Numerical Simulation and Experimental Study of Microstructure Transformation of Droplet Hybrid Arc Additive Manufacturing for Aluminum Alloy

doi:10.3901/JME.2025.18.170

Abstract

Abstract: The additive manufacturing of aluminium alloy with arc as the heat source has the advantages of high efficiency, low cost and high material utilization, but it has the limitations of complex solidification process, unstable performance and difficulty in realizing active control. A macroscopic heat and mass transfer model coupled with a microscopic phase field model is used to calculate the solidification microstructure transition during the droplet hybrid arc additive manufacturing process for aluminum alloy. The Lorentz force, surface tension and arc pressure are considered in the model. The effects of droplets and arc on the molten pool during the deposition process are calculated, and the evolution of temperature field distribution is revealed. The results show that the microstructure at the bottom of the molten pool presents a columnar-grain structure, and gradually the nucleation conditions are satisfied in the liquid phase in the middle and upper part of the molten pool. The microstructure transformation from columnar to equiaxed grains occurs. In addition, the micro-segregation can be obviously observed. The concentration of solute elements is very high in the grain boundary zone, and the concentration in dendrite is low. Finally, in order to verify the numerical simulations, the metallographic and mechanical properties of the samples are tested. The metallographic observations and energy dispersive spectrometer (EDS) analysis results are in high agreement with the numerical simulations. The micro-tensile tests show that the tensile strength and elongation of the upper material in the deposition layer are higher than those of the bottom material in the melt pool.

Key words: additive manufacturing, droplet hybrid arc deposition, microstructure evolution, mechanical properties, aluminum alloy

CLC Number:

TH16

GENG Ruwei, ZHU Congcong, WEI Zhengying, MA Ninshu. Numerical Simulation and Experimental Study of Microstructure Transformation of Droplet Hybrid Arc Additive Manufacturing for Aluminum Alloy[J]. Journal of Mechanical Engineering, 2025, 61(18): 170-180.

