., Vishvesh J. Badheka, Raghavendra S. Darji, Ankit D. Oza, Vivek J. Pathak, Dumitru Doru Burduhos-Nergis, Diana Petronela Burduhos-Nergis, Gautam Narwade, and Gopinath Thirunavukarasu. "The Joining of Copper to Stainless Steel by Solid-State Welding Processes: A Review." Materials 15, no. 20 (October 17, 2022): 7234. http://dx.doi.org/10.3390/ma15207234.

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Joining immiscible materials such as copper and stainless steel together is a significant concern due to distinct mechanical and metallurgical properties across the joint line, such as melting points, the coefficient of linear thermal expansion, and thermal conductivity. The joint properties of copper to stainless steel welds are in great demand for various mechanical components of the international thermonuclear experimental reactor, ultra-high vacuum system, plan wave linear-accelerator or linac structure, and heat exchanger. These dissimilar-metals joints offer excellent flexibility in design and production, leading to a robust structure for many cutting-edge applications. Hence, the present article reviews the copper to stainless steel joining mechanism under different solid-state processing conditions. The present understanding says that defect-free strong joints between the dissimilar metals are systematically possible. Apart from this understanding, the authors have identified and highlighted the gaps in the research exploration to date. Moreover, a sustainable methodology to achieve a desirable weld of copper to stainless steel depends on favorable processing conditions.

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Singh, Prem, Dharmpal Deepak, and Gurinder Singh Brar. "Friction Crush Welding of Similar Metals: An Overview." Asian Journal of Engineering and Applied Technology 7, no. 2 (October 5, 2018): 48–51. http://dx.doi.org/10.51983/ajeat-2018.7.2.957.

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Friction Crush Welding (FCW) is a newly developed technique which can be used for welding of similar materials with or without filler metal. In this process, welding between two work pieces occurs due to relative motion between work pieces and rotating cylindrical tool, which causes crushing of material to produce weld. Similar weld which include welds of aluminium, steel and copper and their alloy have been successfully produced by few researchers. This review covers the work conducted in the field of FCW and throws light on the future use of FCW for welding similar and dissimilar materials.

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Yoon, Byoung-Hyun, Ji-Yeon Shim, and Bong-Yong Kang. "Recrystallization Behavior of CP Ti Welds by Rolling." Journal of Welding and Joining 39, no. 6 (December 30, 2021): 577–81. http://dx.doi.org/10.5781/jwj.2021.39.6.1.

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Electrolytic copper foil is a thin copper film material manufactured by electroplating and is mainly used as a circuit material to transmit electrical signals in printed circuit boards of electronic products such as TVs, PCs, and smartphones. Recently, it has been widely used as a negative current collector for lithium-ion batteries, which is essential for mobile IT and electric vehicles. The electrodeposited drum material is composed of CP Ti, which exhibits corrosion resistance and has a light weight, and welding is essential for processing in the form of a drum. Therefore, when the microstructures of the base metal and the welded part differ, these differences are reflected in the surface of the copper foil, which results in poor quality. Therefore, in this study, a welding process that required a low heat input while minimizing the size of the weld was used, and the change in the grain size was studied through plastic deformation and recrystallization heat treatment of the weld structure. Following the recrystallization heat treatment after the rolling of the plasma welded specimen, it was found that the calculation results of the recrystallization heat treatment were consistent with the actual conditions of the heat treatment, and the microstructure of the weld metal became finer as the rolling reduction rate increased.

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Tremsin, Anton S., Supriyo Ganguly, Sonia M. Meco, Goncalo R. Pardal, Takenao Shinohara, and W. Bruce Feller. "Investigation of dissimilar metal welds by energy-resolved neutron imaging." Journal of Applied Crystallography 49, no. 4 (June 9, 2016): 1130–40. http://dx.doi.org/10.1107/s1600576716006725.

