| CHEN Haijun,ZHU Gangxian,HE Jihong,WANG Lifang.Numerical Simulation on Flow Field of Non-horizontal Molten Pool by Laser Cladding Based on Inside-beam Powder Feeding with Variable Posture[J],53(9):190-199, 208 |
| Numerical Simulation on Flow Field of Non-horizontal Molten Pool by Laser Cladding Based on Inside-beam Powder Feeding with Variable Posture |
| Received:January 30, 2023 Revised:August 02, 2023 |
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| DOI：10.16490/j.cnki.issn.1001-3660.2024.09.018 |
| KeyWord:laser cladding inside-beam powder feeding variable attitude molten pool flow field numerical simulation |
| Author | Institution |
| CHEN Haijun |
School of Mechanical and Electrical Engineering,Jiangsu Suzhou , China |
| ZHU Gangxian |
School of Mechanical and Electrical Engineering,Jiangsu Suzhou , China |
| HE Jihong |
School of Mechanical and Electrical Engineering,Jiangsu Suzhou , China |
| WANG Lifang |
Center of Engineering Training, Soochow University, Jiangsu Suzhou , China |
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| Abstract: |
| Laser cladding and laser remanufacturing technology is based on horizontal reference planes at present, however, this way greatly limits its extensive application. The molten pool flow behavior of the laser cladding has a direct impact on the morphology and forming quality of the cladding layer. However, it is difficult to observe and study the flow behavior in the molten pool by experimental method due to the limitation of high temperature and instantaneous evolution of the molten pool. Consequently, the simulation analysis of the heat transfer, flow behavior and morphology evolution in the molten pool by numerical simulation technology is a research hotspot in laser cladding technology. In addition, the flow field distribution of the non-horizontal molten pool is still lack of systematic research with variable attitudes based on inside-beam powder feeding way by laser cladding. In order to improve the forming quality of cladding layers under variable attitudes based on inside-beam powder feeding, the flow field evolution rules of a non-horizontal molten pool with a substrate inclination angle were studied. In this paper, the discrete phase model based on FLUENT Software was adopted to compute the flow field of the nozzle and obtain the powder distribution rules. And then, the flow field of the molten pool was calculated based on the Volume of Fluid and Melting/Solidification Model. Attitude angles of 30°, 60° and 90° were chosen to compute the flow field of the non-horizontal molten pool, respectively. The flow field of the molten pool was tracked and the interfaces of the cladding layer were analyzed by applying the mass source item and the energy source item to simulate the process of synchronous powder feeding and laser thermal input. Finally, experimental measurements were carried out based on the inside-beam powder feeding cladding process. The results showed that the powder distribution in the powder spot was "even in the middle and dense at both ends". The flow field of the non-horizontal molten pool was characterized by "double annular flow" distribution, but the flow direction was deflected due to the influence of gravity. When the computation time of three attitude angles was 0.3 s, the deflection angles of the fluid at the center of the molten pool were 2°, 4°, and 6°, respectively. With the inclination angle increased, the height of the cladding layer increased by 0.28%, 0.83% and 1.45%, the width of the cladding layer decreased by 1.19%, 1.28% and 1.73%, and the vertex offsets of the cladding layer increased to 48.08 μm, 86.54 μm and 105.76 μm. Finally, the numerical calculations were consistent with the experimental results through the experimental determination. The Marangoni stress makes the fluid flow in the molten pool from the center to the boundary with a double-circle distribution characteristic. The flow direction of the non-horizontal molten pool is deflected by the influence of gravity. While the inclination angle increases, the height of the cladding layer increases, the width of the cladding layer decreases and the vertex offset of the cladding layer gradually increases. It provides guidance for improving the laser cladding and laser remanufacturing quality in the light of parts that are inconvenient to flatten the non-horizontal base surface by the inside-beam powder feeding way. |
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