Chemical compatibility of high entropy alloys with liquid PbLi

Abstract

CuW, CuMo, TaW, to stagnant eutectic PbLi was studied. Three nominal HEAs compositions, Cr35Fe35V20W5Ta5

(H-TaW), Cu5Cr35Fe35V20W5 (H-CuW) and Cu5Cr35Fe35V20Mo5 (H-CuMo) were prepared by vacuum arc melting

under a low pressure He atmosphere using a non-consumable W electrode and starting from pure elemental

pieces with purity > 99.97. Planoparallel specimens of the HEAs were mirror polished and subjected to stagnant

PbLi at the eutectic composition, (14.9 ± 1.99) % of Li, at a temperature of 550 ◦C, corresponding to the working

temperature of the WCLL, for increasing times of 168 and 1344 h. After the tests, the microstructure of the

samples was cleaned to remove adhered PbLi and analyzed by SEM/EDX and EBSD. SIMS measurements were

performed to study the diffusion of into the matrix. From the concentration curves of lithium in the alloys, the

diffusion differences of lithium were determined and correlated with the differences in the alloying elements.

Furthermore, the corrosion behavior of the alloy showed important differences with the composition of the HEAs

and their differences in microstructure. The most significant result is that W has a detrimental effect on the

corrosion resistance of PbLi.