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A nondestructive study of the internal structure and compositional gradient of dissimilar metal-alloy welds through energy-resolved neutron imaging is described in this paper. The ability of neutrons to penetrate thick metal objects (up to several cm) provides a unique possibility to examine samples which are opaque to other conventional techniques. The presence of Bragg edges in the measured neutron transmission spectra can be used to characterize the internal residual strain within the samples and some microstructural features,e.g.texture within the grains, while neutron resonance absorption provides the possibility to map the degree of uniformity in mixing of the participating alloys and intermetallic formation within the welds. In addition, voids and other defects can be revealed by the variation of neutron attenuation across the samples. This paper demonstrates the potential of neutron energy-resolved imaging to measure all these characteristics simultaneously in a single experiment with sub-mm spatial resolution. Two dissimilar alloy welds are used in this study: Al autogenously laser welded to steel, and Ti gas metal arc welded (GMAW) to stainless steel using Cu as a filler alloy. The cold metal transfer variant of the GMAW process was used in joining the Ti to the stainless steel in order to minimize the heat input. The distributions of the lattice parameter and texture variation in these welds as well as the presence of voids and defects in the melt region are mapped across the welds. The depth of the thermal front in the Al–steel weld is clearly resolved and could be used to optimize the welding process. A highly textured structure is revealed in the Ti to stainless steel joint where copper was used as a filler wire. The limited diffusion of Ti into the weld region is also verified by the resonance absorption.

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Demonie, Wim, Koen Faes, and Wim De Waele. "Influence of process parameters on the weld quality of dissimilar Cu-Al magnetic pulse welded sheets." International Journal Sustainable Construction & Design 7, no. 1 (October 21, 2016): 8. http://dx.doi.org/10.21825/scad.v7i1.3637.

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Little is known about the influence of the main geometrical parameters (overlap, stand-off and free length) and the energy input on welds formed by electromagnetic pulse welding. The Taguchi experimental design method was applied for determining the underlying relations for dissimilar sheet welding of copper and aluminium. The weld quality was evaluated based on four output parameters: the weld length, the size of the interfacial layer, the lap shear strength and the thickness reduction of the flyer sheet. The influence of the overlap and free length showed to be non-negligible; this in contrast to the small amount of attention these parameters receive in other publications.

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Silva, Rafael Gomes Nunes, Sylvia De Meester, Koen Faes, and Wim De Waele. "Development and Evaluation of the Ultrasonic Welding Process for Copper-Aluminium Dissimilar Welding." Journal of Manufacturing and Materials Processing 6, no. 1 (January 1, 2022): 6. http://dx.doi.org/10.3390/jmmp6010006.

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The demand for joining dissimilar metals has exponentially increased due to the global concerns about climate change, especially for electric vehicles in the automotive industry. Ultrasonic welding (USW) surges as a very promising technique to join dissimilar metals, providing strength and electric conductivity, in addition to avoid metallurgical defects, such as the formation of intermetallic compounds, brittle phases and porosities. However, USW is a very sensitive process, which depends on many parameters. This work evaluates the impact of the process parameters on the quality of ultrasonic spot welds between copper and aluminium plates. The weld quality is assessed based on the tensile strength of the joints and metallographic examination of the weld cross-sections. Furthermore, the welding energy is examined for the different welding conditions. This is done to evaluate the influence of each parameter on the heat input resulting from friction at the weld interface and on the weld quality. From the obtained results, it was possible to optimise parameters to achieve satisfactory weld quality in 1.0 mm thick Al–Cu plate joints in terms of mechanical and metallurgical properties.

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Faes, Koen, Rafael Nunes, Sylvia De De Meester, Wim De De Waele, Felice Rubino, and Pierpaolo Carlone. "Influence of the Process Parameters on the Properties of Cu-Cu Ultrasonic Welds." Journal of Manufacturing and Materials Processing 7, no. 1 (January 7, 2023): 19. http://dx.doi.org/10.3390/jmmp7010019.

