Papers by Keyword: In-Flight Behavior

Abstract: Tungsten is one of the most promising candidates for the plasma facing materials (PFM) in fusion experiment devices. In this study, tungsten coatings were fabricated on copper alloy substrates via air plasma spraying technology. The in-flight behaviors of tungsten particles in the spraying process were investigated. The microstructure and some properties of the as-sprayed coatings, including surface roughness, bonding strength, microhardness and thermal property, were evaluated. The results showed that the temperature and velocity of the in-flight tungsten particles increased by enhancing the spraying power. Un-melted particles and microcracks were found for the coatings prepared under the low (32.7kW) and high (47.6kW) spraying powers, respectively. The highest bonding strength and microhardness were obtained for the coating prepared under a medium spraying power (42.5kW) by reason of its good in-flight behaviors. The thermal conductivity of tungsten coatings was 32.2 W٠K-1٠m-1 at room temperature, which was much lower than that of bulk tungsten.

Abstract: Plasma spraying has been carried out under different spraying parameters, the particle in-flight behaviors have been measured to analyze the influence of argon flow rate, hydrogen flow rate and electrical current on the particle temperature and velocity. The particle velocity increased remarkably with the increase of the argon flow rate. The particle temperature was mainly influenced by the hydrogen flow rate, and increasing electrical current resulted in the increase of the particle temperature and velocity to some extent.