Detection of Delaminations

Many industries rely on composite materials – from the automotive and aerospace industries through to the semiconductor industry. The key advantages of such components – e.g. high rigidity at a low weight – come into play only with assured quality of the joints between the individual layers. In many areas, coatings are applied to give the products improved characteristics such as increased temperature stability or corrosion resistance.

In the past, delaminations, i.e. separations in the layer joints, could only be detected in complicated destructive tests of random samples. Thermal imaging inspections now enable the non-destructive testing of workpieces.

The test part is briefly heated using a impulsed light source. A bad material joint within a workpiece significantly reduces – albeit only locally – the heat conductivity in that area. The IR camera captures the heat propagation and then the control computer converts the image data into a spatial presentation of how the heat waves propagate. This permits reliable evaluation of the state of the joints between the individual layers. The result can be used for process control.