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Ultrasonic welding (USW) is a solid-state welding process based on the application of high frequency vibration energy to the workpiece to produce the internal friction between the faying surface and the local heat generation required to promote the joining. The short welding time and the low heat input, the absence of fumes, sparks or flames, and the automation capacity make it particularly interesting for several fields, such as electrical/electronic, automotive, aerospace, appliance, and medical products industries. The main problems that those industries have to face are related to the poor weld quality due the improper selection of weld parameters. In the present work, 0.3 mm thick copper sheets were joined by USW varying the welding time, pressure, and vibration amplitude. The influence of the process variables on the characteristics of the joints and weld strength is investigated by using the analysis of variance. The results of the present work indicate that welding time is the main factor affecting the energy absorbed during the welding, followed by the pressure and amplitude. The shear strength, on the other hand, resulted mostly influenced by the amplitude, while the other parameters have a limited effect. Regardless the welding configuration adopted, most welds registered a failure load higher than the base material pointing out the feasibility of the USW process to join copper sheets.

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Silva Dias, Joanes, Hector Reynaldo Meneses Costa, Ricardo Alexandre Amar de Aguiar, Rosemere de Araujo Alves Lima, Marcio Luiz Almeida Cunha, and Ramon Fonseca Ferreira. "Influence of Welding Parameters in Substrate/Coating of Galvanized Sheets Using Resistance Spot Welding." Materials Science Forum 758 (June 2013): 33–39. http://dx.doi.org/10.4028/www.scientific.net/msf.758.33.

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The main objective of this work is to propose an optimization of welding parameters through the process of resistance spot welding, applied to Interstitial Free (IF) steel sheets in order to increase the life of conventional copper electrodes. The methodology consisted of using a weld tester in order to ensure the accuracy of values. The main parameters selected through a survey of the weldability were: force, time and welding current. To evaluate the resistance of the weld and the electrode wear, mechanical tests were performed like tensile-shear, cross-tension, peel test and microhardness. A microstructural evaluation by optical microscopy (OM) and scanning electron microscopy (SEM) was made. The results show reducing the thickness of the coating in the weld region and macro and microstructures were observed. Through the tensile-shear and cross-tension tests were verified using electrodes caps up to 1250 points with acceptable welds. The microhardness test results indicated significant hardness increase in weld nugget elucidated by differences in microconstituents evaluated by OM and SEM. The methodology used for parameter selection has highlighted an optimal combination with 200kgf electrodes force, 9cy welding time and 7.8 kA welding current, in overlap IF steel sheets with 0.75mm of thickness, thereby increasing the lifetime of the electrode and ensures a better quality of welds and the consequent reduction of energy applied to the weld process.

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35

Simoen, Barbara, Koen Faes, and Wim De Waele. "Investigation of the weldability of copper to steel tubes using the electromagnetic welding process." International Journal Sustainable Construction & Design 8, no. 1 (October 30, 2017): 7. http://dx.doi.org/10.21825/scad.v8i1.6811.

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Magnetic pulse welding is an innovative joining method which allows joining of dissimilar metal combinations. However, much remains unknown about the process and its parameters. In this paper, the weldability of copper tubes to steel rods and tubes is discussed, with the goal of examining the influence of the wall thickness of the supporting steel tube on the weld and the deformation of the components. Large deformations were observed, causing an undesirable decrease in diameter of the tubes. The quality of the obtained welds was shown to decrease with decreasing inner tube thickness as well, most likely due to the deformation of the workpieces in radial direction. Because of this, it is advisable to use an internal support to prevent deformation of the support tubes. To gain more insight in the precise mechanisms of weld formation and failure, numerical simulations are advised.

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Kong, Yu Sik, Sang Woo Kwon, and Seon Jin Kim. "Optimization of Dissimilar Friction Welding and Creep Rupture Tests for Nuclear Reactor Component Materials." Key Engineering Materials 306-308 (March 2006): 1019–24. http://dx.doi.org/10.4028/www.scientific.net/kem.306-308.1019.

