Journal of the American Ceramic Society, Vol.103, No.6, 3493-3499, 2020
Microstructural evolution of 3YSZ flash-sintered with current ramp control
The effect of a controlled current ramp during flash sintering (FS) on the densification and microstructural evolution of 3 mol% yttria-stabilized zirconia was investigated. The samples were flash sintered using a current ramp control with six different current ramp rates and compared with samples sintered by FS without current ramp control. In both cases, maximum electric current densities of 100 and 200 mA mm(-2) were used. The microstructure of cylindrical samples was observed, showing grain size heterogeneity between the curved surface and the core for the flash-sintered (FSed) samples regardless of the maximum current density used. By contrast, the current ramp FSed samples exhibited a homogeneous grain size when the electric current density of 100 mA mm(-2) was applied. Thus, controlling a current ramp during FS can be an alternative for avoiding grain size heterogeneity on ceramics sintered by this technique.
Keywords:current ramp control;Field Assisted Sintering Technology (FAST);microstructure;zirconia;zirconia;yttria stabilized