Effects of cross-channel extrusion on the microstructures and superplasticity of a Zn–22 wt.% Al eutectoid alloy

The purpose of this study was to investigate the effects of cross-channel extrusion on the microstructures and superplasticity of a Zn–22 wt.% Al alloy. Extrusion gradually transforms the initial laminar Al-rich phase into a spherical shape, and the particle sizes are refined to 0.3 and 1 μm at extrusion temperatures of 373 and 473 K, respectively. The size and uniformity of the Al-rich phase results in a superplasticity that is enhanced significantly after extrusion for up to 10 passes.