Prodigious Application of Pulsed Flash Thermography for the Characterization and Fault Detection of Surface Material

The aim of the present study is to demonstrate the assistance provided by infrared thermography (IRT) in the characterization of materials. Infrared thermography is a surface temperature mapping technique which is two-dimensional and contactless method which can be practically applied for quality assurance of manufacturing processes and for non-destructive testing (NDT) of end products. Infrared thermography based on NDT can be accomplished in two basic ways: pulse thermography (PT) [1], or modulated lock-in thermography (MT). Here we emphasis on pulse thermography and pulse flash thermography. Pulsed thermography is commonly used as non-destructive technique for evaluating defects within materials and components. However, raw thermal imaging data are usually not suitable for quantitative evaluation of defects. The thermal examination using NDT [2] can find the presence of fault based on temperature distribution irregularities that are created on the surface as a result of a fault. There are many factors that affect the temperature distribution of the surface being tested by Infrared Thermography. We consider a simple structure of the surface with several defects, whose surface we heated with a uniform heat flux impulse. We conducted a theoretical analysis of the method for case of defects on the surface. First, we create intentionally the defects on the surface of material in order to find conditions and boundaries for application of the method. The pulsed flash thermography (PFT) [1] method was performed on simulated defects on surface with air and other compounds which has tendency of Phase Change. Study results indicate that it is possible, using the PFT method, to detect the type of material inside defect holes, whose presence disturbs the homogeneous structure material.