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在250~400°C的温度范围和0.1-50 s-1的应变速率范围内对ZK60合金进行压缩变形,对其流变行为和显微组织进行研究。结果表明,在低应变速率(0.1~1 s-1)下压缩变形时,再结晶主要发生在初始晶界上;在高应变速率(10~50 s-1)下压缩变形时,再结晶同时在初始晶界和孪晶上发生。合金在应变速率10~50 s-1和温度250~350°C的变形条件下获得均匀、细小的再结晶组织。因此,合金的最佳热加工工艺范围为应变速率10~50 s-1、变形温度250~350°C。高应变速率压缩变形条件下的孪生诱发动态再结晶过程分三步,首先,高位错密度孪晶分割初始晶粒;然后,孪晶内的位错发生重排形成亚晶;最后,随着应变的增加而形成再结晶晶粒。
ZK60 alloy was subjected to compressive deformation in the temperature range of 250-400 ° C and strain rate of 0.1-50 s-1, and its rheological behavior and microstructure were studied. The results show that the recrystallization mainly occurs on the initial grain boundary during the compressive deformation at low strain rate (0.1-1 s -1), and at the same time the compressive deformation occurs at high strain rate (10-50 s -1) Occurs on the initial grain boundaries and twins. The alloy obtained uniform and fine recrystallized microstructure under the strain rate of 10-50 s-1 and the temperature of 250-350 ° C. Therefore, the optimum heat treatment process for the alloys is the strain rate of 10-50 s-1 and the deformation temperature of 250-350 ° C. The twin-induced dynamic recrystallization under high strain rate compressive deformation involves three steps: firstly, the high dislocation densities twins the initial grains; then the dislocations within the twin are rearranged to form subgrains; finally, as the strain The formation of recrystallized grains increases.