Advanced self-passivating alloys for an application under extreme conditions

Advanced self-passivating alloys for an application under extreme conditions

Advanced self-passivating alloys for an application under extreme conditions 150 150 Mathew

Self-passivating Metal Alloys with Reduced Thermo-oxidation (SMART) are under development for the primary application as plasma-facing materials of the first wall in a fusion DEMOnstration power plant (DEMO). SMART materials must combine the suppressed oxidation in case of an accident and an acceptable plasma performance during the regular operation of the future power plant. Modern SMART materials contain chromium as a passivating element, yttrium as an active element and the tungsten base matrix. An overview of the structured research and development program on SMART materials is presented and all major areas of the structured R&D are explained. Attaining the desired performance under accident and regular plasma conditions are vital elements of R&D program addressing the viability of the entire concept. An impressive more than 104-fold suppression of oxidation, accompanied with more than 40-fold suppression of sublimation of tungsten oxide was attained during an experimentally reproduced accident event with a duration of 10 days. The sputtering resistance under DEMO-relevant plasma conditions of SMART materials and pure tungsten was identical for conditions corresponding to nearly 20 days of continuous DEMO operation. Fundamental understanding of physics processes undergoing in the SMART material is gained vial fundamental studies comprising the dedicated modeling and experiments. The important role of yttrium, stabilizing the SMART alloy microstructure and improving the self-passivating behavior is under investigation. Activities toward industrial up-scale have been started comprising the first mechanical alloying at the industrial partner and the sintering of the bulk SMART alloy sample with the dimensions of 100 mm × 100 mm × 7 mm using the industrial facility. These achievements opens the way to further expansion of the SMART technology toward its application in fusion and potentially in the other renewable energy sources such as concentrated solar power stations.

Collection:
Journals
Journal:
Metals
Publisher:
MDPI (Multidisciplinary Digital Publishing Institute)