Effect of WC on the residual stress in the laser treated HVOF coating

HVOF coating of diamalloy 1005 containing WC particles onto steel (304) is considered and laser melting of the coating is carried out. The effect of WC content on the residual stress formed in the coating is examined. Temperature rise and the temperature gradient developed in the coating is modeled and predicted. XRD technique is used to measure the residual stress in the coating while the analytical formulation is used to predict the residual stress at the coating base material interface. The indentation tests are carried out to measure the Young's modulus and fracture toughness of the coating with and without WC content. It is found that existing of WC modifies temperature rise and the temperature gradient in the coating; in which case, increasing WC content reduces the temperature gradient. The Young's modulus, the magnitude of the residual stress, and the fracture toughness of the coating increase with increasing WC content in the coating.