Microstructure Evaluation of Al-Mg-Sic Composite through Sintering by Microwave and Electrical Furnace

Spinel refractory has received much interest in industry because of combined ultra good chemical resistance to alkaline salts، high refractoriness and high mechanical strength. In this study samples which were containing Alumina and Magnesia (mole ratio 1-1)، prepared in order to formation of spinel phase. In the next Step، the first group of samples was sintered in a 2. 45GHz Kitchen Microwave for 30 minutes and the others (group 2، 3 and 4) were sintered in an electrical furnace، where second and third groups were heated for 1 hour، at 1350˚C and 1400˚C، respectively and the last ones was sintered at 1400˚C for 2 hours. Due to low loss factor of Alumina and Magnesia at low temperatures، a silicon carbide substrate was used to improve heating during Microwave sintering. Also، the effect of adding silicon carbide on the sintering of samples was investigated. Results showed that the density of sintered samples in electrical furnace were enhanced by increasing silicon carbide content، in contrast with، density of the Microwave sintered samples were decreased. It was seen، the first group reached to the same amount of spinel in a shorter time by consuming lower energy in comparison with other groups.