Properties of low-temperature-sintered high purity α-alumina ceramics

In this study, a commercially available high purity α-alumina was shown to be a low-temperature-sinterable powder. Although the sintering temperature was as low as 1300°C, alumina ceramics with over 98% relative density were achieved because of the high sinter reactivity of the powder. The best mechanical properties and excellent wear resistance were also obtained at this sintering temperature. Overall it was confirmed that the flexural strength and wear resistance of pure alumina increases with decreasing grain size, whereas the fracture toughness and Vickers hardness of alumina ceramics did not directly relate to the grain size.