Laser powder bed fusion processing of a precipitation strengthenable FCC based high entropy alloy

Feasibility Studies and Downselection of New Materials and Manufacturing Technologies for Nuclear Applications

“…In short, the as-deposited conditions of DED-and SLM-processed HEAs exhibited predominantly singlephase fcc microstructure with a negligible fraction of L12 precipitates. Although the SLM(AD) condition revealed B2 + bcc microstructure in the intercellular regions between solidification cells, it is shown to have an insignificant effect on the mechanical properties owing to its low phase fraction, as well as large separation distances [68]. On the other hand, both heat-treated conditions, SLM(HT) and DED(HT), exhibited hierarchically heterogeneous microstructures at multiple length scales, finer recrystallized fcc grains with rod-like L12 precipitates, and coarser non-recrystallized fcc grains with equiaxed/spherical L12 precipitates.…”

“…This HEA was fabricated via two different AM techniques: DED and SLM. The evolution of the heterogeneous microstructures in the AD and subsequently annealed conditions and their tensile properties at RT have been reported previously [68,185]. However, the temperature-dependent mechanical behavior essential for nuclear applications was not yet investigated.…”

“…Considering this process, AM methods such as DED [42,59,60,61] can be beneficial because materials with significantly better properties than the conventionally cast counterparts can be obtained [62,63,64,65,66]. Moreover, straightforward, one-step annealing approaches can be designed by exploiting the residual stresses in these AM techniques to successfully engineer microstructures with multiple interfaces desired for nuclear applications [67,68]. The DED process can also enable the fabrication of functionally graded materials that possess applications across different industries, including nuclear.…”