低温挤压Mg-Sm-Ce系合金的微观组织与力学性能研究  

Microstructure and Mechanical Properties of Low-Temperature Extruded Mg-Sm-Ce Series Alloys

作　　者：潘虎成 蒋彩霞 张元 王森 杜森 任玉平 秦高梧[1,2] PAN Hucheng;JIANG Caixia;ZHANG Yuan;WANG Sen;DU Sen;REN Yuping;QIN Gaowu(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Key Laboratory for Anisotropy and Texture of Materials,Ministry of Education,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学材料科学与工程学院,沈阳110819 [2]东北大学材料各向异性与织构教育部重点实验室,沈阳110819

出　　处：《航空制造技术》2024年第8期14-21,共8页Aeronautical Manufacturing Technology

基　　金：国家重点研发计划子课题(2021YFB3701002);国家自然科学基金(51971053);国家自然科学基金子课题(U2167213)。

摘　　要：大幅提升低成本变形镁合金的绝对强度是轻合金研究领域的关键瓶颈问题之一。本研究基于相图计算设计了一种包含低含量轻稀土元素的新型Mg-Sm-Ce-Mn系合金,通过低温挤压实现了近400 MPa的超高强度。Mg-0.8Sm-0.4Ce-0.4Mn(EM10,质量分数,%)合金经低温挤压后形成了双组态晶粒组织,并表现为典型的丝织构,动态析出了Mg41(Ce,Sm)5和Mg12Ce微米第二相;低的挤压温度及高密度纳米第二相的析出,促进EM10合金的再结晶晶粒尺寸细化至约0.93μm,同时在未再结晶区域内残留有高密度的残余位错;细晶强化、第二相强化、织构强化及位错强化的综合作用,使EM10合金的屈服强度可高达约379 MPa,同时保持约4.7%的延伸率。继续提升Ce和Sm元素的含量,会引入更多的脆性微米级第二相,将损伤合金的塑性。因此,通过低温挤压工艺和成分优化,设计制备出了一种高强度Mg-0.8Sm-0.4Ce-0.4Mn合金,相关结果可为低合金化、超高强度变形镁合金的制备提供理论指导。Significantly improving the absolute strength of low-cost wrought magnesium alloys is one of the key bottlenecks in the field of light alloy research.In this study,a new Mg-Sm-Ce-Mn alloy containing low content of light rare earth elements was designed based on phase diagram calculation,and an ultra-high strength of nearly 400 MPa was achieved by low temperature extrusion.The Mg-0.8Sm-0.4Ce-0.4Mn(EM10,mass fraction,%)alloy formed a dual-configuration grain structure after low temperature extrusion,and showed a typical silk texture,and dynamically precipitated Mg41(Ce,Sm)5 and Mg12Ce micron second phase.The lower extrusion temperature and the precipitation of high-density nano-second phases contributed to the refinement of the recrystallized grain size of EM10 alloy to about 0.93μm,while a high density of residual dislocations remained in the uncrystallized region.The combined effects of fine grain strengthening,second phase strengthening,texture strengthening and dislocation strengthening lead to the yield strength of EM10 alloy can be as high as about 379 MPa,while maintaining the elongation of about 4.7%.Continuing to increase the content of Ce and Sm elements,more brittle micron-sized second phases will be introduced,which will impair the plasticity of the alloy.Therefore,a high-strength Mg-0.8Sm-0.4Ce-0.4Mn alloy was designed and prepared by low-temperature extrusion process and composition optimization.The relevant results can provide theoretical guidance for the preparation of low-alloying and ultra-high-strength wrought magnesium alloys.

关 键 词：变形镁合金 挤压变形 力学性能 第二相 低合金化 

分 类 号：V252[一般工业技术—材料科学与工程]