轧后深冷处理工艺对AZ31镁合金板材组织和力学性能的影响  

Effect of post rolling cryogenic treatment on microstructure and mechanical properties of AZ31 magnesium alloy sheet

作　　者：张家龙 卢立伟[1,2,3] 康伟 车波 李旻昊 范宇田 马旻 ZHANG Jia-long;LU Li-wei;KANG Wei;CHE Bo;LI Min-hao;FAN Yu-tian;MA Min(College of Mechanical and Electrical Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Provincial Overseas-wisdom Innovation Center of New Energy Vehicle in Industrial-Academic-Research Cooperation,Hunan University of Science and Technology,Xiangtan 411201,China;College of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学机电工程学院,湖南湘潭411201 [2]湖南科技大学湖南省新能源汽车产学研海智创新中心,湖南湘潭411201 [3]湖南科技大学材料科学与工程学院,湖南湘潭411201

出　　处：《塑性工程学报》2022年第2期126-133,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(52174362,51975207);湖南省自然科学基金资助项目(2021JJ30257,2020JJ5181);湖南省自然科学基金优秀青年基金资助项目(2019JJ30010);湖南省教育厅基金资助项目(19C0773)。

摘　　要：为了改善传统热轧AZ31镁合金板材的微观组织,提升其综合力学性能,将AZ31镁合金板材经360℃热轧后,采用不同时间液氮浸泡进行深冷处理,研究不同深冷时间处理对热轧AZ31镁合金显微组织和力学性能的影响。结果表明:经深冷处理后,热轧AZ31镁合金中析出第二相,同时合金内部晶粒尺寸得到细化,导致孪晶产生。AZ31镁合金热轧板材经过20 min深冷处理后,综合力学性能得到显著改善,其硬度、屈服强度和极限抗拉强度分别为75.4 HV、182 MPa和278 MPa,较传统热轧分别提高了9.4%、8.3%和14%,此外,随着深冷时间的延长,AZ31镁合金的伸长率逐渐提高,最大伸长率达到14.4%。To improve the microstructure of traditional hot-rolled AZ31 magnesium alloy sheet and its comprehensive mechanical properties, the cryogenic treatment with different soaking time in liquid nitrogen was carried out after the hot rolling for AZ31 magnesium alloy sheet, and the effect of different cryogenic time on microstructure and mechanical properties of hot-rolled AZ31 magnesium alloy was studied. The results show that after cryogenic treatment, the second phase is precipitated in hot-rolled AZ31 magnesium alloy, and the internal grain size of alloy is refined at the same time, which leads to the generation of twins. The comprehensive mechanical properties of hot-rolled AZ31 magnesium alloy sheet are significantly improved after 20 min cryogenic treatment. The hardness, yield strength and ultimate tensile strength are 75.4 HV, 182 MPa and 278 MPa, respectively, which are 9.4%, 8.3% and 14% higher than those in traditional rolling. In addition, with the extension of cryogenic time, the elongation of AZ31 magnesium alloy increases gradually, and the maximum elongation reaches 14.4%.

关 键 词：AZ31镁合金 深冷处理 显微组织 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]