| 摘要 |
1,227,463. Altering physical properties; making hollow-ware. DOW CHEMICAL CO. 1 Oct., 1968 [2 Oct., 1967], No. 46595/68. Headings B3A and B3V. A method for reducing surface cracking upon impact extrusion of extruded magnesium base alloys comprises drawing or rolling in the same direction as it was extruded to reduce the crosssectional area so as to reorientate the surface grains. Thereafter a container, e.g. for a battery anode, may be formed by impact extrusion of the improved metal, preferably after pre-heating it to 400-800‹ F. for 20 seconds to 30 minutes, the impact extrusion die being preheated to 300‹ F. The alloy comprised the following by weight per cent:- the balance being Mg with normal impurities. Drawing or rolling is carried out at 70-500‹ C., with a reduction of 0À5-20%. Reductions of less than about 1% may be followed by annealing at 700‹ F. for 1 hour. The alloy was extruded initially at 600‹ or 800‹ F. |