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An experimental work of dissimilar friction welding was conducted using 15 mm diameter solid bar in copper alloy (Cu-1Cr-0.5Zr) to stainless steel (STS316L) for being used as fusion reactor component materials, not only to optimize the friction welding parameters, but also to investigate the elevated temperature tensile strength and creep rupture properties for the friction welded joints under the optimal welding conditions. The main friction welding parameters were selected to endure good quality welds on the basis of visual examination, tensile tests, Vickers hardness survey of the bond area and HAZ. For friction weld joining of copper alloy to stainless steel bars, the total upset increases lineally as increasing heating time. Optimal welding conditions were selected as follows: Rotational speed 2000rpm, friction pressure 80MPa, upsetting pressure 140MPa, heating time 2 second, upsetting time 5 second and total upset 13mm. The weld interface of dissimilar friction welded steel bars was mixed strongly. And also the creep properties and creep life prediction by Larson-Miller parameter method were presented at the elevated temperatures of 300, 400 and 500oC.

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Gao, Zhongmei, Yuye Yang, Lei Wang, Bin Zhou, and Fei Yan. "Formation Mechanism and Control of Solidification Cracking in Laser-Welded Joints of Steel/Copper Dissimilar Metals." Metals 12, no. 7 (July 5, 2022): 1147. http://dx.doi.org/10.3390/met12071147.

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The solidification cracking behavior in laser welds of steel/copper dissimilar metals was systematically investigated. T2 copper and SUS304 stainless steel were used in the study. The results showed that the occurrence of solidification cracking in welds was the synergistic effect of ε phase liquation, inclusions and composition segregation. During the welding process, the liquation of grain boundaries substantially reduced the cohesion between adjacent grains, as well as the resistance for intergranular crack propagation. The composition segregation inside the grains could induce lattice distortion, thus reducing the plastic deformation capacity of the material itself and concurrently increasing the susceptibility to cracks. In addition, an effective solution for inhibiting solidification cracking was proposed by using an oscillating laser, and the inhibition mechanism was further discussed. Laser oscillating welding significantly promoted grain refinement, solute diffusion and the formation of uniformly distributed ε-Cu precipitated phases in welds. It can improve the intergranular bonding, reduce the susceptibility to solidification cracking and increase the resistance to plastic deformation. The tensile strength of joints using laser oscillating welding is 251 MPa, 35.7% more than 185 MPa using laser welding. Meanwhile, the strain of joints using laser oscillating welding is 3.69, a 96% increase compared to 1.88 using laser welding.

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Mahdianikhotbesara, Ali, M. Hossein Sehhat, and Mohammadjafar Hadad. "A Numerical and Experimental Study into Thermal Behavior of Micro Friction Stir Welded Joints of Al 1050 and Copper Sheets." Advanced Materials Research 1170 (April 19, 2022): 49–60. http://dx.doi.org/10.4028/p-01ag12.

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One of the most important factors influencing the quality of the weld created by the micro friction stir welding is the amount of heat generated during the welding operation. Due to the lack of proper mixing of materials at low temperatures, joints' quality decreases due to the formation of cold welds. Also, overheating takes the process out of solid-state welding, which prevents good joints. Finite element analysis of friction stir welding leads to a better understanding of the effect of different parameters on the process. With the results extracted from such analysis, some of the output can be predicted, such as heat distribution. In the present study, in order to perform finite element analysis of the micro friction stir welding of Al 1050 to pure copper, the coupled Eulerian-Lagrangian method in Abaqus software has been used. The results of finite element analysis showed that the heat distribution on the copper side is wider due to the higher heat transfer coefficient of copper than aluminum. The maximum temperature in the analysis was recorded in the weld line, which was 392°C. The heat generated during the welding process was measured at different points relative to the joint line, and appropriate matching was observed with a comparison of experiments and simulation results.

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Raju, L. Suvarna, A. Kumar, and S. Rajendra Prasad. "Microstructure and Mechanical Properties of Friction Stir Welded Pure Copper." Applied Mechanics and Materials 592-594 (July 2014): 499–503. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.499.

