Volume 24, Issue 5 (September 1996)
Preliminary Characterization of Thermal Diffusivity for Carbon-Carbon Composites Through Pulsed Video Thermal Imaging
Many times complete knowledge of thermal transport properties is needed before a material can be employed in a thermal application. One property of primary concern is thermal diffusivity. What is desirable is not only the magnitude of thermal diffusivity, but also the determination of its non-uniformity. The currently used standard test method by industry is the (ASTM) Standard Test Method for Thermal Diffusivity of Solids by the Flash Method, which measures diffusivity at one point. This method also requires the destructive removal of a small sample for examination, special ad hoc machinery for surface scanning, and is not suitable for quality assessment in a manufacturing environment. There is substantial industrial demand for the nondestructive, rapid, on-line evaluation of the thermal diffusivity of an entire part's surface. Pulsed Video Thermography (PVT) is an emerging thermal wave imaging technique that shows promise for meeting those demands. In this work a brief description of the theory behind PVT and a sample application are given. Preliminary results show that the PVT thermal diffusivity values for a carbon-carbon composite plate compare favorably with those obtained by the widely used laser flash diffusivity method.