Formation of Nano-Microstructured Aluminum Alloy Film Using Thermal Spray Gun with Ultra Rapid Cooling

Abstract

A new thermal spray gun for nitrogen gas cooling and mist cooling has been developed. Aluminum-magnesium alloy lms prepared by nitrogen gas cooling using the thermal spray gun had a partial nano microstructure because residual strains induced by rapid cooling acted as solid nuclei and a small amount of the amorphous phase became crystalline as a result of the heat of the thermal spray. Furthermore, the nano-microstructured aluminum magnesium lms exhibited high corrosion resistance. Moreover, aluminum-magnesium alloy lms containing a small amount of titanium prepared by mist gas cooling exhibited higher corrosion resistance than those without titanium. We consider that the aluminum -titanium compound acted as solid nuclei during ultra rapid solidi cation and that a strong passive layer was formed by mist gas cooling.

Comparison of Microstructure and Tribological Properties of Plasma, High Velocity Oxy-Fuel and Detonation Sprayed Coatings from an Iron-Based Powder

“…However, the particles rapidly cool after flying out of spray gun. 7) The faster the particles arrive at the substrate and form the coating, the better molten state they will keep at that time. Moreover, the particle collision speed depends on the particle flying speed either.…”