Effect of Solid Lubricant in Dry Machining on Al-B₄C Composite

Machining of metal matrix composites is extremely very hard because of its heterogeneity and hardness. However, it is possible through improving its inherent active lubrication. This is one way to reduce cutting forces and tool wear during machining. This work is to evaluate the effect of solid lubricant, hexagonal boron nitride (hBN), on dry machining of aluminum–boron carbide (B₄C) composite. Machining of fabricated composites is done with varying amounts of hBN particle from 5 to 15%. The machining performance is estimated by the measuring magnitude of cutting forces and tool wear with respect to different depth of cuts, feed rates, and cutting speeds. Mechanical property like hardness decreases with the increase in the amount of hBN particle. Polycrystalline diamond (PCD) insert was used to machine the work. Machining parameters like cutting speed reduce the cutting force and tool wear. The spatial presence of boron carbide and hBN particles in the microstructure is affecting machining performance. The presence of hBN particles in the composite spatial microstructure reduces tool flank wear. The reason contributed to the fact a shearing of hBN particles. These particles reduce shear stress between primary cutting zone and tool causing a low magnitude of surface roughness on the work.