A comparative study of microstructural development in the sol–gel derived alumina–mullite nanocomposites using colloidal silica and tetraethyl orthosilicate

摘要: This paper compares the microstructure development of two alumina–15 vol% mullite composites during sintering. The nanopowders alumina–mullite composite were synthesized by sol–gel method using aluminum chloride hexahydrate and different silicon sources (colloidal silica in route 1 tetraethyl orthosilicate 2). prepared pressing sintering nanopowders. Although intergranular mullites observed both routes, there particles 2 formed inside alumina grains (intragranular mullite). Formation intragranular is attributed to drop solubility, which occurs transition from metastable stable alumina. Compared 1, relative density average grain size increased accelerated 2. two-stage not useful for decomposition.