Microstructure,tensile and creep properties of as-cast Mg-3.8Zn-2.2C_(a-x)Ce(x=0,0.5,1 and 2 wt.%) m

• 作 者: 杨明波 郭廷长 秦财源 潘复生
• 机 构: Materials Science and Engineering College, Chongqing University of Technology,Key Laboratory of Auto
• 出 处: Journal of Rare Earths
• 发表日期: 2012年02期
• 关键词: tensile creep a-x)Ce magnesium eutectic ultimate adding refine coarse grains

The microstructure and mechanical properties of as-cast Mg-3.8Zn-2.2Ca alloy with different Ce contents were investigated by both optical and electron microscopy, X-ray diffraction, differential scanning calorimetry analysis, tensile and creep tests. The results indi-cated that adding 0.41 wt.%-1.83 wt.% Ce could refine the grains of the alloy, and the grain size gradually decreased as the Ce content in-creased. Furthermore, addition of either 0.41 wt.% or 0.89 wt.% Ce caused the morphology of the Ca2Mg6Zn3 phase to change partially from semi-continuous block to discrete fine particles. However, after adding 1.83 wt.% Ce, portions of the Ca2Mg6Zn3 and Mg12Ce phases were mixed and this Ca2Mg6Zn3+Mg12Ce eutectic changed to a different coarse semi-continuous morphology. In addition, addition of 0.41 wt.%-1.83 wt.% Ce improved the tensile and creep properties of the alloy. Amongst these Ce-containing alloys, the alloy with 0.89 wt.% Ce exhibited the best ultimate tensile strength and elongation while the alloy with 1.83 wt.% Ce had the best yield strength and creep properties.

The microstructure and mechanical properties of as-cast Mg-3.8Zn-2.2Ca alloy with different Ce contents were investigated by both optical and electron microscopy, X-ray diffraction, differential scanning calorimetry analysis, tensile and creep tests. The results indi-cated that adding 0.41 wt.% - 1.83 wt.% Ce could refine the grains of the alloy, and the grain size gradually decreased as Ce content in-creased. Furthermore, addition of either 0.41 wt.% or 0.89 wt.% Ce caused The morphology of the Ca2Mg6Zn3 phase to change partially from semi-continuous block to discrete fine particles. However, after adding 1.83 wt.% Ce, portions of the Ca2Mg6Zn3 and Mg12Ce phases were mixed and this Ca2Mg6Zn3 + Mg12Ce eutectic changed to a different coarse semi % of 1.83 wt.% Ce improved the tensile and creep properties of the alloy. Among these these Ce-containing alloys, the alloy with 0.89 wt.% Ce exhibited the ultimate ultimate tensile strength and elong ation while the alloy with 1.83 wt.% Ce had the best yield strength and creep properties.