The X-ray unit of the diffusion oven

The Institute of Material Physics in Space, based in Cologne, Germany, is focused on researching material properties and related subjects. This includes gaining a precise understanding of processes that occur as metals melt. During these experiments, X-ray radiography has allowed research scientists to record the entire process from melting to solidification, providing the diffusion in the molten mass to be directly depicted. Irradiation of the test sample with 110 kV X-ray radiation was accomplished by Viscom’s HIBIX X-ray tube, which was developed specifically for this purpose.

Light materials are gaining increased importance for many industrial applications, as is the case with components for the aviation and aerospace industry, automotive technology and other areas. The aluminum foams and alloys used in these areas should save weight, but not at the expense of sufficient strength. Therefore, when designing materials, understanding the processes taking place as metals melt is crucial.

New radiologic technologies make this understanding possible. They provide a view of the entire diffusion process from melt through diffusion annealing to solidification of the sample. The tendency of a liquid to equalize localized differences in its composition through movement of the atoms or molecules (diffusion) is a fundamental process of nature. For example, diffusion regulates liquid solidification and crystal growth.

The physics behind these processes are best investigated under zero gravity conditions. Therefore, the German Federal Ministry of Economics and Labour (BMWi) has initiated a project to construct a compact X-ray diagnostic system to meet this goal. Under the guidance of Prof. Dr. Andreas Meyer, head of the DLR Institute for Material Physics in space, the DLR and partners from both industry and science were brought together to investigate the complex interrelations underlying diffusion.

To support observation of these experiments, Viscom has further developed its proprietary X-ray technology. Based on their longstanding experience in X-ray technology, Viscom AG’s physicists have developed a unique, highly integrated and brilliant X-ray source – the HIBIX tube (Highly Integrated Brilliant Image X-ray tube). This tube is capable of supplying the irradiation power these experiments require, with minimum energy consumption. No external supply components are needed for this performance. Combination with the evacuable test chamber for the melting furnace and a digital detector has yielded an X-ray unit in the smallest possible space, which henceforth will be used by the Institute for Material Physics in Space, an agency of the German Aerospace Center (DLR).