Superplastic flow problems of copper shaped-charge jets

In this paper, we analyze the metallographes of the recovered Cu slug and get the results of reduction in the recrystallized grain size and rise in the temperature, which were caused by the two action processes, i.e. the shock wave action in the liner and the following squeeze-shear plastic deformation of the liner. The analysed result shows that the dynamic superplastic deformation conditions for liner materials were satisfied before the jet was formed. Meanwhile the process of a dynamic superplastics deformation is consistent with a mechanically driven subgrain rotation mechanism.