The processing of cordierite glasses containing AlN

Although cordierite glasses (2MgO·2Al₂O₃·5SiO₂) have been studied by normal glass processing route, little information is available on the processing of cordierite glass containing high nitrogen content. The main thrust of this programme is to study the formability of the materials into useful glass ceramics particularly for electronics and precision structural parts. In this study, the melting, glass forming, nucleation and crystallisation characteristics of glasses containing up to 5% wt. nitrogen have been carried out. Combined heat flux differential scanning calorimetry (DSC) and thermogravimetric analysis have been used to study the reaction kinetics, melting endotherm, nucleation and crystallisation behaviour. The effect of the aluminium nitride on the stability of the melt, microstructures, and the container materials are presented and discussed. XRD and SEM techniques have been used to identify the phases developed, and the morphology of the complex microstructures evolved.