The microstructure of sintered Si-Al-O-N ceramics

摘要: Fine-grained ceramics, based on the substituted β-Si3N4 crystal structure, have been prepared with near theoretical densities by pressureless sintering of compacts containing a large Y2O3 additive concentration. The microstructure contains two phases, β and an Y/Al rich “silicate” glassy matrix, in “as-sintered” condition. matrix may be crystallized heat treatment to Si-substituted yttrium-aluminium garnet phase. phase compositions transformation mechanisms analysed X-ray microanalysis, electron diffraction imaging thin sections.