Abstract
Conventional alloys consist typically of one main base element and minor additions of other elements, e.g. steel where the base element is Fe. Compositionally Complex Alloys (CCA), comprising high entropy alloys, are an emerging class of multicomponent metallic alloys, typically built up of 4-5 elements (or more), all present in significantly large amounts (5-40% for each element), but none of the elements can be considered the main constituent.
These unconventional mixtures of elements can lead to exceptional mechanical and/or corrosion properties. Moreover, one of the most studied systems, the equimolar CoCrFeMnNi or so-called Cantor alloy, with a very stable fcc structure, shows a remarkable resistance against hydrogen embrittlement [1]. However, the knowledge of the behavior of hydrogen in other compositionally complex alloys, for which an almost infinite number of possibilities on chemical composition exist, is very scarce.
In the Horizon 2020 project FORGE, new CCA’s are being explored, via a combination of machine learning and experimental high throughput techniques, for application in energy-intensive industries as high-performance coatings optimised to resist a specified set of degradation mechanisms (e.g. hydrogen embrittlement).
This poster reports on the first wave of screening, where about 30 new alloys have been synthetized via casting and thermomechanical processing. The sensitivity to hydrogen pick-up was monitored via Deuterium charging, combined with Thermal Desorption Spectroscopy. These results were used to select an optimal composition, for which the planned testing method to evaluate the coating performance is also explained.