CHARACTERIZATION OF ALUMINA–MOLYBDENUM COMPOSITES PREPARED BY GEL CASTING METHOD

Abstract

This work concerns the study of ceramic-metal composite materials processed by gel casting method. Due to limited possibilities of fabrication complex-shape elements obtained by classical methods of powder metallurgy (such as isostatic or uniaxial pressing) the colloidal processes are recently willingly applied in manufacturing of ceramic matrix composites. In the present work Al₂O₃–10 vol.% Mo composites were formed by aqueous gel casting process and sintered in argon atmosphere. Selected physical properties and phase composition have been described. The microstructure of the green and sintered samples was examined with a scanning electron microscope. Molybdenum particles were homogeneously distributed in the ceramic matrix. Moreover, Mo₂C was formed during sintering process that had a positive contribution to enhancing the hardness of the composite. The composite after sintering was characterized by a density higher than 95% of theoretical density and high hardness. The performed studies have confirmed the possibility of application of gel casting method to produce Al₂O₃–Mo composite system.