مقاله جوشکاری با عنوان:RESISTANCE SPOT WELDING OF MAGNESIUMALLOY SHEETS WITH COVER PLATESS. Satonaka, C. Iwamoto, G.-i. Murakamiand Y. Matsumotoچکیده مقاله:Lightweight materials such as high-strength steels and aluminum alloys are widely used in automotive componentsfor the purposes of weight reduction and consequent higher fuel effi ciency. As new alloys have beendeveloped, magnesium alloys have become attractive for the production of automotive components due totheir unique properties, such as high specifi c strength, damping capacity, and recyclability. In the assemblyprocess of these materials, resistance spot welding (RSW) is used to construct thin sheet structures. AlthoughRSW of steel sheets with high weld quality has already been established, the following problems remain withregard to RSW of magnesium alloys: high welding current, degeneration of electrodes, and blowholes andexpulsion in or around the nugget. In this study, RSW with cover plates was applied to magnesium alloy sheetsto investigate the performance of spot-welded joints. The weld quality was evaluated based on the tensileshear strength of the joints, the shape and the size of the nugget, and the appearance of blowholes andexpulsion. Since RSW with cover plates is similar to conductive heat resistance seam welding (CHRSMW),the results showed that RSW with cover plates enabled the spot welding of a magnesium alloy with a largenugget and high tensile shear strength in the joint. It was also shown that blowhole-free spot welds with alarge nugget and high tensile shear strength were obtained for welding currents above 8 000 A with a longdown-slope time of welding current and a high electrode force.
مقاله جوشکاری با عنوان:RESISTANCE SPOT WELDING OF MAGNESIUMALLOY SHEETS WITH COVER PLATESS. Satonaka, C. Iwamoto, G.-i. Murakamiand Y. Matsumotoچکیده مقاله:Lightweight materials such as high-strength steels and aluminum alloys are widely used in automotive componentsfor the purposes of weight reduction and consequent higher fuel effi ciency. As new alloys have beendeveloped, magnesium alloys have become attractive for the production of automotive components due totheir unique properties, such as high specifi c strength, damping capacity, and recyclability. In the assemblyprocess of these materials, resistance spot welding (RSW) is used to construct thin sheet structures. AlthoughRSW of steel sheets with high weld quality has already been established, the following problems remain withregard to RSW of magnesium alloys: high welding current, degeneration of electrodes, and blowholes andexpulsion in or around the nugget. In this study, RSW with cover plates was applied to magnesium alloy sheetsto investigate the performance of spot-welded joints. The weld quality was evaluated based on the tensileshear strength of the joints, the shape and the size of the nugget, and the appearance of blowholes andexpulsion. Since RSW with cover plates is similar to conductive heat resistance seam welding (CHRSMW),the results showed that RSW with cover plates enabled the spot welding of a magnesium alloy with a largenugget and high tensile shear strength in the joint. It was also shown that blowhole-free spot welds with alarge nugget and high tensile shear strength were obtained for welding currents above 8 000 A with a longdown-slope time of welding current and a high electrode force.