The effect of B4 C amount on wear behaviors of Al-Graphite/B4 C hybrid composites produced by mechanical alloying

Abstract

In this study, wear behavior of composite materials produced by mechanical alloyingmethod adding different amounts of B4C in the Al-Gr matrix were investigated. Afteradding 2% (vol.) graphite to the aluminum matrix, 3 different amounts (3%, 6% and9%) of B4C were added. The composite powders prepared were mechanically alloyedfor 60 minutes. The milled powders were cold-pressed under 700 MPa pressure. Thegreen compacts produced were sintered at 600 °C for 120 minutes. The sintered B4Creinforced aluminum composite materials were characterized by the Scanning Electron Microscope, X-ray diffraction, and hardness and density measurements. Weartests were performed on a standard pin-on-disc wear testing device with a load of 20N at a sliding speed of 0.5 ms-1 and four different sliding distances (between 250-1000m) according to ASTM G99 standard. As a result of the studies, the hardness increasesas the amount of B4C in the composite material increases, while the density of AMCdecreases. As a result of the wear tests, the highest weight loss was obtained in thenon-reinforced Al-Gr matrix alloy, while the lowest weight loss was obtained in 9% B4Creinforced composite materials. However, it was observed that there was a decreasein the friction coefficient with increasing amount of reinforcement.