Evolution of Microstructure and Mechanical Properties During Casting and Rolling of the ZEK100 Sheet

摘要

The use of magnesium sheet in automotive light-weighting initiatives is low due to its poor formability at room temperature. In this investigation the cast ZEK100 (Mg-l.2Zn-0.35Zr-0.17Nd, in wt%) alloy was subjected to rolling at temperatures from 350 to 450 °C and for each rolling temperature the evolution of microstructure and tensile properties were assessed. To assess strengthening during rolling, properties were also measured after annealing following each rolling. The results show that increasing the rolling temperature caused reduction of tensile strength, yield stress but increasing elongation. A correlation was established between mechanical properties and grain size influenced by the rolling temperature. The results are discussed in terms of the role the rare earth elements play in controlling the formability of magnesium alloys.