Fabrication of 3YSZ with single tetragonal phase by ultrafast high-temperature sintering
R. Murakami, Bin Feng, Koji Matsui, Shun Kondo, Naoya Shibata, Yuichi Ikuhara
Abstract
3 mol% yttria-stabilized zirconia (3YSZ) has been widely used as structural ceramics because of the high toughness of the tetragonal phase. However, since the conventional 3YSZ is sintered in the temperature range of the tetragonal-cubic phase coexistence region for several hours, Y3+ distributed inhomogeneously, and Y3+-rich regions undergo phase transformation into thermodynamically stable cubic phase. As a result, these 3YSZ usually exhibit tetragonal and cubic dual phases. Thus, suppressing the Y3+ redistribution during sintering is a key to prevent the phase transformation. Here, a fully dense 3YSZ with single tetragonal phase was successfully sintered by shorting sintering time using the ultrafast high-temperature sintering (UHS) method. The crystal structure, microstructure, and Y3+ distribution were investigated by XRD, SEM and STEM-EDS. We show that compared with the conventionally sintered 3YSZ, UHS effectively suppress Y3+ redistribution. The present results indicate UHS will be powerful to sinter ceramics in a non-equilibrium state.