Sc对铸造Al-Li合金组织演变及力学性能的影响  

Effect of Sc on Microstructure Evolution and Mechanical Properties of Cast Al-Li Alloy

作　　者：胡奎深 邹鹑鸣[1] 孙少波[2] 肖瑞[2] 王宏伟[1] 魏尊杰[1] Hu Kuishen;Zou Chunming;Sun Shaobo;Xiao Rui;Wang Hongwei;Wei Zunjie(National Key Laboratory for Precision Hot Processing of Metals,Harbin Institute of Technology,Harbin 150006;Beijing Hangxing Technology Development Co.,Ltd.,Beijing 100006)

机构地区：[1]哈尔滨工业大学金属精密热加工国家级重点实验室,哈尔滨150006 [2]北京航星机器制造有限公司,北京100006

出　　处：《特种铸造及有色合金》2024年第1期74-79,共6页Special Casting & Nonferrous Alloys

基　　金：国防基础科研计划资助项目(JCKY2020204B015)。

摘　　要：研究了Sc合金化对铸造Al-Li-Cu-Mg合金组织演变和力学性能的影响。结果表明,添加0.2%的Sc对合金晶粒细化效果显著,同时Sc合金化还会促进时效态合金基体中核/壳状复合结构粒子的析出。在室温及200℃下拉伸时,含Sc合金显示出更优异的强塑匹配性,这归因于细化强化和沉淀强化(δ′-Al3Li相及核/壳状复合结构粒子)的综合作用;当拉伸试验温度升高至300℃时,晶界弱化效应使含Sc合金的强度急剧下降而伸长率显著提升。断口形貌观察发现,基准合金室温的断裂模式为准解理断裂,温度对合金的断裂模式无显著影响;含Sc合金室温的断裂模式为典型的沿晶断裂,200℃下该合金的断裂模式转变为沿晶和穿晶混合断裂,拉伸试验温度提高至300℃,断裂模式最终变为微孔聚集型断裂。The effects of Sc alloying on microstructure evolution and mechanical performance of Al-Li-Cu-Mg alloy were investigated. The results indicate that 0. 2% Sc addition has significant effect on grain refinement of the alloys.Meanwhile, Sc alloying obviously enhances the precipitation density of the core/shell composite particles in as-aged alloy. Sc-containing alloy exhibits excellent matching of strength and plasticity at room temperature and 200 ℃, which is attributed to the synergy of the grain refining strengthening and precipitation strengthening(δ′-Al3Li phase and core/shell composite structure particles). When the temperature is increased to 300 ℃, the strength of Sc-containing alloy is decreased sharply, while elongation is increased significantly due to the grain boundary weakening effect. The fracture morphology observation reveals that the fracture mode of the reference alloy presents quasi cleavage fracture at room temperature, which is stable with the variation of temperature. The fracture mode of Sc-containing alloy at room temperature is characterized by intergranular fracture, which is transformed to mixing fracture of intergranular and transgranular at 200 ℃, and microporous aggregation fracture at 300 ℃.

关 键 词：铸造Al-Li合金 Sc合金化 力学性能 断裂模式 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG156.93[金属学及工艺—金属材料]