Synthesis Thermodynamics and Properties of MgAlON Ceramics
MgAlON陶瓷的合成热力学与相关性能

The thermodynamic properties of Mg-Al-O-N system were evaluated and the phase stability diagram of MgAlON was established. Based on the thermodynamic analysis, MgAlON with different compositions was synthesized. The microstructures, crystalline characteristics, mechanical properties and oxidation resistance of the synthesized materials were experimentally measured and discussed. A standard diffraction file of MgAlON was suggested. X-ray diffraction and TEM analysis show that there is no other phase than MgAlON detected. HREM analysis of MgAlON indicates that there is no glass phase existed at the grain boundaries, the grains are bounded directly. Three-point bending strength of MgAlON keeps very high until 1723K. Oxidation experiments of MgAlON show that the activation energies of oxidation during the chemical reaction rate controlling stage and that during the diffusion controlling stage are 260 kJ/mole and 573 kJ/mole, respectively.