Phase Relationships in the Silicon Carbide‐Aluminum Nitride System

摘要: Phase relationships in the SiC-AlN system were determined by analytical electron microscopy of local equilibria among adjacent phases hot-pressed samples and diffusion couples. At 2100° to 2300°C, a 4H–2H equilibrium exists, 4H field extending from ∼2 mol% AlN an upper limit 11 14 AlN. The wurtzite-type 2H (δ) solid solution extends impurity-sensitive lower 17 24 up 100 Semiquantitative Auger spectroscopy energy dispersive X-ray ultrathin-window detector measurements confirmed assumption that solutions have general formula (SiC)1-x(AlN)x belong pseudobinary system. existence miscibility gap below 1950°C was confirmed, but its limits not accurately. A faulted metastable cubic phase, β′, exists ∼2000°C contains ∼4 transformations into stable structures occur through diffusion-controlled stacking rearrangements.