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Source : Company data sheets from Coors Ceramics, Ceradyne Inc., and Saint-Gobain Advanced Ceramics Corporation. ZTZ = zirconia-toughened alumina, TTZ = transformation-toughened zirco-nia, and YTZP = yttria tetragonal zirconia polycrystal.

Source : Company data sheets from Coors Ceramics, Ceradyne Inc., and Saint-Gobain Advanced Ceramics Corporation. ZTZ = zirconia-toughened alumina, TTZ = transformation-toughened zirco-nia, and YTZP = yttria tetragonal zirconia polycrystal.

lists some properties of commercial grades of alumina compared to several other advanced ceramics. New laboratory grades of alumina have even better properties. For example, one fine-grained (0.56 ^m) sintered alumina being evaluated for cutting tool inserts has average bending strength of 650-700 MPa and Vickers hardness (with 10 kgf load) of 22.1 ± 0.9 GPa [4]. This alumina has substantially out-performed cubic boron nitride and Al2O3-TiC for cutting cast-iron and hardened steel by turning on a lathe at 300 m/min.

Alumina is presently the lowest cost high-performance ceramic because of the large quantity produced. The alumina suppliers have an enormous design and experience database so that they should be consulted when seeking an alternate material for increased corrosion resistance, wear resistance, dimensional stability, decreased friction, and higher temperature use.

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