Thermal-wave detection and characterisation of sub-surface defects

Abstract

Results of the analysis of air-gap and thermal-contact resistance defects are presented. The analysis is illustrated by model predictions of the influence of such defects in a number of important coated and uncoated materials. Experimental results of defects in steel and aluminium coated steel samples are presented and compared with theory. These results show the importance of the lateral extent of the defect and the presence of contact points within the defect.