Cavitation Erosion of the Surface of Protective Coating Based on Cordierite Filler and Epoxy Matrix

The goal of this study was to investigate the surface morphology changes induced by cavitation erosion of a coating based on cordierite with epoxy matrix for aluminium substrate. The literature review shows a certain gap in knowledge regarding coating's resistance to wearing induced by water flow, which is a highly important property of the material immersed in or in contact with water streams. The main idea behind the investigation is that such protective coating will also improve the cavitation erosion resistance of metal substrates. The protective coatings were based on cordierite filler (88 wt.%) and epoxy resin (7 wt.%). The filler made of mixture of kaolin, alumina, and talc is obtained by a sintering procedure that took place at 1350°C. X-ray diffraction analysis and scanning electron microscopy were employed in the characterization of the produced filler. Adherence of the obtained epoxy-based protective coating and resistance to water flow were tested by the ultrasonic vibration method (i.e., cavitation erosion testing). Scanning electron microscopy was used for analysis of the coating's morphology upon cavitation erosion. Based on the value of the cavitation erosion rate and the analyzed final surface damage, it was assessed that the investigated protective coating is resistant to cavitation erosion.