超塑变形中“晶粒群”运动初探

PRELIMINARY STUDY ON GRAIN GROUP MOVEMENT IN SUPERPLASTIC DEFORMATION

通过两种钛合金超塑性拉伸的实例，本文对超塑性变形微观机制中的晶粒群运动问题进行了初步的分析和讨论。晶粒群运动是材料中某一区域内若干晶粒以有别于周围介质的规律参与物质流变。非典型等轴细晶材料超塑变形中复杂多变的显微组织易于产生晶粒群的运动形式。晶粒群运动易于诱发变形的不均匀。而通过控制变形参数，可以对包括晶粒群运动的微观机制进行控制，从而改善材料超塑性。

Preliminary analysis and discussion on the movement of grain groups in superplastic deformation is given based on the examples of superplastic tension for two kinds of Ti--alloys. Grain group movement means that a number of grains in some area in the material of a specimen flow in a different way from neighboring substance. Grain group movement is easy found in superplastic deformation of the materials with complex microstructure. Heterogeneous deformation can be brought out by this kind of flow. However,the micro-mechanism of deformation could be controlld by controlling deformation parameters, so superplasticity of the materials could be improved.