(1)Alumina (Al2O3 )      •Al2O3>85%   •Al2O3  >92%   •Al2O 3 >96%   •Al2O3 >99.5%   •Al203  >99.9%   (2)Zirconia (ZrO 2)      •Y2O 3-ZrO2   •MgO-ZrO2   •CeO 2-ZrO2   (3)Silicon Nitride (Si3N 4)   (4)Aluminum Nitride (AlN)   (5)Boron Nitride (BN)   (6)Silicon Carbide (SiC)   (7)Boron Carbide (B4C) (8)BN+Si3N4 (or AlN)   (9)BN+EC   (10)Silicon Dioxide (SiO2)