Micro-abrasive Wear Behavior of Nitrided and Multilayer Coated High Vanadium Powder Metallurgy Alloy

Abstract

The micro-abrasive behavior of plasma nitrided Vanadis 10, a high vanadium powder metallurgy alloy, combined with TiCN/AlTiN/CrAlTiN/CrN multilayer film was evaluated and compared with different treatment conditions. Microstructural evolution with treatments was evaluated. The tribological behavior was accessed using the fixed ball micro-abrasion test and SiC as abrasive. The counter-body was an AISI 52100 steel sphere (O 25.4 mm), the SiC abrasive slurry concentration was 0.50 g/cm3, the rotary speed was set at 75 rpm, and the applied load was 0.49 N. The wear crater was characterized by scanning electron microscopy (SEM). Results indicated that the film is effective in reducing the wear coefficient in more than 80 pct for all conditions compared with Vanadis 10. Nitriding treatments impaired the samples’ wear resistance because of the presence of cracks in this layer. Sliding/grooving abrasion was observed for the conditions with higher wear coefficients. The change in the micro-abrasion wear mechanism from grooving abrasion to rolling abrasion is attributed to the protection of the surface by the hard multilayer coating, producing a reduction in the wear coefficient.