| 摘要 |
PURPOSE:To stabilize the quality of a product by inserting a thin lead sheet into the contact part between copper and Al or Al alloy then welding the contact part by an electron beam. CONSTITUTION:The thin lead sheet 5 having about 0.1-0.2mm. thickness is inserted between an upper piston part 2 made of copper and a lower piston part 3 made of Al. The sheet and the piston parts are then welded by electron beam welding 6. The thin sheet contg. about 99.9% lead is used for the lead sheet and the electron beam welding is executed under suitable welding conditions. The sheet 5 acts consequently as a diluent to weld the Al part 3 and the copper part 2 to each other. A weld zone 7 which produces no clearances is thus formed in the contact part. The weld strength is considerably increased by the above-mentioned method and since the variance of the joint strength is decreased, the product quality is improved. |
