The Effects of B4C Amount on Hardness and Wear Behaviours of 7075-B4C Composites Produced by Powder Metallurgy Method

In this study, the effects of B4C amount on hardness and wear behaviours of 7075 Al-B4C composites produced by powder metallurgy method were investigated. Within the scope of work, different amount of B4C (3, 6, 9%) added into gas atomized 7075 Al powders. The powders were mixed in Turbula with 67 rpm for 45 min. Then the composite powders were pre-shaped by cold pressing under 600 MPa pressure. Pre-shaped samples were sintered in atmosphere controlled furnace at 580 degrees C for 4 h. Scanning electron microscope, X-ray diffraction examinations and hardness measurements were carried out after standard metallographic processes. Wear tests were performed in a pin on type wear apparatus under 30 N with 1 m s(-1) sliding speed, at six different sliding distances (500-3000 m). Results show that the hardness was increased with increasing of amount of B4C. At the end of wear tests the lowest weight loss were found to 9% B4C containing composites. In addition, it is determined that the weight loss increased with increasing sliding distance.