Residual chlorine prevents full densification of flash sintered yttria-stabilized zirconia ceramics

Journal article

The densification of yttria-stabilized zirconia (YSZ) during flash sintering is strongly dependent on the amount of residual chlorine in the sintered bodies. The residual chlorine, present as a remnant from powder synthesis, hinders densification after it is trapped and vaporized in the rapidly closing pores, limiting the final density at around 87 – 93% of theoretical. We show that this phenomenon is likely to affect all YSZ powders synthesized from chloride precursors unless the residual chlorine is reduced to ≤ 0.03 wt% before the onset of the flash sintering. This can be universally achieved by thermal purification of green bodies at a high temperature or by chemical purification in ammonium hydroxide. Furthermore, added binder in commercially available Tosoh zirconia TZ-powders (TZ-3YB, TZ-3YB-E) helps to significantly reduce chlorine content during binder burnout which in turn allows flash sintering into a high density even without green body purification.

Authors: Prajzler, V; Maca, K; Todd, R

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Journal of the European Ceramic Society
• Volume: 44
• Issue: 11
• Pages: 6660-6667
• Publication date: 2024-04-09
• Acceptance date: 2024-04-08
• DOI: 10.1016/j.jeurceramsoc.2024.04.017
• EISSN: 1873-619X
• ISSN: 0955-2219
• Language: English
• Keywords: FFR