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

doi:10.3901/JME.2016.04.060

Abstract

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

CLC Number:

TG142

BAI Xingwang, ZHANG Haiou, ZHOU Xiangman, WANG Guilan. Electromagneto-fluid Coupling Simulation of Arc Rapid Prototyping Process with External High-frequency Magnetic Field[J]. Journal of Mechanical Engineering, 2016, 52(4): 60-66.

References

[1] KARUNAKARAN K P,SURYAKUMAR S,PUSHPA V,et al. Low cost integration of additive and subtractive processes for hybrid layered manufacturing[J]. Robotics and Computer Integrated Manufacturing,2010,26(5)：490-499.
[2] WANG F,WILLIAMS S,COLEGROVE P,et al. Microstructure and mechanical properties of wire and arc additive manufactured Ti-6Al-4V[J]. Metallurgical and Materials Transactions A,2012,44 (2)：968-977.
[3] XIONG J,ZHANG G,HU J,et al. Bead geometry prediction for robotic GMAW-based rapid manufacturing through a neural network and a second-order regression analysis[J]. Journal of Intelligent Manufacturing,2014,25(2)：157-163.
[4] 符卫,胡绳荪,尹玉环. 熔滴过渡对脉冲熔化极氩弧焊快速成形的影响[J]. 机械工程学报,2009,45(4)：95-99.
FU Wei,HU Shengsun,YIN Yuhuan. Effect of droplet transition on rapid prototyping by P-MIG[J]. Journal of Mechanical Engineering,2009,45(4)：95-99.
[5] SPENCER J D,DICKENS P M,WYKES C M. Rapid prototyping of metal parts by three-dimensional welding[J]. Proceedings of the Institution of Mechanical Engineers Part B-Journal of Engineering Manufacture,1998,212(3)：175-182.
[6] 陶文琉,赵升吨,林文捷. A356铝合金半固态浆料电磁搅拌法制备过程的数值模拟[J]. 机械工程学报,2012,48(14)：51-57.
TAO Wenliu,ZHAO Shengdun,LIN Wenjie. Numerical simulation on A356 aluminum alloy semi-solid slurry preparation with electromagnetic stirring[J]. Journal of Mechanical Engineering,2012,48(14)：51-57.
[7] YU Y D,LI C X. The effect of alternative low frequency electromagnetic field on the solidification microstructure and mechanical properties of ZK60 alloys[J]. Materials & Design,2013,44(3)：17-22.
[8] LIM Y,YU X,CHO J,et al. Effect of magnetic stirring on grain structure refinement：Part I-Autogenous nickel alloy welds[J]. Science and Technology of Welding & Joining,2010,15 (7)：583-589.
[9] 王艳,边秀房,徐昌业,等. 直流磁场作用下Al-18Si合金的凝固行为[J]. 金属学报,2000,36(2)：159-161.
WANG Yan,BIAN Xiufang,XU Changye,et al. Solidification of Al-18Si alloy under direct magnetic field[J]. Acta Metallurgical Sinica,2000,36(2)：159-161.
[10] WANG S,ZHAO X,XIAO N,et al. High magnetic field influence on the widmanstätten transformation in high purity Fe-0.36 wt% C alloy[J]. Journal of Materials Science & Technology,2012,28(6)：552-557.
[11] YIN X,GOU J,ZHANG J,et al. Numerical study of arc plasmas and weld pools for GTAW with applied axial magnetic fields[J]. Journal of Physics D：Applied Physics,2012,45(28)：285203.
[12] LIN Z Q,LI Y B,WANG Y S,et al. Numerical analysis of a moving gas tungsten arc weld pool with an external longitudinal magnetic field applied[J]. The International Journal of Advanced Manufacturing Technology,2005,27(3-4)：288-295.
[13] TORREY M D,MJOLSNESS R C,STEIN L R. NASA-VOF3D：A three-dimensional computer program for incompressible flows with free surfaces[J]. NASA STI/Recon Technical Report N,1987,88(7)：10288.
[14] BENNON W,INCROPERA F. A continuum model for momentum, heat and species transport in binary solid-liquid phase change systems—I. Model formulation[J]. International Journal of Heat and Mass Transfer,1987,30(10)：2161-2170.
[15] BRACKBILL J,KOTHE D B,ZEMACH C. A continuum method for modeling surface tension[J]. Journal of Computational Physics,1992,100(2)：335-354.
[16] ZHANG W. Heat and fluid flow in complex joints during gas metal arc welding,Part I：Numerical model of fillet welding[J]. Journal of Applied Physics,2004,95(9)：5210-5218.
[17] XU G,HU J,TSAI H L. Three-dimensional modeling of arc plasma and metal transfer in gas metal arc welding[J]. International Journal of Heat and Mass Transfer,2009,52(7)：1709-1724.
[18] GOLDAK J,CHAKRAVARTI A P,BIBBY M. A new finite element model for welding heat sources[J]. Metallurgical Materials Transaction B,1984,15B(2)：300-305.
[19] 饶政华. 熔化极气体保护焊传热与传质过程的数值研究[D]. 长沙：中南大学,2010.
RAO Zhenghua. Modeling of heat and mass transfer during gas metal arc welding[D]. Changsha：Central South University,2010.