Oxidation Resistant Carbon-Ceramic Alloys

Recent work at Leeds has aimed to synthesise boron-containing carbon alloys which are inherently self-protecting against oxidation via (regeneration of glassy coatings. Two approaches are described here; the first (a) involves combining sp² carbon with isoelectronic and isostructural BN units to produce a mesophase pitch precursor to C-BN alloys. The second (b) involves direct grafting of silicon and boron onto a pitch fraction, yielding C-Si-B alloy precursors. The oxidation behaviour of both alloy types is compared with that of corresponding non-boronated materials.