The determination of “ultra” fast fracture strengths of five silicon nitride ceramics at elevated temperatures has been made by using constant stress-rate (“dynamic fatigue”) testing with a series of “ultra” fast test rates. The test materials included four monolithic and one SiC whisker-reinforced composite silicon nitrides. Of the five test materials, four silicon nitrides exhibited the elevated-temperature strengths that approached their respective room-temperature strengths at an “ultra” fast test rate of 3.3 × 104 MPa/s. This implies that slow crack growth responsible for elevated-temperature failure can be eliminated or minimized by using the “ultra” fast test rate. These ongoing experimental results have shed light on laying a theoretical and practical foundation on the concept and definition of elevated-temperature “inert” strength behavior of advanced ceramics.
Issue Section:
Gas Turbines: Ceramics
1.
Lange
F. F.
1974
, “High-Temperature Strength Behavior of Hot-Pressed Si3N4: Evidence for Subcritical Crack Growth
,” J. Am. Ceram. Soc.
, Vol. 57
, pp. 84
–87
.2.
Evans
A. G.
Wiederhorn
S. M.
1974
, “Crack Propagation and Failure Prediction in Silicon Nitride at Elevated Temperatures
,” J. Mater. Sci.
, Vol. 9
, pp. 270
–278
.3.
Kossowsky
R.
Miller
D. G.
Diaz
E. S.
1975
, “Tensile and Creep Strengths of Hot-Pressed Si3N4
,” J. Mater. Sci.
, Vol. 10
, pp. 983
–997
.4.
Weston
J. E.
Pratt
P. L.
1978
, “Crystallization of Grain Boundary Phases in Hot-Pressed Silicon Nitride Materials
,” J. Mater. Sci.
, Vol. 13
, pp. 2147
–2156
.5.
Tighe
N. J.
1978
, “The Structure of Slow Crack Growth Interfaces in Silicon Nitride
,” J. Mater. Sci.
, Vol. 13
, pp. 1455
–1463
.6.
McHenry
K. D.
Tressler
R. E.
1980
, “Fracture Toughness and High-Temperature Slow Crack Growth in SiC
,” J. Am. Ceram. Soc.
, Vol. 63
, pp. 152
–156
.7.
Tsai
R. L.
Raj
R.
1980
, “The Role of Grain-Boundary Sliding in Fracture of Hot-Pressed Si3N4 at High Temperatures
,” J. Am. Ceram. Soc.
, Vol. 63
, pp. 513
–517
.8.
Jakus
K.
Service
T.
Ritter
J. E.
1980
, “High-Temperature Fatigue Behavior of Polycrystalline Alumina
,” J. Am. Ceram. Soc.
, Vol. 63
, pp. 4
–7
.9.
Govila
R. K.
1990
, “Strength of Slip-Cast, Sintered Silicon Nitride
,” J. Am. Ceram. Soc.
, Vol. 73
, pp. 1744
–1751
.10.
Quinn, G. D., 1990, “Fracture Mechanism Maps for Advanced Structural Ceramics Part I: Methodology and Hot-Pressed Silicon Nitride Results,” MTLTR 90-6, U.S. Army Materials Technology Laboratory, Watertown, MA.
11.
Evans
A. G.
Lange
F. F.
1975
, “Crack Propagation and Fracture in Silicon Carbide
,” J. Mater. Sci.
, Vol. 10
, pp. 1659
–1664
.12.
Miller, D. G., Anderson, C. A., Singhal, S. C, Lange, F. F., Diaz, E. S., and Kossowsky, R., 1976, “Brittle Materials Design, High Temperature Gas Turbine Material Technology,” AMMRC CTR 76-32, Army Materials and Mechanics Research Center, Watertown, MA.
13.
Govila, R. K., 1980, “Ceramic Life Prediction Parameters,” AMMRC TR 80-18, Army Materials and Mechanics Research Center, Watertown, MA.
14.
Khandelwal
P. K.
Chang
J.
