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: Z00037

Bibliographic Information

Reference:
"Mechanical Properties of Hot-Pressed Silicon Nitride with Different Grain Structures," G. Himsolt, H. Knoch, H. Heubner, and F.W. Kleinlein, Journal of the American Ceramic Society, Vol. 62 [1], pp. 29-32 (1979), published by American Ceramic Society.
Language: English

General Materials Processing Notes

"A Si3N4 powder (H. C. Stark, Goslar) (6 % (mass fraction) β phase, average grain size 0.3 µm) was mixed with 5 % MgO in a Teflon jar with agate balls under isopropanol and vacuum hot pressed at 1973 K and 2053 K for 10 min, 30 min, 50 min, 70 min, and 90 min under a pressure of 31 MN/m2. The hot pressed disks (75 mm in diameter and 5 mm to 6 mm high) were diamond ground and cut into bars (3.5 mm by 4.5 mm by 45 mm)."

Measurement Methods

Mechanical resonance
"The elastic constants were determined by a resonance frequency technique." No additional measurement details were noted.
Four-point bend test
The authors cite J. Nakayama, J. Am. Ceram. Soc., Vol. 48 (11), 583-587 (1965), and summarize the procedure as follows. "...samples were loaded to fracture in 4-point bending parallel to the hot pressing direction. The outer span length was 40 mm and the inner span length 20 mm; eight samples were broken to obtain each data point. The specific work of fracture was evaluated on bend specimens from the area under the load deflection curve. ... In these tests the span lengths 43 mm and 10 mm. The KIc was tested on two specimens of each grade, which contained sharp and natural cracks... But in this case, the test is stopped when the crack extends through the whole thickness of the specimen. These precracked samples were put on smaller span lengths (28 mm and 10 mm) and loaded at a higher strain rate to obtain catastrophic failure."

Index of Materials and Properties

Material Number 1: Si3N4·xMgO

Material Specification and Properties for Si3N4·xMgO

Material number 1 of 1
in SCD Citation Number: Z00037
Chemical Class: Nitride
Chemical Family: Si-N:MgO
Formula: Si3N4·xMgO
Informal Name: silicon nitride
Structure Type: Polycrystalline
Manufacturer: In-House
Production Form: Disk
Process: Hot Pressing

Si3N4·xMgO

Material number 1 of 1
in SCD Citation Number: Z00037
Elemental Composition
Amount of
Element
( formula units )
Element
 
( no unit )
3 Si
4 N

Measurement Method: Reported Formula
Evaluation Status: Unevaluated

Si3N4·xMgO

Material number 1 of 1
in SCD Citation Number: Z00037
Sintering Aids
Sintering Aid
Mass Fraction
( % )
Sintering Aid
 
( no unit )
5 MgO

Measurement Method: Reported Formula
Evaluation Status: Unevaluated

Si3N4·xMgO

Material number 1 of 1
in SCD Citation Number: Z00037
Elastic Modulus
Measurement
Temperature
( °C )
Hot Pressing
Time
( min )
Hot Pressing
Temperature
( K )
Elastic
Modulus
( GPa )
22 10 1973 317.5
22 50 1973 311.1
22 90 1973 302.8
22 90 2053 309.6
Measurement Method: Mechanical resonance
Evaluation Status: Unevaluated

Si3N4·xMgO

Material number 1 of 1
in SCD Citation Number: Z00037
Flexural Strength
Measurement
Temperature
( °C )
Hot Pressing
Time
( min )
Hot Pressing
Temperature
( K )
Flexural
Strength
( MPa )
22 10 2053 478
22 30 2053 675
22 50 2053 706
22 70 2053 629
22 90 2053 586

Measurement Method: Four-point bend test
Evaluation Status: Evaluated by acceptance criteria
Cautions:
Digitized data were obtained from Figure 1 of the paper.

Si3N4·xMgO

Material number 1 of 1
in SCD Citation Number: Z00037
Fracture Energy
Measurement
Temperature
( °C )
Hot Pressing
Time
( min )
Hot Pressing
Temperature
( K )
Fracture
Energy
( J m-2 )
22 10 1973 16.5
22 50 1973 30.4
22 90 1973 67.8
22 90 2053 47.4

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

Si3N4·xMgO

Material number 1 of 1
in SCD Citation Number: Z00037
Fracture Toughness
Measurement
Temperature
( °C )
Hot Pressing
Time
( min )
Hot Pressing
Temperature
( K )
Fracture
Toughness
( MPa m1/2 )
22 10 1973 3.20
22 50 1973 4.96
22 90 1973 7.81
22 90 2053 6.59

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

Si3N4·xMgO

Material number 1 of 1
in SCD Citation Number: Z00037
Poisson's Ratio
Measurement
Temperature
( °C )
Hot Pressing
Time
( min )
Hot Pressing
Temperature
( K )
Poisson's
Ratio
( no unit )
22 10 1973 0.258
22 50 1973 0.256
22 90 1973 0.271
22 90 2053 0.265

Measurement Method: Mechanical resonance
Evaluation Status: Unevaluated