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Abstract. Conventional welding of copper and its alloys tends to degrade the mechanical strength at the welded area due to high thermal diffusivity and melting point. Friction stir welding (FSW) is an excellent alternative for joining of these materials against fusion joining. FSW is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The main objective of this investigation is to use FSW for joining of 3 mm thick copper sheet using taper cylindrical tool pin profile. The defect free welds were obtained at a tool rotational speed of 900rpm and 1120 rpm and traverse speeds of 25, 31.5, 40 and 50 mm/min respectively. Mechanical and microstructure analysis has been performed to evaluate the characteristics of friction stir welded copper. From the investigation it is found that the joints fabricated at a tool rotation speed of 900 rpm and traverse speed of 40mm/min resulted in better mechanical properties compared to other tool rotation and traverse speeds. The tensile properties of all the weld joints showed a relative correspondence to the variation of the hardness in the weld zone. The observed results were correlated with the microstructure and fracture features.

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Mian, A., C. Taylor, and H. Vijwani. "Microstructural analysis of laser micro-welds between copper and aluminum." Microsystem Technologies 22, no. 2 (December 10, 2014): 261–67. http://dx.doi.org/10.1007/s00542-014-2385-3.

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., Sriramula Sai kumar. "CHARACTERIZATION AND PROCESSING OF FRICTION STIR WELDING ON COPPER WELDS." International Journal of Research in Engineering and Technology 04, no. 11 (November 25, 2015): 86–89. http://dx.doi.org/10.15623/ijret.2015.0411015.

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Marya, M., and S. Marya. "Interfacial microstructures and temperatures in aluminium–copper electromagnetic pulse welds." Science and Technology of Welding and Joining 9, no. 6 (December 15, 2004): 541–47. http://dx.doi.org/10.1179/174329304x8685.

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Titilayo, Akinlabi Esther, Madyira Daniel Makundwaneyi, and Akinlabi Stephen Akinwale. "Reconfiguration of a Milling Machine to Achieve Friction Stir Welds." Applied Mechanics and Materials 232 (November 2012): 86–91. http://dx.doi.org/10.4028/www.scientific.net/amm.232.86.

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This paper reports on the reconfiguration of a milling machine to produce friction stir welds of aluminium and copper and friction stir processing of 6086 aluminium alloy. Friction stir welding tools were designed and manufactured from tool steel. The tools were inserted into the chuck of the milling machine. A backing plate was also specially designed and manufacturedfrom mild steel to protect the milling machine table and was placed on the bed with the use of T-nuts. The plates were secured firmly on the backing plate with the use of specially designed clamping fixtures. The varied welding speeds and the rotational speeds were achieved using the control system on the vertical milling machine. The reconfigured milling machine was successfully employed to produce friction stir processing of aluminium and friction stir welds of aluminium and copper. An optimum joint strength of 74% was achieved.

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44

Sadeghian, Amirhossein, Subhasisa Nath, Yuze Huang, Ranveer S. Matharu, Noppawee Wadee, Nicolas Pembrey, and David G. Waugh. "Quasi-Continuous Wave Pulsed Laser Welding of Copper Lap Joints Using Spatial Beam Oscillation." Micromachines 13, no. 12 (November 27, 2022): 2092. http://dx.doi.org/10.3390/mi13122092.

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Laser beam welding of copper (Cu) using near-infrared radiation is extremely challenging due to its high thermal conductivity and large laser reflectivity. In the present study, the challenges and benefits of using spatial beam oscillation during quasi-continuous wave (QCW) pulsed laser beam welding of 0.4 mm Cu to 1 mm Cu in lap joint configuration are presented. This work demonstrates how laser beam oscillating parameters can be used to control the laser weld quality and laser weld dimensions for Cu-Cu joining. Compared to a non-oscillated laser beam, welds made using laser beam oscillation showed fewer spatters, porosities, and better surface quality. Four levels of oscillating amplitudes (0.2 mm, 0.4 mm, 0.6 mm, and 0.8 mm) and oscillating frequencies (100 Hz, 200 Hz, 300 Hz, and 400 Hz) were compared to reveal the effect of beam oscillation parameters. The weld width was mainly controlled by oscillating amplitude, while weld penetration was affected by both oscillating amplitude and frequency. As the oscillating amplitude increased, the weld width increased while the weld penetration decreased. Increasing the oscillating frequency reduced the weld penetration but had a negligible effect on the weld width. The maximum tensile force of approximately 1944 N was achieved for the joint with a high width-to-depth ratio with an oscillating amplitude of 0.8 mm and an oscillating frequency of 200 Hz.

