Development of High Strength and High Thermal Conductivity Semi-Solid Magnesium Alloy by Thixomolding Process

Abstract

This paper investigates the influence of Cu addition on the microstructure, mechanical properties, and thermal conductivity of a semi-solid Mg-10Zn alloy produced by Thixomolding process. Microstructure of the Mg-10Zn alloy consists of α-Mg matrix and Mg2Zn second phase. The formation of Cu3Zn phase was found after the addition of Cu particles. Besides, the volume fraction of solid phase decreased in the Mg-Zn/Cu alloy compared with that of binary Mg-Zn alloy. The yield strength of the alloy was enhanced from 157MPa to 188MPa after Cu addition at the sacrifice of a small amount of ductility. Thermal conductivity, on the other hand, were kept the same level of 115-117 (W/m·K) in the Mg-10Zn alloy and Mg-10Zn/Cu alloy. This work demonstrates the potential for developing Mg alloys with high strength and high thermal conductivity via proper alloy design using Thixomolding process.