High velocity oxy fuel (HVOF) thermal spray process is one of the most widely thermal spraying techniques used for the repair of worn parts such as transmission shafts, air cylinders and hydraulic cylinders. The properties of coating depended on the process parameters. In this study, the experimental results for 67Ni18Cr5Si4B powder coating on C45 steel shaft by HVOF thermal spray were presented. The effect of HVOF process parameters on the porosity and the adhesive strength of the coating to the substrate were investigated, which can help us choose the optimal process parameters of HVOF spray for recovering the damaged equipment
