Fabrication of Al2O3/AlN micro-composites designed for tailored physical properties

Abstract

Simple mixing of powders does not always result in sound composite materials with designed properties after sintering owing to the inherent solid solution of constituent phases at high temperatures. A modified sintering process, where the relative particle sizes of constituent phases are controlled to minimize interdiffusion between starting materials, has been proposed to achieve the formation of a composite having tailored physical properties. A 0.5 Al2O3-0.5 AlN ceramic composite which was fabricated by the proposed powder process showed design-based thermal and electrical conductivities following Rayleigh's derivation, contrary to conventional Al2O3/AlN, which undergoes detrimental interdiffusion.