预变形量对2219铝合金的力学性能及显微组织影响  

Effects of pre-deformation on microstructure and mechanical properties of 2219 aluminum alloy

作　　者：周蓉蓉[1] 贺爱国[2] 方华婵[1] 王博[2] 罗丰华[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]中国航天科技集团公司长征机械厂,四川成都600100

出　　处：《材料热处理学报》2016年第4期45-49,共5页Transactions of Materials and Heat Treatment

基　　金：中国航天科技集团2014重大工艺专项研究

摘　　要：采用维氏硬度测试、拉伸性能测试等方法研究了不同拉伸预变形量对2219铝合金在177℃时效时的力学性能影响,并利用光学显微镜、扫描电镜和透射电镜观察了其微观形貌和显微组织。结果表明:合金经过预拉伸变形后晶粒伸长,时效后晶粒中析出大量的正交片状析出相,合金强度明显提高;增大预变形量可以促进过渡相θ″向θ'的转变析出,15%预拉伸样品在6 h即达到峰值时效,屈服强度和伸长率由时效前的322.9 MPa、14.0%变为368.8 MPa和9.6%;在同一时效时间,合金的强度随着预拉伸量的增加而提高,伸长率降低。The effects of different pre-elongation（ 2%,8% and 15%） on mechanical properties of 2219 alloy aged at 177 ℃ were investigated by Vickers hardness test and tensile test. The microstructure of the alloy was observed by optical microscope,scanning electron microscopy and transmission electron microscopy. Results show that grains elongate after deformation and amounts of orthotropic strengthening second-phases appear after aging. As a result of the analysis,increasing pre-deformation can promote the transformation of θ″ into θ＇ phase.Without aging process,the yield strength and the elongation of the alloy are 322. 9 MPa and 14. 0%,respectively. Compared with original mechanical properties,the sample elongated with 15% reaches peak-age with yield strength 368. 8 MPa and the elongation 9. 6% after aging at 177 ℃ for 6 h. With pre-elongation increasing,the strength of the alloy can be improved and the elongation reduced.

关 键 词：2219铝合金 预拉伸量 时效 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]