Multi-physics simulation of wobbling laser melting injection of aluminum alloy with SiC particles: SiC particles gradient distribution in fusion zone

• Published in: International journal of heat and mass transfer 2022-01, Vol.182, p.121960, Article 121960
• Main Authors: Xu, Boan, Jiang, Ping, Wang, Yilin, Zhao, Jintian, Geng, Shaoning
• Format: Article
• Language: English
• Subjects: Aluminum alloys; Aluminum base alloys; CFD; Computational fluid dynamics; DEM; Discrete element method; Drag; Fusion zone; Keyholes; Laser beam melting; Lasers; Liquid-solid interfaces; Multiphase flow; SiC particles gradient distribution; Simulation; Solidification; Wobbling laser melting injection
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2021.121960

•A novel process of wobbling laser melting injection is introduced to improve the distribution uniformity of particles in fusion zone for the first time.•The dynamic behaviors of keyhole, molten pool and particles during wobbling laser melting injection are reproduced by CFD-DEM model for the first time.•It is innovative that the physical mechanisms of optimizing the gradient distribution of particles by wobbling laser melting injection were illustrated. Laser melting injection (LMI) with SiC particles can strengthen fusion zone of metal alloy. How to improve the distribution uniformity of SiC particles are critical. In this work, a novel process of wobbling laser melting injection (WLMI) is proposed to suppress the gradient distribution of SiC particles in fusion zone of aluminum alloy. Moreover, a multiphase flow model by bi-directionally coupling the discrete element method and computational fluid dynamics is developed to simulate this WLMI process. The exchanges of both momentum and energy between particles and liquid are incorporated. It is the first time that the dynamic behaviors of both the liquid and particles during melting-solidification process under WLMI are reproduced in computational modeling. Both experimental and simulated results indicate that the distribution uniformity degree of SiC particles under WLMI, along depth and width directions, improves significantly compared with LMI. Physical mechanisms accounted for this phenomenon can be more thoroughly understood by the model. Firstly, the wobbling laser can increase the keyhole opening area, and decrease the distance between keyhole and molten pool bottoms, leading to a greater possibility that particles are captured by the liquid-solid interface in the bottom. Secondly, the reflected wobbling laser rays distributed unevenly on keyhole wall and the impact on melt surface caused by injected particles will produce downward drag forces, making the particles float to the center or the middle of molten pool. [Display omitted]