Influence of turning parameters on the machinability of Al6061/ZrB2 & ZrC hybrid in-situ Aluminium Matrix Composite

Abstract

ABSTRACT This paper presents the machining characteristics of AA6061/(0–9 wt%) ZrB2+ ZrC aluminium metal matrix composites using polycrystalline Diamond(PCD). In the present investigation, AMCs were fabricated by in situ reactions between K2ZrF6, KBF4 and SiC particles. The electric stir casting furnace was used to fabricate the AMCs under a controlled environment. X-ray diffraction patterns (XRD) and field emission scanning electron microscope (FESEM) were used to ascertain the formation of ZrB2 and ZrC particles in the AMCs. FESEM micrographs confirmed the uniform distribution of ZrB2 and ZrC particulates along with good interfacial bonding with matrix aluminium alloy. The effect of varying wt% of ZrB2+ ZrC along with cutting speed, feed and depth of cut on machining forces and surface roughness were analysed. FESEM was used to study the morphology of cutting tool, machined surface and chip formation. It was observed that cutting forces reduce with increase in cutting speed due to decrease in built-up edge (BUE) formation and deprivation of dislocation density. The tool wear increased with increase in cutting speed, depth of cut and ZrB2 + ZrC content due to the increase in abrasive action of ceramic particles and reduction of stable BUE.