Applications of Lockin-Thermography Methods

The basic idea of nondestructive testing is that a sample is characterised by its response to a certain kind of excitation. The excitation may be an electric or elastic field with a time pattern described by a step, a pulse, or a sine wave type. The field can be applied locally to characterise the area around a certain sample spot. A raster scan image is then performed by measuring many spots one after the other.</p

Inline drift detection using monitoring systems and machine learning in selective laser melting

Direct metal laser sintering, an additive manufacturing technique, has a huge growing demand in industries like aerospace, biomedical, and tooling sector due to its capability to manufacture complex parts with ease. Despite many technological advancements, the reliability and repeatability of the process are still an issue. Therefore, there is a demand for inline automatic fault detection and postprocessing tools to analyze the acquired in situ monitoring data aiming to provide better-quality assurance to the user. Herein, the treatment of the data obtained using the EOSTATE optical tomography monitoring system is focused. A balanced dataset is obtained with the help of computer tomography of the certified part (Stainless Steel CX cylindrical samples), through which a feature matrix is prepared, and the layers of the part are classified either having "Drift" or "No-drift." The model is trained with the feature matrix and tested on benchmark parts (Maraging Steel) and on an industrial part (knuckle, automotive part) manufactured in AlSi10Mg. The proposed semisupervised approach shows promising results for presented case studies. Thus, the semisupervised machine learning approach, if adopted, could prove to be a cost effective and fast approach to postprocess the in situ monitoring data with much ease

Infrared Thermography

Infrared thermography also commonly referred as thermal imaging, or simply thermography, is a nondestructive testing (NDT) technique that has received vast and growing attention for diagnostics and monitoring in the last few decades. This is mainly due to the fact that commercial infrared or thermal cameras, the main instrument for performing infrared thermography, are continuously improving in both sensibility and in spatial resolution, and they are getting faster and relatively less expensive. Every year or so, it is possible to acquire a better camera for about the same cost as the preceding model from the year before

Thermal (IR) and Other NDT Techniques for Improved Material Inspection

International audienc