Machining performance of phase transformation toughened alumina and partially stabilised zirconia composite cutting tools

Phase transformation toughened zirconia (TTZ) doped with yttria or ceria has excellent properties such as higher order fracture toughness, thermal shock resistance and moderate hardness. With these qualities, they are able to exhibit machining performance comparable to cold-compacted Al₂O₃ cutting tools. With an addition of 20% aluminium oxide to TTZ, i.e. the composites of alumina and partially stabilised zirconia (PSZ) exhibit improved toughness, enhanced thermal shock resistance and hardness. The alumina and PSZ composite ceramic tools exhibit cutting performance better than TTZ tools and comparable to zirconia toughened alumina tools.