Surface Modification and Analysis of St37 Steel with Al2O3-TiO2, ZrO2, and Cr2O3 Ceramic Coatings: Structural, Mechanical, and Tribological Properties

Abstract

St37 steel, widely used in many engineering applications, experiences significant losses in its mechanical and physical properties over time due to reasons such as corrosion or wear. In this study, the aim was to improve the surface properties of St37 steel using the plasma spray method. To achieve this, the surface of St37 was coated with four different oxide layers: zirconium oxide (ZrO2), chromium oxide (Cr2O3), and aluminum oxide-titanium oxide at different ratios [Al2O3-%13 TiO2 (AT13) and Al2O3-%40 TiO2 (AT40)]. Microhardness measurement, wear test, scratch test, and structural analyses (XRD and SEM) were performed on the samples. The highest coating thickness (311 µm) was observed in the chromium oxide-coated sample. All applied coatings significantly increased the hardness of St37 steel, with the chromium oxide-coated sample exhibiting the highest hardness value (1664 HV0.1). The highest adhesion strength was determined to be 59 N in the aluminum oxide-titanium oxide (AT13) coated sample, while the lowest adhesion strength was found to be 28 N in the chromium oxide-coated sample. In this study, the analysis results of untreated and differently oxide-coated St37 steel samples are presented comparatively.