TWI Industrial Member Report Summary 614/1997
G A Georgiou and M B Saintey*
Infrared non-destructive testing (NDT) techniques ( ie photothermal radiometry (PTR) and transient thermography), offer a number of advantages over other NDT methods for detecting and characterising flaws associated with thermally sprayed coatings. This study evaluates their suitability.
Continuing development of thermal spraying processes over the last two decades has made it possible to extend the application of coatings to virtually all major industry sectors. Currently, only a handful of organisations, in the UK for example, carry out routine NDT for thermally sprayed coatings. Increasing competitiveness is placing a greater burden on industry to adopt more formal quality systems. A major part of this study has involved evaluating and developing infrared NDT techniques applied to thermally sprayed coatings. Mathematical modelling has played a significant role in understanding heat flow in these coatings, and in identifying practical ways to optimise the infrared NDT techniques to detect, locate, size and image flaws at the coating/substrate interface.
- To develop a predictive mathematical model for heat flow to assess the capabilities and limitations of infrared NDT techniques.
- To develop neural networks for providing a more accurate representation of detected flaws.
- To develop infrared NDT techniques for assessing the quality of thermally sprayed coatings.