To synthesize the surface of the metal bodies, a thermal spray coating is used. There is a great need for this new coating technology in today's progressive world where modification of the substrate material is carried out a great deal. Thermal spray covering, electroplating, powder metallurgy and other metallurgical processes are used very quickly in the field of surface modification. We have presented the summary of all different types of thermal spray coating in this review paper and the advantages of high-speed oxy fuel coating. There is a literature review and an experiment was conducted on behalf of that to demonstrate the effect of coating on mild steel plate. Through Robot, we present a proposed optimization of the spraying process in a thermal power plant. We will explore the thermal spraying and oxidation effect on deposited aluminium and bronze in this research work. We present a detailed assessment of the robot kinematics and optimize the generation of the robot trajectory with a focus on the constant relative scanning speed.The results show that the motion behavior of each axis of robot permits to identify the motion problems in the trajectory. This approach enables the generation of robot trajectories in a limited working envelope to be optimised.