The Engineering and Services Group of the Energy Research Centre (ECN) in the Netherlands has developed an extreme thermo-shock proof tungsten based material, which is converted into complex shaped components used for nuclear fusion applications by powder injection moulding (PIM).
ECN uses a special yttria doped tungsten powder to achieve the required property characteristics under extreme heat load conditions. Testing of the PIM tungsten-yttria components at an absorbed capacity of 1.13 GW/m2 during 1000 cycles of 1 ms did not lead to any cracking, contrary to conventional materials. Particularly the ductility, the fatigue resistance and the hardness of the material have been optimised.
The good properties of the PIM material are due to its homogenous and fine microstructure that is similar in three dimensions, contrary to the directional dependence of conventional materials. The material therefore shows no signs of recrystallisation between 1200 and 1440°C, but remains stable well above 2000°C.
The unique characteristics of the obtained material are largely determined by the use of the PIM technology which ECN believes is highly suited for a wide range of new doping alloy applications.
The PIM process offers unlimited freedom of shaping, which eliminates the need for finish machining. For tungsten this is highly relevant, both for cost and performance reasons.
For more information contact Jan Opschoor,
email: [email protected]