Violation of Schmid's law and tension–compression asymmetry in L1₂ alloys: role of ordered structure

Abstract

Hypostoichiometric Ni₃Al(B) undergoes a structural transformation from its initial L1₂ structure to DO₂₂ structure during cold rolling. It has been found that this DO₂₂ structure reverts back to L1₂ structureduring annealing. The transformation to DO₂₂ structure as well as back to L1₂ at higher temperature is very much dependent on the degree of cold reduction. Based on thesefindings, the possible reason for abnormal behaviour of these L1₂ordered alloys, i.e. violation of Schmid's law and orientation dependence of flow stress is hypothesised.

Keywords:

• NICKEL ALUMINIDES
• STRUCTURAL TRANSFORMATION
• TEXTURE
• FLOW STRESS ASYMMETRY
• SCHMID'S LAW