Microstructure and high temperature tensile properties of Al-Si-Cu-Mn-Fe alloys prepared by semi-solid thixoforming  

半固态触变成形Al-Si-Cu-Mn-Fe合金的显微组织和高温拉伸力学性能

作　　者：Bo LIN Tao FAN Hao-yu LI Yu-liang ZHAO Wei-wen ZHANG Kun LIU 林波;范滔;李浩宇;赵愈亮;张卫文;刘坤(贵州大学机械工程学院,贵阳550025;东莞理工学院机械工程学院,东莞523808;华南理工大学机械与汽车工程学院,广州510640;Department of Applied Science,University of Quebec at Chicoutimi,Quebec,Canada)

机构地区：[1]School of Mechanical Engineering,Guizhou University,Guiyang 550025,China [2]School of Mechanical Engineering,Dongguan University of Technology,Dongguan 523808,China [3]School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,China [4]Department of Applied Science,University of Quebec at Chicoutimi,Quebec,Canada

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第8期2232-2249,共18页中国有色金属学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51704084,52074131);the Science and Technology Plan of Guizhou Province,China(Nos.ZK2021(267),ZK2021(067));the Cultivation Project of Guizhou University,China(No.2019(23))。

摘　　要：The differences in the microstructure and elevated temperature tensile properties of gravity die cast,squeeze cast,and semi-solid thixoformed Al-Si-Cu-Mn-Fe alloys after thermal exposure at 300℃were discussed.The results demonstrate that the elevated temperature tensile properties of semi-solid thixoformed alloys were significantly higher than those of gravity die cast and squeeze cast alloys,especially after thermal exposure for 100 h.The ultimate tensile strength(UTS)of semi-solid thixoformed alloys after thermal exposure at 300℃for 0.5,10 and 100 h were 181,122 and 110 MPa,respectively.The UTS values of semi-solid thixoformed alloys were higher than those of heat resistant aluminum alloys used in commercial applications.The enhanced elevated temperature tensile properties of semi-solid thixoformed experimental alloys after thermal exposure can be attributed to the combined reinforcement of precipitation strengthening and grain boundary strengthening due to thermally stable intermetallic phases as well as suitable grain size.对比分析重力铸造、挤压铸造、半固态触变成形制备的Al-Si-Cu-Mn-Fe合金在300℃热暴露下的组织演变和高温拉伸力学性能。结果表明:相比重力铸造和挤压铸造合金,半固态触变成形Al-Si-Cu-Mn-Fe合金具有更优异的高温力学性能,尤其是当热暴露时间为100 h时。半固态触变成形Al-Si-Cu-Mn-Fe合金在300℃热暴露时间为0.5、10和100 h时的高温极限抗拉强度分别为181、122和110 MPa,高于大部分商用耐热铝合金。半固态触变成形Al-Si-Cu-Mn-Fe合金获得高强热暴露力学性能的主要原因是耐热相导致的晶界和晶内弥散协同强化以及合适的晶粒尺寸。

关 键 词：Al-Si alloys iron-rich intermetallics semi-solid thixoforming MICROSTRUCTURE tensile properties thermal exposure 

分 类 号：TG146.21[一般工业技术—材料科学与工程]