On the Martensitic Transformation Temperatures and Mechanical Properties of NiTi Alloy Manufactured by Selective Laser Melting: Effect of Remelting  

作　　者：Jian-Bin Zhan Yan-Jin Lu Jin-Xin Lin 

机构地区：[1]College of Chemistry and Materials Science,Fujian Normal University,Fuzhou 350007,China [2]Key Laboratory of Optoelectronic Materials Chemistry and Physics,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China

出　　处：《Acta Metallurgica Sinica(English Letters)》2021年第9期1223-1233,共11页金属学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51801198);the Funds of Scientific and Technological Plan of Fujian Province(No.2020Y0083);the National Key Technologies Research and Development Program of China(2016YFC1100502);the Joint Funds of Scientific and Technological Innovation Program of Fujian Province(No.2017Y9059);the Natural and Science Foundation of Fujian Province(No.2019I0027);the Funds of Scientific and Technological Plan of Fujian Province(No.2020L3026)。

摘　　要：In this study, the infl uence of laser remelting on the relative density, martensitic transformation temperatures(MTTs), and mechanical properties of a NiTi alloy fabricated by selective laser melting(SLM) at a laser power between 15 and 75 W were investigated. A relative alloy density of approximately 99% was achieved in the power range of 45–60 W corresponding to the forming energy density range of 65.45–87.27 J/mm3. The MTTs increased with the increase in the energy density;thus, the initial contents of the B2 and B19′ phases of the SLM-produced NiTi alloy can be tailored by the utilized technique. However, the number of defects such as metallurgical pores and microcracks considerably increased at higher energy densities(> 87.27 J/mm3). Interestingly, the concentration of these defects was reduced by remelting in the energy density range of 21.82–65.45 J/mm3, while the alloy relative density increased to 99.7% ± 0.1% at a remelting energy density of 65.45 J/mm3. The results of tensile testing revealed that when the remelting energy was 75% or 100% of the forming energy input, the ultimate tensile strength and elongation of the alloy significantly increased. Therefore, the remelting strategy represents a promising route for manufacturing NiTi alloys with desired MTT ranges and mechanical properties.

关 键 词：Selective laser melting NiTi alloy Laser remelting Martensitic transformation temperature 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TG146.15[一般工业技术—材料科学与工程]