本文研究了Zn—22％Al—0.2％Cu合金的宽广应变速率下的最大延伸率。研究了各种超塑处理的组织变化及其对超塑性的影响。对应变速率敏感系数和超塑形变激活能进行了测定。研究了超塑形变中晶粒度的变化和面缩率的关系,对超塑形变中晶粒长大规律进行了讨论。研究了不同应变速率下,各种晶粒度与延伸率的关系。实验上观察了晶界滑动,晶粒转动,晶粒间相互运动。并对该合金的超塑性机理作了讨论。 In this paper, the maximum elongation of Zn-22% Al-0.2% Cu alloy under a wide strain rate was studied. The microstructural changes of various superplasticisation treatments and their effects on superplasticity were investigated. Sensitivity of strain rate and activation energy of superplastic deformation were measured. The relationship between the variation of grain size and the reduction of surface area during superplastic deformation was studied. The rules of grain growth during superplastic deformation were also discussed. The relationship between grain size and elongation at different strain rates was studied. Experimentally observed grain boundary sliding, grain rotation, grain movement between each other. The superplasticity mechanism of the alloy was discussed.