Influence of Ca addition on microstructure, mechanical properties and corrosion behavior of Mg-2Zn alloy.

The microstructure, mechanical properties and corrosion behaviors of as-cast ternary Mg-2Zn-xCa (x=0, 0.2, 0.4, 0.8) alloys have been investigated in this study. Results indicate that the microstructure of Mg-Zn-Ca alloys can be significantly refined with increasing Ca concentration. Moreover, the alloys with different contents of Ca exhibit the different phases formation behaviors, i.e. a-Mg + Ca2Mg6Zn3 phases for Mg-2Zn-0.2Ca and Mg-2Zn- 0.4Ca alloys, and a-Mg + Ca2Mg6Zn3 + Mg2Ca phases for Mg-2Zn-0.8Ca alloy, respectively. Among all the alloys, the maximum ultimate tensile strength and elongation (161 MPa and 9.1%) can be attained for the Mg-2Zn-0.2Ca alloy. Corrosion tests in Hanks' balanced salt solution indicated that Ca addition is detrimental to corrosion resistance of Mg-2Zn alloy. The relationship between as-cast microstructure and properties for different Ca-containing alloys is also discussed in detail. [ABSTRACT FROM AUTHOR]