Acoustic Emission Sensors for NDC of Carbon/Carbon
This report demonstrates how acoustic sensors can monitor changes in microstructure during the pyrolysis of Carbon/Carbon. In particular, we have demonstrated on flat plates up to one foot square in size that Acoustic Emissions (AE) are significantly different between normal microcracking associated with the chemo/physical changes during pyrolysis and the catastrophic delaminations that occur if the processing temperature/time treatment is incorrect. About 30 experimental runs have now been carried out, which show that AE provide precursor information in advance of delaminations so that the potential exists for making corrective changes during the processing treatment.
KeywordsAcoustic Emission Stress Drop Acoustic Emission Event Acoustic Sensor Acoustic Emission Activity
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- 1.“Process Science for 2D Carbon-Carbon Exit Losses”, prepared by Aerojet Strategic Propulsion Co., AFWAL Report No. TR 86-4028, July 1986.Google Scholar
- 2.K. T. Clemens and S. C. Brown, “Real-Time Acoustic Emission Monitoring/Control Technique for Carbonization of 2-D Phenolic-Carbon Composites”, 8th JANNAF RNTS Mfg., Patrick AFB, October 1986.Google Scholar
- 3.W. J. Pardee, M. R. Mitchell, A. Gupta, F. Montgomery and J. Sheehan, “Effect of Carbonization Kinetics on In-Process Mechanical Properties”, Proceedings of the ASM Conference, Indianapolis, IN, October 1989, in press.Google Scholar
- 4.J. R. Bulau, “AE Monitoring for Control of Carbon-Carbon Pyrolysis”, Proceedings of IEEE 1988 Ultrasonics Symposium (B. R. McAvoy, Editor), IEEE Cat. No. 88 CH 2578-3, pp. 1057-1063 (1988).Google Scholar
- 5.B. R. Tittmann and J. R. Bulau, “Acoustic Emission and Ultrasonics Sensing for Carbon-Carbon Pyrolysis Monitoring”, Proceedings of the ASM Conference, Indianapolis, In, October 1989, in press.Google Scholar
- 6.B. R. Tittmann, “Acoustical Studies of Damage Mechanism in Carbon-Carbon during First Carbonization”, Proceedings of the 1989 IEEE Ultrasonics Symposium, in press.Google Scholar
- 7.B. R, Tittmann, “High Temperature Young’s Modulus of Carbon-Carbon Composite Material” Proceedings of The ASME Conference, San Francisco, Ca 1989, in press.Google Scholar
- 8.B. R. Tittmann and J. R. Bulau, “NDE of Delaminations during Processing of Carbon-Carbon Composites”, Proceedings of the International Symposium on Acoustical Imaging, Santa Barbara, Ca, 1989, in press.Google Scholar
- 9.W. J. Pardee, R. C. Addison, D. J. Miley, B. S. Seely, M. A. Shaff and B. R. Tittmann of Rockwell International; A. Gupta of Ioptix; and F. Montgomery and J. Sheehan of General Atomics, “Intelligent Control of Carbon-Carbon Pyrolysis”, Proceedings of the 1989 TMS Fall Meeting, Indianapolis, IN, October 1989, in press.Google Scholar