Mg、Si对Al-Cu-Mn-Zr合金时效析出行为及热稳定性的影响  

Effect of Mg and Si on aging precipitation behavior and thermal stability of Al-Cu-Mn-Zr alloy

作　　者：张浩 吴美娴 郭科宏 文胜平 態湘沅 聂祚仁[1] ZHANG Hao;WU Mei-xian;GUO Ke-hong;WEN Sheng-ping;TAI Xiang-yuan;NIE Zuo-ren(Key Laboratory of Advanced Functional Materials,Education Ministry of China,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学新型功能材料教育部重点实验室,北京100124

出　　处：《材料热处理学报》2023年第5期68-75,共8页Transactions of Materials and Heat Treatment

基　　金：国家重点研究开发项目(2021YFB370902,2021YFB3704204,2021YFB3704205);国家自然科学基金创新研究项目(51621003)。

摘　　要：采用显微硬度计与透射电镜等研究了Mg和Si的添加对AlCuMnZr合金时效析出行为和微观组织的影响。结果表明:同时添加Mg和Si显著提高了合金的时效硬度并保证了良好的热稳定性,Al5.5Cu0.25Mg0.3Mn0.2Zr0.15Si合金经540℃固溶7 h及175℃时效24 h后达到峰值硬度,为156.3 HV0.2。Mg的添加细化了AlCuMnZr合金中θ′相尺寸,增加了θ′相数密度,使其分布更弥散、均匀。而在添加Si后,由于σ相、Q相的析出和θ′相周围Si的偏聚,使θ′析出相尺寸进一步减少、粗化速度降低。但在225℃长时间热暴露后,会因为Si的偏聚消失,使部分θ′相粗化,合金的热稳定性下降。Effect of Mg and Si addition on aging precipitation behavior and microstructure of AlCuMnZr alloy was studied by microhardness tester and transmission electron microscopy.The results show that the Mg and Si addition can significantly improve the aging hardness of the alloy and ensure good thermal stability.The peak hardness of the Al5.5Cu0.25Mg0.3Mn0.2Zr0.15Si alloy can reach 156.3 HV0.2 after solution treatment at 540℃for 7 h and aging at 175℃for 24 h.The addition of Mg refines the size of theθ′phase in the AlCuMnZr alloy and increases the number density of theθ′phase,makes its distribution more disperse and uniform.However,after the addition of Si,due to the precipitation ofσphase and Q phase and the segregation of Si around theθ′phase,the size and the coarsening speed of theθ′phase precipitates are reduced.However,after a long time of thermal exposure at 225℃,due to the disappearance of Si segregation,part of theθ′phases will be coarsened and the thermal stability of the alloy will be reduced.

关 键 词：AlCuMnZr合金 热稳定性 θ′相 微合金化 

分 类 号：TG146.2[一般工业技术—材料科学与工程]