| 摘要 |
PURPOSE:To produce easily and surely a securely joined composite blank by pressurizing plural sheets of metallic plates which are superposed into a laminar state by means of a punch from an upper or lower direction to press-weld the adjacent metallic plates to each other thereby causing spot-like metallic bond. CONSTITUTION:The bottom surface of an upper aluminum plate 2 and the upper surface of a lower aluminum plate 3 are subjected to a defatting treatment and a grinding treatment using a wire brush to remove oxide films and to clean the surfaces thereof. Two sheets of the plates 2, 3 are superposed on each other by matching the clean surfaces and the superposed plates are placed on a metallic receiving base 20 having a flat top surface. The plates are kept pressed from above by a cylindrical hold-down member 21 made of a rigid urethane resin. A freely vertically movable punch 22 is thereafter lowered in the member 21 to press the two plates 2, 3 from above, thereby forming a metallic bond part 4. The two plates 2, 3 are thus metallurgically bonded to a spot shape by cold press welding without using a costly device and the composite blank is obtd. |
