Nanocrystalline yttria-doped zirconia sintered by fast firing

• 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.

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 (10 min 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).Figure optionsDownload as PowerPoint slide