Preparation of Al-Cu-Li alloy single crystal by cyclic strain-high temperature annealing

Al-Cu-Li alloy single crystals were prepared by cyclic pre-tensile strain-high temperature annealing. The paper discussed the effects of tensile strain, number of cyclic strain annealing, and strain annealing temperature on grain growth of Al-Cu-Li alloy and the process and mechanism of grain growth during cyclic pre-tensile strain-high temperature annealing. The research results showed that the alloy grains could grow abnormally through cyclic pre-tension strain annealing, and the centimeter-level macro coarse grains were successfully prepared. Their growth mechanism was mainly nucleation recrystallization abnormal grain growth by strain-induced grain boundary migration. In addition, studying the effects of the pre-stretching strain of Al-Cu-Li alloy, the number of cyclic strain annealing and the temperature of strain annealing on the grain growth was quite helpful to develop the best single crystal preparation. The results showed that the optimal process of the Al-Cu-Li alloy was annealed at 540 ℃ for 48 h after pre-tensioned strain of about 0.8%, with cycle number 2 to 3 times.