Feasibility of Plasma Spraying in Developing MMC Coatings: Modeling the Heating of Coated Powder Particles

Abstract

Coated powder particles composed of a ceramic core and a metallic coating are being considered for plasma spray applications. The goal of using these powders is to produce particulate-reinforced metal-matrix composite coatings. In this work, the feasibility of plasma spray processing in producing these composite coatings is evaluated. A numerical model is presented to analyze the in-flight thermal behavior and physical state of moderate-size particles (10–30 μm radius) in arc-jet DC plasma under low loading conditions. The pairs of materials for the base and coating that are considered in this work are WC-Co, SiC-Ni, and SiC-Al. The plasma was taken to be atmospheric argon plasma. The study suggests that plasma processing is capable of melting the coating without excessive evaporation while retaining the base in the solid state over a range of particle sizes and base/coating proportions. Hence plasma processing appears suitable to develop particulate-reinforced metal-matrix composite coatings.