Improvement of Mild Steel Surface Properties by Fly-ash + Quartz + Illmenite Composite Coating

Abstract

Plasma spray of fly-ash composite gives a stable improvement of surface properties for industrially used materials/equipments, which has become a major technological research area encompassing studies in a broad range from medical field, chemical field to ceramic field. In the present investigation, coatings are developed on mild steel substrates using fly-ash + quartz + illmenite composite (in a weight percentage ratio of 60:20:20) at various plasma torch input power levels ranging from 11 to 21 kW DC. Metallographic and chemical characterization of the produced composite coatings was performed with the aid of scanning electron microscopy (SEM) and XRD analysis. The adhesion strength was measured by using coating pull-out method. Maximum adhesion strength 6.56 MPa was found between coating and mild steel substrate. The adhesion strength was found to be higher than that of other fly-ash composite coatings. It was found that the quality and properties of the composite coating are significantly affected by the operating power level of the plasma spray torch.