Carolyn Moorlag's 01997 master's thesis #paper #PDF on reacting alumina #materials with phosphoric acid and other #phosphates in a #sol-gel process to produce CBC #ceramics, surveying a lot of the work since Kingery's original explorations. She talks about composite sol-gel ceramic systems (with majority ceramic inert functional #fillers), and mentions that for "metal-matrix composites" the ceramic-reinforcement/phosphate binder mix is cured at 400-900° and then infiltrated with metal.