Abstract

The microwave process offers several advantages over conventional processes, including energy savings, shorter processing time, improved product uniformity and yields, and improved properties. In the present work, AL2O3/mullife/SiC powders were synthesized through the carbothermal reduction reaction of aluminosilicates in the presence of carbon black as a reducing agent. Precursor powders were compacted in pellet form and then reacted in a microwave oven operating at 2,45 GHz with a maximum power level of 980 W. In order to maintain a uniformly reactive atmosphere inside the microwave cavity, a Pyrex glass reaction chamber was introduced. The resulting powders, analyzed by SEM, presented features similar to those of products obtained by a conventional carbothermal reduction in the same temperature range, including whiskers, fibrous clusters and spheres of SiC, Al2O3, and mullite particles.