Real-time X-ray radioscopy on metallic foams using a compact micro-focus source

A measurement apparatus for observing the foaming of metals is described. It consists of a microfocus X-ray source, a small heater and a panel detector. The foaming of samples can be recorded in real-time with frequencies up to 9 Hz and resolutions down to 5 mum due to the small spot size. Magnifications up to 10x are obtained by simply changing the distance between source, sample and detector. Foaming. of Al alloys and sandwiches was investigated applying different final foaming temperatures, heating rates and blowing agent pre-treatments.An image analysis program was developed to automatically recognise the foam expansion.