References

[1] 张志强，勾青泽，路学成，等. 高强铝合金CMT+P电弧增材制造熔滴过渡行为[J]. 航空学报，2023，44(13)：427881. ZHANG Zhiqiang，GOU Qingze，LU Xuecheng，et al. Droplet transfer behavior of high strength aluminum alloy CMT+P arc additive manufacturing[J]. Acta Aeronautica et Astronautica Sinica，2023，44(13)：427881.
[2] 管仁国，娄花芬，黄晖，等. 铝合金材料发展现状、趋势及展望[J]. 中国工程科学，2020，22(5)：68-75. GUAN Renguo，LOU Huafen，HUANG Hui，et al. Development of aluminum alloy materials：Current status，trend，and prospects[J]. Strategic Study of CAE，2020，22(5)：68-75.
[3] AYARKWA K，WILLIAMS S，DING J. Assessing the effect of TIG alternating current time cycle on aluminium wire+arc additive manufacture[J]. Additive Manufacturing，2017，18：186-193.
[4] KHORASANI M，Loy J，GHASEMI A，et al. A review of Industry 4.0 and additive manufacturing synergy[J]. Rapid Prototyping Journal，2022(28)：1462-1475.
[5] 陈嘉伟，熊飞宇，黄辰阳，等. 金属增材制造数值模拟[J]. 中国科学：物理学力学天文学，2020，50：090007. CHEN Jiawei，XIONG Feiyu，HUANG Chenyang，et al. Numerical simulation on metallic additive manufacturing [J]. Sci. Sin. Phys. Mech. Astron.，2020，50：090007.
[6] 肖文甲，许宇翔，宋立军. 面向增材制造的熔池凝固组织演变的相场研究[J]. 力学学报，2021，53(12)：3252-3262. XIAO Wenjia，XU Yuxiang，SONG Lijun. Phase-field study on the evolution of microstructure of the molten pool for additive manufacturing[J]. Chinese Journal of Theoretical and Applied Mechanics，2021，53(12)：3252-3262.
[7] FRANCOIS M，SUN A，KING W，et al. Modeling of additive manufacturing processes for metals：Challenges and opportunities[J]. Curr. Opin. Solid State Mater. Sci.，2017，21：198.
[8] 吕飞阅，王磊磊，高转妮，等. CMT电弧增材制造过程电弧特性对熔滴过渡行为的影响机理研究[J]. 机械工程学报，2023，59(15)：267-281. Lü Feiyue，WANG Leilei，GAO Zhuanni，et al. Influence mechanism of arc characteristics on droplet transfer behavior in CMT-based additive manufacturing[J]. Journal of Mechanical Engineering，2023，59(15)：267-281.
[9] VENKATESH P，MORITZ S，ULRICH K，Understanding the mechanism of columnar-to-equiaxed transition and grain refinement in additively manufactured steel during laser powder bed fusion[J]. Additive Manufacturing，2023，73：103702.
[10] KELLER T，LINDWALL G，GHOSH S，et al. Application of finite element，phase-field，and CALPHAD-based methods to additive manufacturing of Ni-based superalloys[J]，Acta Materialia，2017，139：244-253.
[11] 耿汝伟，王林，魏正英，等. 铝合金熔滴复合电弧增材组织演化及外延生长特性研究[J]. 金属学报，2024，60(11)：1584-1594. GENG Ruwei，WANG Lin，WEI Zhengying，et al. Study on microstructure evolution and epitaxial growth characteristics of droplet and arc deposition additive manufacturing for aluminum alloy[J]. Acta Metall. Sin.，2024，60(11)：1584-1594.
[12] LI H，JIANG S，LU Y，et al. Columnar to equiaxed transition in additively manufactured CoCrFeMnNi high entropy alloy[J]. Materials & Design，2020，197：109262.
[13] DU J，WANG D，XU S. Gas tungsten arc welding assisted droplet deposition manufacturing of steel/lead bimetallic structures[J]. Journal of Materials Processing Technology，2021，292(1)：117069.
[14] 贺鹏飞，魏正英，杜军，等. 铝合金熔滴复合电弧沉积同步WC颗粒强化增材制造工艺研究[J]. 机械工程学报，2022，58(5)：258-267. HE Pengfei，WEI Zhengying，DU Jun，et al. Investigation of droplet+arc deposition additive manufacturing with WCP simultaneous reinforcement for aluminum alloy[J]. Journal of Mechanical Engineering，2022，58(5)：258-267.
[15] TSAO K，WU C. Fluid flow and heat transfer in GMA weld pools[J]. Welding Journal，1988，67(3)：70s-75s.
[16] SAHOO P，DEBROY T，MCNALLAN M. Surface tension of binary metal surface active solute systems under conditions relevant to welding metallurgy[J]. Metallurgical & Materials Transactions B，1988，19(3)：483-491.
[17] HAN S，CHO W，NA S，et al. Influence of driving forces on weld pool dynamics in GTA and laser welding[J]. Welding in the World，2013，57(2)：257-264.
[18] RAMIREZ J，BECKERMANN C，KARMA A，et al. Phase-field modeling of binary alloy solidification with coupled heat and solute diffusion[J]. Physical Review E Statistical Nonlinear & Soft Matter Physics，2004，69(1)：051607.
[19] ECHEBARRIA B，FOLCH R，KARMA A，et al. Quantitative phase-field model of alloy solidification[J]. Physical Review E Statistical Nonlinear & Soft Matter Physics，2004，70(1)：061604.
[20] GENG R，DU J，WEI Z，et al. Modelling and experimental observation of the deposition geometry and microstructure evolution of aluminum alloy fabricated by wire-arc additive manufacturing[J]. Journal of Manufacturing Processes，2021，64：369-378.
[21] KARMA A. Phase-field formulation for quantitative modeling of alloy solidification[J]. Physical Review Letters，2001，87(11)：115701.
[22] WU Q，Mukherjee T，LIU C，et al. Residual stresses and distortion in the patterned printing of titanium and nickel alloys[J]. Additive Manufacturing，2019，29：100808.
[23] 高义民. 金属凝固原理[M]. 西安：西安交通大学出版社，2010. GAO Yimin. Principle of metal solidification [M]. Xi’an：Xi’an Jiaotong University Press，2010.
[24] WANG J，WANG H，GAO H，et al. Effect of microsegregation behaviors on solidification microstructure of IC10 superalloy fabricated by directed energy deposition[J]. Additive Manufacturing，2022，59：103158.
[25] AMIR H，SHALLCHI A，JIAN L，et al. Columnar to equiaxed transition during direct metal laser sintering of AlSi10Mg alloy：Effect of building direction[J]. Additive Manufacturing，2018，23：121-131.
[26] ZHAO W，SUN Y，CHE P，et al. The columnar to equiaxed transition of CrCoNi medium-entropy alloy fabricated by laser direct energy deposition[J]. Materials & Design，2023，237：112538.