Effect of Y Alloying on Microstructure and Mechanical Properties of AZ61 Magnesium Alloy Sheets Applied as 3C Electronic Product Shells

Abstract

AZ61 magnesium alloy sheets can be applied as 3C (computer, communication, and consumer) electronic product shells. However, due to their poor plasticity and relatively low strength, the application of AZ61 alloy sheets is limited. The composition modification of AZ61, especially rare earth element alloying, is a good choice to improve the strength and plasticity of AZ61 alloy sheets. In this paper, the strength and plasticity of AZ61 sheets with different contents of Y were studied in detail. We found that the addition of 0.9 wt.% of Y not only improved the strength, but also significantly enhanced the plasticity. As a result, the yield strength of AZ61 increased from 167 MPa to 186 MPa, and the elongation increased from 9.5% to 18%. The reasons can be explained as follows: the Al2Y phase formed by adding Y consumed a large amount of the Al element, thus avoiding the formation of the brittle phases Al8Mn5 and resulting in the improved mechanical properties of the sheets. At the same time, the weakened texture and dispersed grain orientation also effectively improved the plasticity of the sheets. This study will provide a good solution to improve the strength and plasticity of AZ61 sheets without significantly increasing the production cost.