Enhanced superplasticity of 1 wt.%Ca-AZ80 Mg alloy with ultrafine grains

Abstract

Ultrafine grained (UFG) 1 % Ca-AZ80 (1CaAZ80) alloy in sheet form could be fabricated by means of high-ratio differential speed rolling (HRDSR) technique. During the rolling, the grain size was markedly reduced from 11.5 to 0.8 mu m, and Al(2)Ca particles were broken up to smaller ones and dispersed into the matrix. The UFG 1CaAZ80 alloy exhibited a high strength (yield stress = 340 MPa) at room temperature and excellent superplasticity at elevated temperatures. A maximum elongation of similar to 700% was obtained at 2 x 10(-4) s(-1) - 523 K. The currently proposed HRDSR process opens a new opportunity of producing high-performance superplastic magnesium alloy sheets. (C) 2010 Elsevier B.V. All rights reserved.