Processing of $MgO-MgAl_2O_4$ Ceramics and Study of its Microstructure, Strength and Thermal Shock resistance

摘要

MgO rich spinel precursor containing $Al_2O_3 : MgO$ in weight proportions of 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4 is prepared by solid-state reaction route. The processed and calcined powders are characterized by Particle Size analysis, X-ray diffraction analysis and sintering behavior. The processed and calcined powder exhibits a bimodal distribution because of the presence of partially agglomerate and unagglomerated particle. However, the average particle size varies from 6.84μm to 3.48μm with increasing milling time. The optimized milling time and subsequent particle size are found 60h and 3.48μm respectively. In the calcined powder spinel phase evolution starts around 1000oC and follows an increasing trend in crystallinity and spinelization with increasing temperature. The crystallite size is 19nm for lowest calcination temperature and lowest content of MgO and gradually increases with increasing temperature and maximum 33nm has been detected for powder with highest MgO content at 1300oC f...