NIST Structural Ceramics Database (SCD) Database

NIST Standard Reference Database 30

Last Update to Data Content: 2002

DOI: http://dx.doi.org/10.18434/T4F30D


SCD Citation Number: Z00029

Bibliographic Information

Reference:
"Strength Characterization of Yttria/Alumina-Doped Sintered Silicon Nitride," R.K. Govila, International Journal of High Technology Ceramics, Vol. 3, pp. 179-197 (1987), published by Elsevier Applied Science.
Language: English

General Materials Processing Notes

"This study was undertaken to characterize the strength of an in-house (Ford Scientific Laboratory) developed yttria/alumina-doped sintered silicon nitride (Ford material-RM 20)... This material... is a sintered silicon nitride and contained 8 % yttria and 2 % alumina (mass fractions) as the major sintering additives."

Measurement Methods

Four-point bend test
"Flexural test specimens ( about 32 mm long by 6 mm wide by 3 mm thick) were machined from two billets, namely, A42 and A40. All faces were ground lengthwise using 320 grit diamond wheels; the edges were chamfered (lengthwise) to prevent notch effects. For flexural strength evaluation, specimens were tested in 1/4-point, 4-bending (inner span is one-half of outer span) in an Instron testing machine (model 1125) using specially designed self-aligning ceramic fixtures made from hot-pressed SiC. The outer and inner knife edges of the testing fixture were spaced 19 mm and 9.5 mm apart, respectively. The high temperature bend tests were conducted in air using a rapid temperature-response furnace attached to the testing machine head. In high temperature tests, specimens were held at the test temperature for 15 min to achieve equilibrium before testing was begun. No preload was applied on test specimens for either room temperature or high temperature tests. All specimens were tested at a machine crosshead speed of 0.5 mm/min."

Index of Materials and Properties

SCD Citation Number: Z00029
Material Number 1: Si3N4·xAl2O3·yY2O3

Material Specification and Properties for Si3N4·xAl2O3·yY2O3

Material number 1 of 1
in SCD Citation Number: Z00029
Chemical Class: Nitride
Chemical Family: Si-N:Al2O3,Y2O3
Formula: Si3N4·xAl2O3·yY2O3
Informal Name: silicon nitride
Structure Type: Polycrystalline
Manufacturer: Ford Scientific Laboratory
Process: Sintering

Si3N4·xAl2O3·yY2O3

Material number 1 of 1
in SCD Citation Number: Z00029
Elemental Composition
Amount of
Element
( formula units )
Element
 
( no unit )
3 Si
4 N

Measurement Method: Reported Formula
Evaluation Status: Unevaluated

Si3N4·xAl2O3·yY2O3

Material number 1 of 1
in SCD Citation Number: Z00029
Sintering Aids
Mass Fraction
 
( % )
Sintering Aid
 
( no unit )
8 Y2O3
2 Al2O3

Measurement Method: Reported Formula
Evaluation Status: Unevaluated

Si3N4·xAl2O3·yY2O3

Material number 1 of 1
in SCD Citation Number: Z00029
Flexural Strength
Temperature
 
( °C )
Sample
Number
 
Flexural
Strength
( MPa )
20 A42 873 ± 79
400 A42 872 ± 71
600 A42 772 ± 22
800 A42 700 ± 18
1000 A42 637 ± 40
1200 A42 563 ± 58
1300 A42 316 ± 12
1400 A42 327 ± 200
20 A40 777 ± 59
400 A40 792
500 A40 771 ± 178
600 A40 781 ± 96
800 A40 726 ± 69
1000 A40 679 ± 64
1200 A40 530 ± 17

Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria
Cautions:
"(The) two billets, A42 and A40, ... were of identical composition but processed at different times."

Si3N4·xAl2O3·yY2O3

Material number 1 of 1
in SCD Citation Number: Z00029
Weibull Modulus
Temperature
 
( °C )
Sample
Number
 
Weibull
Modulus
( no unit )
20 A42 13
20 A40 16

Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria

Si3N4·xAl2O3·yY2O3

Material number 1 of 1
in SCD Citation Number: Z00029
Weibull Strength
Temperature
 
( °C )
Sample
Number
 
Weibull
Strength
( MPa )
20 A42 899
20 A40 800

Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria