An Investigation the Effects of Particulate Reinforcement Volume Fraction and Heat treatment on the Hardness and Wear Properties of Al-%4 Cu-〖MoSi〗_2 Composites

In this study, the mechanical properties and wear resistance of Al-%4 Cu aluminum alloy reinforced with different amounts (5, 15 and%25) of intermetallics particles MoSi_2 have been investigated. The aluminum alloy Al-%4 Cu powder was produced by gas atomization method and the MoSi_2intermetallic particles were produced through combustion synthesis. The Al-4 Cu matrix powder was mechanically blended with different amounts (5, 15 and%25) MoSi2 using a ball milling mixer. The blended powder mixture was encapsulated and then hot extruded to composite bars. The heat treatment T6 was carried out on some of the composite samples. Wear tests were performed on both as-extruded and heat-treated samples using a pin on disk apparatus with a tool steel counterpart. The friction coefficient was measured and the wear mechanism was determined through the evaluation of weight loss of the composite samples. A complete study was done using the scanning electron microscopy (SEM) and EDS analyzing of the worn surfaces. The heat treatment improved the wear resistance and hardness of the composite samples for in comparison with the as-extruded samples. The results indicated that the main wear mechanism is the adhesive wear, however, the oxide and abrasive wear mechanisms were observed to slightly happen.