The investigation on friction and wear properties of cast iron matrix surface compact vanadium carbide layer

Abstract

To enhance the wear resistance of cast iron, a cast iron matrix compact vanadium carbide layer was fabricated by two step in-situ solid-phase diffusion processes. The vanadium carbide layer consist of V2C dense layer, V8C7 dense layer, and V8C7/α-Fe gradient transition layer with 7.6 μm, 35.7 μm, and 86.3 μm in thickness, respectively. The friction and wear properties of the compact vanadium carbide layer and the cast iron substrate were evaluated using the pin-on-disc abrasive wear tests and ball-on-flat dry sliding wear tests. Abrasive wear results show that the wear resistance of the compact vanadium carbide layer is 11.67 times higher than that of matrix. The main abrasive wear mechanism is fracture and peel off of vanadium carbide particle. Ball-on-flat dry sliding wear results show that the friction coefficient of the layer increased first and then decreased with the temperature changing from 25 °C to 800 °C. The main friction wear mechanism is spalling at 25 °C, forming mechanical mixture layer at 400 °C, and delamination wear at 800 °C.