SYNTHESIS OF ALUMINUM NITRIDE BORON-NITRIDE COMPOSITE-MATERIALS

Aluminum nitride/boron nitride composite was synthesized by using bori c acid, urea, and aluminum chloride (or aluminum lactate) as the start ing compounds. The starting materials were dissolved in water and mixe d homogeneously. Ammonolysis of this aqueous solution resulted in the formation of a precomposite gel, which converted into the aluminum nit ride/boron nitride composite on further heat treatment. Characterizati on of both the precomposite and the composite powders included powder X-ray diffraction, Fourier transform infrared spectroscopy, and scanni ng electron microscopy. Analysis of the composite revealed that the al uminum nitride phase had a hexagonal structure, and the boron nitride phase a turbostratic structure.