Thermal Spray Processes and Coatings
This article presents the major thermal spray processes and their subsets, presenting each of the commercially significant processes together with some of their important variations. Each process is presented along with the attributes that influence coating structure and performance. The article summarizes the essential equipment components and necessary controls. The various thermal spray processes are conventional flame spray, detonation gun, high-velocity oxyfuel spray, electric arc spray, and plasma arc spray. Other processes, such as cold spray, underwater plasma arc spray, and extended-arc and other high-energy plasma arc spray, are also considered.
The distinguishing feature of the cold spray process, when compared with the conventional thermal spray process, is its ability to produce coatings with high-velocity rather than high-temperature particle jet. This article provides an overview of the cold spray process and the parameters that affect both the process deposition efficiency and properties of the prepared coatings. It describes a variety of cold spray coating materials, namely, pure metals, ferrous and nonferrous metal alloys, composites, and cermets. The article presents various industrial applications of cold spray coatings.