Study of the Deformation Mechanisms of the Superplastic Alloy Ai–Li 2090 by Texture Analysis

Abstract

The deformation mechanisms of a superplastic Al–Li 2090 alloy have been investigated by means of texture analysis. It has been found that both crystallographic slip (CS) and grain boundary sliding (GBS) operate in response to the applied stress over a wide range of deformation, conditions. This is in contrast to well-accepted creep models, which predict that only one mechanism should operate and that the transition from one mechanism to another is abrupt and takes place over a narrow range of deformation conditions. Additionally, according to geometric (Taylor-type) models of uniaxial deformation for CS, the 〈110〉, 〈111〉, or 〈001〉 fibers should appear when 4, 6, or 8 slip systems operate. Here, however, CS contributes to stabilize orientations belonging to the α and β fibers.