Statistical analysis and multi-objective process optimization of laser cladding TiC-Inconel718 composite coating

Laser cladding is an effective method of surface strengthening. Reasonable selection of laser cladding process parameters is critical to the clad geometry and mechanical characteristics of the coating. In this research, to investigate process parameters and properties of laser cladded TiC-Inconel718 composite coating, a statistical relationship between processing parameters (laser power, scanning speed and powder feeding rate) and responses (including dilution rate, microhardness, the ratio of layer width to height) was established using an experimental approach with response surface method and analysis of variance. The analysis of variance showed that the scanning speed was the most significant factor on the ratio of layer width to height, dilution rate and microhardness of the coating. In addition, in terms of microstructure, with the increase of laser power and the decrease of scanning speed, the distance between primary dendrite arm spacing increased. On the contrary, the microhardness of the coating decreased. Then, the desirability optimization method was employed to obtain the desired coating. Finally, validation experiments under optimal conditions showed that the predicted results agreed well with the experimental results and the errors were less than 10%. This research provides guidance for the multi-objective process optimization of laser cladding composite coatings.