Microstructural evolution of 3YSZ flash‐sintered with current ramp control

• Published in: Journal of the American Ceramic Society Vol. 103; no. 6; pp. 3493 - 3499
• Main Authors: R. Lavagnini, Isabela, Campos, João V., Ferreira, Julieta A., A. Pallone, Eliria M. J.
• Format: Journal Article
• Language: English
• Published: Columbus Wiley Subscription Services, Inc 01.06.2020
• Subjects: Current density; current ramp control; Densification; Electric currents; Evolution; Field Assisted Sintering Technology (FAST); Grain size; Heterogeneity; Microstructure; Resistance sintering; Yttrium oxide; zirconia; zirconia: yttria stabilized; Zirconium dioxide
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.17037

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.