Nanostructured alumina—20 vol% 3‐yttria‐stabilized zirconia (3YSZ) powder composites were synthesized by the wet‐milling technique. The starting materials were a mixture of alumina micropowder and 3YSZ nanopowders. The mixtures were optimized for good sintering behaviors, high hardness, and toughness. Nano‐crystalline grains were obtained after milling for 24h. The nano‐structured powders were then processed to full density at different temperatures by high‐frequency induction heat sintering. Effects of sintering temperature on the hardness, toughness, and microstructure properties have been studied. Al2O3–3YSZ composites with higher hardness, toughness, and smaller grain size have successfully been developed at relatively low temperatures by this technique.

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A novel nanocomposite has been introduced to improve the fracture toughness of hydroxyapatite (HAp) bioceramics. Composites of HAp/NiO with 1–5 wt% of electrospun NiO nanofibers were developed and studied. The mixtures were consolidated very rapidly to full density by high‐frequency induction heat sintering (HFIHS). The role of NiO nanofibers in enhancing the toughness, hardness, and microstructure properties of the HAp bioceramic was investigated. Field emission scanning electron microscopy was used to examine the morphology of the bioceramic composites and fracture surfaces to reveal the dominant toughening mechanisms. The results showed that the sintering behaviors, toughness, and hardness of the resulting composites were significantly enhanced by the inclusion of NiO nanofibers. The fracture toughness of the heat sintered HAp/NiO electrospun nanofiber composites was 1.8 times higher, as the concentration of NiO electrospun nanofibers reached 5 wt%.

High‐frequency induction heat sintering (HFIHS) is a comparatively new technique that consolidates metals and ceramics very rapidly to full density. In this work, superfast densification behavior and the attendant microstructural features of Al2O3–(ZrO2+8% mol Y2O3) composites processed by HFIHS were investigated. The effects of processing parameters such as sintering temperatures, pressures, and heating rate, on the mechanical and microstructural properties were studied. The results indicated that HFIHS was effective in the preparation of fine‐grained, nearly fully dense Al2O3–8YSZ ceramics from the powder with a smaller particle size by optimizing the overall processing parameters.

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