Abstract
The effect of WO
3 on mullite formation and mullite whisker morphology, in oxide mixtures activated by a high-energy ball milling process, was investigated. Differential thermal analysis (DTA) measurement indicated that WO
3 enhanced the mullite phase formation, with mullitization temperature of 951 °C, 921 °C and 835 °C for the samples doped with 5, 10 and 20 mol% WO
3, respectively. However, the presence of WO
3 had an undesired effect on the whisker morphology. A decrease in the length of mullite whisker was observed with increasing WO
3 content. The effect of WO
3 on the mullite phase formation temperature, as well as the whisker morphology, was explained using a dissolution-precipitation mechanism.