@article{Chai2024, 
author = {Ze Chai and Bo Peng and Xukai Ren and Kaiyuan Hong and Xiaoqi Chen},
title = {The microstructural evolution and relaxation strengthening for nano-grained Ni upon low-temperature annealing},
year = {2024},
journal = {Nano Materials Science},
volume = {6},
number = {6},
pages = {726-734},
keywords = {Nano-grained metal, Microstructure, Relaxation, Microhardness, X-ray diffraction},
url = {https://www.sciopen.com/article/10.1016/j.nanoms.2023.12.007},
doi = {10.1016/j.nanoms.2023.12.007},
abstract = {The microstructural evolution and relaxation strengthening of nano-grained Ni annealed at a temperature range of 493–553 ​K were studied by in situ X-ray diffraction technique, transmission electron microscopy, and microhardness evaluation. Upon low-temperature annealing, the rather limited variations of anisotropic grain size and root-mean-square strain, conforming to an exponential relaxation model, yield a consistent activation energy of approximately 0.5 ​eV, which corresponds to the localized, rapid diffusion of excess vacancies on nonequilibrium surfaces/interfaces and/or defective lattice configurations. Microstructure examinations confirm the grain boundary ordering and excess defect reduction. The relaxation-induced strength enhancement can be attributed to the linear strengthening in the regime of small elastic lattice strains. This study provides an in-depth understanding of low-temperature nanostructural relaxation and its relation to strengthening.}
}