| 摘要 |
PURPOSE:To obtain the titled material suitable to superplasticity working without bringing deterioration of productivity, etc., by hot rolling Al alloy material having a specified compsn., then heating the plate to the vicinity of soln. heat treating temp., cooling then heating to recrystallization temp. or more for recrystallization. CONSTITUTION:Al alloy material contg. by weight one kind or more among 0.05-1.5% Mn, 0.05-0.4% Cr, 0.05-0.3% Zr is hot rolled to the required plate thickness. Next, the rolled plate is heated to >=80% of soln. heat treating temp. and held at the temp. for 0.5-24hr, and slowly cooled from the temp. to 40-80% temp. of soln. heat treating temp. by 0.001-0.05 deg.C/sec rate. In this way, grains of intermetallic compd. such as MnAl6, Cr2Mg3Al18 is coarsely pptd. Next, rolled material after the treatment is cooled favorably to room temp. at >=0.1 deg.C/sec rate, then cold worked by >=60% draft. Thereafter the rolled material is recrystallized by >=1 deg.C/sec heating rate at temp. of recrystallization temp. or more to obtain the aimed Al alloy material having fine grains. |
