Combined Infrared Thermal Imaging and Laser Heating for the Study of Materials Thermophysical and Processing Properties at High Temperatures

Abstract

Focused laser irradiation can easily drive materials to extreme temperatures with very high precision and control. In combination with infrared imaging and material characterization techniques, the resulting thermal load can be assessed to derive meaningful thermophysical properties avoiding interferences that would normally occur with direct contact measurements of temperature. In this focused article we first address technical challenges with the experimental implementation involved in obtaining laser-induced temperature field data from infrared imaging. We then discuss suitable heat transport models for analysis of thermal data and, finally, describe specific examples of thermophysical material parameters derived from combined infrared imaging and laser heating. The aim is to illustrate general principles of this combined laser-based heating and IR thermal imaging approach that are useful for experimentation under extreme conditions, which often remain out of reach of conventional methods.

Keywords:

• infrared
• imaging
• temperature
• laser
• heating
• thermophysical
• thermal
• model
• pyrometry
• thermography
• rheology

ACKNOWLEDGMENTS

The authors would like to thank the following for contributing to the studies reviewed here: Dr. Nan Shen, Dr. Ted Laurence, Dr. Rajesh Raman, Dr. Isaac Bass, Gabe Guss, Dr. Michael Feit, and Dr. Jeff Bude for useful discussions on silica IR emissivity measurements. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.