• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2016, Vol. 52 ›› Issue (4): 60-66.doi: 10.3901/JME.2016.04.060

• 材料科学与工程 • 上一篇    下一篇

外加高频磁场下电弧快速成形过程的电磁-流体耦合数值模拟

柏兴旺1, 张海鸥2, 周祥曼2, 王桂兰3   

  1. 1. 南华大学机械工程学院 衡阳 421001;
    2. 华中科技大学机械科学与工程学院 武汉 430074;
    3. 华中科技大学材料科学与工程学院 武汉 430074
  • 出版日期:2016-02-15 发布日期:2016-02-15
  • 作者简介:柏兴旺(通信作者),男,1982年出生,博士,讲师。主要研究方向为金属增材制造过程的工艺设备与数值模拟。E-mail:pancard@126.com;张海鸥,男,1955年出生,博士,教授,博士研究生导师。主要研究方向为航空航天零件的增材制造。E-mail:zholab@mail.hust.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(51505210,51374113)

Electromagneto-fluid Coupling Simulation of Arc Rapid Prototyping Process with External High-frequency Magnetic Field

BAI Xingwang1, ZHANG Haiou2, ZHOU Xiangman2, WANG Guilan3   

  1. 1. School of Mechanical Engineering, University of South China, Hengyang 421001;
    2. School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074;
    3. School of Material Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074
  • Online:2016-02-15 Published:2016-02-15

摘要: 外加电磁作用是改善电弧快速成形零件组织和性能的有效方式之一。为了揭示高频磁场对熔池传热、对流和形态的影响机理,采用有限元电磁计算和有限体积流体分析耦合的方法,建立电磁场、熔池温度场和流体流动场分析的三维模型,分析工件和熔池中高频电磁力/热的分布特征,研究高频电磁力与表面张力、电弧力以及熔滴冲击共同作用下的熔池表面动态变形,对比分析有/无外加高频磁场情况下熔池温度分布和流体流动模式上的差异,并由此预测外加高频磁场对凝固组织和熔池形态的改变。结果表明,高频电磁力驱动熔池流体在垂直焊接方向的平面内形成单漩涡旋转对流,有利于熔断枝晶细化晶粒,熔池表面形状向远离线圈一侧倾斜,熔宽增大。金相和焊道横截面测试证实了上述模拟结果。

关键词: 高频磁场, 快速成形, 熔池流动, 数值模拟

Abstract: External electromagnetic field is an effective tool to improve the microstructure and properties of the components fabricated by arc rapid prototyping. To reveal the effect mechanism of high-frequency magnetic field on the heat transfer, convection and shape of weld pool, the coupling simulation of electromagnetic calculation by finite element method and fluid analysis by finite volume method is used, 3D models are developed for the analyses of electromagnetic field, temperature field and fluid flow field. The distributions of electromagnetic force and heat in workpiece and weld pool are investigated; the dynamic deformation of weld pool surface is calculated taking into account electromagnetic force, surface tension, arc pressure and droplet impingement. The temperature and flow fields of weld pool are compared between the cases with and without external magnetic field, thereby predicting the effect of high-frequency magnetic field on the microstructure and weld pool shape. The results indicate that single-vortex rotary convection is formed in the section perpendicular to welding direction when applying high-frequency transversal magnetic field. Convection carrying high-temperature metal imposes a tangential impingement on the bottom of melt pool, which melts dendrites and leads to refined grain. The melt pool profile slopes to the far side of coil, causing larger weld bead width. The simulation results have been confirmed by metallographic examination and macrograph of bead profile.

Key words: high-frequency magnetic field, numerical simulation, rapid prototyping, weld pool flow

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