The Effects of Reinforcement with TaC on the Microstructure and Wear Properties of Lamellar Graphite Cast Irons

Abstract

Lamellar graphite cast irons are prevalently used in several industrial applications, especially the automotive industry, due to their high compressive strength, high thermal conductivity, high castability, vibration damping ability, good mechanical strength, friction and wear resistance, better machinability than other cast irons, and good mold filling. In this study, changes in the wear volumes, wear rates, wear track profiles, and friction coefficients of lamellar graphite cast irons in which Tantalum Carbide (TaC) was added at different reinforcement ratios (A (0.025 wt.%), B (0.155 wt.%), C (0.285 wt.%), and K (unreinforced, 0 wt.%)) were investigated. Additionally, by examining the wear surfaces of the samples using a scanning electron microscope (SEM), their wear mechanisms were determined. As a result of the analyses, it was determined that different reinforcement ratios did not have a noticeable effect on wear track profiles under a load of 1 N. On the other hand, different reinforcement ratios showed an effect on wear track profiles under loads of 3 N and 5 N. The most perceptible wear track profile was formed in Sample C under 5 N. It was observed that increased load values resulted in increased wear volumes, but the increases in the wear rates of the samples were not significant, and the numerical values were close to each other. The highest wear volumes were determined in the reinforced C sample and the unreinforced K sample under 5 N load. As the magnitude of the load that was applied increased, the friction coefficients of Samples B and C decreased, but the friction coefficients of Samples K and A increased.