Sintering of Si3N4-Y2O3-Al2O3

Sintering kinetics of the system Si3N4‐Y2O3‐Al2O3 were determined from measurements of the linear shrinkage of pressed disks sintered isothermally at 1500° to 1700°C. Amorphous and crystalline Si3N4 were studied with additions of 4 to 17 wt% Y2O3 and 4 wt% A12O3. Sintering occurs by a liquid‐phase m...

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Bibliographic Details
Published in:Journal of the American Ceramic Society 1980-01, Vol.63 (3-4), p.144-148
Main Authors: LOEHMAN, RONALD E., ROWCLIFFE, DAVID J.
Format: Article
Language:English
Online Access:Get full text
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Summary:Sintering kinetics of the system Si3N4‐Y2O3‐Al2O3 were determined from measurements of the linear shrinkage of pressed disks sintered isothermally at 1500° to 1700°C. Amorphous and crystalline Si3N4 were studied with additions of 4 to 17 wt% Y2O3 and 4 wt% A12O3. Sintering occurs by a liquid‐phase mechanism in which the kinetics exhibit the three stages predicted by Kingery's model. However, the rates during the second stage of the process are higher for all compositions than predicted by the model. X‐ray data show the presence of several transient phases which, with sufficient heating, disappear leaving mixtures of β′ ‐Si3N4 and glass or β′‐Si3N4, α′‐Si3N4, and glass. The compositions and amounts of the residual glassy phases are estimated.
ISSN:0002-7820
1551-2916
DOI:10.1111/j.1151-2916.1980.tb10679.x