Multiphase Heat Transfer and Fluid Flow

Professor Roger H. Rangel

Postgraduate Researcher: A. M. Ahmed

In-Flight Oxidation of Composite Powder Particles During Thermal Spraying

Composite Particle Stainless Steel Particle

This research presents a mathematical model of the in-flight thermal behavior and oxidation of powder particles during thermal spray deposition. In particular, stainless steel and Cr₃C₂-NiCr particles are investigated. The in-flight model accounts for the acceleration and deceleration of the particles during flight under variable fluid velocity, while the thermal model takes into account heating, melting, cooling and possible solidification as the particle travels towards the substrate. A finite-difference method is used to solve the thermal energy conservation equation of the particles. The model includes non-equilibrium calculations of the phase change phenomena in the liquid-solid (mushy) zone and dissolution of the ceramic reinforcement in the composite particles. The growth of the oxide layer at the particle surface is represented by a modified boundary condition, which includes finite-rate oxidation. The results obtained give the interrelations between various process parameters and the oxidation phenomenon.

Publications

Ahmed, A.M., Rangel, R. H., Sobolev, V. and Guilemany, J.M. " In-Flight Oxidation of Composite Powder Particles During Thermal Spraying" , International Journal of Heat and Mass Transfer, Submitted, 2000.

Ahmed, A.M., Rangel, R. H., Sobolev, V. and Guilemany, J.M. "Simulacion Matematica de la oxidacion en Vuelo de Particulas Metalicas durante la Proyeccion Termica", IBEROMET VI Ciencia Tecnologica de los materiales, Barcelona de Junio 2000.

Ahmed, A.M., Rangel, R. H., Sobolev, V. and Guilemany, J.M. "In-Flight Oxidation of Metal Particles During Thermal Spraying", ITSC Conference, Montreal, Canda, 8-11 May 2000.

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This page has been last updated by A. M. Ahmed 10/13/2000