Microstructure stability and evolution in CVD carbonyl Ni materials upon annealing – Grain growth and detwinning process

Optimal microstructural design for high thermal stability of pure FCC metals based on studying effect of twin boundaries character and network of grain boundaries

“…thermal stability. This was demonstrated for nickel deposits, where, among others, multi-twinned grains were observed to have the highest thermal stability [33], [34].…”

“…However, it has been shown that in FCC materials these junctions are relatively stable [61]. High thermal stability is reported, specifically for nickel electrodeposits with a <110> fiber texture and five-fold twin boundary junctions [33], [34] which are encompassed by g-HAGB forming isolated units (unlike sample S3 which has a connected helical struture of five-fold junctions). Therefore, to understand the poor thermal stability, the dynamics of grain boundary interaction and the effect of connectivity of the grain boundaries should be considered.…”

“…Twin boundaries that form a unit enclosed by g-HAGBs such as sample S1, Fig. 5, or five-fold twins shown in [33] are more thermally stable as the exterior of the unit (HAGBs) interacts with other HAGBs and protects the interior of the unit composed of twin boundaries, as experimentally observed [28], [33], [34]. This means that the fragmented network of g-HAGBs in a GBE microstructure cannot protect the high density of CTBs and CTBs can be annihilated easily without effective drag of g-HAGBs on the movement of mobile boundaries.…”