深冷处理对7A62铝合金微观组织和力学性能的影响
Effect of cryogenic treatment on microstructure and mechanical properties of 7A62 Al alloy
刘文辉 1李蓝宁 2黄浩 3余杰 3宋宇峰 2胡强 2岳小明2
作者信息
- 1. 湖南科技大学 机电工程学院,湘潭 411201;集美大学 海洋装备与机械工程学院,厦门 361021
- 2. 湖南科技大学 机电工程学院,湘潭 411201
- 3. 江麓机电集团有限公司,湘潭 411100
- 折叠
摘要
采用XRD、SEM、TEM、硬度测试以及拉伸测试等研究T6处理、时效前深冷DCT5h-T6处理和时效后深冷T6-DCT5h处理对7A62铝合金微观组织及力学性能的影响.结果表明:相比于T6处理,深冷处理后合金析出相的尺寸减小、数密度增大,位错密度提高;受析出相与位错密度的共同影响,DCT5h-T6处理合金的强度和伸长率均有所提升.与DCT5h-T6处理相比,T6-DCT5h处理进一步促进了析出相的形核,其尺寸细化且分布更加均匀,数密度约提高5%;T6-DCT5h处理可使得合金获得较优的综合力学性能,合金的屈服强度、抗拉强度和伸长率分别为584 MPa、637 MPa和10.7%,较常规T6处理分别提高28 MPa、10 MPa以及37%.
Abstract
The effects of T6 treatment,cryogenic DCT5h-T6 treatment before aging and cryogenic T6-DCT5h treatment after aging on the microstructure and mechanical properties of 7A62 Al alloy were systematically compared by means of XRD,SEM,TEM,hardness test and tensile test.The results show that the precipitated phase size of DCT5h-T6 alloy decreases,while the number density and dislocation density increase after cryogenic treatment,which result in the improvement of strength and elongation of compared with T6 treatment.Compared with the DCT5h-T6 treatment,the cryogenic treatment after aging further promotes the nucleation of the precipitated phase,the numerical density of the precipitated phase increases by 5%,besides,the precipitates have been refined and the distribution is more uniform,so that the T6-DCT5h alloy obtains the higher comprehensive mechanical properties,and its yield strength,tensile strength and elongation reach to 584 MPa,637 MPa and 10.7%,respectively,which are higher than conventional T6 treatment by 28 MPa,10 MPa and 37%,respectively.
关键词
7A62铝合金/深冷处理/微观组织/力学性能Key words
7A62 aluminum alloy/cryogenic treatment/microstructure/mechanical property引用本文复制引用
基金项目
国家自然科学基金资助项目(U21A20130)
国家自然科学基金资助项目(52375332)
湖湘高层次人才聚集工程(2021RC5010)
出版年
2024
NETL
NSTL
万方数据