THE SOLIDIFICATION MICROSTRUCTURE AND PRECIPITATION INVESTIGATION OF MAGNESIUM-RICH ALLOYS CONTAINING Zn AND Ce

摘要

Mg-Zn-Ce system has been identified as the alloy system for high-ductility wrought magnesium alloy development for automotive applications. The solidification microstructure and precipitation of Mg-Zn-Ce alloys were investigated to understand the phase equilibria and strengthening phases in this alloy system. The characterized microstructures of four directionally solidified Mg-Zn-Ce alloys agree well with the calculated solidification paths using computational thermodynamics coupled with the Scheil model. The precipitation of Mg_7Zn_3 intermetallic phase upon heat treatment was characterized using high-resolution transmission electron microcopy (HRTEM), a potential strengthening mechanism which will be explored in future research.