Phase selection-oriented mechanical properties tailoring forβ-type TiNbZrTaSi alloy fabricated by laser powder bed fusion  

作　　者：Xuan Luo Tao Song Feng Wang Haizhou Lu Limei Kang Hongwei Ma Dongdong Li Annett Gebert Chao Yang 

机构地区：[1]National Engineering Research Center of Near-net-shape Forming for Metallic Materials,Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic Materials,South China University of Technology,Guangzhou 510640,China [2]State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China [3]Institute for Complex Materials,Leibniz Institute for Solid State and Materials Research Dresden,01069,Dresden,Germany [4]Guangzhou Railway Polytechnic,Guangzhou 510430,China

出　　处：《Advanced Powder Materials》2023年第3期77-87,共11页先进粉体材料（英文）

基　　金：supportedfinancially by the National Natural Science Foundation of China(No.U19A2085);the Key Basic and Applied Research Program of Guangdong Province(No.2019B030302010);the Science and technology innovation project of Guangdong special support plan (No. 2021TX06C111);the Optical Valley Science Research Project,WEHDZ (No. 2019001);the University Scientific Research Project ofGuangzhou Education Bureau (No. 202032783);the Special Project inKey-Area of the Universities in Guangdong Province (No.2020ZDZX2072);the Guangzhou Basic and Applied Basic ResearchFoundation (No. 202102080463);Xuan Luo acknowledges funding fromChina Scholarship Council (No. 202006150137).

摘　　要：The morphology and distribution of silicides inα/αþβtype titanium alloys impress on their properties.Nevertheless,the types of silicide precipitates and their formation mechanisms remain unclear inβ-type Ti–Nb–Zr–Ta alloys.In this study,we report the precipitation behavior of silicides formed upon aging treatment of a laser powder bed fusion(LPBF)-fabricatedβ-type Ti–34.5Nb–6.9Zr–4.9Ta–1.4Si(wt%,TNZTS)alloy.We further discuss their underlying formation mechanism and silicide selection-oriented mechanical properties tailoring for LPBF-fabricated TNZTS alloy.Two novel silicide precipitates were formed:a supersaturated Si–richβ–Ti matrix in the form of a network that can further transform into the(Ti,Zr)2Si(S2)phase with the increase of aging temperature;and a short,rod-like S2 precipitate adjacent to pre-existing dot-shaped S2.The former results from the aggregation of Si solute atoms towards to the dislocation walls/microbands and the subsequent precipitation reaction,while the latter arises from the considerable micro-strain around the phase boundary between the dotshaped S2 andβ-Ti owing to the large difference in their thermal expansion coefficients.The aging-treated TNZTS alloy exhibits a good combination of tensile strength(10835 MPa)and fracture strain(5.6%1.0%),which is attributed to precipitation strengthening,grain-boundary strengthening,and discontinuous intergranular silicide derived from phase selection.The obtained results provide a basis for the design and fabrication of biomedical Sicontainingβ-type Ti alloys with excellent mechanical properties.

关 键 词：Laser powder bed fusion β-type titanium alloys Silicide precipitates Microstructure Mechanical propertie 

分 类 号：TG1[金属学及工艺—金属学]