Characterization of the internal temperature and phase state of amorphous materials using ultrasonic non-destructive evaluation.

Ultrasound has a wide range of applicability and is used across many industries for non-destructive evaluation. Temperature is one of the key parameters in thermodynamic systems, and ultrasound has been studied as a means of temperature measurement for many years. Polymer, petro-chemical, power plant, food processing, and composites are just some of the industries which already make use of ultrasonics and stand to benefit from advances in the understanding and technology surrounding ultrasonic testing and evaluation. This research uses an amorphous wax with a low coefficient of thermal expansion; it is highly attenuative, and that attenuation change is a function of the temperature of the wax. The results of this research demonstrate the ability of this method to approximate 2D planar temperature and phase behavior of the wax using only ultrasonic data and externally located thermocouples, making it a truly non-invasive method.