Abstract
Solid‐liquid equilibria at 1750°C and subsolidus phase relations in the system Si3N4−AlN‐SiO2−Al2O3 were determined for the composition region bounded by the β‐Si3N4 solid solution line and silica‐alumina join X‐ray diffraction and optical microscopy were used to determine the phases present in specimens cooled rapidly after equilibration. The extent of a single liquid‐phase region and the tie lines for the βsolid solution + liquid field at 1750°C were established from quantitative X‐ray diffractometry and lattice parameter measurements of βsolid solutions in equilibrium with liquid. The results were corroborated by optical microscopy and melting behavior observations. A new composition, Si12Al18O39N8, is suggested for the x1 phase. The lowest melting temperature in the system is ≅ 1480°C and the corresponding composition is 10 eq% Al‐90 eq%O.
Submitted Version (
Free)
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call