Low-temperature sintering of α-alumina-seeded boehmite gels

α-Al₂O₃ can be sintered at lower temperatures when derived from a seeded boehmite gel. The extended vermicular microstructure, which is characteristic of α-Al₂O₃ derived from Al₂O₃ precursors, is avoided by using a large number of seed particles. The scale and uniformity of the microstructure formed by the in situ growth of α-Al₂O₃ are the key factors that allow for low-temperature sintering. Herring's scaling law can be used to predict the approximate sintering temperature and demonstrates that, if scale of microstructure can be reduced to <20 nm, sintering below 1000 °C may be possible.