关键词: 激光熔覆, 中心复合设计, 复合材料, 形貌, 熔覆效率

Abstract: In order to investigate the influence of laser cladding process parameters and TiC powder ratio on the cladding morphology and forming efficiency of composite materials ，improve the cladding morphology in terms of surface quality and substrate melting depth, and improve the forming efficiency of composite materials, the central composite design module of the response surface methodology(RSM) was adopted to analyze the effects of laser power, scanning speed, gas flow and TiC powder ratio on the morphology of composite claddings. A mathematical model was established between process parameters and TiC powder ratio, and composite cladding efficiency and substrate melting depth. The accuracy of the model was verified by variance analysis. Results show that, the effect of gas flow on the morphology of composite claddings is not significant. The cladding morphology is remarkably improved by increasing laser power, decreasing scanning speed and reducing TiC powder ratio. The scanning speed and TiC powder ratio have the most remarkable effects on the cladding efficiency. Therefore, reducing the TiC powder ratio and increasing the scanning speed appropriately could improve the cladding efficiency. Laser power has the most significant influence on the melting depth of the substrate and shows a secondary positive correlation, and the remaining parameters show a negative linear correlation. The analysis reveals that different materials’ requirement for cladding energy is the most important cause of the difference in the cladding efficiency and the morphology of composite materials with different compositions. With the maximum cladding efficiency and the minimum melting depth of the substrate as the goal of optimization, a comparison was made between the predicted and test values and found that the error rate of the cladding efficiency and that of the melting depth of the substrate were 3.450% and 5.386% respectively. This research provides a theoretical guidance for composite materials in improving the cladding morphology, and for predicting and controlling the cladding efficiency.

Key words: laser cladding, central composite design, composite materials, morphology, cladding efficiency