A novel synthesis of B–Al–Ca–O–(N) glasses by self-propagating high-temperature combustion method

Glasses in the B–Al–Ca–O–(N) system have been prepared by self-propagating high-temperature combustion synthesis (SHS) directly from mixed powders of B, Al and CaO under pressurized dry-air of 3 MPa. The nitrogen content of the SHS product is 0.63 mass%, the value of which is about 30 times higher than that of conventional molten glass fabricated in air. Their initial reactants, B and Al when ignited, transform instantaneously into oxides, nitrides and oxynitride with a high exothermic heat of reaction. Sequentially the reacted products in a liquid state solidify into a glass material by rapid cooling. The glass forming region is similar to that of the same oxide glass system prepared by the conventional melting method.