Experimental Investigations on Effect of Ceramic B4C Particulate Addition on Cutting Forces and Surface Roughness during Turning of 6061Al Alloy

Abstract

ABSTRACTAluminium matrix composites are of great interest for researchers in recent years because of their excellent combinations of engineering properties over traditional materials. The machinability of these aluminium matrix composites has become vital for manufacturing industries. During machining of aluminium matrix composites, the cutting forces and surface roughness are dependent on machining parameters (feed rate, cutting speed and depth of cut) and manufacturing parameters (size of the particles, volume fraction, porosity, hardness). With this backdrop, the present work is aimed at investigating the effect of machining parameters, viz. cutting speed, feed rate and depth of cut on the cutting force components, namely, feed force (Ff), radial force (Fd), cutting force (Fc) and surface roughness. The experiments were performed on 0, 5, 7 and 9 wt% B4C particulate of 88 µm size reinforced composite specimens. The prepared specimens were subjected to turning operation on a conventional lathe machine using polycrystalline diamond (PCD) tool to evaluate the effect of B4C particulate addition with varying percentages on cutting forces and surface roughness. Results reveal that the cutting force components decrease with the increase in the wt% of ceramic B4C particulate reinforcement, which can be attributed mainly to increase in porosity, hardness and dislocation densities. SEM image obtained from composite having low wt% of ceramic B4C particulates (5 wt%), which is machined at higher cutting speed and higher depth of cut, has clearly shown the presence of built-up edge (BUE) at the tip of polycrystalline diamond tool. Further, cutting forces increased with increase in feed rate and depth of cut for both 6061Al matrix and 6061Al-B4C composites. It is observed that the surface quality is significantly improved when the cutting speed is increased, and depth of cut and feed rate are decreased.