Enhancing wear and erosion resistance of partially oxidized NiCrBSiFeC coating by plasma spray on MDN431 substrate

This study investigates the enhancement of wear and erosion resistance through partial oxidization of NiCrBSiFeC alloy powders applied as coatings on MDN431 steel. Using a flame spray process, alloy powders were sprayed into water under controlled parameters to produce partially oxidized powders with approximately 50% oxide layer and 50% metallic core, balancing hardness and ductility. These powders were deposited onto MDN431 steel via plasma spray to form coatings, which were characterized for microstructure, hardness, and phase composition. Wear and erosion tests, conducted from room temperature to 600°C, revealed superior performance of the coatings. At 600°C, 2 m/s, and 30 N load, the NiCrBSiFeC coating exhibited six times higher wear resistance than the MDN431 substrate. However, erosion tests at 600°C showed higher weight loss in coatings compared to the substrate, attributed to alumina particle embedment. The formation of oxide phases in the coating significantly enhanced its high- temperature wear and erosion resistance.