Based on the microscopic tem and sem observations , relationships between dislocation structure and rate - dependent / rate - independent behaviors under certain range of temperature and strain rate were presented . interactions between grain boundaries and dislocations were analyzed 利用tem 、 sem分析手段,观察到一定温度和应变速率区间内率相关与率无关变形的位错组态区别,及晶界对位错的不同作用。