Al6061-GRAPHITE-TUNGSTEN CARBIDE HYBRID COMPOSITES

This Book describes the investigations carried out on base Al6061 alloy, Al6061-WC MMCs and Al6061-WC-Gr MMHCs. The composites were developed by liquid metallurgy technique. In the development of Al6061-WC MMCs and Al6061-WC-Gr MMHCs the tungsten carbide of 1-4 wt% used as a primary reinforcement, and a constant 4 wt% graphite (Gr) used as a secondary reinforcements in Al6061-WC-Gr MMHCs.The manufactured composites were treated with T6 heat treatment for different ageing times of 1, 3 and 5 h. As-cast and heat treated composites were characterized for their physical, mechanical and tribological properties. The mechanical and wear properties were investigated according to the ASTM standard testing procedures. The composites properties were investigated in as- cast and heat treated conditions.Scanning Electron Micrographs (SEM) of tensile fracture surfaces of the MMCs and MMHCs revealed that there was an excellent bond between matrix and reinforcements. The strong bond allows the effective transfer of applied load between the matrix and reinforcements. The fractured surfaces confirm the brittle failure mechanism of the composites.