Drilling of (Al2O3)p/6061 metal matrix composites

Metal matrix composites have been found to be quite useful in a number of engineering applications including the consumer goods. However, the machining of these materials is tough because of the abrasive characteristics of the reinforced particulates. In this paper drilling studies on Al2O3 aluminum-based metal matrix composites have been conducted by using different drills (high-speed steel, carbide-tipped, and polycrystalline diamond (PCD) drills) to produce holes in 10 and 20 vol.% (Al2O3)p/6061. The drilling forces were recorded using dynamometer. Surface finish was evaluated by a surface profilometer, and tool wear and geometry were inspected using optical and scanning electron microscopes (SEM). The drilling characteristics were evaluated in terms of drilling forces, tool wear, chip formation, and drilled-hole quality. It was found that PCD drills outperformed all other drills in terms of drilled-hole quality and minimum drilling forces induced. Better results achieved with the PCD drills are inline with other similar studies with other processes.