Investigation of surface coating properties of magnesium alloy coated with ceramic based powders by plasma spraying method

In this study, the surface of AZ91D magnesium uptake was coated with Cr2O3, Al2O3-40TiO2 and Cr2O3-40TiO2 powders. Plasma spray method was used as surface coating method. Surface coatings were carried out at two different spray distances (110 mm and 130 mm) and two different currents (580 A, 500 A). The microstructures of the coated surface layers were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDS) methods. Microhardness measurements were performed on microhardness test device. Dry sliding wear properties were determined using disc-on-disc type wear test device. Wear tests were performed at a load of 2.5 N, 5 N, 7.5 N and a sliding distance of 150 m. Cr2O3 and Cr were detected in the coating layers of the samples coated with Cr2O3. Al2O3-Ti2O3 and TiO were determined in the coating layers of the samples coated with Al2O3-40TiO2, Cr2O3, TiO2 and TiO were determined in the coating layers of the samples coated with Cr2O3-40TiO2. The samples with the highest surface roughness are those coated with Cr2O3. The highest hardness value was measured at 845 HV0.1 in the sample coated with Al2O3-40TiO2 at high heat input and low spray distance. At all applied force values, the wear resistance of the coated samples was higher than the substrate material. The sample with the highest abrasion resistance was the sample coated with Cr2O3 at high heat input and low spray distance. At all load values, the coefficient of friction (µ) of the substrate was lower than the coated samples. AZ91D and coated samples µ values increased as normal force increased. Al2O3-40TiO2 coated samples µ values were lower than other samples. In addition, the µ values of the coated samples increased with decreasing current and increasing spray distance.