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: Z00027

Bibliographic Information

Reference:
"Fracture Phenomenology of a Sintered Silicon Nitride Containing Oxide Additives," R.K. Govila, Journal of Materials Science, Vol. 23, pp. 1141-1150 (1988), published by Chapman and Hall.
Language: English

General Materials Processing Notes

The authors cite K. Matsuhiro et al., US Patent 4535063 (1985), and summarize the procedure as follows. "The material used in this study was sintered silicon nitride commercially known as SN-73 (NGK Insulators Ltd, Nagoya, Japan) obtained in the form of a cylinder (length = 138 mm, inside and outside diameters 80 mm and 100 mm, respectively). The sintered silicon nitride contained various oxide additives (CeO2, MgO, ZrO2 and SrO) as sintering aids, and had a density of 3.26 g cm-3. ... The test component (cylinder) was isostatically pressed and contained an organic binder. The burnout of the component was carried out at 150 °C to 225 °C in a nitrogen gas environment and finally pressureless sintered at 1700 °C."

Measurement Methods

Four-point bend test
The author cites R.K. Govila, J. Mater. Sci., Vol. 20, 4345 (1985), and summarizes the procedure as follows. "Flexural test specimens (approximately 32 mm long x 6 mm wide x 3 mm thick) were machined from the cylinder (test component) wall. All faces were ground lengthwise using 320 grit diamond wheels; the edges were chamfered (lengthwise) to prevent notch effects. ... (Some specimens) were precracked using the Vickers diamond pyramid and Knoop microhardness indenters. ... For various indentation loads used, the corresponding surface crack lengths as seen optically were measured. ... specimens were tested in four-point bending..." A self-aligning, hot-pressed SiC fixture with an outer span of 19 mm and an inner span of 9.5 mm was used with a crosshead speed of 0.5 mm/min.


Index of Materials and Properties

SCD Citation Number: Z00027
Material Number 1: Si3N4

Material Specification and Properties for Si3N4

Material number 1 of 1
in SCD Citation Number: Z00027
Chemical Class: Nitride
Chemical Family: Si-N
Formula: Si3N4
Informal Name: silicon nitride
Structure Type: Polycrystalline
Manufacturer: NGK
Commercial Name: NGK-SN73
Process: Sintering

Si3N4

Material number 1 of 1
in SCD Citation Number: Z00027
Elemental Composition
Amount of
Element
( formula units )
Element
 
( no unit )
3 Si
4 N

Measurement Method: Reported Formula
Evaluation Status: Unevaluated

Si3N4

Material number 1 of 1
in SCD Citation Number: Z00027
Flexural Strength
Temperature
 
( °C )
Indentation
Load
( g )
Indenter
Type
 
Flexural
Strength
( MPa )
20 -- -- 790 ± 60
800 -- -- 860 ± 65
900 -- -- 655 ± 30
1000 -- -- 440 ± 45
1100 -- -- 395 ± 20
1200 -- -- 345 ± 20
20 1000 Knoop 599 ± 8
20 2000 Knoop 460 ± 50
20 4000 Knoop 358 ± 10
1200 1000 Knoop 323
1200 2000 Knoop 323
1200 4000 Knoop 336
20 1000 Vickers 655 ± 10
20 2000 Vickers 549 ± 6
20 4000 Vickers 424 ± 30
1000 4000 Vickers 413
1200 4000 Vickers 331

Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria
Cautions:
Digitized data were obtained from Figure 4 or derived from Table II of the paper.