航空学报 > 2019, Vol. 40 Issue (12): 423089-423089   doi: 10.7527/S1000-6893.2019.23089

激光功率与底面状态对选区激光熔化球化的影响

冯一琦1, 谢国印2, 张璧3, 乔国文1, 高尚1, 白倩1   

  1. 1. 大连理工大学 机械工程学院, 大连 116024;
    2. 中国航空发动机集团 西安航空发动机有限公司, 西安 710021;
    3. 南方科技大学 机械与能源工程系, 深圳 518055
  • 收稿日期:2019-04-16 修回日期:2019-05-07 出版日期:2019-12-15 发布日期:2019-06-24
  • 通讯作者: 白倩 E-mail:baiqian@dlut.edu.cn
  • 基金资助:
    国家自然科学基金(51605077);深圳市协同创新计划(GJH20180411143506667);深圳市基础研究布局(JCYJ20170817111811303);深圳市基础研究计划(JCYJ20180504165824643)

Influence of laser power and surface condition on balling behavior in selective laser melting

FENG Yiqi1, XIE Guoyin2, ZHANG Bi3, QIAO Guowen1, GAO Shang1, BAI Qian1   

  1. 1. School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China;
    2. Xi'an Aero Engine Ltd., Aero Engine Corporation of China, Xi'an 710021, China;
    3. Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, China
  • Received:2019-04-16 Revised:2019-05-07 Online:2019-12-15 Published:2019-06-24
  • Supported by:
    National Natural Science Foundation of China (51605077); Collaborative Innovation Program of Shenzhen (GJH20180411143506667); Fundamental Research Layout of Shenzhen (JCYJ20170817111811303); Fundamental Research Program of Shenzhen (JCYJ20180504165824643)

摘要: 为研究激光功率与底面状态对选区激光熔化熔池流动的影响,基于离散单元法建立了选区激光熔化铺粉模型,采用粒径分布与实验相符的马氏体时效钢粉末分别铺展到平坦底面和增材底面上,将计算获得的粉末分布导入到基于有限体积法建立的选区激光熔化熔池计算流体力学模型中,研究激光功率和基板底面粗糙度对熔池流动和熔道表面形貌的影响。采用激光单道扫描实验验证铺粉模型和选区激光熔化模型。结果表明:随着激光功率的降低,单位长度的球化数量增加;由于增材底面使熔池润湿性变差,同时又对熔池流动行为产生扰动,使得增材粗糙底面上熔道的球化数量增加。选区激光熔化铺粉模拟及激光单道扫描模拟结果与实验结果吻合较好。本研究可为选区激光熔化工艺中工艺参数的选择提供理论指导。

关键词: 选区激光熔化, 球化现象, 离散元方法, 计算流体力学, 熔池流动

Abstract: This study proposes a Powder Spreading (PS) model and a Computational Fluid Dynamics (CFD) model to investigate the influence of laser power and surface condition on balling behavior for Selective Laser Melting (SLM). Metal powders are spread on a flat surface and an as-built surface. The simulated powder bed is then imported into a molten pool of the SLM-CFD model based on the finite volume method. The effect of laser power and substrate surface condition on the flow behavior of the molten pool and induced single track morphology are studied. To verify the PS and SLM-CFD models on both substrate surfaces, an SLM experiment is also conducted. The results show that the balling number decreases with the increase of laser power. Due to the poor wettability and disturbance in the molten pool induced by the as-built surface, the balling behavior on the as-built surface becomes more serious. The simulated results has a good agreement with experimental results. The study provides a theoretical guide to the selection of the processing parameters for SLM processes.

Key words: selective laser melting, balling behavior, discrete element method, computational fluid dynamics, melt pool flow

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