Metal-Matrix Composites (MMC) are being developed for high wear resistance applications. A new MMC, a graphitic aluminum metal matrix composite consisting of an aluminum matrix reinforced with SiC particles and nickel-coated graphite particles, GrA-Ni™, has been developed by INCO Limited. The addition of nickel-coated graphite to SiC particulate reinforced aluminum plays a similar role to flake graphite in grey cast iron. However, like other MMCs, this composite is demanding in terms of requirements for cutting conditions and cutting tool materials.
This paper assesses the machining data for this new composite, in regards to tool life, surface finish and cutting forces. The tests included milling, turning, and drilling conducted with carbide and diamond tools. The test results showed that GrA-Ni™ with 10 vol% SiC – 5 vol% Gr, is easier to machine than existing aluminum composites reinforced with SiC particles, such as 20 vol% SiC reinforced aluminum composite.