Influence of solute effects on the saturation grain size and rate sensitivity in Cu-X alloys

Three Cu-alloys (CuSn5, CuZn5, CuZn30) have been selected, to study the influence of solutes on the saturation grain size after high pressure torsion as well as the resulting mechanical properties with an emphasis on strain rate sensitivity. Compared to each other, the alloys exhibit either similar stacking fault energies or similar solid solution strengthening, allowing a separation of both parameters. The results indicate that the saturation grain size correlates with the solid solution strengthening but not with the stacking fault energy. Moreover, a reduced strain rate sensitivity with reduced grain size is observed, which is attributed to the microstructural stability.