Influence of graphite particles on surface roughness and chip formation studies in turning metal matrix composites

Abstract

This study presents an experimental investigation on surface roughness and chip formation in turning of Al 2219/15SiCp and Al 2219/15SiCp-3Gr (hybrid) composites. Experiments were conducted with different cutting conditions using carbide, coated carbide and polycrystalline diamond (PCD) tools. The results reveal that the surface roughness values are less for coated carbide tools compared to carbide and are minimum for PCD tools. The incorporation of graphite in Al 2219/15SiCp composite increases the surface roughness. This is due to smearing and removal of softer and amorphus graphite particles on the surface of the specimen, creates pits on the machined surface which increases the surface roughness values. The graphitic composite produced discontinuous chips leads to easy machining. PCD tool performs better than carbide and coated carbide tools.

Keywords

• graphite
• metal-matrix composites (MMCs)
• surface roughness
• chip formation