Variant selection in transformation texture from the beta to alpha phase in Cu-40 mass% Zn alloy

The rolling texture and variant selection in texture during the phase trans formation from beta to alpha in Cu-40 mass% Zn were investigated using X-ra y back reflection and electron back-scatter diffraction pattern (EBSP) tech niques. The rolling texture of the beta parent phase, before the phase tran sformation, was composed of {111}[1 (1) over bar 1], {001}[110] and {111}[( 1) over bar (1) over bar 2]. Variant selection occurred during the beta to alpha phase transformation from the cold-rolled parent beta phase, even whe n the phase transformation following the Kurdjumov-Sachs relationship was c ontrolled by a diffusion process. The variant selection was related to the Bain distortion for each alpha variant during the phase transformation from the beta to alpha phase. A limited set of alpha variants was chosen to min imize the residual stress induced in the deformed beta parent phase by the Bain distortion. The type of selected variants changed with the rolling tex ture of beta parent phase. The selectivity of specific Variants increased a nd was stimulated by both annealing temperature and rolling reduction. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights r eserved.