Tool wear and its mechanism for cutting SiC particle-reinforced aluminium matrix composites

Tool wear in the cutting of SiC particle-reinforced aluminium matrix composites has been investigated with special attention paid to the effects of material structures on the tool wear mechanism. The results of experiments show that the major damage mechanism is abrasive wear for conventional tools and brittle break for high hardness tools in the cutting of SiC particle-reinforced aluminium matrix composites. Even though a built-up edge can occur on the face of the tool at a lower cutting speed, it cannot protect the flank face of the tool from abrasive wear. The volume fraction and the size of SiC particle are found to be the major factors affecting the tool life. When the composites are cut by conventional tools or by most ceramic tools, SiC particles in the composites also micro-cut these tools due to their high hardness. However, when the size of SiC is fine enough, the matrix of the composites coordinates the particle into deformation. Thus, it is concluded that the cutting of composites reinforced by coarse SiC particles requires tools which have high hardness: conventional tools are only adaptable to cut composites reinforced by fine SiC particles.