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: Z00035

Bibliographic Information

Reference:
"Effects of Oxidation and Oxidation Under Load on Strength Distributions of Si3N4," T.E. Easler, R.C. Bradt, and R.E. Tressler, Journal of the American Ceramic Society, Vol. 65 [6], pp. 317-320 (1982), published by American Ceramic Society.
Language: English

General Materials Processing Notes

"The sintered silicon nitride (SNW-1000, GTE Sylvania, Towanda, PA) contains both yttria and alumina as sintering aids and has a density of 3.00 g/cm3. The hot-pressed silicon nitride (NCX-34, Norton Co., Worcester, MA) has an 8% yttria addition and a density of 3.36 g/cm3. Specimens were cut from large billets, all of each type from a single billet, and then machined with a 600-grit diamond wheel to a final size of 0.25 cm by 0.25 cm by 3.0 cm. Grinding was always along the long dimension. The edges were not beveled."

Measurement Methods

Four-point bend test
"The as-machined strength distributions were determined by fracturing 50 specimens in a 4-point bend test geometry, over an outer span of 2.22 cm (1/3-point loading). All strength testing was carried out at a crosshead speed of 0.127 cm/min. Oxidation was performed at 1370 °C in air for various exposure times ...in an SiC resistance-heated furnace. Oxidation under static load was carried out at 1370 °C for 1 h. These specimens were loaded in 4-point bending over a span of 2.22 cm (1/4-point loading). For the static loading, a testing machine was used in the constant load mode after rapidly loading to the desired level. All specimens were fractured at room temperature for comparison with the as-machined strength distributions."
Mechanical resonance
The authors cite S. Spinner et al., Proc. Am. Soc. Test. Mater., Vol. 61, 1121-1138 (1961), and summarize the procedure as follows. "The elastic modulus (was) determined using the mechanical resonance technique."
Controlled Flaw
The authors cite P.L. Land et al., J. Mater. Sci., Vol. 12 (7), 1421-1425 (1977), and summarize the procedure as follows. "The controlled microflaw technique yielded a fracture toughness."

Index of Materials and Properties (Click on a selected Material Number to expand material properties menu)

Material Specification and Properties for Si3N4·xAl2O3·yY2O3

Material number 1 of 2
in SCD Citation Number: Z00035
Chemical Class: Nitride
Chemical Family: Si-N:Al2O3,Y2O3
Formula: Si3N4·xAl2O3·yY2O3
Informal Name: silicon nitride
Structure Type: Polycrystalline
Manufacturer: GTE
Commercial Name: SNW-1000
Process: Sintering

Si3N4·xAl2O3·yY2O3

Material number 1 of 2
in SCD Citation Number: Z00035
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 2
in SCD Citation Number: Z00035
Elastic Modulus
Temperature
 
( °C )
Elastic
Modulus
( GPa )
22 240
Measurement Method: Mechanical resonance
Evaluation Status: Evaluated by acceptance criteria

Si3N4·xAl2O3·yY2O3

Material number 1 of 2
in SCD Citation Number: Z00035
Flexural Strength
Oxidation
Time
( h )
Number of
Samples
 
Static
Load
( MPa )
Flexural
Strength
( MPa )
0.0 50 0 420
0.5 10 0 465
1.0 53 0 375
12.0 11 0 325
20.0 11 0 305
50.0 10 0 260
1.0 15 23 515
1.0 15 45 435
Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria

Si3N4·xAl2O3·yY2O3

Material number 1 of 2
in SCD Citation Number: Z00035
Fracture Toughness
Temperature
 
( °C )
Fracture
Toughness
( MPa m1/2 )
22 4.0
Measurement Method: Controlled Flaw
Evaluation Status: Evaluated by acceptance criteria

Si3N4·xAl2O3·yY2O3

Material number 1 of 2
in SCD Citation Number: Z00035
Weibull Modulus
Oxidation
Time
( h )
Static
Load
( MPa )
Weibull
Modulus
( no unit )
0.0 0 8.2
0.5 0 7.7
1.0 0 10.9
12.0 0 17.2
20.0 0 8.3
50.0 0 19.6
1.0 23 10.2
1.0 45 7.0
Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria

Material Specification and Properties for Si3N4·xY2O3

Material number 2 of 2
in SCD Citation Number: Z00035
Chemical Class: Nitride
Chemical Family: Si-N:Y2O3
Formula: Si3N4·xY2O3
Informal Name: silicon nitride
Structure Type: Polycrystalline
Manufacturer: Norton Company
Commercial Name: NCX-34
Process: Hot Pressing

Si3N4·xY2O3

Material number 2 of 2
in SCD Citation Number: Z00035
Elemental Composition
Amount of
Element
( formula units )
Element
 
( no unit )
3 Si
4 N
Measurement Method: Reported Formula
Evaluation Status: Unevaluated

Si3N4·xY2O3

Material number 2 of 2
in SCD Citation Number: Z00035
Elastic Modulus
Temperature
 
( °C )
Elastic
Modulus
( GPa )
22 320
Measurement Method: Mechanical resonance
Evaluation Status: Evaluated by acceptance criteria

Si3N4·xY2O3

Material number 2 of 2
in SCD Citation Number: Z00035
Flexural Strength
Oxidation
Time
( h )
Number of
Samples
 
Static
Load
( MPa )
Flexural
Strength
( MPa )
0.0 53 0 810
0.5 10 0 825
1.0 54 0 705
12.0 11 0 590
20.0 12 0 605
50.0 12 0 625
1.0 14 45 650
1.0 13 158 545
Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria

Si3N4·xY2O3

Material number 2 of 2
in SCD Citation Number: Z00035
Fracture Toughness
Temperature
 
( °C )
Fracture
Toughness
( MPa m1/2 )
22 4.2
Measurement Method: Controlled Flaw
Evaluation Status: Evaluated by acceptance criteria

Si3N4·xY2O3

Material number 2 of 2
in SCD Citation Number: Z00035
Weibull Modulus
Oxidation
Time
( h )
Static
Load
( MPa )
Weibull
Modulus
( no unit )
0.5 0 7.0
1.0 0 14.1
12.0 0 7.0
20.0 0 14.3
50.0 0 7.6
1.0 45 9.7
1.0 158 7.9
Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria