Abstract
Ordinal thermal spray process has so many advantages, that is, any kinds of industrial materials can be sprayed by the process, thick coating formation up to mm level with higher deposition rate can be attained, coating can be made easily without chamber, high quality coating with higher adhesion strength and lower porosity can be given by the process currently advanced, and so on. Consequently, it is said that the process has almost matured practically. However, the controllability or reliability of the process has not always been established yet. Current situation on controlling method of thermal spray process is mainly introduced in this review. On the other hand, new coating formation process by using not melted but solid state particles has been growing up rapidly. The process is typically represented by cold spray and aero-sol deposition, and based on the reflection that the materials melting is a kind of necessary evil on the coating formation in an air atmosphere. By summarizing both academic and technological issues on the particle deposition process from ordinal thermal spray to newly developed processes, future prospect in this technology field was given in the paper.
