INVESTIGATION OF SIC-ALN SYSTEM .1. MICROSTRUCTURE AND SOLID-SOLUTION

The primary aim of this present work was to investigate the solubility, microstructure, thermal stability, AIN polytypes, and interfacial reactions in the SiC-AlN system. Alpha SiC particles of different sizes were incorporated into AlN and hot pressed at 2050 degrees C for 1 to 3 h. XRD, OM, STEM, WDS, and SAD patterns were utilized in analyzing phases, morphology, and distribution of elements. The surface area of SiC particles was found to have substantial effects on the formation of solid solution. Multilayered polytypes, which are usually associated with stacking faults, grew and impeded one another. Additionally, the number of planes between subsequent stacking increased with the increase of either hot-pressing temperature or time. Affinity of oxygen to AlN probably played an essential role in the formation of polytypes and stacking faults.