The effect of the selection of the secondary solidification phase on the mechanical properties of the Mg-Sn-Zn and Mg-Sn-Zn-Al alloy rolled sheets has been investigated in the present study. The as-cast microstructure of Mg-7Sn-2Zn (in wt.%) alloy consists of α-Mg dendrite and interdendritic Mg 2Sn and MgZn2 phases, while that of Mg-7Sn-5Zn-2Al alloy consists of α-Mg dendrite and interdendritic Mg2Sn and icosahedral (I-) phases. The micron scale interdendritic I-phase in the as-cast Mg-7Sn-5Zn-2Al alloy dissolves into the matrix during homogenizing treatment, and appears again in the α-Mg matrix as 0.1-0.5 μm size fine spherical precipitates after rolling process. As a result, the Mg-7Sn-5Zn-2Al alloy exhibits high yield strength of 318 MPa in as-rolled state. The high level of strength is attributed to the presence of finely distributed Mg2Sn and I-phase particles embedded in the α-Mg matrix.
Bibliographical noteFunding Information:
This study was supported by the World Premier Materials (WPM) project funded by the Korea Ministry of Knowledge and Economy, and the Global Research Laboratory Program of Korea Ministry of Education, Science and Technology. Y.K. Kim is grateful for the support from the Third Stage of Brain Korea 21 Project in 2012.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry