Smart Materials for Extreme Conditions
Jülich, 13 July 2017 – The inside walls of future fusion reactors will be exposed to extreme heat flux densities comparable to those faced by the outer walls of spacecraft upon re-entering the Earth’s atmosphere. This is in addition to dealing with intensive particle and neutron fluxes which lead to material erosion and defects. Tungsten is currently regarded as the preferred wall material, in part due to its high melting point. However, problems with the material include its brittleness and its high rate of oxidation in the event of a rare intake of air at high temperatures. A solution to these problems could be the new, smart material concepts based on tungsten that scientists at Forschungszentrum Jülich have developed together with national and international partners. The concepts consist of fibre-reinforced composites, which help to reduce the spread of harmful cracks, as well as smart alloys made of tungsten, chromium, and the light metal yttrium (W-Cr-Y), which exhibit an oxidation rate roughly 100,000 times lower than pure tungsten.