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3015 |
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Peculiarities of splats formation under impact with substrate of decamicron metal droplets characterizing by a high volume content of solid carbide inclusions |
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Oleg Solonenko / Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences, Russia Anton Chesnokov/ Khristianovich Institute of Theoretical and Applied Mechanics, SB RAS, Russia Igor Gulyaev/ Khristianovich Institute of Theoretical and Applied Mechanics, SB RAS, Russia Vladimir Gavrilov/ Khristianovich Institute of Theoretical and Applied Mechanics, SB RAS, Russia |
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The use, in plasma spray process, of composite powders with particles formed by very hard inclusions in a metal alloy matrix presents a promising strategy in synthesis of wear-resistant coatings. The high carbide phase inclusions volume content in the cermet powder particles, 50&80%, provides for a high viscosity of the binder melt with high-melting inclusions suspended in it. In addition, during SHS and plasma spray processes the carbide inclusions in individual cermet particles may undergo sintering, which results in the formation of a solid ultra-fine particles skeleton. All those processes define a low value of deformation of the particles impinging onto the substrate or onto previously deposited coating layers. That is why cermet coatings plasma-sprayed from powder materials have comparatively high porosity at the interfaces between individual cermet splats and at the coating/substrate interface. It is a well-known fact that, during plasma spraying, the coating is formed from splats successively laid onto the base (substrate or previously deposited layer) from individual powder particles. In this connection, of obvious interest is the morphology of individual splats deposited onto the polished surface of the steel substrate. In the paper presented there will be fullfiled a comprehensive analysis of splats formed from TiC+Ni-Cr composite particles upon their impingement onto smooth steel substrates at full control of key physical parameters of particle substrate interation: temperature, velocity and size of particles, substrate temperature. The splats have been deposited on substrate under different size of composite particles and different volume content of solid titanium carbide inclusions finely dispersed in a liquid metal binder. |