Effect of reinforcement particles on the abrasive assisted electrochemical machining of Aluminium-Boron carbide-Graphite composite

Aluminium metal matrix composites (AMMCs) are now gaining their used in aerospace and automotive industries. Among many AMMCs, Aluminium metal matrix reinforced with Boron Carbide (B4C) is a novel composite. This composite is widely used in automotive industries (brake pads and brake rotor) due to high wear resistance, high strength to low weight ratio, elevated temperature toughness and high stiffness. Boron carbide shows exotic properties such as neutron absorbing compared to other reinforcements such as Al2O3 and SiC. In order to improve tribological characteristics of Al-B4C, the graphite is added as a solid lubricant. Due to the presence of hard ceramic reinforcement in metal matrix, it is very difficult to machining by conventional methods. Even nontraditional processes such as laser jet machining and electro discharge machining result in significant subsurface damage and heat affected zone to the work. Electrochemical machining (ECM) is an advanced machining process that is used for the machining of aerospace and automotive components, and dies and molds, etc. In order to increase the material removal rate and surface quality of the work, fine size abrasive particles are mixed with electrolyte. This abrasive particles working along with anodic dissolution can increase the material removal rate.