Q NET Engineering GmbH
Thermography
Situation
Thermal testing methods have been optimised and perfected during the past years. They are now gaining importance as non-destructive testing methods for industrial use and thus for the characterisation of modern high performance materials. The use of different induction techniques or evaluation methods enables us to provide tailor-made thermal testing methods for many different problems. We optimally adjust these methods to the problem in order to get best results. Due to the high testing speed, the modular build-up, and the contact-free mode of operation (apart from the induction in ultrasound-induced thermography), the thermal testing techniques are highly suited for online testing also of geometrically complex parts within industrial quality control as well as for 100-percent quality control and recurrent testing of safety-relevant parts and components.
Active Thermal Testing Techniques
At Fraunhofer IZFP, different variants of thermal testing techniques are developed and implemented. Different evaluation methods and different physical effects as energy supply (heating) are used in order to get the best results in all the different fields of non-destructive material characterization. Q NET Engineering supports Fraunhofer IZFP in their continuous further development of thermal testing methods. We act as partners of our clients for the implementation of thermographic testing methods for industrial use. In the following, we want to introduce some examples of thermal testing techniques:
Impulse Thermography
High-speed impulse thermography uses the generation of transient heat conduction by light absorption at the surface of the material in order to detect imperfections like delaminations or lack of fusion and to measure the layer thickness of composite material. The method is extremely fast and contact-free.
Example 1: Impulse thermography on a steel ring with nickel coating (Source: IZFP, U. Netzelmann, G. Walle)
Example 2: Impulse thermography on a cylinder head gasket (Source: IZFP)
Electromagnetically Induced Thermography
In case of electromagnetically induced thermography, the component is heated by a pulsed and continuous eddy current. In this way, near-surface cracks can be detected due to the fact that the orientation of the crack within the component changes the flow of the induced current which leads to a local change in temperature. The rise in temperature is detected with highly sensitive infrared cameras and then evaluated. The advantage of this electromagnetic induction technology is the short inspection time, the high detection sensitivity and the possibility to also detect cracks beneath the surface.
Example 3: Electromagnetically induced thermography on a forged piece of metal with crack in the shell (Source: IZFP)
Ultrasound-Induced Thermography
In case of ultrasound-induced thermography, the material is charged with ultrasound. Due to the friction caused by the ultrasonic vibrations within the test item, cracks or delaminations within different materials can be detected which could not be detected with impulse thermography.
Example 3: Ultrasound-induced Thermography on steel sample with natural flaw (Source: IZFP, U.Netzelmann, G. Walle
Contact
Paul KröningPhone: +49 (0) 6 81/9 76 71 53
Fax: +49 (0) 6 81/9 76 71 58