Machinability of SiC particle reinforced 2009Al matrix composites when high-speed milling with PCD tools

The high-speed milling machinability of SiCp/2009Al composites was investigated when using PCD tools at the cutting speed range of 600-1,200 m/min. The result shows that PCD tool life was in the range of 25-240 min when a 0.1 mm tool wear criterion was chosen. PCD tools mainly suffered from tool grain breaking-off, chipping, abrasive wear, micro cracks and adhesive wear due to the very high-frequency impact, sever cutting vibration and scrape of SiC particles. The value of the cutting force Fy was in the range of 700-2550 N. The cutting temperature was in the range of 240-580°C. A surface roughness value Ra0.207-0.542 µm and Rz2.02-5.2 µm can be attained when tool flank wear VB is less than 0.09mm. The machined surfaces presented many defects such as pits, voids, grooves, protuberances and matrix. The depth of deformation layers was confined to 20-35 µm. The chip took the form of semi-flow type or saw-toothed type.