Plasma Spray of Nano Composite Ceramics Using Solution Precursors and Combustion Synthesized Nano Powders

Abstract

AbstractPlasma spraying is a well-established method for depositing nanostructured ceramic coatings on structural components. Two different plasma spraying techniques - solution precursor plasma spray (SPPS) and suspension plasma spray (SPS) - have been used to produce MgO-50vol% ZrO2 composite coatings. The microstructural features of the coatings were characterized using Environmental Scanning Electron Microscopy (ESEM) and X-Ray Diffractometry (XRD). The micro hardness of the coatings was measured on cross-sectional samples. The coatings produced using the SPS process with ethanol-based suspensions at a high plasma torch power (45.5 kW) exhibited the densest microstructures with hardnesses as high as ∼1350 HV. However, the backscattered electron (BSE) ESEM characterization of these coatings revealed that the coatings obtained using the SPPS technique had superior chemical homogeneity over those obtained using the SPS technique.