微量Ce对热挤压态Mg-2Zn-0.4Ca-0.2Mn合金微观组织、力学性能及导热性的影响  

Effect of trace Ce on microstructure,mechanical properties,and thermal conductivity of hot-extruded Mg-2Zn-0.4Ca-0.2Mn alloy

作　　者：唐贝 王海丽 付金龙 胥珊娜 Tang Bei;Wang Haili;Fu Jinlong;Xu Shanna(School of Materials Science and Engineering,Xian Shiyou University,Xi'an Shaanxi 710065,China;Xian Rare Metal Materials Institute Co.,Ltd.,Xi'an Shaanxi 710016,China)

机构地区：[1]西安石油大学材料科学与工程学院,陕西西安710065 [2]西安稀有金属材料研究院有限公司,陕西西安710016

出　　处：《金属热处理》2024年第3期222-229,共8页Heat Treatment of Metals

基　　金：陕西省自然基础研究计划(2022JQ-305;2024JC-YBQN-0604)。

摘　　要：通过近固相线温度挤压方法制备了一种具有高热导率、高伸长率的Mg-2Zn-0.4Ca-0.2Mn(wt%)合金,并探索了微量Ce元素对其微观组织及性能的影响。结果表明,热挤压态合金中晶粒呈双峰结构分布,其平均晶粒尺寸相比铸态晶粒显著下降。Ce的加入一方面使得合金内的第二相由Ca_(2)Mg_(6)Zn_(3)相转变为(Mg,Zn)_(11)Ce相,另一方面未再结晶区域占比从5.4%降低到了1.6%,平均晶粒尺寸从5.29μm下降到3.68μm,合金的基面织构强度明显弱化。由于晶粒细化和含Ce第二相的强化作用,合金的屈服强度从原来的163.67 MPa显著提升到237.44 MPa,伸长率从27.45%降低到19.58%,而Ce的添加虽然增加了组织中的第二相体积分数,但同时降低了Zn在基体中的固溶度,因此并未明显降低合金的热导率。Mg-2Zn-0.4Ca-0.2Mn(wt%)alloy with high thermal conductivity and elongation was prepared by near solidus temperature extrusion method,and the effect of trace Ce element on microstructure and properties was explored.The results indicate that the grain size in the extruded alloy exhibits a bimodal distribution,and the average grain size is significantly decreased compared with that of as-cast state.The addition of Ce not only transforms the second phase in the alloy from Ca_(2)Mg_(6)Zn_(3) phase to(Mg,Zn)_(11)Ce phase,but also reduces the unrecrystallized area fraction from 5.4%to 1.6%,with an average grain size of 5.29μm dropping to 3.68μm,and the basal texture intensity of the alloy is significantly weakened.Due to the grain refinement strengthening effect and that of the second phase containing Ce,the yield strength of the alloy is significantly increased from 163.67 MPa to 237.44 MPa,while the elongation is reduced from 27.45%to 19.58%.The addition of Ce increases the volume fraction of the second phase in the microstructure,but it also reduces the solid solubility of Zn in the matrix,so the thermal conductivity of the alloy is not significantly reduced.

关 键 词：Mg-Zn-Ca-Mn镁合金 微量CE 热挤压 微观组织 力学性能 导热性 

分 类 号：TG146.2[一般工业技术—材料科学与工程]