The influence of processing parameters on the micro-hardness and wear resistance of a Ni-based alloy and titanium carbide (TiC) composite cladding layer was studied. Mathematical models were developed to predict the micro-hardness and wear resistance of the cladding layer by controlling the laser cladding processing parameters. Key processing parameters were the laser power, scanning speed, gas flow, and TiC powder ratio. The models were validated by analysis of variance and parameter optimization. Results show that the micro-hardness is positively correlated with laser power and TiC powder ratio, where the TiC powder ratio shows the most significant impact. The wear volume decreased with an increasing TiC powder ratio. The targets for the processing parameter optimization were set to 62 HRC for micro-hardness and a minimal volume wear. The difference between the model prediction value and experimental validation result for micro-hardness and wear volume were 1.87% and 6.33%, respectively. These models provide guidance to optimize the processing parameters to achieve a desired micro-hardness and maximize wear resistance in a composite cladding layer.

Die-cutting tools have been widely applied in industrial production. However, different forms of failure on a blade, such as wear and fracture, can greatly reduce its service life. In this research, the die-cutting tool was selected as the object, a mixture of high speed steel powder and 304 stainless steel powder was coated as a gradient cladding layer onto the surface of AISI/SAE 1045 steel by laser cladding. The central composition design of the response surface methodology was adopted to establish a mathematical model between the pore area of the multi-layer, multi-track cladding, and its processing parameters: Laser Power (LP), Scanning Speed (SS), Gas Flow (GF), and Overlapping Rate (OR). This model was validated by variance analysis and inspection indicators. The actual experiment value by processing parameters optimization for achieving the smallest pore area showed a 4.41% error compared with the predicted value. The internal structure of the cladding layer is uniform. The defects, such as pores and cracks, meet the requirements. The wear resistance on the cutting edge is about 4.5 times compared with the substrate. The results provide a theoretical guidance for the controlling and prediction of the laser cladding forming quality on a two-dimensional gradient material and the optimization of the processing parameters.