SUPERPLASTICITY OF Al-Zn-Mg-Zr-RE AND Al-Zn-Mg-Ti ALLOYS AND THEIR CAVITA-TION BEHAVIOUR DURING DEFORMATION
Al-Zn-Mg-Zr-RE和Al-Zn-Mg-Ti合金的超塑性及形变中的空洞行为

The superplasticity of the Al-Zn-Mg-Zr-RE (alloy A) and Al-Zn-Mg-Ti (alloy B), their change of volume fraction of metastable micro-cavitiesunder various reduction and strain rates, as well as the growth of stable cavitiesin them have been studied by small X-ray scattering analysis and quantitative me-tallography respectively. Experimental results show that the volume fraction ofmetastable micro-cavities of the alloy A is more than that of the alloy B, butthe growing rate of stable cavities of the alloy A is less than that of the alloyB. Thus, it is believed that the superplasticity of the al1oy A is superior to thatof the alloy B.