Alumina-aluminide alloys (3A) technology: II. Modeling of TixAly-Al2O3 composites formation

The reaction sintering of TixAly-Al2O3 composites from TiO2/Al starting pow der mixtures has been characterized by thermogravimetry and differential th ermal analysis (TG/DTA), in situ temperature measurements, and predictions via a continuum model. In order to model the TiO2/Al reaction system, it wa s necessary to first determine the postmill reactant concentrations and the dominant reaction. The postmill reactant concentrations were obtained from TG/DTA measurements in air, while X-ray diffraction (XRD) was used to gain insight into the reaction mechanisms. A continuum model of the process was fitted to in situ temperature measurements by adjusting two parameters. Th e model was then used to investigate the effects of various processing cond itions on the reaction behavior.