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Elimination of Grain Boundary Glass in α‐Sialon by Adding Aluminium Nitride
Author(s) -
Shuba Roman,
Chen IWei
Publication year - 2006
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00844.x
Subject(s) - sialon , materials science , nitride , aluminium nitride , sintering , microstructure , aluminium , annealing (glass) , metallurgy , precipitation , grain boundary , grain growth , fracture toughness , mineralogy , composite material , chemistry , layer (electronics) , meteorology , physics
The elimination of residual glass in hot‐pressed Y‐α‐SiAlON was demonstrated by varying the nitride composition. This was readily achieved by adding excess aluminium nitride (AlN), while the addition of excess Si 3 N 4 had little effect. The amount of excess AlN required for this purpose increased with increasing Al and O content in α‐SiAlON, and was higher if α‐SiAlON contained larger interstitial cations. These results were explained by the thermodynamics of α‐SiAlON precipitation. The elimination of liquid also led to suppressed grain growth, refined microstructure, and improved oxidation resistance. Grain coarsening by post‐sintering annealing was required to obtain high fracture toughness.