Nanocrystalline yttria-doped zirconia sintered by fast firing

• Published in: Materials letters 2016-03, Vol.166, p.196-200
• Main Authors: Gómez, S.Y., da Silva, A.L., Gouvêa, D., Castro, R.H.R., Hotza, D.
• Format: Article
• Language: English
• Subjects: 3YSZ; 8YSZ; Densification; Fast firing; Grain growth; Grain size; Hot pressing; Nanocrystals; Sintering; Sintering (powder metallurgy); Spark plasma sintering; Zirconium dioxide
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2015.12.042

Sintering of powders commonly leads to simultaneous densification and grain growth, particularly for nanocrystalline materials. Currently, methods such as spark plasma sintering (SPS), hot pressing (HP), two-step sintering (TSS) and fast firing (FF) are employed to hinder grain growth while maintaining a high densification. In this work, FF consisting in thermal treatments with high heating rates (>500° C/min) and shorter holding times (10min or less) and conventional sintering (CS) approaches were experimentally compared in the sintering of commercial yttria doped zirconia (3YSZ and 8YSZ) compacts. CS-samples presented larger grain sizes by a factor of ~2 and ~4 in comparison to the initial 3YSZ and 8YSZ powders. Conversely, FF method significantly suppressed grain growth with a growth factor of ~1. Those results and comparison with previous work indicated that high heat inputs could indeed minimize grain growth. Near full dense YSZ sintered at 1400°C by conventional sintering (CS) and fast firing (FF). [Display omitted] •Fast firing (FF) at >500°/min was compared to conventional sintering (CS) at 10°C/min.•Final densities were similar with both FF and CS samples.•CS-samples presented larger grain sizes by a factor of ~2 (3YSZ) and ~4 (8YSZ).•FF method significantly suppressed grain growth with a growth factor of ~1.