LPBF工艺参数对Inconel 718成形缺陷的影响  

Effect of LPBF process parameters on forming defects of Inconel 718 alloy

作　　者：段现银 李俊 段伟 容芷君[1] 林志雄 DUAN Xianyin;LI Jun;DUAN Wei;RONG Zhijun;LIN Zhixiong(Key Laboratory of Metallurgical Equipment and Control Technology,Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China;Institute of Intelligent Processing Technology,National Innovation Institute of Digital Design and Manufacturing,Wuhan 430074,China)

机构地区：[1]武汉科技大学冶金装备及其控制教育部重点实验室,湖北武汉430081 [2]国家数字化设计与制造创新中心智能加工技术研究所,湖北武汉430074

出　　处：《粉末冶金工业》2024年第4期126-133,共8页Powder Metallurgy Industry

基　　金：国家自然科学基金资助项目(52175359);湖北省重点研发计划资助项目(2022BAA059)

摘　　要：激光粉末床熔融(Laser Powder Bed Fusion,LPBF)技术具有复杂结构快速成形的显著优势,在诸多领域应用广泛。然而,LPBF复杂的工艺特点使其成形件易出现气孔和未熔合等孔隙缺陷。针对航空航天、船舶和能源等领域广泛应用的Inconel 718合金,开展了激光粉末床熔融实验与数值模拟研究。分析了激光功率、扫描间距和扫描速度等关键工艺参数对成形缺陷的影响,结合实验检测与离散元模拟,讨论了气孔和未熔合等孔隙缺陷的产生机制。研究结果表明:当激光扫描间距减小时,试样纵截面孔隙率降低;激光扫描速度增加时,试样边缘未熔合缺陷增加;激光功率增加时,试样内部气孔数量显著减少,同时在熔道边缘出现不规则未熔合缺陷。在激光扫描间距为80μm、激光扫描速度为500 mm/s、激光功率为200 W时,可以得到熔道宽度合适,试样成形缺陷较少、孔隙率较低的试样。Laser Powder Bed Fusion(LPBF)technology has significant advantages in rapid prototyping of complex structures and is widely used in many fields.However,the complex process characteristics of LPBF make its formed parts prone to pore defects such as porosity and lack of fusion.Laser powder bed melting experiments and numerical simulations were conducted on Inconel 718 alloy which was widely used in aerospace,shipbuilding,and energy fields.This article combined experimental forming and numerical simulation methods to conduct research.The discrete element method was used to establish a random powder bed model,and the dynamic flow evolution process of the LPBF melt pool was simulated through computational fluid dynamics methods.This article analyzed the influence of key process parameters such as laser power,scanning spacing,and scanning speed on forming defects.Combining experimental detection and discrete element simulation,the mechanism of pore defects such as porosity and lack of fusion was discussed,and the optimal process parameter data was obtained through analysis.When the laser scanning spacing decreases,the porosity of the longitudinal section of the sample decreases.When the laser scanning speed increases,the number of non fusion defects at the edges of the sample increases.When the laser power increases,the number of pores inside the sample significantly decreases,and irregular non fusion defects appear at the edge of the melt.At a laser scanning interval of 80μm.When the laser scanning speed is 500 mm/s and the laser power is 200 W,a sample with appropriate melt width,fewer forming defects,and lower porosity can be obtained.

关 键 词：金属激光粉末床熔融 Inconel 718合金 工艺参数 孔隙缺陷 离散元模拟 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TF124[冶金工程—粉末冶金]