Preparation and Properties of WC-Based Alloy Coatings with Controlled Co and Cr via High Velocity Oxy-Fuel Spray Technique

WC based alloy coatings included different mass percent of Co and Cr have been synthesized on high carbon steel by using a facile high velocity oxy-fuel spray method. The mechanical nature of the coating films has been investigated by micro vickers hardness and fracture toughness. X-ray diffraction (XRD) and EDX analyses indicate that the three different samples (WC-10Co-4Cr, WC-17Co, and WC-12Co) consist of pure WC, W, Cr, and Co constituents as well as W2C and Co6W6C phases. The SEM and image analysis results show that WC-10Co-4Cr condition has higher porosity than those of WC-17Co, and WC-12Co coatings. WC-17Co coating showed the highest value in the hardness and fracture toughness test among three different samples. The obtained results revealed that the mechanical properties of WC based alloy coatings synthesized by a facile high velocity oxy-fuel spray method is very sensitive to Co content.