Infrared thermal imaging based on active thermal excitations has been widely used for nondestructive evaluation (NDE) of materials. While the experimental systems have remained essentially the same during the last few decades, development of advanced data-processing methods has significantly improved the capabilities of this technology. However, many limitations still exist. One fundamental limitation is the requirement, either explicitly or implicitly, of the tested material to be homogeneous such that detected thermal contrasts may be used to determine an average material property or attributed to flaws. In this paper, a new thermal tomography (TT) method is introduced, which for the first time can evaluate heterogeneous materials by directly imaging their thermal-property variations with space. It utilizes one-sided flash thermal-imaging data to construct the three-dimensional (3D) distribution of thermal effusivity in the entire volume of a test sample. Theoretical analyses for single and multilayer material systems were conducted to validate its formulation and to demonstrate its performance. Experimental results for a ceramic composite plate and a thermal barrier coating (TBC) sample are also presented. It was shown that thermal diffusion is the primary factor that degrades the spatial resolution with depth for TT; the spatial resolutions in the lateral and axial directions were quantitatively evaluated.
Quantitative Three-Dimensional Imaging of Heterogeneous Materials by Thermal Tomography
Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received March 5, 2012; final manuscript received June 17, 2016; published online July 19, 2016. Assoc. Editor: Ali Khounsary.
The United States Government retains, and by accepting the article for publication, the publisher acknowledges that the United States Government retains, a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for United States government purposes.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Sun, J. G. (July 19, 2016). "Quantitative Three-Dimensional Imaging of Heterogeneous Materials by Thermal Tomography." ASME. J. Heat Transfer. November 2016; 138(11): 112004. https://doi.org/10.1115/1.4033998
Download citation file:
- Ris (Zotero)
- Reference Manager