DRY SLIDING WEAR RESISTANCE OF HVOF SPRAYED IRON-BASED COMPOSITE COATINGS ALLOYED WITH CARBIDES ACROSS VARIOUS TEMPERATURES

Abstract

Maraging steel, widely used in aerospace applications for its remarkable strength and toughness, often faces challenges related to surface wear resistance in high-stress environments. This study investigates the dry sliding wear performance of Fe-based coatings allied with carbides, applied onto maraging 250-grade steel using the High-Velocity Oxy-Fuel (HVOF) thermal spraying surface modification technique. The objective is to assess the tribological behavior of these as-sprayed samples under varying circumstances. Dry wear tests were conducted at both room temperature and 300 °C under a normal load of 30 N. The study comprehensively investigates the factors influencing wear resistance by analysing key microstructural and mechanical properties, including microhardness, porosity, and bond strength. Advanced characterisation techniques were employed, including Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) for surface morphology and elemental analysis and X-ray diffraction (XRD) for phase identification. A 3D profilometer was utilised to measure wear scar volume and quantify volumetric wear loss precisely. At room temperature, abrasive wear dominated, with ploughing and furrows as primary material removal mechanisms. Notably, the 316L-20%Cr3C2 coating exhibited better wear resistance compared to the 17-4ph-20%Cr3C2 coating. This enhanced performance is attributed to the carbide reinforcements, which significantly increased hardness and improved wear resistance under high temperatures. These findings emphasize the potential of carbide-reinforced HVOF coatings as an effective surface engineering approach for enhancing the performance and service life of maraging steel under harsh operational conditions, particularly those involving high temperatures and severe wear. © © 2025 by ASME.