Fabrication and sinterability in Y2O3-CeO2-ZrO2

Abstract

CeO2-stabilized tetragonal zirconia polycrystal (Ce-TZP) containing 1 to 6 mol % YO1.5 have been fabricated as fine powders by a coprecipitation technique. The microstructure of the as-sintered surface and fracture surface were examined by electron microscopy. CeO2 dopants reduced the phase transformation temperature from amorphous to tetragonal and stabilized the tetragonal phase at low temperature. The addition of Y2O3 to Ce-TZP inhibited the grain growth. The sintered density reached 99% theoretical for short sintering times at 1440 and 1540° C, but decreased slightly to 97 to 98% theoretical for longer sintering times. The decrease in density is attributed to the morphological development of agglomerates, which induce large pores during sintering. The average grain size decreased significantly as the yttrium content increased from 1 to 3 mol %. Specimens aged in water at low temperatures exhibited no phase transformation. This implies fairly good thermal stability in the Y2O3-doped Ce-TZP system. © 1989 Chapman and Hall Ltd.