(1)Alumina (Al2O3 ) •Al2O3 >85% •Al2O3 >92% •Al2O3 >96% •Al2O3 >99.5% •Al2O3 >99.9% (2)Zirconia (ZrO2 ) •Y2O3 -ZrO2 •MgO-ZrO2 • CeO2 -ZrO2 (3)Silicon Nitride (Si3N4 ) (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 )