The temperature varying principal of the molten pool is crucial to coatings’ cross-section sizes during laser cladding process, which can influence the performance of the coatings. In this study, a modified three-dimensional (3D) transient finite element model was presented to simulate the temperature evolution and clad geometry of the molten pool of TiAlSi coatings. The difference of thermal properties in TiAlSi powders and TiAlSi alloys were distinguished to improve the precision of simulation results through theoretical calculation. The Gaussian body heat source model was established. A temperature selection judgment mechanism was utilized to compare the average temperature of the element and the melting point of the material to distinguish powder and alloy elements. An exponential distribution of energy attenuation along penetration direction was employed to simulate the laser beam deflected by the powder particles and the void among the particles to correct Gaussian heat source. The effect of different laser power and scan speeds on the cladding layer morphologies were investigated. The track depth and width calculated by simulation were analyzed by polynomial fitting curves. The results showed that the track depth and width were directly proportional to laser power, whereas inversely to scanning speed. Geometric dimensions of cladding layers at arbitrary laser power (600–1800 W) and scan speed (0.005–0.025 m/s) can be computed by polynomial fitting equation. Track depth was more impressed by scanning speed. The track width and longitudinal size of cross-section geometry from the simulation results and experiment measurement were matched to validate the presented model. The modified 3D transient finite element model is able to describe the geometry of single-track laser cladding.

熔池的温度变化原理对激光熔覆过程中涂层的横截面尺寸至关重要，这会影响涂层的性能。在这项研究中，提出了一种改进的三维 (3D) 瞬态有限元模型来模拟 TiAlSi 涂层熔池的温度演变和包层几何形状。通过理论计算，区分了TiAlSi粉末和TiAlSi合金的热性能差异，提高了模拟结果的精度。建立高斯体热源模型。利用温度选择判断机制，比较元素的平均温度和材料的熔点，以区分粉末元素和合金元素。采用能量衰减沿穿透方向的指数分布来模拟粉末颗粒偏转的激光束和颗粒之间的空隙，以校正高斯热源。研究了不同激光功率和扫描速度对熔覆层形貌的影响。通过多项式拟合曲线分析仿真计算出的轨道深度和宽度。结果表明，轨道深度和宽度与激光功率成正比，而与扫描速度成反比。在任意激光功率 (600-1800 W) 和扫描速度 (0.005-0.025 m/s) 下，熔覆层的几何尺寸可以通过多项式拟合方程计算。扫描速度对轨道深度印象更深。将模拟结果和实验测量中的轨道宽度和横截面几何形状的纵向尺寸相匹配，以验证所提出的模型。修改后的 3D 瞬态有限元模型能够描述单轨激光熔覆的几何形状。