On Line Process Control of Plasma Sprayed Ceramic Coatings with IR Thermographic Imaging

This paper discusses the use of IR thermography in the development and control of thermal spraying processes. In the experiments, Al₂O₃ layers are plasma sprayed on steel, aluminum, and glass substrates while recording surface temperatures. The measurements are then used to establish a correlation between temperature control and internal stress in the layer composite. The work shows that substrate preheating and torch kinematics have a significant effect on residual stress. Paper includes a German-language abstract.