Effect of Mg content on microstructure and properties of Zn-Al-Cu Alloy

Abstract

Abstract Zn-Cu-Al-xMg (x=0,0.25,0.5) zinc alloy was prepared by metal mould casting. The effects of Mg addition on the structure, electrical conductivity and mechanical properties of Zn-Al-Cu alloy were studied. The results show that without Mg addition, the alloy consists of Zn solid solution(ƞ phase) containing of Cu and Al and layered α+η eutectic structure. With the addition of Mg, the η phase grains were refined, the layered eutectic structure disappeared, and the intermetallic compound Mg2Zn11 appeared, and its content increased with the increase of Mg content. The hardness of the alloy increases with the increase of Mg content. When the content of Mg is 0.5wt.%, the hardness reaches the maximum value of 151HV. Tensile strength and electrical conductivity first increase and then decrease. When the addition of Mg is 0.25wt.%, the maximum tensile strength and electrical conductivity are 270 MPa and 26.4% IACS, respectively. The wear mechanism of zinc alloy is a mixture of adhesive wear and abrasive wear, and the adhesive wear is dominant.