In this study,the effects of Ca addition on the microstructure,thermal properties,and mechanical properties of a Mg-6.0Zn-1.2Y-0.7Zr(ZWK611)alloy at room temperature and 150℃ were investigated.With an increase in the...In this study,the effects of Ca addition on the microstructure,thermal properties,and mechanical properties of a Mg-6.0Zn-1.2Y-0.7Zr(ZWK611)alloy at room temperature and 150℃ were investigated.With an increase in the Ca content,the ignition resistance of the ZWK611 alloy improved and the grains became finer.The as-cast ZWK611 alloy consisted mainly of the dendriticα-Mg matrix and I-phase(Mg_(3)Zn_(6)Y)at the grain boundaries.On the other hand,theτ-(Ca_(2)Mg_(6)Zn_(3))and I-phases were formed in the Ca-added ZWK611 alloy.The fraction of theτ-phase increased with an increase in the Ca content.After the solid-solution treatment,these phases remained partially at the grain boundaries of the Ca-added ZWK611 alloys and an additional W-phase(Mg_(3)Zn_(3)Y)was observed.The phases remaining at the grain boundaries restricted the grain growth through the grain boundary pinning effect.The aging treatment resulted in the formation of MgZn'precipitates in theα-Mg matrix of the alloys.These precipitates were more uniformly distributed in the Ca-added alloys than in the alloys without Ca.Thus,the heat treatment-induced precipitation improved the tensile and creep properties of the T6-treated alloys.The T6-treated ZWK611+0.7Ca alloy exhibited the best mechanical properties at room temperature and 150℃ among all the tested alloys.展开更多
基金the support of the Korea Institute of Industrial Technology as"Enterprise demand-based production technology commercialization project(KITECH JG-20–0003)"。
文摘In this study,the effects of Ca addition on the microstructure,thermal properties,and mechanical properties of a Mg-6.0Zn-1.2Y-0.7Zr(ZWK611)alloy at room temperature and 150℃ were investigated.With an increase in the Ca content,the ignition resistance of the ZWK611 alloy improved and the grains became finer.The as-cast ZWK611 alloy consisted mainly of the dendriticα-Mg matrix and I-phase(Mg_(3)Zn_(6)Y)at the grain boundaries.On the other hand,theτ-(Ca_(2)Mg_(6)Zn_(3))and I-phases were formed in the Ca-added ZWK611 alloy.The fraction of theτ-phase increased with an increase in the Ca content.After the solid-solution treatment,these phases remained partially at the grain boundaries of the Ca-added ZWK611 alloys and an additional W-phase(Mg_(3)Zn_(3)Y)was observed.The phases remaining at the grain boundaries restricted the grain growth through the grain boundary pinning effect.The aging treatment resulted in the formation of MgZn'precipitates in theα-Mg matrix of the alloys.These precipitates were more uniformly distributed in the Ca-added alloys than in the alloys without Ca.Thus,the heat treatment-induced precipitation improved the tensile and creep properties of the T6-treated alloys.The T6-treated ZWK611+0.7Ca alloy exhibited the best mechanical properties at room temperature and 150℃ among all the tested alloys.
