636 S.R. Choi et al. /Journal of the European Ceramic Society 25(2005)1629-1636 monolithic ceramics at elevated temperatures. The rate de- 6.(a)Choi, S.R. and Gyekenyesi, J. P, Fatigue strength as a function pendency of ultimate tensile strength, the applicability of reloading in dynamic fatigue testing of glass and ceramics. Trans the preload technique, and the predictability of life from one MME.J. Eng. Gas Turbines Power, 1997, 119(3), 493-499 loading configuration(constant stress rate)to another(con- b)Choi, S.R. and Salem, J. A, Effect of preloading on fatigue rength in dynamic fatigue testing of ceramic materials at elevated stant stress)for the Nicalon/BSAS composite suggested that temperatures. Ceram. Eng. Sci. Proc 1995, 16(4),87-94 the overall failure law of the composites would be governed 7. Halbig, M. C, The influence of temperature, stress, and environment by a power-law type of slow crack growth(or damage evo- on the oxidation and life of C/SiC composites. Ceram. Eng. Sci. Proc lution/accumulation ) It was further confirmed that constant stress-rate testing could be utilized as a means of life predic- 8. Calomino, A, verrilli, M.J. and Thomas, D. J, Stress/life behavion of C/SiC composites in a low partial pressure of oxygen environment. tion test methodology for composites when short lifetimes lI-Stress rupture life and residual strength relationship. Ceram. Eng are expected and when ultimate tensile strength is used as a Sc.PPoc.,2002,23,443-451. ilure criterion 9. Evans, A.G., Slow crack growth in brittle materials under dynamic 10. ASTM C 1368. Standard test method fo wth parameters of advanced ceramics by constant stress-rate flex- Acknowledge ng at ambient atureIn Anmual Book of AsTM Standards This work was supported in part by Higher Operating Tem- 1. ASTM C 1465. Standard test method for determination of slow crack perature Propulsion Components(HOTPC) Program and the owth parameters of advanced ceramics by constant stress-rate fl Ultra-Efficient Engine Technology (UEET) Program, NASA ural testing at elevated temperatures. In Annual Book of ASTM Stan- dards(Vol 15.01). ASTM, West Conshohocken, PA, 2001 lenn Research Center, Cleveland, OH, USA. The authors 12. Choi, S. R, Gyekenyesi, J. P. et al., Ultra-fast fracture strength of are grateful to R. Pawlik for experimental work during the advanced structural ceramics at elevated temperatures: an approach to course of this research high-temperature"inert "strength. In Fracture Mechanics of Ceramics 13, ed. R. C. Bradt. Kluwer Academic/Plenum Publishers, New 13. Halbig, M. C, Modeling the oxidation of carbon fibres in a C/SiC References omposite under stressed oxidation. Ceram. Eng. Sci. Proc., 2002 23(3),427-434 1. Choi, S.R and Gyekenyesi, J. P, Effect of load rate on tensile 14. Sorenson, B F and Holmes, J w, Effect of loading rate on the mono- ngth of various CFCCs at elevated temperatures: an a tonic tensile behavior of a continuous-fiber-reinforced glass-ceramic prediction testing. Ceram. Eng. Sci. Proc., 2001, 22(3), 597-606 matrix composite. J. Am. Ceram Soc, 1996, 79(2), 313-320 2. Bansal, N P and Setlock, J. A, Fabrication of fiber-reinforced celsian 15. Curtin, w.A. and Halverson, H. G, High Temperature Deforma- matrix composites Composites Part 4, 2001, 32, 1021-1029 tion and Failure in Oxide/oxide Composites, HITEMP Review 1999 3. Worthen. D. Thermomechanical Fatigue Behavior of Three re Engine Materials Technology Project CFCC's. NAS CR-195441. NASA Glenn Research Center, Cleve. (NASA/CP-1999-208915/ol 2, Paper 48). NASA Glenn Research enter. Cleveland. OH. 1999 4. Verrilli, M. J, Calomino, A and Thomas, D. J. Stress/life behavior of 16. Lewinsohn, C. A, Henager Jr, C. H. and Jones, R. H, Environmen a C/SiC composite in a low partial pressure of oxygen environment: tally induced time-dependent failure mechanisms in CFCCs at elevated I-Static strength and stress rupture database. Ceram. Eng. Sci. Proc. temperatures. Ceram. Eng. Sci. Proc., 1998, 19(4), 11-18 2002,23(3),435-442. 17. Henager, C. H. and Jones, R. H, Subcritical crack growth in CVI 5. ASTM C 1359, Standard test method for monotonic tensile streng silicon-carbide reinforced with Nicalon fibers-experiment and model esting of continuous fiber-reinforced ceramics with solid JAm. Ceram.Soc,1994,77(9),2381-2394 mperatures. In An- 18. Spearing, S. M, Zok, F. W. and Evans, A. G, Stress-corrosion crack mal Book of ASTM Standards (ol 15.01). ASTM, West Con- ng in a unidirectional ceramic-matrix composite. J. Am. Ceram. Soc. shohocken. PA. 2001 1994,77(2),562-5701636 S.R. Choi et al. / Journal of the European Ceramic Society 25 (2005) 1629–1636 monolithic ceramics at elevated temperatures. The rate de￾pendency of ultimate tensile strength, the applicability of the preload