Comprehensive analysis of laser cladding coatings formed on gray cast ion substrates for brake disc applications: Electrochemical, microstructural, and mechanical studies

Abstract

The surface modification of HT250 gray cast iron brake disc was carried out by Ferritic Nitrocarburizing (FNC) and laser cladding. The effects of process parameters on the microstructure, mechanical properties and corrosion resistance performance of the brake disc were investigated. The results indicated that the microstructures of FNC samples were mainly white bright ε phase, and the main compositions of Ni40A coating were plane crystal, columnar crystal, dendrite and equiaxed crystal from the fusion line zone to the top zone. The grains of the coating were refined after adding WC particles, and with the increase of WC ratio, the grain refinement degree and the average hardness of the coating were improved. The Ni40A laser cladding coating with 15 wt% WC showed the best corrosion resistance.