MICROSTRUCTURES AND CORROSION RESISTANCE OF MOLYBDENUM-ALUMINA MATERIALS

Molybdenum-alumina(Mo/Al2O3) composites with different volume ratio of Mo to Al2O3 were prepared by pressure less sintering.Their microstructure and corrosion resistance to acid were studied.After sintered at 1 440 ℃ ,the Al2O3 phase distribution in the Mo/Al2O3 composite with 60%(volume fraction,the same below) Mo is unevenly,but the Mo phase distribution in the Mo/Al2O3 composite with 40% Mo is unevenly.It was found by composition analysis with election probe that there is no obvious diffusion between the Mo and Al2O3 phases.The acid corrosion tests show that the Mo/Al2O3 composites have resistant ability to the corrosions of hydrochloric,sulfuric and hydrofluoric acids;and the best corrosion resistance to the hydrochloric acid.The Mo/Al2O3 composites couldn’t be resistant to nitric acid corrosion.The corrosion first occurs in the boundary of molybdenum and alumina.