PURPOSE: To economically execute T6 heat treatment in a short time, at the time of subjecting the cast part of an Al alloy to T6 heat treatment, by executing solution treatment in such a manner that the cast part is rapidly cooled immediately after its mold releasing
CONSTITUTION: An Al alloy of AN-Si series or the like is cast into a mold. The Al alloy cast part of a high temp. close to the eutectic temp. directly after the solidification of the Al alloy is released from the mold. Immediately after that, it is rapidly cooled by water and is subjected to solution treatment. The Al alloy casting subjected to the solution treatment is subjected to T6 heat treatment by executing aging treatment by an ordinary method. Since the conventional solution treatment 1 in which the air-cooled Al alloy casting is heated to about the eutectic temp. and is held for a long time can be eliminated, energy for heating is not required and long time holding is not required as well, so that solution treatment can be executed in a short time with the conserved energy, and by the subsequent aging treatment, T6 heat treatment for the Al alloy casting can be executed with good productivity.
KOGA MASAAKI
IIZUKA YASUO
TAKAAI TETSUYA
