Sc对铸造Al-Li合金组织及力学性能的影响  

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

作　　者：张亮[1] 张深 杨东辰 吴国华[1,2] ZHANG Liang;ZHANG Shen;YANG Dongchen;WU Guohua(National Engineering Research Center of Light Alloy Net Forming,Shanghai Jiao Tong University,Shanghai 200240,China;State Key Laboratory of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学轻合金精密成型国家工程研究中心,上海200240 [2]上海交通大学金属基复合材料国家重点实验室,上海200240

出　　处：《铸造技术》2024年第5期419-424,共6页Foundry Technology

基　　金：国家自然科学基金(51821001,51871148)。

摘　　要：铸造Al-Li合金可用于成型复杂薄壁构件,在航空航天、国防军工等领域具有广阔的应用前景。细化铸造Al-Li合金组织,提高合金强塑性对其实际应用具有重要意义。本文通过金属型铸造制备不同Sc含量的Al-2Li-2Cu-0.5Mg-xSc合金,分析了Sc含量对合金组织及力学性能的影响规律。结果表明,随着Sc含量逐渐增加,合金晶粒由树枝晶向近等轴晶转变,晶粒尺寸逐渐减小。δ'(Al_(3)Li)相倾向于以Al_(3)Sc相为形核核心,形成Al_(3)(Li, Sc)复合粒子,这些粒子在变形过程中不易被位错切过,减少了Al_(3)Li粒子引起的共面滑移。当添加0.3%Sc(质量分数)时,合金具有较好的综合力学性能,经过175℃/32 h的峰值时效处理后,屈服强度、抗拉强度和伸长率分别可以达到381.3 MPa、449.5 MPa和5.8%。Cast Al-Li alloys can be used to shape complex thin-walled components and currently have broad application prospects in aerospace,military and other fields.Refining the microstructure and improving the strength and plasticity of cast Al-Li alloys is highly important for practical applications.In this work,Al-2Li-2Cu-0.5Mg-xSc alloys containing different Sc contents were prepared by metal mold casting,and the effects of the Sc content on the microstructure and mechanical properties of the alloys were analysed.The results indicate that as the Sc content gradually increases,the alloy grains transform from dendrites to near-equiaxed grains,and the grain size gradually decreases.Theδ′(Al_(3)Li)phase tends to nucleate with the Al_(3)Sc phase,forming Al(3)(Li,Sc)composite particles that are not easily cut by dislocations during deformation,reducing the coplanar slip caused by Al3Li particles.When 0.3 wt.%Sc is added,the alloy has good comprehensive mechanical properties,and the yield strength,tensile strength and elongation can reach 381.3 MPa,449.5 MPa and 5.8%,respectively,after the peak aging treatment at 175℃/32 h.

关 键 词：铸造Al-Li合金 Sc含量 微观组织 力学性能 

分 类 号：TG146.451[一般工业技术—材料科学与工程] TG113.25[金属学及工艺—金属材料]