Anneal hardening in α-brass

Abstract

The effect of different amounts of prior cold-rolling deformation on the anneal-hardening response of Cu-15Zn, Cu-30Zn, and supersaturated Cu-37Zn has been investigated. It is demonstrated that the hardness enhancement is highly dependent on the amount of deformation, the enhancement being very small below 40% and easily discernible at rolling strains above 5%. This change in hardness is associated with the formation of shear bands, a highly localized form of plastic deformation which is characteristic of cold-rolled low stacking fault energy materials. Cold rolling of the order of 5% performed after anneal hardening removes the strength increment and the material then behaves in a manner almost identical to samples not subjected to annealing.