The Effect of B4C Amount on Wear Behaviors of Al-Graphite/B4C Hybrid Composites Produced by Mechanical Alloying

Abstract

In this study, wear behavior of composite materials produced by mechanical alloying method adding different amounts of B 4 C to Al-Graphite matrix were investigated. After adding 2% (vol.) graphite to the aluminum matrix, 3 different amounts (3%, 6% and 9%) of B 4 C were added. The composite powders prepared were mechanically alloyed for 60 minutes. The milled powders were cold-pressed under 700 MPa pressure. The green compacts produced were sintered at 600 °C for 120 minutes. The sintered B 4 C reinforced aluminum composite materials (AMCs) are characterized by the scanning electron microscope (SEM+EDS), X-ray diffraction (XRD), and hardness and density measurements. Wear tests were performed on a standard pin-on-disc wear testing device with a load of 20 N at a sliding speed of 0.5 ms -1 and four different sliding distances (250-1000 m). As a result of the studies, the hardness increases as the amount of B 4 C in the composite material increases, while the density of AMC decreases. As a result of the wear tests, the highest weight loss was obtained in the non-reinforced AlGr matrix alloy, while the lowest weight loss was obtained in 9% B 4 C reinforced composite materials. However, it was observed that there was a decrease in the friction coefficient with increasing amount of reinforcement.