SiC/SiC ceramic matric composites: A turbine engine perspective

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1 Engineering Conferences International ECI Digital Archives Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II Proceedings Spring SiC/SiC ceramic matric composites: A turbine engine perspective Adam Chamberlain Rolls-Royce Jay Lane Rolls Royce Follow this and additional works at: Part of the Materials Science and Engineering Commons Recommended Citation Adam Chamberlain and Jay Lane, "SiC/SiC ceramic matric composites: A turbine engine perspective" in "Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II", W. Fahrenholtz, Missouri Univ. of Science & Technology; W. Lee, Imperial College London; E.J. Wuchina, Naval Service Warfare Center; Y. Zhou, Aerospace Research Institute Eds, ECI Symposium Series, (2013). This Conference Proceeding is brought to you for free and open access by the Proceedings at ECI Digital Archives. It has been accepted for inclusion in Ultra-High Temperature Ceramics: Materials For Extreme Environmental Applications II by an authorized administrator of ECI Digital Archives. For more information, please contact franco@bepress.com.

2 SiC/SiC Ceramic Matrix Composites A Turbine Engine Perspective Dr. Adam Chamberlain and Dr. Jay Lane Ultra-High Temperature Ceramics Materials for Extreme Environment Applications II May 13-18, 2012 Hernstein, Austria 2012 Rolls-Royce Corporation The information in this document is the property of Rolls-Royce Corporation and may not be copied or communicated to a third party, or used for any purpose other than that for which it is supplied without the express written consent of Rolls- Royce Corporation. This information is given in good faith based upon the latest information available to Rolls-Royce Corporation, no warranty or representation is given concerning such information, which must not be taken as establishing any contractual or other commitment binding upon Rolls-Royce Corporation or any of its subsidiary or associated companies.

3 Future trends in turbine engines Future platforms require significant increases in performance Decreased fuel consumption Decreased emissions Requires higher temperatures and pressure ratios Potential solutions High temperature materials - Single crystal nickel alloys with high Re and Ru concentrations - Niobium/molybdenum intermetallics - Ceramic matrix composites - Low k TBCs Advanced cooling - Transpiration cooling - Cooled cooling air Unique Properties of CMCs CMCs are one of few technologies that have the temperature and structural capability to meet next generation turbine engine needs

4 CMC turbine components Combustion liners Increased wall temperature Reduced emissions Bladetracks/shrouds Increased temperature Reduced weight Improved SFC Airfoils (blades/vanes) Increased temperature Reduced weight Improved SFC Typical large civil 3-shaft cross section

5 Material and component design Service life requirements Temperature range Pressure loads Thermal loads Interfaces Environment CMC component design Material design Iterative process between design and material engineers Final part and material designed for full service life

6 Reliability requirements Hypersonic vehicle RATTLRS Powered by RR YJ102R AE3007 Trent 1000 Industrial Trent Minutes hours 25,000 + hours 50,000 + hours Race car hours Passenger Vehicle hours Semitruck hours LCD TV ~ hours Rolls-Royce products have a wide range of service time due to customer requirements and cost

7 Temperature requirements RIT = C T gas >T max (SOA SiC/SiC) Attachment temperature controlled by metallic limits (T < 800 C)

8 Current SOA SiC/SiC Residual Silicon Melt infiltrated product GE HiperComp NASA N24 Strength reduction after thermal exposures Silicon diffusion Stress limited at cold attachment regions Damage tolerance limited at attachment regions Need to consider full temperature range

9 Future material needs Increased temperature capability Small improvements can have a big impact - Additional reductions in cooling air - Removal or simplification of cooling schemes Reduces thermal gradients Reduces manufacturing cost - Increased insertion opportunities Potential solutions exist CVI or PIP SiC/SiC New MI systems Metals can utilize cooling technologies that are not available to CMCs (Lamilloy ) (*) (#) # C.E. Lundin, The System Zirconium and Silicon, Trans. Am. Soc. Met., Vol. 45, p * Data from : J. Moustapha, M.F. Zelesky, N. Baines, and D. Japikse, Axial and Radial Turbines, Concepts NREC, 2003

10 Environmental stability Environmental barrier coatings Current solution (*) Future Solution? 1200 C, 10 atm, 500 hrs1200 C, 10 atm, 3500 hrs Images from: P. Tortorelli and K. More, Effects of High Water- Vapor Pressure on Oxidation of Silicon Carbide at 1200 C, J. Am. Ceram. Soc, 86 [8] (2003) ZrO 2 stable in H 2 O Are zirconates stable in H 2 O? Can you incorporate this into a fiber composite? (*) Images from: D. Jayaseelan, et.al., In-situ Formation of Oxidation Resistant Refractory Coatings, SiC-Reinforced ZrB 2 UHTC, J. Am. Ceram. Soc, 95 [4] (2012)

11 Component lifing Fillet in an inner cavity Parasitic part Structural part Features can push into the non-linear region Attachment transition airfoil Spend 95% of your time resolving or validating local stresses that exceed matrix cracking.

12 CMC testing and analysis CMC testing with monitoring Local strain measurements NDE (IR, x-ray) Acoustic measurements Accurate design inputs Elastic constants Elastic inputs vs. load Statistical variation Proper FEA definition Mesh size Global vs. local Understanding of damage progression Initiation and growth Life limiting features CMC component design Optimized design for weight Robust design for life

13 Finite Element Models Strain visualization output Average strain at notches and center Good correlation expected in models Models calibrated on a bulk response Mesh size is representative of material length scale for homogeneity Good correlation to failure strain (5%) Cannot capture damage mechanisms Insufficient to provide optimized designs without component testing

14 Refined FEA mesh for lifing Models need to understand local responses Poor correlation to failure strain Model inputs are a bulk responses Mesh size is below the length scale of homogeneity Further refinement in mesh needed for damage and life models Future stress analyst must be trained to understand the impact of material inhomogeneity on mesh size After matrix cracking behavior is a function location and area Material inhomogeneity critical after cracking

15 Summary CMCs have the opportunity to provide a step-change in engine technology Significant improvements in performance, emissions, and fuel consumption Insertion requires an understanding of all requirements Temperature range, service life, environment Further improvement in material capability would increase insertion opportunities and further enhance performance Increased temperature and environmental stability Optimized designs will need improved models that capture the local behavior after matrix cracking Critical for lifing attachment regions Transition to more structural parts