| Abstract Scope |
Pseudo binary diffusion couples provide a rapid and systematic approach for mapping microstructural evolution in HEAs as a function of composition. Our broader motivation is the development of low Z HEAs for use as plasma facing materials in future fusion reactors, where controlled phase stability and irradiation resistance are crucial. As a proof of concept, diffusion couples were constructed between quaternary alloys and pure elements within the Al–Co–Cr–Fe–Ni system, generating continuous composition gradients. The microstructures and phase transitions observed along these gradients were fully consistent with those found in corresponding quinary cast HEAs, confirming the validity of the method. In addition, the pseudo binary approach yields valuable metallurgical information, including solubility limits in solid solutions, predictions of eutectic compositions, and insights into competitive diffusion behavior. Because it produces accelerated microstructure maps, this technique can be directly extended to the discovery and design of new HEAs for advanced applications. |