Improvements in Cavitation and Slurry Wear Erosion of Inconel 718 Laser Cladding Through NiNb Addition

Abstract

Developing new materials and alloys for coatings is increasingly crucial to reduce costs in manufacturing. Inconel, a widely used alloy, is known for its chemical inertness and resistance to high temperatures, but it lacks sufficient resistance to erosive wear. This study evaluated the wear resistance of Inconel 718 and Inconel 718 + 10% NiNb coatings produced by laser cladding, focusing on cavitation and slurry erosion. Scanning electron microscopy (SEM-EDS), x-ray diffraction, and microhardness profiling were employed to analyze the microstructure and wear. Cavitation erosion tests followed the ASTM G32 standard (2016), and slurry erosion resistance was tested according to ASTM G73-10 (2017). Mass loss and wear rates were assessed for both coatings. The laser-cladding IN718 and IN718 + 10% NiNb coatings exhibited solidification structures with fine dendrites, low dilution, no cracks, and minimal porosity. Adding 10% NiNb refined the microstructure, reducing dendrite size and improving the overall coating quality. This also resulted in a 45% increase in microhardness for the IN718 coating. A higher dispersion in microhardness was observed in the IN718 + 10% NiNb coating. The addition of 10% NiNb promoted the formation of thicker interdendritic zones in an interconnected network, with a higher concentration of the Laves phase. This enhancement increased cavitation resistance and improved slurry erosion resistance by 33% at a 60° impact angle. However, at a 30° impact angle, the improvement was less effective. This study demonstrates the potential of IN718 + 10% NiNb coatings for applications demanding enhanced cavitation and slurry erosion resistance, particularly at higher impact angles.