- Author
- Bentz, D. P. | Martin, J. W.
- Title
- Thermographic Imaging of Surface Finish Defects in Coatings on Metal Substrates.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
- Materials Evaluation, Vol. 50, No. 2, 242-246, February 1992
- Keywords
- coatings | substrates | metals | heating | temperature | thickness
- Identifiers
- infrared thermography; surfacfe finish; thermal emission
- Abstract
- A technique for detecting and quantifying coating surface defects is presented. The technique is based on heating the coating system slightly above ambient temperature and viewing it with an infrared thermography camera attached to a computer image procesor. Surface finish defects are visible in the resultant thermographic image due to coating thickness variations between the defect and nondefect areas. These thickness variations influence the thermal radiaiton emission/reflection/transmission properties of the coating system detected by the thermographic camera. The theory for a model coating system is presented and several application areas explored. Theoretical limitations on the use of this technique are discussed.