Lifetime and Wear Behavior of Near Net Shaped Si 3 N 4 /SiC Wood Cutting Tools

The introduction of ceramics into the market of wood cutting tools has been difficult because of the generally low toughness of ceramics which causes brittle failure. That is why the improvement of mechanical performance of ceramics with potential to be used as cutting tools is important. The newly developed Si 3 N 4 /SiC wood cutting tools have a bending strength of 740 MPa, a fracture toughness of 5.4 MPam 1/2 , a hardness of 16.8 GPa and a grain size of 1 μm. These Si 3 N 4 /SiC tools were tested in a lifetime cutting trial on wood and showed twice as long lifecycles than standard tungsten carbide tools. Furthermore, the static corrosion resistance in tannic acid, the friction coefficients between wood and the tool material and the cutting forces were measured for both the ceramic composite and the tungsten carbide tools.