INFLUENCE OF NIO ON PHASE STABILIZATION IN 6 MOL-PERCENT YTTRIA-STABILIZED ZIRCONIA

Yttria (6 mol%)-stabilized zirconia powders with addition of 0, 5 and 10 mol% NiO were prepared by means of radio frequency plasma synthesis . As-prepared and sintered (up to 1600 degrees C) samples have been in vestigated by x-ray diffraction. The dissolution of NiO is found to en hance the formation of the cubic zirconia during plasma synthesis. Sin gle-phase cubic zirconia solid solution forms if samples doped with 5 and 10 mol% NiO are heat treated at elevated temperatures. The cubic p hase is stable at 1600 degrees C, but undergoes a cubic-to-tetragonal phase transformation on cooling. (C) 1997 Elsevier Science S.A.