The high intensity aluminum alloy null whose port hole extrusion is

摘要

PROBLEM TO BE SOLVED: To produce a high strength Al alloy easy of porthole extrusion by regulating the hardness of a high strength Al alloy to specific Vickers hardness by annealing treatment before extrusion and further regulating its hardness to specific Vickers hardness by plastic working. ;SOLUTION: At the time of extruding a high strength Al alloy, an Al alloy ingot before extrusion is heated and held at about 440-550°C and cooled to remove internal stress and homogenize the ingot, by which a Vickers hardness of ≥Hv40 is provided. Subsequently, plastic working is applied to the homogenized Al alloy ingot at ≤ about 400°C at ≥40% working rate to develop work hardening, by which a Vickers hardness of ≥Hv20 is provided. By this method, the high strength Al alloy easy of porthole extrusion can be obtained.;COPYRIGHT: (C)1997,JPO