Yahui Huang, Motoyoshi Ohwatari and Masahiro Fukumoto
Department of Production Systems Engineering, Toyohashi University of Technology, Toyohashi 441
The effect of substrate material on the flattening behavior of the plasma sprayed Ni particle was investigated. The results obtained are summarized as follows:
(1) From the study of the splat behavior of Zr and Fe particles, it was clear that the splashing tendency of the plasma sprayed metallic particles can be evaluated by the relationship between surface tension and initial solidification rate of the powder material.
(2) It was observed that the transition temperature varied with substrate materials as evidenced by the splatting behavior of Ni particles. It was found that the flattening of the particle was influenced by the substrate material.
(3) Under the same wetting conditions between particles and substrate, it was found that the larger the thermal conductivity of the substrate material, the higher the transition temperature. Therefore, it was clarified that the particle's splashing was influenced considerably by the initial solidification of the particle.
(4) Under the same solidification coditions, it was observed that the higher the substrate material's activity, the higher the transition temperature. This seems to depend on the wetting of the Ni particle on the oxide surface. The effect of wettability on the flattening of the particle cannot be neglected.
(Received July 18, 1996)
plasma spraying, splat behavior, nickel, splashing, transition temperature, substrate, thermal conductivity, wettability
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