Figure 5: DFT calculations of SESF and nanotwin energies.
From: Phase transformation strengthening of high-temperature superalloys
(a) Energetic cost of twin formation by shearing along a SESF before reordering in Ni3Al, ME501 with a random solid solution, that is, no segregation (RSS), and ME501 where η has nucleated along the fault as observed experimentally. Note the relatively large energy cost to form a twin along a SESF with η phase. (b) Energy difference due to reordering after twin formation. The small difference found for ME3 suggests that the segregation of γ formers (Co, Cr, and Mo) replacing Ni and Al has removed nearest-neighbor violations in the precipitate near the fault, making twinning easier for ME3.
