| 摘要 |
PURPOSE:To obtain a composite Al alloy material with less grain growth by coating a specific Al alloy material on the surface of the core material of the same Al alloy as said alloy material by a specific extruding method. CONSTITUTION:A die 2 is disposed in one opening of a container 1 and A billet A of an as-cast outside layer material consisting of a 2,000, 3,000, 5,000, 6,000 or 7,000 Al alloy is supplied on the die 2 side of the container 1. A billet B of the core material which consists of the same Al alloy as the billet A and is subjected to a prescribed soaking treatment is supplied on the counter die side of the billet A. A stem 3 is advanced through the opening on the counter die side of the container 1 to extrude simultaneously the billets A, B, thereby coating the surface of the extruded material with the billet A. The grain growth on the surface layer is thus prevented and the defectless composite Al alloy having no problems at all in the material quality is obtd. |
