High strength Al-Cu-Mg based alloy with synchronous improved tensile properties and hot-cracking resistance suitable for laser powder b e d fusion  

作　　者：Q.Z.Wang N.Kang X.Lin M.EL Mansori W.D.Huang 

机构地区：[1]State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China [2]Arts et Metiers Institute of Technology,MSMP,HESAM Université,Châlons-en-Champagne F-51006,France [3]Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design,MIIT China,Northwestern Polytechnical University,Xi’an 710072,China [4]Texas A&M Engineering Experiment Station,Institute for Manufacturing Systems,College Station,TX 77843,USA

出　　处：《Journal of Materials Science & Technology》2023年第10期155-170,共16页材料科学技术（英文版）

基　　金：supported by the National Key R&D Program of China(No.2016YFB1100100);the National Natural Sci-ence Foundation of China(No.52005411);the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(No.2020-TZ-02).One of the authors,Q.Z.Wang,is grateful for the fi-nancial supports provided by the China Scholarship Council(Grant No.202106290075).

摘　　要：In present work,a novel crack-free Al-Cu-Mg-Si-Ti alloy with synchronous improved tensile properties and hot-cracking resistance was proposed and successfully manufactured by laser powder bed fusion(LPBF).The microstructure evolution behaviors and the corresponding strengthening mechanisms were investigated in detail.The LPBF-processed Al-Cu-Mg-Si-Ti alloy presents a heterogeneous microstructure consisting of ultrafine equiaxed grains(UFGs)at the boundary and coarse columnar grains(CGs)at the center of the single molten pool.Pre-precipitated D022-Al 3 Ti particles were found to act as the nuclei to refine the grains at the boundary of the molten pool during solidification process,which is attributed to the low cooling rate providing the sufficient incubation time for the precipitation of D022-Al 3 Ti.There are two orientation relationships(ORs)betweenα-Al and D022-Al 3 Ti,i.e.[001]α-Al//[001]D022-Al3Ti,(200)α-Al//(200)D022-Al3Ti and[1¯1¯2]α-Al//[¯111]D022-Al3Ti,(1¯11)α-Al//(¯11¯2)D022-Al3Ti,which are two of the eight ORs predicted with the E2EM model.Refined grains in present alloy,no matter for UFGs or CG,exhibited high critical hot-cracking stress,which means a strong hot-cracking resistance.Dual-nanoprecipitation of Cu-,Mg-,and Si-rich Q’and S’phases was introduced to enhance the mechanical performance ofα-Al matrix.The as-built sample exhibits superior tensile properties,with the yield strength(YS)of 473±8 MPa,ultimate tensile strength(UTS)of 541±2 MPa and elongation(EI)of 10.9%±1.2%.

关 键 词：Laser powder bed fusion High strength Al-Cu-Mg alloys Duplex microstructure Precipitation Tensile properties 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TG146.21[一般工业技术—材料科学与工程]