COMPOSITIONS FOR EXTERNAL SUSCEPTORS AND EXTERNAL SUSCEPTORS FOR THE SINTERING OF CERAMICS BY MICROWAVES

摘要

Compositions and external susceptores used as auxiliary heating agents for sintering ceramics by microwaves at the frequencies of 2.45 GHz and 912 MHz, with said susceptors being based on mixtures of calcium aluminates and/or calcium aluminates and phases of SiC and/or ZrO2 and/or AlN, in both cases in specific proportions, being used after the curing of the cementing material or after curing and firing at determined temperatures and times and presenting the main characteristics of high heating capacity when exposed to microwaves, high structural stability at high temperatures and resistance to degradation of the heating properties when exposed to microwaves even subsequent to several heating cycles. The use of said susceptors allows obtaining ceramics with densities exceeding 98% of the theoretical density of the material in firing cycles of less than 30 minutes.