TiVNbTa高熵合金球形粉末制备及选区激光熔化成形  

Spherical powder preparation and selective laser melting of TiVNbTa refractory high-entropy alloy

作　　者：龙雁[1] 蒋兆霖 杨继荣 彭海燕 孟文星 王芬[1] LONG Yan;JIANG Zhaolin;YANG Jirong;PENG Haiyan;MENG Wenxing;WANG Fen(National Engineering Research Center of Net-Shape Forming for Metallic Materials,School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,China;School of Mechatronic Engineering,Guangdong Polytechnic Normal University,Guangzhou 510635,China)

机构地区：[1]华南理工大学机械与汽车工程学院,国家金属材料近净成形工程技术研究中心,广州510640 [2]广东技术师范大学机电学院,广州510635

出　　处：《中国有色金属学报》2024年第4期1140-1153,共14页The Chinese Journal of Nonferrous Metals

基　　金：广东省自然科学基金资助项目(2021A1515012469,2023A1515011199);广州市基础研究计划资助项目(202102080463)。

摘　　要：利用氢化脱氢、机械球磨、等离子体球化技术成功制备了TiVNbTa难熔高熵合金球形粉末,并采用选区激光熔化(SLM)技术将此球形粉末制备成TiVNbTa难熔高熵合金块体试样,研究不同SLM工艺参数对合金显微组织和力学性能的影响。结果表明:所制备的粉末球形度高、分散良好,平均粒度为48μm;SLM成形的TiVNbTa难熔高熵合金具有超细晶组织,其熔池心部为胞状晶区,熔池边缘为柱状晶区。随着激光功率的增加,合金的压缩屈服强度整体变化不大,但塑性应变呈下降趋势;然而,随着扫描速率的增加,合金的压缩屈服强度和塑性应变持续下降。当激光功率为175 W、扫描速率为400 mm/s时,沉积态合金具有最低的孔隙率,XOY面和YOZ面的孔隙率分别降低至0.26%和1.42%,压缩屈服强度σ_(0.2)为1001 MPa,最大抗压强度σ_(bc)为1741 MPa,塑性应变ε_(p)为10.0%。TiVNbTa refractory high-entropy alloy spherical powder was successfully prepared using hydrogenation-dehydrogenation,ball milling and plasma spheroidization techniques.Subsequently,using the spheroidized powder,the TiVNbTa refractory high-entropy alloy bulk samples were fabricated via the selective laser melting(SLM)process.The microstructure and mechanical properties of the samples were analyzed to investigate the impact of different SLM process parameters.The results reveal that the spheroidized powder,with an average particle size of 48μm,exhibits excellent dispersion and good sphericity;the SLM-deposited alloy has ultrafine-grained microstructure,characterized by a cellular zone in the center of the melting pool and a columnar zone at the pool edges.Increasing the laser power results in a relatively stable compression yield strength,while decreasing the plastic strain.However,increasing the scanning speed leads to continual decreases in both compression yield strength and plastic strain.The alloy deposited at a laser power of 175 W and scanning speed of 400 mm/s exhibits the lowest porosity.Specifically,the porosity values are 0.26%and 1.42%in the XOY and YOZ planes,respectively.The compression yield strength(σ_(0.2))of the sample reaches 1001 MPa,the compressive strength(σ_(bc))reaches1741 MPa,and the plastic strain(ε_(p))reaches 10.0%.

关 键 词：TiVNbTa难熔高熵合金 氢化脱氢 等离子体球化 激光选区熔化 显微组织 力学性能 

分 类 号：TG665[金属学及工艺—金属切削加工及机床]