The use of infrared thermography for materials characterization

The aim of the present experimental study is to highlight the help provided by infrared thermography in the characterization of materials. Infrared thermography is a two-dimensional, non-contact technique of surface temperature mapping which can be usefully exploited for quality assurance of manufacturing processes as well as for non-destructive evaluation of end products. Non-destructive evaluation with infrared thermography can be performed in two basic ways: pulse thermography (PT), or modulated lockin thermography (MT). Both techniques are able to reveal material inhomogeneties, which can arise either during manufacturing processes, or in service. In particular, within the MT technique a phase angle value may be associated to a specific characteristic (density, porosity, hardness, etc.) of the material. Thus, MT can be exploited for characterization of many materials either metallic, or plastics, composites, etc. which are commonly used in different fields: alimentary, architectural, automotive, aeronautical, mains. Results prove the capability of MT to discriminate between materials very similar and this feature can be advantageously exploited to evaluate modifications that occur in material characteristics as consequence of ageing, or exposure to adverse environmental conditions.