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Fabrication of Reaction‐Sintered Sialon
Author(s) -
WILLS R. R.,
STEWART R. W.,
WIMMER J. M.
Publication year - 1977
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.1151-2916.1977.tb16096.x
Subject(s) - sialon , materials science , fabrication , phase (matter) , factorial experiment , ceramic , mineralogy , metallurgy , composite material , chemical engineering , chemistry , medicine , alternative medicine , statistics , mathematics , organic chemistry , engineering , pathology
A factorial design experiment was conducted to determine the major parameters affecting the densification of mixtures having the composition (in mol%) 50 Si 3 N 4 , 25 A1 2 O 3 , and 25 A1N. Improved densities of the resulting sialon were achieved using a longer milling time and SN‐502 Si 3 N 4 powder. However, sialon samples prepared from the SN‐502 powder contained some of the X‐phase, whereas those fabricated from AME Si 3 N 4 powder did not. This difference is considered to be due to the higher SiO 2 content of the SN‐502 powder and its greater susceptibility to partial hydrolysis during the milling process. Reaction‐sintered sialon (97.2% theoretical density) fabricated using AME powder had a room‐temperature bend strength of 352 MN/m 2 (51,000 psi) and exhibited slow crack growth at 1300° and 1400°C. It is suggested that this is not an inherent property of sialon but is due to the presence of a calcium‐containing grain‐boundary phase, as in hot‐pressed Si 3 N 4 .