21 August 1996 Evaluation of TiN and CrN surface coatings with laser-supported thermography
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Proceedings Volume 2786, Vision Systems: Applications; (1996); doi: 10.1117/12.248578
Event: Lasers, Optics, and Vision for Productivity in Manufacturing I, 1996, Besancon, France
Abstract
With the PVD (physical-vapor-deposition) technology various metallic and ceramic coatings, for example coatings like TiN and CrN, can be used on different materials as wear- resistant coatings. To verify the quality of the coating especially on components with a complex shape the nondestructive testing of the coating properties is very important. Established nondestructive testing techniques like ultrasonic and eddy current techniques often fail for thin coatings because of the large wavelength. In this article the possibilities and limits of the laser supported thermography for the characterization of such coatings are presented and discussed. Beside the thermal wave technique using a periodic laser heating and an infrared detection from the front side of the component the transient behavior of the temperature in the case of a step like heating is analyzed. By a systematic variation of the measurement parameters and comparison with calculations about the heat flow in coating systems the thermal properties near the surface of the component are analyzed. The results of the laser supported thermography are compared with the results of a metallography of the coatings.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Uwe Radtke, Horst-Artur Crostack, "Evaluation of TiN and CrN surface coatings with laser-supported thermography", Proc. SPIE 2786, Vision Systems: Applications, (21 August 1996); doi: 10.1117/12.248578; https://doi.org/10.1117/12.248578
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KEYWORDS
Diffusion

Thermography

Modulation

Optical coatings

Tin

Phase shift keying

Nondestructive evaluation

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