Performance and Defect Control Method of Ni35A + SiC Cladding Layer in Laser Cladding

The work established the mathematical model of the powder ratio, laser power, scanning speed, and airflow rate on the hardness of the cladding layer and stomatal area based on the central composite design and response surface methodology to explore the coupling effect of the powder ratio and process parameters of the preset powder process in laser cladding on the performance and defects of the Ni35A + SiC cladding layer. The experimental results showed that the hardness increased with the increased powder ratio and scanning speed, and decreased with the increased laser power. The four selected process parameters affected the stomatal area, and the stomatal area could be reduced by increasing the laser power and gas flow rate and decreasing the scanning speed and powder ratio. The model accuracy was further verified with the optimization objectives of maximum hardness and minimum stomatal area, and the errors of the predicted and actual values of hardness and stomatal area were 0.9 and 4.07%, respectively. The results provide a theoretical basis for exploring the properties of SiC hard-phase cladding layers and the control and prediction of defects.