Laser Cladding of Inconel 625 on AISI 316L: Microstructural and Mechanical Evaluation of Parameters Estimated by Empirical-Statistical Model

The present work aimed to assess the combination of the use of an empirical-statistical model and design of experiments (DoE) to minimally validate the geometrical characteristics (dilution, coating height, waviness and porosity) of a laser-induced Inconel 625 coating on AISI 316L substrate. Employing the estimated laser processing parameters, a verification coating was deposited to assess its microstructure, microhardness and bending resistance. The statistical model showed to be an efficient computational tool for the planning of the design of experiments (DoE), resulting in errors less than 15% for all geometrical characteristics evaluated. The presence of some pores along the verification Inconel 625 coating was observed. Additionally, the verification coating showed good dilution and low waviness. Regarding the microstructure and microhardness, the verification coating showed a columnar dendritic microstructure, and its microhardness was about 110% higher than that observed for the AISI 316L substrate. Its resistance to bending was 30% higher when compared to that of the uncoated samples. By considering the experimental conditions explored within this work, one can state that the laser-cladded Inconel 625 coatings performed well on AISI 316L stainless steel substrate.