PRODUCTION OF MgAlON BY CARBOTHERMAL REDUCTION AND NITRIDATION
DAI Wenbin, WANG Xinli, YU Jingkun, ZOU Zongshu
School of Materials and Metallurgy, Northeastern University, Shenyang 110819
Cite this article:
DAI Wenbin WANG Xinli YU Jingkun ZOU Zongshu. PRODUCTION OF MgAlON BY CARBOTHERMAL REDUCTION AND NITRIDATION. Acta Metall Sin, 2011, 47(11): 1440-1444.
Abstract Gravimeter, pycnometer, SEM, XRD, carbon analyzer, XFS and oxygen-nitrogen analyzer were utilized to study the production of magnesium aluminium oxynitride (MgAlON) by carbothermal reduction and nitridation (CRN) under different temperatures and its formation mechanism was also discussed in the present paper. The results show that all of the raw MgO are completely consumed to form MgAl2O4ss at 1100℃. At sintered temperatures higher than 1300℃, the CRN reaction is taken place, and MgAlON is formed by solid solving N into MgAl2O4ss. The consumption of Al2O3 during CRN reaction causes the particle size of Al2O3 in the sample heated at 1600℃ to be smaller than that heated at 1500℃. Finally, the monophase MgAlON is obtained at 1650℃ when all the graphite and Al2O3 have been consumed. Moreover, because of the solid solution of N into MgAl2O4ss, the amount of defects in the lattice of MgAlON is raised leading to the solubility of Al in MgAlON being higher than that in MgAl2O4ss. Lots of closed pores are remained in grains even if the heating temperature has been raised to 1800℃ due to higher volatile Mg partial pressure and the gas phase product of CRN reaction at high temperature.