The evolution of cold-rolled deformation microstructure of {0 01 }(110) grains in Ta-7.5 wt%W alloy foils

摘要

The deformation structure of {0 01}{110) grains in cold-rolled Ta-7.5 wt%W alloy foils has been investigated by transmission electron microscopy (TEM) and electron backscattering diffraction (EBSD). The results show that there are two kinds of {0 01 }(110) grains formed during the cold-rolled deformation process. Type A grains are surrounded by a-fiber, while type B grains are surrounded by 7-flber. Dislocation analysis reveals a continuous evolution of dislocation substructures from dislocation arrays, to high dense dislocation walls, and to microbands in type A grains, while in type B grains from dislocation mesh to dislocation cells as a function of plastic strain. By both the analysis of EBSD and TEM, a new deformation mode in type A grains is developed.