Abstract: A dense coating deposition process by powder spraying is disclosed. A compressed gas is expanded through a supersonic nozzle and powder containing a mixture of at least one material selected from the group consisting of metals and metal alloys and at least one ceramic material is introduced into the gas flow slightly downstream of the throat of the nozzle. The coating is formed by the powder impacting and metallurgically bonding to the substrate and can be applied in multiple layers. The coating can suffice as a finished surface, corrosion protectant, leak sealer, and material build up application.