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Erak, D. Yu, A. A. Chernobaeva, K. I. Medvedev, D. A. Zhurko, V. N. Kochkin, M. A. Skundin, S. A. Bubyakin, N. V. Pal, and A. A. Reshetnikov. "Study of the metal of the irradiated weld of the WWER-440 reactor body after 45 years of operation." Voprosy Materialovedeniya, no. 4(108) (February 1, 2022): 202–15. http://dx.doi.org/10.22349/1994-6716-2021-108-4-202-215.

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This work presents the results of a study of the mechanical characteristics and chemical composition of metal samples cut from a non-irradiated weld seam of a WWER-440 reactor vessel after 45 years of operation. The calculated distribution of the critical temperature of brittleness over the thickness of the irradiated weld seam of the WWER-440 reactor vessel (140 mm) is obtained taking into account the distribution of the initial properties, the content of phosphorus and copper, and the density of the fast neutron flux over the thickness of the seam. Since all the circumferential welds connecting the shells in the WWER-440 reactor vessel are manufactured using the same technology, the results of the study of the non-irradiated weld can be used to assess the distribution of properties in the irradiated weld. At the same time, it is assumed that the effect of thermal aging at a temperature of 270°C (operating temperature of a non-irradiated weld) is small and can be neglected.

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Kohl, Stefanie, Florian Kaufmann, and Michael Schmidt. "Why Color Matters—Proposing a Quantitative Stability Criterion for Laser Beam Processing of Metals Based on Their Fundamental Optical Properties." Metals 12, no. 7 (June 29, 2022): 1118. http://dx.doi.org/10.3390/met12071118.

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With its excellent automation capability and localized energy input enabling precise, reproducible welds, laser beam welding represents a preferred industrial joining technology. Electro-mobility drastically increases the need for defect-free and automatable copper joining technologies. However, copper welds that are produced with state-of-the-art infrared lasers often suffer from spattering and porosity. Recent publications show distinct improvements using novel beam sources at visible wavelengths, attributing them to increased absorptivity. Nevertheless, this cannot fully explain the steadier process behavior. This wavelength-dependent process stability has not yet been investigated sufficiently. Therefore, we have developed a predictive material-dependent criterion indicating process stability based on the example of copper heat-conduction spot welding. For this purpose, we combined energy balances with thermo-physical material properties, taking into account the wavelength and temperature dependence of the optical properties. This paper presents the key mechanism that we identified as decisive for process stability. The criterion revealed that X-points (unique, material-specific wavelengths) represent critical stability indicators. Our calculations agree very well with experimental results on copper, steel and aluminum using two different wavelengths and demonstrate the decisive, material-dependent wavelength impact on process stability. This knowledge will help guide manufacturers and users to choose and develop beam sources that are tailored to the material being processed.

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47

Flores, R. D., L. E. Murr, and E. A. Trillo. "Characterization o Solid-State Vortices Associated with the Friction-Stir Welding of Copper to Aluminum." Microscopy and Microanalysis 4, S2 (July 1998): 530–31. http://dx.doi.org/10.1017/s1431927600022777.

