| Popis: |
The present article reveals the surface characteristics of zinc-aluminum alloy (ZA43) reinforced with silicon carbide (SiC) particulate conventional composite and SiC+Graphite dual reinforced hybrid metal matrix composites. Both the composites were prepared using a liquid metallurgy technique. A base alloy of metal matrix composites (MMC) containing zinc—57 %, aluminum—43 % was reinforced with SiC (5 %) with an average particle size of 60 μm and hybrid composite with 5 % SiC and 5 % graphite. The coated carbide tool SNMG was used to machine the two varieties of composites under dry condition. Machining parameters were considered at three different levels, keeping a constant depth of cut. It was observed from the results that the surface finish was greatly influenced by cutting speed and feed. Unhybridized composites exhibit (without graphite) higher roughness values than composites with graphite during the machining trials. The reasons for higher roughness values include particle pullout, particle fracture, and built-up edge formation on the cutting tool during the machining process. |
