The objective of this study is to understand and quantify the role of coincidence site lattice boundary (CSLB) population on creep deformation of Ni-16Cr-9Fe at ;Dislocation absorption kinetics were measured by comparing extrinsic grain boundary dislocation (EGBD) density in TEM. Results showed that CSLBs contain an EGBD density which is 3 times higher than HABs at 1.25% strain indicating lower absorption kinetics of CSLBs compared to that in HABs. The observed increase in the yield and flow strength of the CSLB-enhanced sample is attributed to the difference in the EGBD density between CSLBs and HABs.;Internal stress was measured by the stress dip test and was found to be ;Comparisons of the CSLB fraction in the system, creep rates and IG cracking reveal that both creep rates and the amount of IG cracking decrease rapidly with increasing CSLB faction. Studies on grain boundary sliding and cavitation of crept coarse grain samples also revealed that HABs are more susceptible to sliding and cavitation than CSLBs. These results provide encouragement that grain boundary can be engineered to tailor the bulk properties of alloys.
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