Mg-6Gd-1Er-6Zn-0.5Zr合金轧板显微组织、力学性能与导热性能  

Microstructure,mechanical property and thermal conductivity of Mg-6Gd-1Er-6Zn-0.5Zr alloy sheets

作　　者：侯健捷 李旭东 朱训明 王云峰 娄峰 丁宁[1] 杜宪[1] 李淑波[1] 杜文博[1] HOU Jianjie;LI Xudong;ZHU Xunming;WANG Yunfeng;LOU Feng;DING Ning;DU Xian;LI Shubo;DU Wenbo(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;Weihai Wanfeng Magnesium Science and Technology Development Co.,Ltd.,Weihai 264209,China)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]威海万丰镁业科技有限公司,威海264209

出　　处：《中国有色金属学报》2024年第5期1541-1554,共14页The Chinese Journal of Nonferrous Metals

基　　金：国家重点研发计划资助项目(2021YFB3701100)。

摘　　要：结构−功能一体化镁合金在国防军工、交通运输、电子通信等领域具有广阔的应用前景,开发力学性能和导热性能协同提升的镁合金板材是实现结构功能一体化镁合金应用的关键。本文以固溶态Mg-6Gd-1Er-6Zn-0.5Zr(质量分数,%,简称GEZ616K)合金为研究对象,研究了轧制温度和变形量对轧制态GEZ616K合金微观组织及力学性能和导热性能的影响规律。结果表明:随着轧制变形温度的上升,变形量80%的板材组织经历了从低温混晶→均匀细小再结晶→高温粗大晶粒的变化过程,并伴随基面织构减弱、大角度晶界比例增加以及合金中位错密度降低;当轧制温度一定时,随着变形量的增加,合金中孪晶数量降低,再结晶比例增加,合金力学性能和导热性能同步提升。当轧制温度为425℃时,经80%轧制变形的GEZ616K合金展现出优良的力学性能和导热性能,其抗拉强度、屈服强度和伸长率分别为280 MPa、227 MPa和11.4%,热扩散系数为72.9 mm^(2)/s,热导率为135.3 W/(m·K)。Magnesium(Mg)alloys with integrated structural-functional performance have broad applications in the fields of defense and military industry,transportation and electronic communication,etc.Developing Mg alloy sheets with synergistic mechanical property and thermal conductivity is a key to achieving these applications.The effects of rolling temperature and cumulative strain on the microstructure evolution and mechanical property and thermal conductivity of solid-solution Mg-6Gd-1Er-6Zn-0.5Zr(mass fraction,%,GEZ616K)alloy were investigated.The results show that,as the rolling temperature increasing,the microstructures of the sheet with cumulative deformation strain of 80%undergo transformation process from mixed crystallization at low-temperature to uniform fine recrystallization and grain coarsening at high temperature.At the same time,the basal texture weakens,the proportion of large angle grain boundary increases,and dislocation density in the alloy decreases.At a certain rolling temperature,the number of twins gradually decreases and the proportion of recrystallization gradually increases with the increase of the cumulative strain,resulting in a synchronous improvement of mechanical property and thermal property.The GEZ616K alloy rolled at 425℃with cumulative strain of 80%exhibits the excellent mechanical property and thermal property,the tensile strength,yield strength and elongation are 280 MPa,227 MPa and 11.4%,respectively,as well as the thermal diffusion coefficient of 72.9 mm2/s and the thermal conductivity of 135.3 W/(m·K).

关 键 词：镁−稀土合金 轧制 显微组织 导热性能 力学性能 

分 类 号：TG335.3[金属学及工艺—金属压力加工]