Synthesis of Al8B4C7 and its oxidation properties in air

Al8B4C7 has been synthesized and its oxidation properties have been evaluat ed in both powder and sintered state. Al8B4C7 can be synthesized at above 1 250 degrees C by using Al + B4C + C as a starting material mixture. At 1800 degrees C, no other phase could be identified. The process is achieved via gas phase. In the temperature range 700-1000 degrees C, the results show t hat oxidation occurred by a parabolic kinetic process, the activation energ y of the process is 25.8 kJ/mol, indicating that Al8B4C7 powder is liable t o oxidation, A sintered pure Al8B4C7 body cannot be satisfactorily used in air at temperatures higher than 1200 degrees C because of its low oxidation resistance.