Microstructure stability of fine-grained silicon carbide ceramics during annealing

摘要: Fine-grained silicon carbide ceramics with an average grain size of ∼140 nm or smaller were prepared by low-temperature hot-pressing very fine β-SiC powders using Al2O3-Y2O3-CaO (AYC) Y-Mg-Si-Al-O-N glass (ON) as sintering additives. The microstructure stability the resulting fine-grained SiC was investigated annealing at 1850°C and evaluating quantitatively growth behavior image analysis. β → α phase transformation in AYC-SiC responsible for accelerated abnormal platelet-shaped grains. In contrast, ON-SiC suppressed, which resulted a stable microstructure.