Crack elimination and strength enhancement mechanisms of selective laser melted Si-modified Al−Mn−Mg−Er−Zr alloy  

激光选区熔化Si改性Al−Mn−Mg−Er−Zr合金裂纹消除及强化机理

作　　者：Jiang YU Yao-xiang GENG Hong-bo JU Zhi-jie ZHANG Jun-hua XU 于江;耿遥祥;鞠洪博;张志杰;许俊华(江苏科技大学材料科学与工程学院,镇江212100;Department of Mechanical Engineering,CEMMPRE-Centre for Mechanical Engineering Materials and Processes,University of Coimbra,Coimbra,Portugal)

机构地区：[1]School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212100,China [2]Department of Mechanical Engineering,CEMMPRE-Centre for Mechanical Engineering Materials and Processes,University of Coimbra,Coimbra,Portugal

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第8期2431-2441,共11页中国有色金属学报（英文版）

基　　金：the National Natural Science Foundation of China(Nos.51801079,52001140);the Portugal National Funds through FCT Project(No.2021.04115).

摘　　要：In order to increase the processability and process window of the selective laser melting(SLM)-fabricated Al−Mn−Mg−Er−Zr alloy,a novel Si-modified Al−Mn−Mg−Er−Zr alloy was designed.The effect of Si alloying on the surface quality,processability,microstructure,and mechanical properties of the SLM-fabricated alloy was studied.The results showed that introducing Si into the Al−Mn−Mg−Er−Zr alloy prevented balling and keyhole formation,refined the grain size,and reduced the solidification temperature,which eliminated cracks and increased the processability and process window of the alloy.The maximum relative density of the SLM-fabricated Si/Al−Mn−Mg−Er−Zr alloy reached 99.6%.The yield strength and ultimate tensile strength of the alloy were(371±7)MPa and(518±6)MPa,respectively.These values were higher than those of the SLM-fabricated Al−Mn−Mg−Er−Zr and other Sc-free Al−Mg-based alloys.为了提升激光选区熔化(SLM)成形Al−Mn−Mg−Er−Zr合金的成形性和工艺窗口,应用SLM技术制备Si改性的Al−Mn−Mg−Er−Zr合金,系统研究Si合金化对合金表面质量、成形性、显微组织和力学性能的影响。结果表明,Si的合金化能有效抑制合金的表面球化现象及未熔合孔的产生,细化合金的晶粒尺寸,降低合金的凝固温度,并形成Al−Mg2Si低熔点共晶组织,从而有效抑制合金成形过程中热裂纹的产生,提升合金的成形性和工艺窗口。SLM成形Si/Al−Mg−Mn−Er−Zr合金的最大相对密度为99.6%。该SLM成形合金的屈服和抗拉强度分别为(371±7)MPa和(518±6)MPa,高于目前报道的SLM成形Al−Mg−Mn−Er−Zr及其他SLM成形非Sc改性Al−Mg基合金。

关 键 词：selective laser melting Al−Mn−Mg−Er−Zr−Si alloy surface roughness PROCESSABILITY mechanical properties 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG665[金属学及工艺—金属材料]