IDT Sensors for Detection of Heat Sensitization in Aluminum Alloys Navy SBIR FY2010.3 Sol No.: Navy SBIR FY2010.3 Topic No.: N103-215 Topic Title: IDT Sensors for Detection of Heat Sensitization in Aluminum Alloys Proposal No.: N103-215-0204 Firm: Mound Laser & Photonics Center, Inc. P.O. Box 223 Miamisburg, Ohio 45343 Contact: Ronald Jacobsen Phone: (937) 865-4046 Web Site: mlpc.com Abstract: An innovative surface acoustic wave (SAW) sensor for in situ detection and real-time monitoring of heat sensitization in 5XXX series aluminum alloys will be developed. These active sensors generate ultrasonic Rayleigh waves at a fundamental frequency and then detect higher harmonics of that frequency produced when the sound waves scatter off of regions of beta phase Al3Mg2 that form during heat sensitization. The degree of harmonic sound detection will be correlated to how the alloy would respond to the ASTM-G67 chemical test. This will create a calibrated method for direct in situ measurement of changes in physical properties of the alloy as well as the risk of future anodic degradation, stress corrosion cracking or exfoliation - or alternatively, the expected remaining life of the material. The sensors will be durable and field deployable either for spot checks for material or permanent emplacement in the structure of interest. Due to the long range of Rayleigh waves, the surface are coverage standard for the sensor will easily be met. The low power requirements are consistent with methods of self powering. Operation in adverse conditions will be demonstrated and are not expected to pose any barriers for the technology. Benefits: In situ monitoring of aluminum alloys aboard ships will enable degradation to be detected before stress corrosion cracking or exfoliation occur, allowing for remedial action because any overt threat to mission readiness of ships appears. Sensor data will also improve scientific understanding and modeling of structural health of the fleet. This will improve the ability of the Navy to keep ships in service longer, thereby improving mission readiness and reducing overall costs by avoiding or delaying the need to replace platforms. Return