Investigation of the properties and characteristics of a hardfacing of Stellite 6 + Al2O3 made by the GTAW-P process

This work aimed to investigate the effect that the addition of aluminum oxide brought to the surface coatings made with the alloy Stellite 6 and deposited by the GTAW-P welding process.The main motivation for inserting alumina was to increase the hardness of the coating without losing the original toughness of the Stellite 6 alloy, thus preventing the appearance of intensive cracks that other alloys provided us (e.g. Stellite 1).The coatings reached values of microhardness in the range of 400 HV0.5 to 500 HV0.5, such numbers corresponded to the values found in the literature for pure Stellite 6 alloy. The diffractograms presented the formation of the characteristic phases of Stellite 6 and in addition to these phases, the presence of phases formed through the addition of aluminum oxide, Al2O3 and Cr2O3, was confirmed with more pronounced peaks in 2θ around 45°. Thus, the incorporation of alumina maintained the main characteristics of the coatings of Stellite 6, allowed the formation of oxides. These results indicate that with proper control of the process dilution, coating properties, such as microhardness and abrasive wear resistance will improve.