Microstructure dependence of a Cu–38Zn alloy on processing conditions of constrained groove pressing

Grain reduction and the rate of grain refinement as a function of the processing conditions of constrained groove pressing (CGP) for a Cu–38Zn alloy is investigated. It is found that during the early stage of CGP more effective grain refinement can be achieved using the pressing die with narrower groove widths. Similarly, during this stage the cross-orientation pressing procedure results in finer grains than the single-orientation pressing procedure even though both pressings have the same plastic strain. However, the grain sizes from different pressing conditions merge at large plastic strains. These phenomena have been interpreted based on the complexity of the deformation field and the change of the dislocation generation rate over multiple pressing cycles. The result of this study demonstrates that the rate of grain refinement is affected by the complexity of the deformation field.