RECOVERY BEHAVIOR OF COLD-WORKED METALS

Abstract : Recovery of tensile flow stress of four binary aluminum alloys and of the high-purity base aluminum was studied under no-load condition at temperatures of 80, 120, 160, and 200 C, and under conditions of creep strain at 160 C, for recovery times up to 1,000 hr. At the three higher recovery temperatures, 120, 160, and 200 C, and for the longer recovery times, the alloys Al-Mg, Al Zn, and Al-Cu all experienced a greater degree of recovery than the high-purity base aluminum. Of these three alloys, the Al-Cu alloy clearly exhibited the greatest degree of recovery. The Al-Ag alloy was excluded from the comparison be cause of an apparent strengthening process which occurred during recovery. All the alloys showed a strong increase in flow-stress recovery during creep strain over that experienced during no-load recovery; however, the relative order of recovery for the different alloys did not change.