应用激光, 2018, 38 (5): 742, 网络出版: 2018-12-18
选区激光熔化成形AlSi10Mg孔隙的产生与降低
Generation and Reduction of Porosity in AlSi10Mg Fabricated by Selective Laser Melting
选区激光熔化 数值模拟 扫描策略 孔隙 selective laser melting numerical simulation scanning strategy AlSi10Mg AlSi10Mg porosity
摘要
选区激光熔化是一种利用高能激光束选择性地熔化金属粉末, 进而直接制造复杂几何形状产品的增材制造技术。采用选区激光熔化技术成形AlSi10Mg样品, 通过改变扫描策略研究成形试样孔隙的分布与含量的变化; 借助ANSYS数值模拟, 从熔池特性的变化分析孔隙产生的原因。研究发现, 热量的过度累积会增加熔池的最高温度、液相时间和熔池尺寸, 降低熔池的冷却速度, 从而导致孔隙率增加; 隔层交替扫描和激光重熔扫描有效地降低了孔隙率, 孔隙分布均匀化; 激光重熔有助于成形高致密的铝合金零件。
Abstract
Selective laser melting is an additive manufacturing technique which directly fabricate complex geometrical parts by using a high energy laser beam to selectively melt metal powder.The AlSi10Mg samples were formed by selective laser melting technique, and the distribution and content of pores in the formed samples were studied by changing the scanning strategy. The cause of pores was investigated from the changes in the characteristics of the molten pool by ANSYS numerical simulation. The study found that excessive heat accumulation increased the maximum temperature of the molten pool, liquid phase time and molten pool size, and decreased the cooling rate of the molten pool, resulting in an increase in porosity. Interlayer alternate scanning and laser remelting scanning effectively reduced porosity, and uniformed pore distribution. Laser remelting helped shape high density aluminum alloy parts.
李保强, 李忠华, 刘斌, 蒯泽宙, 梁敏洁. 选区激光熔化成形AlSi10Mg孔隙的产生与降低[J]. 应用激光, 2018, 38(5): 742. Li Baoqiang, Li Zhonghua, Liu Bin, Kuai Zezhou, Liang Minjie. Generation and Reduction of Porosity in AlSi10Mg Fabricated by Selective Laser Melting[J]. APPLIED LASER, 2018, 38(5): 742.