Abstract：SiCp/Al composites have poor machinability because of a large amount of SiC hard particles in them. In view of the high speed and high efficiency machining of this material, the face milling tests of SiCp/Al composites with volume fraction of 20% is carried out by means of carbide coated cutters. Through single factor experiments, the effects of cutting speed, feed rate and axial cutting depth on the wear process of the rake and flank faces were investigated, and the rules of tool wear initiation and propagation were studied. The experimental results show that in the process of finishing SiCp/Al composites with cemented carbide coated tools, the contact form between knifepoint and workpiece is convex arc contact at first, then turn into concave arc contact, and turn into plane contact at last. The tool wear increases with the increase of cutting speed and axial cutting depth, and decreases with the increase of feed rate. The main reason for the failure of cemented carbide coated cutting tools is the ploughing of the flank face, and the VBmaxexceeds 0. 6 mm. The main sources of wear are the abrasive wear and the peeling of the coating.

Keyword：SiCp/Al composites;tool wear;milling;cemented carbide coated tool;