Heitman
P. W.
1986
, “Slow Crack Growth in Silicon Nitride
,” in Fracture Mechanics of Ceramics
, Vol. 8
, R. C. Bradt, et al., eds., Plenum Press, New York, pp. 351
–362
.15.
Rawlins
M. H.
Nolan
T. A.
Allard
L. F.
Tennery
V. J.
1989
, “Dynamic and Static Fatigue of Sintered Silicon Nitride: II, Microstructure and Failure Analysis
,” J. Am. Ceram. Soc.
, Vol. 72
, pp. 1338
–1342
.16.
Braue, W., Goring, J., and Ziegler, G., 1989, “Correlation of Slow Crack Growth and Microstructure in HIP-SiC,” in Ceramic Materials & Components for Engines, V. J. Tennery, ed., The American Ceramic Society, Westerville, OH, pp. 817–830.
17.
Tajima, Y., Urashima, K., Watanabe, M., and Matsuo, Y., 1989, “Static, Cyclic and Dynamic Fatigue Behavior of Silicon Nitride,” in Ceramic Materials & Components for Engines, V. J. Tennery, ed., The American Ceramic Society, Westerville, OH, pp. 719–728.
18.
Hecht, N. L., McCullum, D. E., and Graves, G. A., 1989, “Investigation of Selected Si3N4 and SiC Ceramics,” in Ceramic Materials & Components for Engines, V. J. Tennery, ed., The American Ceramic Society, Westerville, OH, pp. 806–816.
19.
Hecht, N. L., 1993, Ceramic Technology Project, Semiannual Progress Report for October 1992 Through March 1993, ORNL/TM-12428, Oak Ridge National Laboratory, Oak Ridge, TN, pp. 329–342.
20.
Choi
S. R.
Salem
J. A.
1996
, “Inert” Strength of Silicon Nitride Ceramics at Elevated Temperatures
,” Ceram. Eng. Sci. Proc.
, Vol. 17
, pp. 454
–461
.21.
Choi
S. R.
Salem
J. A.
1998
, “Ultra-Fast Fracture Strength of Advanced Ceramics at Elevated Temperatures
,” Mat. Sci. Eng.
, Vol. A242
, pp. 129
–136
.22.
Wiederhorn
S. M.
1978
, “Subcritical Crack Growth in Ceramics
,” in Fracture Mechanics of Ceramics
, Vol. 2
, R. C. Bradt, et al., eds., Plenum Publishing Co., New York, pp. 613
–646
.23.
Ritter
J. E.
1978
, “Engineering Design and Fatigue Failure of Brittle Materials
,” in Fracture Mechanics of Ceramics
, Vol. 4
, R. C. Bradt, et al., eds., Plenum Publishing Co., New York, pp. 667
–686
.24.
ASTM C 1368, 1998, “Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress-Rate Flexural Testing at Ambient Temperature,” Annual Book of ASTM Standards, Vol. 15.01, American Society for Testing and Materials, Philadelphia, PA.
25.
ASTM C 1259, 1997, “Standard Test Method for Dynamic Young’s Modulus, Shear Modulus, and Poisson’s Ratio for Advanced Ceramics by Impulse Excitation of Vibration,” Annual Book of ASTM Standards, Vol. 15.01, American Society for Testing and Materials, Philadelphia, PA.
26.
ASTM PS070, 1998, “Provisional Test Method for Determination of Fracture Toughness of Advanced Ceramics at Ambient Temperature,” Annual Book of ASTM Standards, Vol. 15.01, American Society for Testing and Materials, Philadelphia, PA.
27.
ASTM C 1327, 1997, “Standard Test Method for Vickers Indentation Hardness of Advanced Ceramics,” Annual Book of ASTM Standards, Vol. 15.01, American Society for Testing and Materials, Philadelphia, PA.
28.
Morey, R. E., and Lucas, G. A., 1980, 18th Bimonthly Report, ATTAP, 7-8/1990, NASA Lewis Research Center, Cleveland, OH.
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