大粒径Ti6Al4V粉末激光选区熔化成形工艺研究  

Selective Laser Melting Process of Large-Size Ti6Al4V Powder

作　　者：王宁 黎振华[1] 姚碧波 滕宝仁 Wang Ning;Li Zhenhua;Yao Bibo;Teng Baoren(School of Materials Science&Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;School of Mechanical and Electrical Engineering,Kunming Universityof Science and Technology,Kunming 650500,Yunnan,China)

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]昆明理工大学机电工程学院,云南昆明650500

出　　处：《中国激光》2024年第20期188-198,共11页Chinese Journal of Lasers

基　　金：云南省重大科技专项(202202AG050007);云南省基础研究重点项目(202101AS070017)。

摘　　要：激光选区熔化通常使用粒径为15~53μm的球形粉末,其制备时收得率低,成本较高,导致激光选区熔化成形时的成本高昂。粒径100μm以上的大粒径粉末收得率高,价格低廉,随着激光器功率的不断提高,大粒径粉末在激光选区熔化中的应用成为可能。以常用的Ti6Al4V合金为对象,研究了100~200μm大粒径Ti6Al4V粉末在铺粉层厚为120μm的条件下的激光选区熔化成形,通过数值模拟与实验研究的结合,研究了激光功率、扫描速度和扫描间距等工艺参数对激光选区熔化成形的影响,优化了成形工艺参数,并获得了成形速率快、致密度高和性能优良的试样。结果表明,当激光功率为370 W、扫描速度为1050 mm/s和扫描间距为0.10 mm时,制备的试样致密度达到99.64%,拉伸强度、屈服强度和延伸率分别达到1197 MPa、1112 MPa和8.2%,成形速率达到12.6 mm^(3)/s。Objective Spherical powders with particle sizes of 15‒53μm are usually employed in selective laser melting(SLM)process.The difficulty in producing SLMed parts results in high costs.Large particle size powders with particle sizes of over 100μm are comparatively easier to produce and inexpensive.Hence,the application of large-size powders in the SLM process reduces the cost of the SLMed parts because high-power lasers are available.Additionally,the use of large-size powders for high layer-thickness SLM can significantly reduce the manufacturing costs and enhance efficiency.However,the process is challenging,owing to the potential defects associated with the SLM of high layer-thickness large-size powders,which ultimately results in lower density and inferior mechanical properties.Research on the large-size powder SLM is still in its early stages,and the process parameters are not optimized.In this study,large-size Ti6Al4V powder with a particle size of 100‒200μm is used in a SLM process to fabricate samples with a layer thickness of 120μm.The effects of the laser power,scanning speed,and hatch spacing on the SLM process,defects,microstructures,and properties of the fabricated samples are investigated based on the results of numerical simulations and experiments.The process parameters are optimized,and high-density samples are further analyzed to explore their microstructure and mechanical properties.Hence,this study provides guidance for the application of large-size Ti6Al4V powder in the SLM process.Methods The ANSYS software is used to simulate and track the temperature field of a single layer and calculate the size of the molten pool.Ti6Al4V powder with a particle size of 100‒200μm,produced via the gas atomization method,is employed to fabricate the SLMed parts.The process parameters are:a layer thickness of 120μm,laser power of 340 W to 370 W,and scanning speed of 800 mm/s to 1100 mm/s.Samples and tensile blocks are fabricated via laser scanning with an interlayer rotation of 67°,and the parameters

关 键 词：激光选区熔化 大粒径粉末 TI6AL4V 高层厚 工艺参数 

分 类 号：TN249[电子电信—物理电子学]