Microstructure in Zn-Al Alloys after Equal-Channel-Angular Extrusion

Abstract

Experiments were conducted to evaluate the grain refinement in Zn–22Al alloys subjected to equal-channel-angular extrusion (ECAE) under three different conditions. In the first condition (Route 1), ECAE was performed during the phase transformation at room temperature. In the second condition (Route 2), ECAE was carried out after the phase transformation at room temperature. In the third condition (Route 3), ECAE was performed after the phase transformation at 373 K. The average grain sizes after ECAE exhibited 0.35, 0.3 and 0.6 μm for Route 1, 2 and 3, respectively. Route 1 was efficient to develop the material with a finer microstructure, and reduce the processing time. It was also verified that reasonably equiaxed and homogeneously distributed grains were obtained by ECAE after solution treatment without rolling process.