Effect of inhomogeneity of texture on mechanical behaviour of an AI-6% Cu-0.4% Zr superplastic alloy

Abstract

Mechanical and microstructural characterization was carried out at 480 °C/5.10^-4s^-1 on an Al-6% Cu-0.4% Zr superplastic alloy. The as-received material showed a fine deformed substructure. A texture gradient was present through the thickness of the rolled sheet. At the surface, the texture found was close to the orientation {311}<233> whereas in the midplane of the sheet it was {631}<113>. The (s)-(e) tensile test curve presented three deformation stages called, stage I, II and III. The global texture in stage I increased slightly. In stage II, the intensity of orientation {311}<233> decreased, suggesting that a grain boundary sliding deformation process should take place near the surface. However, in the center of the sheet, the {631}< 113> orientation transformed to the orientation (110}< 111 > by slip process. This behaviour continued in the stage III, where the orientation {631}<113> totally disappeared.