Microstructures and tensile properties of a twin roll cast and heat-treated Mg-2.4Zn-0.1Ag-0.1Ca-0.1Zr alloy

An Mg-2.4Zn-0.1Ag-0.1Ca-0.1Zr alloy sheet, with a tensile yield strength of 316 MPa, an ultimate tensile strength of 342 MPa and an elongation of 17%, has been processed by twin roll casting (TRC), hot rolling and heat treatment. The high yield strength has been attributed to a uniform distribution of fine rod-like precipitates of MgZn(2) phase. The TRC and hot-rolled sheet also showed an exceptionally high stretch formability with a limiting dome height much larger than those of other Mg alloys. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.