Effect of Graphite Particles in Drilling of Hybrid Aluminum Matrix Composite

In aluminum matrix composites, presence of hard particles inside the matrix which causes tool wear, poor surface finish and high cutting forces while machining. This paper discusses the influence of graphite particles and cutting parameters on drilling characteristics of hybrid aluminum matrix composites (AMCs)—Al6063/6%Al2O3p and Al6063/6%Al2O3p/1%Grp. The composites are fabricated using stir casting method. Experiments were conducted with TiN coated carbide tools and commercial carbide tools at various cutting speeds and feeds. Design of experiment of full factorial design is employed to analyze the drilling characteristics of these composites. Burr height and surface roughness of the drilled hole was investigated with special attention paid to the effects of graphite particles. The chips formed when machining graphitic composites are more discontinuous which led to better surface finish than non graphitic composite.