In situ interlocking structure in gel-derived mullite matrix induced by mechanoactivated commercial mullite powders

A unique technique was developed to render dense mullite ceramics with an in situ tough interlocking structure. The microstructures were achieved by using a commercial mullite powder mechanoactivated with tungsten carbide milling media as seeds and a gel-derived nanosized mullite precursor as a matrix. Only less than 1 wt.% seed was sufficient to trigger the in situ formation of mullite whiskers uniformly distributed in a dense submicron-grained mullite matrix after sintering at 1450 °C for 5 h.