A Dislocation Reaction Model for Variant Selection During theAustenite‐to‐Martensite Transformation

Abstract

Variant selection rules are described that predict the austenite‐to‐martensite transformation textures of an Fe‐30%Ni alloy. The occurrence of variant selection is explained in detail using the crystal plasticity model of Bishop and Hill and the Kurdjumov‐Sachs transformation relationship. A correlation is established between the slip systems of the former and the rotation axes of the latter. The selection criteria are based on a combination of slip activity, that is, active slip systems, and permissible dislocation reactions. Thus some of the variants selected are associated with slip systems that are active while the remainder are accounted for by the in‐plane reaction of active dislocations to form inactive or unstressed dislocations. The variant selection criteria are tested against the experimental findings of Liu and Bunge ( Materials Letters , 10(7,8), 336–343, 1991) and found to be in good agreement.