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Although friction-stir welding has been developing as a viable industrial joining process over the past decade, only little attention has been given to the elucidation of associated microstructures. We have recently produced welds of copper to 6061 aluminum alloy using the technique illustrated in Fig. 1. In this process, a steel tool rod (0.6 cm diameter) or head-pin (HP) traverses the seam of 0.64 cm thick plates of copper butted against 6061-T6 aluminum at a rate (T in Fig. 1) of 1 mm/s; and rotating at a speed (R in Fig. 1) of 650 rpm (Fig. 1). A rather remarkable welding of these two materials results at temperatures measured to be around 400°C for 6061-T6 aluminum welded to itself. Consequently, the metals are stirred into one another by extreme plastic deformation which universally seems to involve dynamic recrystallization in the actual weld zone. There is no melting.

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Alléhaux, Delphine, and François Marie. "Mechanical and Corrosion Behaviour of the 2139 Aluminium-Copper Alloy Welded by the Friction Stir Welding Using the Bobbin Tool Technique." Materials Science Forum 519-521 (July 2006): 1131–38. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.1131.

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The present study deals with the properties assessment of a new generation aluminium-copper alloy, developed by ALCAN and designed 2139, welded by the bobbin tool technique of the FSW process. Considering the best performances of this age formable alloy after T8 aging, both the T4 and T8 tempers prior to welding are assessed. Therefore, the behaviour under static and fatigue load conditions and also in damage tolerance including both fracture toughness and fatigue crack propagation of the FSW bobbin tool weld on 2139 after T8 post aging and on the T8 as welded condition are discussed. The corrosion resistance of the welds is investigated through an accelerated corrosion test with intent to evaluate the intergranular corrosion sensitivity of the weld and the impact of an artificial aging on the properties developed by the T8 as welded condition is also presented.

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Schricker, Klaus, Andreas Baumann, and Jean Pierre Bergmann. "Local Shielding Gas Supply in Remote Laser Beam Welding." Journal of Manufacturing and Materials Processing 5, no. 4 (December 17, 2021): 139. http://dx.doi.org/10.3390/jmmp5040139.

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The use of shielding gases in laser beam welding is of particular interest for materials interacting with ambient oxygen, e.g., copper, titanium or high-alloy steels. These materials are often processed by remote laser beam welding where short welds (e.g., up to 40 mm seam length) are commonly used. Such setups prevent gas nozzles from being carried along on the optics due to the scanner application and a small area needs to be served locally with inert gas. The article provides systematic investigations into the interaction of laser beam processes and parameters of inert gas supply based on a modular flat jet nozzle. Based on the characterization of the developed nozzle by means of high-speed Schlieren imaging and constant temperature anemometry, investigations with heat conduction welding and deep penetration welding were performed. Bead-on-plate welds were carried out on stainless steel AISI 304 for this purpose using a disc laser and a remote welding system. Argon was used as shielding gas. The interaction between Reynolds number, geometrical parameters and welding/flow direction was considered. The findings were proved by transferring the results to a complex weld seam geometry (C-shape).

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Demirorer, Mete, Wojciech Suder, Supriyo Ganguly, Simon Hogg, and Hassam Naeem. "Development of laser welding of high strength aluminium alloy 2024-T4 with controlled thermal cycle." MATEC Web of Conferences 326 (2020): 08005. http://dx.doi.org/10.1051/matecconf/202032608005.

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An innovative process design, to avoid thermal degradation during autogenous fusion welding of high strength AA 2024-T4 alloy, based on laser beam welding, is being developed. A series of instrumented laser welds in 2 mm thick AA 2024-T4 alloys were made with different processing conditions resulting in different thermal profiles and cooling rates. The welds were examined under SEM, TEM and LOM, and subjected to micro-hardness examination. This allowed us to understand the influence of cooling rate, peak temperature, and thermal cycle on the growth of precipitates, and related degradation in the weld and heat affected area, evident as softening. Although laser beam welding allows significant reduction of heat input, and higher cooling rates, as compared to other high heat input welding processes, this was found insufficient to completely supress coarsening of precipitate in HAZ. To understand the required range of thermal cycles, additional dilatometry tests were carried out using the same base material to understand the time-temperature relationship of precipitate formation. The results were used to design a novel laser welding process with enhanced cooling, such as with copper backing bar and cryogenic cooling.

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Journal articles on the topic 'Copper welds'

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