Abstract: Upon the analysis of the friction features at the interface between tool and chip in the cutting process of aluminum composite reinforced with SiC particle or SiC whisker, a friction formula characteristic of close contact is presented and verified. The wear mechanisms of the cutting tools and the machined composites were analyzed with SEM. Compared with the results of the cutting experiments and the computer simulation, it has been found that the real friction condition at the interface between tool and chip can be well described by the formula. The wear resistance of the aluminum based composites is better than that of aluminum alloy matrix. The cutting tool made of K type cemented carbides is suitable for crude and semi precise machining. At a small cutting speed and larger feed of precise machining, PCD tool is the best cutting tool candidate.