Author : Alain Kusmoko

Stellite 6 was welded by laser cladding on an Inconel 718 (NIS) substrate with laser powers of 1 kW (NIS 1) and 1.8 kW (NIS 1.8). The chemical compositions and microstructures of these coatings were analysed by X-Ray Florescense spectroscopy, optical microscopy, and scanning electron microscopy. The microhardness of the coatings was characterised and the wear mechanism of the coatings was assessed using a ball-on-plate (reciprocating) wear testing machine. The results indicated less cracking and pore development with Stellite 6 coatings applied to the Inconel 718 (NIS) substrate at a lower laser power (NIS 1), while NIS 1 was much harder than that obtained for NIS 1.8. The results of the wear test indicated that the weight loss for NIS 1 was much lower than NIS 1.8. The evaluations of dilution and calculation of the C content showed that dilution for NIS 1 was less than for NIS 1.8 while the C content for NIS 1.8 was less than NIS 1. It was concluded that the lower hardness of the coating for NIS 1.8 was due to a higher level of dilution and lower concentration of C, which markedly reduced the wear resistance of the Stellite 6 coating.

Keywords: Dilution, Laser Cladding, Inconel 718, Stellite 6 coating

Article published in International Journal of Current Engineering and Technology, Vol.6, No.4 (Aug-2016)