The Spray and Fuse Coating Process is a two-step process involving the application in most cases, of a self-fluxing alloy coating usually using a combustion thermal spray process and then fusing the coating by applying very high heat (1900-20000F). During the fusing process, the molten alloy forms a metallurgical bond with the substrate.
The advantages of spray and fused coatings are that you can use high performance alloys typically found in welding materials, you have a metallurgical bond to the substrate, and a very dense, high wear resistant coating similar in performance to a hardface weld overlay.
The major disadvantage of spray and fused coatings is the risk Of distortion Of the component during the fusing stage of the process by the use of excessively high heat. Care must also be taken to ensure that the coating material and the substrate are metallurgically compatible.