Gas tunnel type plasma system for clay coating

Abstract

Modification on powder feeder concept enables better performance for gas tunnel plasma spraying. A powder delivery system with axial sandblast spray concept was modified and fabricated using 3D modelling. The present work was undertaken to investigate the difference in structure and thickness of clay coating manufactured by new system with manipulated flowrate and platting distance. Coating process using clay powder feed stock and stainless steel (316H) substrate was performed for different flowrate (4L/min and 5L/min) and at platting distance from 2mm to 10mm. Surface morphology of the coatings were characterized by Scanning Electron Microscope (SEM) and phase analyses was done by X – Ray Diffractometer (XRD). Optimum parameter was obtained at 5 L/min and distance of 10mm which producing an average coating thickness of 493 µm, good adhesion, smooth surface and changes of phases from illite and albite into Quartz. The results have indicated the sustainability of the plasma technique with regards to the production of a good quality of ceramic coated and having good adherence to the metal substrate.