抄録
Mullite exhibits low dielectric constant, high strength and relatively low thermal expansion coefficient, and therefore, is useful as a substrate for high-speed computer. Mullite is also a candidate material for high-performance low-temperature co-fired ceramic (LTCC) substrate because of the same reasons mentioned above. To apply the mullite substrate to LTCC, the reactivity of the mullite with elements that are contained in the glasses for low-temperature sintering should be investigated to choose the sintering aid for LTCC. In this paper, effect of the small amount of solution-derived yttoria addition on the sinterability of the mullite was investigated for the low-temperature sintering as well as the optimum amount of the alumina addition. The amount of the alumina addition was restricted within the solubility limit in mullite. As a result, faint amount of solution-derived yttria addition greatly enhanced the sinterability of the mullite because of the promotion of the liquid phase sintering by the uniformly dispersed yttria phase. In this paper, the relation between microstructures and the mechanical properties of the resultant mullite ceramics was discussed.
