Effects of Ce Addition on Mechanical and Corrosion Properties of the As-Extruded Mg-Zn-Ca Alloy

摘要

The microstructure and corrosion properties of the as-extruded Mg-Zn-Ca alloy with and without Ce addition are investigated. The microstructure was characterized by optical microscopy, scanning electron microscopy coupled with electron backscatter diffraction detector. Ce addition retarded dynamic recrystallization during deformation, which resulted in the formation of bimodal microstructure with finely dynamically recrystallized (DRXed) grains and coarsely unDRXed grains. Texture of the DRXed region was weakened after small addition of Ce, mainly attributing to particle stimulated nucleation. The strength enhancement for the Ce containing Mg-Zn-Ca alloy was attributed to the fine microstructure and strong texture. Corrosion results indicated that Ce addition deteriorated corrosion resistance in 3.5 wt.% NaCl solution of the as-extruded Mg-Zn-Ca alloy, which was related to the dispersed second phases, refined microstructure and weak basal texture in DRXed region.