Machinability of various aluminum matrix composites

Examples for milling aluminium matrix composites are presented: small series of parts made of particulate reinforced Al-alloys, which are prototypes of components for brakes and combustion engines, and continuous fibre reinforced test specimens. Emphasis is given to the SiC particulate reinforced foundry alloys, which are the most difficult to machine. Therefore polycrystalline diamond tipped tools (PCD) are employed. The flank wear of the PCD cutting tools is mainly proportional to the milling distance and more or less independent of the depth of cut (<2 mm) and of the feed rates (<0,5mm per revolution and tooth). It is important to adjust the tool geometry to the machining operation and to provide stable mounting of both the tool and the work piece to avoid vibrations. Estimates of milling costs are given and the potential savings are indicated.