REACTION SINTERING OF MULLITE AND ALUMINU M TITANATE IN A 2.45 GHZ MICROWAVE-OVEN

Microwave (2.45 GHz, 1.2 kW) reaction-sintering of powder mixtures was compared with conventional (electric furnace) sintering. Mixtures of alumina and silica lead to mullite (3Al(2)O(3)-2SiO(2)) and those of a lumina and titania lead to aluminum titanate (beta-Al2TiO5). The uncer tainty of temperature measurement was estimated using two calibration methods. Microwave heating was found to lead to very large temperature gradients within the heated samples. ''The microwave effect'', which is a decrease in the temperature that is required to reach a given str uctural state, in comparison with a conventional treatment, does not e xceed about 50 degrees C.