Review of Progress in Quantitative Nondestructive Evaluation
As with many aerospace applications, commercial jet engine components are operated in demanding environments, often at extreme temperature and stress conditions. The predominant used surface inspection method used on these components is fluorescent penetrant inspection. Research has been ongoing for a number of years on a new technology using a short burst of low frequency ( ∼ 20 KHz) ultrasound to “heat up” cracks and make them visible in the infrared range. The basic premise of the Thermal Acoustic method is to use an energy source with recent efforts using an ultrasonic horn originally intended for use in ultrasonic welding to excite the component. The energy source causes an increase in local heating, which is detectable with infrared cameras typically used in Thermographic inspection. While considerable research is underway, additional information on the sensitivity and applicability of this technique to engine components and alloys is needed prior to widespread use in the aviation industry. The purpose of this program is to provide additional data to determine applicability of this method to engine components.
American Institute of Physics
Lively, John; Ouyang, Zhong; Brasche, Lisa; Holland, Stephen D.; Eisenmann, David J.; Bantel, Tom; and Hassan, Waled, "Status of FAA Studies in Thermal Acoustics" (2007). Aerospace Engineering Conference Papers, Presentations and Posters. 7.