Comparative investigation on thermally sprayed Al2O3, Al2O3-13%(TiO2) and Al2O3-40%(TiO2) composite coatings from room to 400 °C temperature

In the present study, three coatings of Al2O3, Al2O3-13%(TiO2) and Al2O3-40%(TiO2) composite coatings were deposited by the thermally flame spray process. The comparative wear behaviour of the Al2O3-TiO2 coatings has been studied under high temperature levels up to 400 degrees C with the help of a high temperature tribometer at a constant load of 40N. Prior to the tribo-test, the coating morphology and elemental analysis has been examined with the help of field emission scanning electron microscope (FESEM), elemental dispersion spectroscopy (EDS) and x-ray powder diffraction (XRD) techniques. The mechanical properties have been also analyzed and reported. The results reveal that specific wear rate decreases with an increase in temperature for all the deposited coating except Al2O3 coating at 400 degrees C. The overall friction coefficient of the coatings is decreasing with the increasing temperature. The Al2O3-40%TiO2 coating showed maximum sustainability against wear as well as a low coefficient of friction because of its low hardness and high adhesion properties. The examined worn surface validates the presence of brittle fracture and abrasive wear behaviour mechanism along with the oxidation wear, from room temperature to 400 degrees C.

Automated summary

In this study, three coatings were deposited using the thermally flame spray process and their wear behavior under high temperature conditions was examined. The results showed that the wear rate decreased with increasing temperature for all coatings except for the Al2O3 coating at 400 degrees C. The friction coefficient of the coatings also decreased with increasing temperature. The Al2O3-40%TiO2 coating demonstrated the highest wear resistance and lowest friction coefficient due to its low hardness and high adhesion properties.