International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The scanning nozzle hot air system for thermographic detection of the surface incorporated hidden defects is proposed. Subsurface defects in the sample are detected using the high resolution thermal imaging camera FLIR SC7000. To introduce additional energy in are searched sample, a scanning hot air (about 110°C) nozzle is applied (a patent application P.403346). The hidden defect causes a temperature increase in comparison with the remaining area what is a result of changes in emissivity. The results are compared with the pulse thermography method using the xenon lamp for excitation.

Thermography measurements allow to detect the defects that may appear on a joint at welding of components. Energy pulse generated by a xenon lamp with adequate power in a short period of time is sufficient for thermal excitation and enables to register the temperature distribution using the thermography high resolution camera FLIR SC7000. The impulse with 6kJ energy and 6ms time generate sufficient power to measure the temperature distribution on the surface of the weld tested. During cooling the temperature of the area with defect changes more slowly than in the areas without defects, because of to the less intense heat dissipation. This allows the registration of defects in welds "on-line" at the production process. Material used for analysis detection of defects in the welded joints is Inconel 718, stainless steel 410 and stainless steel 321. The peak energy which flow throw the samples with defects in the welded joints its completely or partially blocked. It cause different temperature distribution on the surface in the places where the connection discontinuity take place.

Turbine blades used in the jet engines are subjected to frequent and rapid temperature changes. As a result of the hot gases influence the temperatures excess 1000°C. Certain conditions for the blades generate local thermal stresses. In this paper the thermal stresses are calculated on base on experimental measurements of the temperature distributions using the high resolution thermal imaging camera FLIR SC7000 registered the distribution of temperature field for the blades with TBC and without TBC. The distribution of stresses in the blades based on the collected measurement data has been calculated. The calculations were made using FEM method implemented in COMSOL.