| 摘要 |
PURPOSE:To manufacture an Al-alloy material most suitable for superplastic working material, by subjecting an Al alloy containing specific percentage of Mn, Cr, and Zr to primary recrystallization treatment, overageing treatment, cold working, and secondary recrystallization treatment in succession under respectively conditions. CONSTITUTION:An Al-alloy stock containing, by weight, one or two kinds among 0.05-1.5% Mn, 0.05-0.4% Cr, and 0.05-0.3% Zr is subjected to primary recrystallization treatment where hot rolling is finished at <=230 deg.C and rapid heating is applied at >=0.1 deg.C/sec temp.-rise rate up to the recrystallization temp. or above so as to regulate recrystallized-grain size to <=100mu. Subsequently, the above plate is held at a temp. of >=50% of the solution-heat-treating temp. for 5min-24hr and cooled slowly at 0.001-0.05 deg.C/sec cooling rate to precipitate a coarse precipitated phase at recrystallized grain boundaries. Then, the above plate is cold-worked at >=30% draft and heated up to a temp. of the recrystallization temp. or above at >=0.1 deg.C/sec temp.-rise rate to undergo secondary recrystallization treatment. In this way, the Al-alloy material suitable for superplastic working and having extremely fine crystalline grains can be obtained. |
