Phase composition and fracture toughness of Si3N4-ZrO2 with CeO2 additions
Zirconia toughened Si3N4 was prepared with addition of CeO2 by applying hot pressing technique. Phase composition, densification, fracture toughness and hardness were investigated as a function of hot pressing temperature and CeO2 content. The absence of nitrogen containing zirconia phase was discussed. Fracture toughness of Si3N4-ZrO2(+CeO2) with 12 mol% of CeO2 in ZrO2 reached 15 MPa m(1/2). Dominating toughening mechanism according to our data seems to be stress induced microcracking. (C) 1998 Elsevier Science Limited and Techna S.r.l. All rights reserved.