Article Periodicals » Materials Evaluation » Article
Thermal Diffusivity Mapping of Carbon/Carbon Composites

In order to develop new capabilities to simultaneously nondestructively determine discontinuities and measure thermal diffusivity in carbon/carbon (C/C) composites, a study was conducted of NDT methods for identifying subsurface discontinuities in C/C composites by thermal diffusivity measurements using a step-heating technique. Since traditional NDT methods are effective for thin carbon/epoxy composites, but are not very effective in detecting discontinuities in thick C/C composites, there is substantial industrial demand for nondestructive, rapid, online testing of the thermal diffusivity of an entire C/C composite part’s surface. Therefore, this paper applied a stepheating infrared thermography technique to conduct through-thickness thermal diffusivity measurements and NDT for whole-field C/C disk brakes. In this work, a brief description of the theory behind the step-heating technique and a sample application are given. Finite element analysis (FEA) was also used for comparison with the experimental results and it was found that they were in good agreement with one another. The results established that this technique is capable of evaluating discontinuities in C/C composite materials. With more research, it is believed that this technique will be found to be efficient, economically feasible, easy to implement, and capable of providing rapid assessment of discontinuities in C/C composite materials that will be able to be incorporated into a manufacturing process quality control system.

ASTM, ASTM E 1461: Standard Test Method for Thermal Diffusivity by the Flash Method, West Conshohocken, Pennsylvania, ASTM International, 2007. Balageas, D.L. and A.M. Luc, “Transient Thermal Behavior of Directional Reinforced Composites: Applicability Limits of Homogeneous Property Model,” AIAA Journal, Vol. 24, 1986, pp. 109–114. Brittle, R.R. and R.E. Taylor, “Step-Heating Technique for Thermal Diffusivity Measurements of Large-Grained Heterogeneous Materials,” Journal of the American Ceramic Society, Vol. 67, 1984, pp. 186–190. Butler, C.P. and E.C.Y. Inn, “Thermal Diffusivity of Metals at Elevated Temperature,” Thermodynamic and Transport Properties of Gases, Liquids and Solids, Transports, New York, ASME, 1959, pp. 377–390. Dobiaova, L., V. Stary, P. Glogar and V. Valvoda, “X-ray Structure Analysis and Elastic Properties of a Fabric Reinforced Carbon/Carbon Composite,” Journal of Carbon, Vol. 40, 2002, pp. 1419–1426. Hatsulade, Y., T. Inaba, N. Kasai, Y. Maruno, A. Ishiyama and S. Tanaka, “Detection of Deep-Lying Defects in Carbon Fiber Composites Using SQUID-NDE System Cooled by a Cryocooler,” Journal of Physics C, Vols. 412-414, 2004, pp. 1484–1490. Ilcewicz, L.B., D.J. Hoffman and A.J. Fawcett, Comprehensive Composite Materials, Amsterdam, Elsevier, 2000. Miller, R., T.P. Chu, P. Filip and J. Don, “Detection of Defects in C/C Composites Using Infrared Thermography,” Proceedings of the 2008 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, Orlando, 2008. Ruosi, A., “Nondestructive Detection of Damage in Carbon Fibre Composite,” Physica Status Solidi C, Vol. 2, 2005, pp. 1153–1155. Vozar, L. and T. Sramkova, “Two Data Reduction Methods for Evaluation of Thermal Diffusivity from Step-Heating Measurements,” International Journal of Heat Mass Transfer, Vol. 40, 1997, pp. 1647–1655. Yang, H.C., J.H. Chen, S.Y. Wang, C.H. Chen, J.T. Jeng, J.C. Chen, C.H. Wu, S.H. Liao and H.E. Horng, “Superconducting Quantum Interference Device: The Most Sensitive Detector of Magnetic Flux,” Tamkang Journal of Science and Engineering, Vol. 6, 2003, pp. 9–18. Zhang, Y. and T.P. Chu, “Thermal Diffusivity Evaluation on C/C Brake Using Step-Heating Method,” Proceedings of the 2007 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, Springfield, Massachusetts, 2007.
Usage Shares
Total Views
26 Page Views
Total Shares
0 Tweets
0 PDF Downloads
0 Facebook Shares
Total Usage