technique, and the predictability of life from one loading configuration (constant stress rate) to another (con￾stant stress) for the Nicalon/BSAS composite suggested that the overall failure law of the composites would be governed by a power-law type of slow crack growth (or damage evo￾lution/accumulation). It was further confirmed that constant stress-rate testing could be utilized as a means of life predic￾tion test methodology for composites when short lifetimes are expected and when ultimate tensile strength is used as a failure criterion. Acknowledgments This work was supported in part by Higher Operating Tem￾perature Propulsion Components (HOTPC) Program and the Ultra-Efficient Engine Technology (UEET) Program, NASA Glenn Research Center, Cleveland, OH, USA. The authors are grateful to R. Pawlik for experimental work during the course of this research. References 1. Choi, S. R. and Gyekenyesi, J. P., Effect of load rate on tensile strength of various CFCCs at elevated temperatures: an approach to life-prediction testing. Ceram. Eng. Sci. Proc., 2001, 22(3), 597–606. 2. Bansal, N. P. and Setlock, J. A., Fabrication of fiber-reinforced celsian matrix composites. Composites Part A, 2001, 32, 1021–1029. 3. Worthem, D. W., Thermomechanical Fatigue Behavior of Three CFCC’s, NASA CR-195441. NASA Glenn Research Center, Cleve￾land, OH, 1995. 4. Verrilli, M. J., Calomino, A. and Thomas, D. J., Stress/life behavior of a C/SiC composite in a low partial pressure of oxygen environment: I—Static strength and stress rupture database. Ceram. Eng. Sci. Proc., 2002, 23(3), 435–442. 5. ASTM C 1359, Standard test method for monotonic tensile strength testing of continuous fiber-reinforced advanced ceramics with solid rectangular cross-section specimens at elevated temperatures. In An￾nual Book of ASTM Standards (Vol 15.01). ASTM, West Con￾shohocken, PA, 2001. 6. (a) Choi, S. R. and Gyekenyesi, J. P., Fatigue strength as a function of preloading in dynamic fatigue testing of glass and ceramics. Trans. ASME. J. Eng. Gas Turbines Power, 1997, 119(3), 493–499; (b) Choi, S. R. and Salem, J. A., Effect of preloading on fatigue strength in dynamic fatigue testing of ceramic materials at elevated temperatures. Ceram. Eng. Sci. Proc., 1995, 16(4), 87–94. 7. Halbig, M. C., The influence of temperature, stress, and environment on the oxidation and life of C/SiC composites. Ceram. Eng. Sci. Proc., 2002, 23, 419–426. 8. Calomino, A., Verrilli, M. J. and Thomas, D. J., Stress/life behavior of C/SiC composites in a low partial pressure of oxygen environment. II—Stress rupture life and residual strength relationship. Ceram. Eng. Sci. Proc., 2002, 23, 443–451. 9. Evans, A. G., Slow crack growth in brittle materials under dynamic loading conditions. Int. J. Fracture, 1974, 10(2), 251–259. 10. ASTM C 1368, Standard test method for determination of slow crack growth parameters of advanced ceramics by constant stress-rate flexu￾ral testing at ambient temperature. In Annual Book of ASTM Standards (Vol 15.01). ASTM, West Conshohocken, PA, 2001. 11. ASTM C 1465, Standard test method for determination of slow crack growth parameters of advanced ceramics by constant stress-rate flex￾ural testing at elevated temperatures. In Annual Book of ASTM Stan￾dards (Vol 15.01). ASTM, West Conshohocken, PA, 2001. 12. Choi, S. R., Gyekenyesi, J. P. et al., Ultra-fast fracture strength of advanced structural ceramics at elevated temperatures: an approach to high-temperature “inert” strength. In Fracture Mechanics of Ceramics, Vol 13, ed. R. C. Bradt. Kluwer Academic/Plenum Publishers, New York, 2002, pp. 27–46. 13. Halbig, M. C., Modeling the oxidation of carbon fibres in a C/SiC composite under stressed oxidation. Ceram. Eng. Sci. Proc., 2002, 23(3), 427–434. 14. Sorenson, B. F. and Holmes, J. W., Effect of loading rate on the mono￾tonic tensile behavior of a continuous-fiber-reinforced glass–ceramic matrix composite. J. Am. Ceram. Soc., 1996, 79(2), 313–320. 15. Curtin, W. A. and Halverson, H. G., High Temperature Deforma￾tion and Failure in Oxide/oxide Composites, HITEMP Review 1999: Advanced High Temperature Engine Materials Technology Project (NASA/CP—1999-208915/Vol 2, Paper 48). NASA Glenn Research Center, Cleveland, OH, 1999. 16. Lewinsohn, C. A., Henager Jr., C. H. and Jones, R. H., Environmen￾tally induced time-dependent failure mechanisms in CFCCs at elevated temperatures. Ceram. Eng. Sci. Proc., 1998, 19(4), 11–18. 17. Henager, C. H. and Jones, R. H., Subcritical crack growth in CVI silicon-carbide reinforced with Nicalon fibers—experiment and model. J. Am. Ceram. Soc., 1994, 77(9), 2381–2394. 18. Spearing, S. M., Zok, F. W. and Evans, A. G., Stress–corrosion crack￾ing in a unidirectional ceramic-matrix composite. J. Am. Ceram. Soc., 1994, 77(2), 562–570