NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Mechanical Property Evaluation at Elevated Temperature of Sintered β-Silicon Carbide," M.J. Slavin and G.D. Quinn, International Journal of High Technology Ceramics, Vol. 2 [1], pp. 47-63 (1986), published by Elsevier Applied Science.Language: English
"This report presents findings on a commercially available sintered β-silicon carbide manufactured by the General Electric Co. ... It is fabricated from a submicrometer β-silicon carbide powder with small additions ( of about 0.5% mass fraction, each) of boron and carbon, and is sintered in a reducing atmosphere at approximately 2100 °C. ... The sintered β-silicon carbide was supplied by the General Electric Company's Manufacturing Division, Houston, Texas in the form of eight 50.8 mm x 50.8 mm x 12.7 mm tiles in March 1984."
"Four of these tiles were machined into flexure specimens according to MIL-STD-1942(MR) specimen configuration `B'. Specimen size was 3.0 mm x 4.0 mm x 44.5 mm with a 45° chamfer along the four long edges. Chamfer depths were inadvertently machined to approximately 0.28 mm which is greater than the 0.15 ± 0.05 mm the standard requires. Although this causes only a 1.25% decrease in the cross-sectional area, the strengths reported in this study (based on elastic theory with a rectangular cross-section) are 3.4% lower than if the chamfer were within the prescribed limits. ... A universal testing machine (Model TT-DL, Instron Corp., Canton, Massachusetts) was used with four-point fixtures in accordance with MIL-STD-1942(MR). The spans were 40.0 mm and 20.0 mm and the crosshead speed was 0.5 mm/min. The relative humidity was 35% at 23°C. ... A two-parameter Weibull modulus was determined by a least square fitted line through the strength data when plotted on a standard Weibull format..."Vickers indentation
"Microhardness testing was performed on a mounted and polished specimen with a load of 19.6 N. Using both Vicker's and Knoop indenters, 10 indentations each were made with a standard microhardness indenter (Miniload II, Leitz, FRG). Fracture toughness was estimated from crack lengths emanating from Vicker's indentations at loads of 19.6 N, 24.9 N, and 34.3 N, using a standard microhardness indenter (Tukon Tester FB, Wilson Mechanical Instrument Co. Inc., New York)."Archimedes' method
"...densities (were) measured (by the) Archimedes method."Ultrasonic method
"Time-of-flight C-scan (data were obtained) ... using a 10 MHz undamped transducer. ... The ultrasonic longitudinal wave propagation time C-scan maps ... were ... evaluated for the elastic modulus and Poisson's ratio."
| Amount of Element ( formula units ) | Element ( no unit ) |
|---|---|
| 1 | Si |
| 1 | C |
| Relative Density ( % ) | Sample Number | Density ( g cm-3 ) |
|---|---|---|
| 96.7 | 1 | 3.10 |
| 95.6 | 2 | 3.07 |
| 95.1 | 3 | 3.05 |
| 95.4 | 4 | 3.06 |
| 96.8 | 5 | 3.11 |
| 95.9 ± 0.8 | Average | 3.08 ± 0.03 |
| Sample Number | Elastic Modulus ( GPa ) |
|---|---|
| 1 | 404.0 |
| 2 | 389.6 |
| 3 | 384.4 |
| 4 | 388.3 |
| 5 | 405.9 |
| Average | 395 ± 10 |
| Temperature ( °C ) | Flexural Strength ( MPa ) |
|---|---|
| 22 | 346 ± 34 |
| Numbers of Indents | Load ( N ) | Temperature ( °C ) | Fracture Toughness ( MPa m1/2 ) |
|---|---|---|---|
| 5 | 19.5 | 22 | 2.82 |
| 6 | 29.4 | 22 | 2.81 |
| 6 | 34.3 | 22 | 2.78 |
| Temperature ( °C ) | Hardness ( GPa ) |
|---|---|
| 22 | 23.9 ± 0.4 |
| Sample Number | Poisson's Ratio ( no unit ) |
|---|---|
| 1 | 0.17 |
| 2 | 0.16 |
| 3 | 0.16 |
| 4 | 0.16 |
| 5 | 0.16 |
| Relative Density ( % ) | Sample Number | Porosity ( % ) |
|---|---|---|
| 96.7 | 1 | 3.3 |
| 95.6 | 2 | 4.4 |
| 95.1 | 3 | 4.9 |
| 95.4 | 4 | 4.6 |
| 96.8 | 5 | 3.2 |
| 95.9 ± 0.8 | Average | 4.1 ± 0.8 |
| Temperature ( °C ) | Weibull Modulus ( no unit ) |
|---|---|
| 22 | 11.0 |
| Temperature ( °C ) | Weibull Strength ( MPa ) |
|---|---|
| 22 | 362 |