Environmental barrier coatings (EBCs) are used as a coating material on fiber-reinforced ceramic matrix composites (CMC) for various aerospace and turbine engines applications. In order to validate physics-based analytical models for predicting the spallation life of EBCs, the fracture strength of the EBC and the kinetics of crack growth in EBC layers need to be experimentally determined under engine operating conditions. In this study, a coating layer of barium strontium aluminum silicate (BSAS)–based melt-infiltrated silicon carbide fiber-reinforced silicon carbide matrix composite (MI SiC/SiC) is applied on a CMC specimen and tensile tested at room temperature. Multiple tests are performed on a single specimen with increasing predetermined stress levels until final failure. Damage progression due to the load applied is monitored using a digital image correlation (DIC) system. After unloading from the predetermined stress levels, the specimen is evaluated by optical microscopy and computed tomography (CT). The inspection forms the imaging which implied that primary and secondary cracks developed during tensile loading until failure. DIC showed formation of a primary crack at ~50% of the ultimate tensile strength, and this crack grew with increasing stress and eventually led to final failure of the specimen.
Abdul-Aziz, Ali, Adam C. Wroblewski, Ramakrishna T. Bhatt, Martha H. Jaskowiak, Daniel Gorican, and Richard W. Rauser. 2015. “Assessment of NDE methods for detecting cracks and damage in environmental barrier coated CMC tested under tension,” Proc. SPIE 9436, Smart Sensor Phenomena, Technology, Networks, and Systems Integration 2015, 943609 (27 March 2015); https://doi.org/10.1117/12.2087600.
Amirkhanov, Alexander, Dietmar Salaberger, Johann Kastner, Christoph Heinzl, and Eduard Gröller. 2017. “Comparison of Final Fracture Extraction Techniques for Interrupted In situ Tensile Tests of Glass Fiber Reinforced Polymers” 7th Conference on Industrial Computed Tomography (iCT) 2017, 7-9 Feb, Leuven, Belgium (iCT 2017), NDT.net Issue 2017-03. ndt.net/app.iCT2017.
DiCarlo, J.A., H.M. Yun, G.N. Morscher, and R.T. Bhatt. 2005. “SiC/SiC Composites for 1200°C and Above.” In: Handbook of Ceramic Composites, edited by N.P. Bansal (Boston, MA: Springer). https://doi.org/10.1007/0-387-23986-3_4.
Jorgensen, P. J., M. E. Wadsworth, and I. B. Cutler. 1959. “Oxidation of silicon carbide.” Journal of the American Ceramic Society 42 (12): 613–16. https://doi.org/10.1111/j.1151-2916.1959.tb13582.x.
Lau, S.K., S.J. Calandra, and R.W. Ohnsorg, 1996, “Process for making silicon carbide reinforced silicon carbide composite,” US Patent No. 5,840,221A, filed 2 December 1996 and issued 24 November 1998.
Lee, K.N., D.S. Fox, R.C. Robinson, and N.P. Bansal. 2001. “Environmental Barrier Coatings for Silicon-Based Ceramics.” In High Temperature Ceramic Matrix Composites, ed. W. Krenkel, R. Naslain, and H. Schneider, 224–229. Weinheim, Germany: Wiley-Vch.
Lee, K. N., D. S. Fox, and N. P. Bansal. 2005. “Rare Earth Silicate Environmental Barrier Coatings for SiC/SiC Composites and Si3N4 Ceramics.” Journal of the European Ceramic Society 25 (10): 1705–15. https://doi.org/10.1016/j.jeurceramsoc.2004.12.013.
McCormick, N., and J. Lord. December 2010. “Digital Image Correlation.” Materials Today 13 (12): 52–54. https://doi.org/10.1016/S1369-7021(10)70235-2.
Morscher, G.N., J.A. DiCarlo, J.D. Kiser, and H.M. Yun. 2010. “Effects of Fiber Architecture on Matrix Cracking for Melt-Infiltrated SiC/SiC Composites.” International Journal of Applied Ceramic Technology 7 (3): 276–90. https://doi.org/10.1111/j.1744-7402.2009.02422.x.
Schreier, H., J.-J. Orteu, and M. A. Sutton. 2009. Image Correlation for Shape, Motion and Deformation Measurements: Basic Concepts, Theory and Applications. Boston, MA: Springer-Verlag US. https://doi.org/10.1007/978-0-387-78747-3.
Smialek, J. L., R. C. Robinson, E. J. Opila, D. S. Fox, and N. S. Jacobson. 1999. “SiC and Si3N4 recession due to SiO2 scale volatility under combustor conditions.” Advanced Composite Materials 8 (1): 33–45. https://doi.org/10.1163/156855199X00056.
Stress Engineering Services Inc. n.d. “Using Digital Image Correlation to Measure Large Areas of Strain and Displacement.” Testing, Stress Engineering Services Inc., accessed 5 October 2022, stress.com/dic-to-measure-large-areas-of-strain-displacement.
Zhu, D., N.R. Bansal, and R.A. Miller. 2012. “Thermal Conductivity and Stability of Hf02-Y203 and LajZr207 Evaluated for 1650°C Thermal/Environmental Barrier Coating Applications.” In Advances in Ceramic Matrix Composites IX, edited by Narottam P. Bansal, J.P. Singh, Waltraud M. Kriven, Hartmut Schneider. Ceramic Transactions Series (Hoboken, NJ: Wiley), 331.
88 Page Views
0 PDF Downloads
0 Facebook Shares