Effects of annealing on cold-worked Zr3Al

A study has been made of the effects of isothermal annealing on the hardness, the tensile properties and the microstructure of cold-worked Zr3Al (L12 type). For material rolled to a true strain of 0.29, complete recrystallization accounts for a recovery of hardness of 65 to 70 percent and for a reduction in yield strength of about 50 percent, independent of temperature. Grain growth accounts for further changes. The yield strength sigma/sub y/ obeys the relationship sigma/sub y/ = sigma0 + k/sub y/(anti d)/sup -1/2/ where sigma0 and k/sub y/ are constants and anti d is the average grain diameter of the fully recrystallized matrix. Recrystallization and grain growth kinetics, respectively, satisfy the expressions f = 1 -- exp(--kt/sup n/) and anti d = Kt/sup m/ where f is the fraction recrystallized, t is time, k and K are parameters which increase with increasing temperature and m and n are constants. 13 figures