Ag、Sc联合微合金化对Al-Cu-Li合金组织及高温性能的影响  

Effect of Ag and Sc combined microalloying on microstructure and high-temperature properties of Al-Cu-Li alloy

作　　者：郝时嘉 李国爱 刘惠 罗开军 陈宗强 李占强 Hao Shijia;Li Guoai;Liu Hui;Luo Kaijun;Chen Zongqiang;Li Zhanqiang(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院,北京100095

出　　处：《金属热处理》2025年第4期80-84,共5页Heat Treatment of Metals

摘　　要：通过250℃、300℃下的力学性能测试和显微组织分析,研究了Ag、Sc元素微合金化对Al-Cu-Li合金组织和高温性能的影响。结果表明:Ag、Sc元素联合微合金化的Al-Cu-Li合金在250℃下拥有较高的高温力学性能,其抗拉强度、屈服强度和伸长率分别为340 MPa、297 MPa和11.1%;用Sc代替Ag微合金化时Al-Cu-Li合金在300℃下拥有优异的力学性能,其抗拉强度、屈服强度和伸长率分别为325 MPa、292 MPa和9.3%。250℃时,高温稳定强化相T 1相在晶界和晶内的大量析出是提高Al-Cu-Li合金的高温强度的主要原因。Ag、Sc联合微合金化会细化Al-Cu-Li合金晶粒,用Sc代替Ag微合金化后,Al-Cu-Li合金铸态组织得到进一步细化,细化的晶粒更有利于再结晶,高温保温促进再结晶晶粒粗化,二次中温热轧使再结晶晶粒再次变形,使合金在300℃下拥有较好的高温强塑性匹配。Effect of Ag and Sc combined microalloying on microstructure and high-temperature properties of Al-Cu-Li alloys was studied through mechanical property testing at 250℃and 300℃and microstructure analysis.The results show that the Al-Cu-Li alloy with Ag and Sc combined microalloying has high high-temperature mechanical properties at 250℃,and its tensile strength,yield strength and elongation are 340 MPa,297 MPa and 11.1%,respectively.Microalloying with Sc instead of Ag makes Al-Cu-Li alloy have excellent mechanical properties at 300℃,and its tensile strength,yield strength and elongation are 325 MPa,292 MPa and 9.3%,respectively.The main reason for improving the high-temperature strength of the Al-Cu-Li alloy at 250℃is the large amount of the high temperature stable strengthening T 1 precipitates at the grain boundary and inside the grain.The Ag and Sc combined microalloying can refine the grain of the Al-Cu-Li alloy,and the as-cast microstructure of the Al-Cu-Li alloy can be further refined when microalloying with more Sc instead of Ag.The refined grain is more conducive to recrystallization,the high temperature holding promotes the coarsening of the recrystallized grain,and the recrystallized grain is deformed again by the secondary medium temperature hot rolling,so that the alloy has better high temperature strength and plasticity matching at 300℃.

关 键 词：AL-CU-LI合金 Ag、Sc联合微合金化 人工时效 高温力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]