As one advanced manufacturing process, laser polishing has been widely used in precision machining of metal or nonmetal materials. However, the evolution mechanism of molten pool formed during polishing process has not been thoroughly studied. This paper studies the polishing process of Ti6Al4V with a continuous wave (CW) fiber laser under the top-hat distributed heat source. A two-dimensional (2D) axisymmetric numerical transient model is established to simulate the formation process of the surface of Ti6Al4V after laser heating to form a molten pool and then cooling. It reveals that the evolution mechanism of physical processes involved in heat transfer, heat radiation, heat convection, melting and solidification during the polishing process. Particularly, the capillary and thermocapillary regimes (Marangoni flow) play a key role in smoothing the free-form surface of molten pool. The freedom surface can be smoothed effectively before the solidification of molten pool. In order to verify the correctness of the simulation model and explore the influence of laser irradiation duration on the material, the surface topography of the polished sample was investigated. It is found that the errors of the depth and width of the remelting zone are respectively less than 8 % and 22 % by the comparison of simulation and experimental results. Likewise, the depth and width of molten pool expand with the laser radiation duration increasing. Meanwhile, the polished surface topography becomes smoother.

作为一种先进的制造工艺，激光抛光已广泛用于金属或非金属材料的精密加工。但是，尚未彻底研究抛光过程中形成的熔池的演变机理。本文研究了在连续分布的热源作用下，连续波（CW）光纤激光器对Ti6Al4V的抛光工艺。建立了二维（2D）轴对称数值瞬态模型，以模拟激光加热形成熔池然后冷却后Ti6Al4V表面的形成过程。它揭示了在抛光过程中涉及热传递，热辐射，热对流，熔化和凝固的物理过程的演化机理。尤其，毛细作用和热毛细作用（Marangoni流动）在使熔池的自由表面光滑方面起着关键作用。在熔池凝固之前，可以有效地平滑自由表面。为了验证仿真模型的正确性并探讨激光辐照时间对材料的影响，对抛光样品的表面形貌进行了研究。通过模拟和实验结果的比较发现，重熔区深度和宽度的误差分别小于8％和22％。同样，熔池的深度和宽度随着激光辐射持续时间的增加而扩大。同时，抛光的表面形貌变得更光滑。在熔池凝固之前，可以有效地平滑自由表面。为了验证仿真模型的正确性并探讨激光辐照时间对材料的影响，对抛光样品的表面形貌进行了研究。通过模拟和实验结果的比较发现，重熔区深度和宽度的误差分别小于8％和22％。同样，熔池的深度和宽度随着激光辐射持续时间的增加而扩大。同时，抛光的表面形貌变得更光滑。在熔池凝固之前，可以有效地平滑自由表面。为了验证仿真模型的正确性并探讨激光辐照时间对材料的影响，对抛光样品的表面形貌进行了研究。通过模拟和实验结果的比较发现，重熔区深度和宽度的误差分别小于8％和22％。同样，熔池的深度和宽度随着激光辐射持续时间的增加而扩大。同时，抛光的表面形貌变得更光滑。通过模拟和实验结果的比较发现，重熔区深度和宽度的误差分别小于8％和22％。同样，熔池的深度和宽度随着激光辐射持续时间的增加而扩大。同时，抛光的表面形貌变得更光滑。通过模拟和实验结果的比较发现，重熔区深度和宽度的误差分别小于8％和22％。同样，熔池的深度和宽度随着激光辐射持续时间的增加而扩大。同时，抛光的表面形貌变得更光滑。