Influence of Particle Size and Spray Parameters on Structural, Mechanical and Electrical Insulation Properties of Alumina Coatings by Atmospheric Plasma Spraying

摘要

Influence of particle size and spray parameters on structural, mechanical and electrical insulation properties has been studied for alumina coatings by atmospheric plasma spraying. It has been found that combination of the powder material, Metco 6051, having relatively finer particles (D_(50) -15 μm) and high velocity plasma by TriplexPro-210~(TM) are effective for formation of denser coating, which has also resulted in high dielectric strength. On the other hand, with the combination of standard particles (D_(50) ~ 30 μm), standard plasma conditions of lower plasma velocity and traditional plasma gun, it is difficult to achieve better coatings with high dielectric strength. The correlation between dielectric strength and others, such as deposition efficiency, coating hardness, crystal structures and surface roughness has been studied.