激光熔覆粉末粒径对熔覆层成形控制的影响

目的 揭示激光熔覆过程中TiC粉末粒径及工艺参数对复合材料熔覆形貌的影响规律，实现熔覆层成形控制。方法 采用响应面法中心复合设计模块分析扫描速度、激光功率、粉末粒径对复合材料熔覆形貌的影响，建立工艺参数及TiC粉末粒径与复合材料熔覆层面积、熔覆层高度、熔覆层宽度之间的数学模型，通过方差分析和模型检验验证模型的准确性。结果 激光功率对复合材料熔覆形貌的影响不显著，粉末粒径对熔覆面积影响最为显著，熔覆层面积随着扫描速度的减小和粉末粒径的增大而增大;粉末粒径对熔覆层高度影响最为显著，熔高随着粉末粒径的增大而增大，随着扫描速度的降低而减小;扫描速度对熔覆层宽度的影响最为显著，熔宽随着扫描速度的增大而下降，随着粉末粒径的增大而增大。结论 以熔覆面积最大及熔宽熔高最大为优化目标，对比预测值与实际值，熔覆层面积、熔覆层高度、熔覆层宽度的误差率分别为6.81%，3.9%，7.7%。该研究成果为提高复合材料熔覆形貌的预测与控制提供了理论依据。

Effect of Powder Particle Size of Laser Cladding on the Forming Control of Cladding Layer

The work aims to reveal the effect of different TiC powder particle sizes and process parameters on the cladding morphology of composite materials and realize the forming control of cladding layer. The center composite design of response surface method was adopted to analyze the effects of scanning speed, laser power, and particle size on the cladding morphology of composite materials. The mathematical models between process parameters, TiC powder particle size and the cladding area, height, and width of the composite cladding layer were established and confirmed by variance analysis and model verification. The laser power had no significant effect on the cladding morphology, while the powder particle size had the most significant effect on the cladding area. The cladding area became larger with the decrease of the scanning speed and decrease of the particle size. The powder particle size had the most significant effect on the cladding height. The cladding height increased with the increase of particle size and decreased with the decrease of scanning speed. Scanning speed had the most significant effect on the cladding width. The cladding width decreased with the increase of scanning speed and increased with the increase of powder particle size. The optimization of process parameters is carried out with the target of maximizing the cladding area and height. The error rates between prediction and experiment for the cladding area, height, and width are 6.81%, 3.9%, and 7.7% respectively. The results provide a reference for the prediction and control of the cladding morphology of composite materials.