Lock-in infrared thermography as non-destructive test for material characterization

Abstract

The Research Institute for Materials, located at the university campus in Diepenbeek, comprises a research group, imo-imomec, committed to the development and characterization of new material systems. Material characterization can be done by means of destructive or non-destructive testing methods. However, the destructive testing methods are time consuming and economically inefficient since the test specimens are damaged during the process. The main objective of this master's thesis is to realize a demo setup to perform lock-in infrared thermography, a non-destructive testing method for material characterization.

The development of the demo setup comprised two parts. First, the hardware is compiled and consists of three major parts, i.e. the infrared camera, the excitation source and the data analyzer. Some of the hardware components, such as the power amplifier, are built for this specific application. Second, the software, which captures and processes the data images, was realized using LabVIEW. Algorithms for both continuous and moving averaging are included.

Lock-in infrared thermography is relatively fast and economically more efficient compared to destructive testing methods. Test results show that minor defects that are not visible to the naked eye, such as inhomogeneities, delaminations and internal fractures can be shown using this demo setup for lock-in infrared thermography.