The rather limited microstructural evolution in electrodeposited nanocrystalline Ni isothermally annealed at 453–493 K is investigated by using in situ X-ray diffraction technique. The nanostructural relaxation features roughly linear lattice contraction, based on which the kinetics analysis yields the activation energy of about 0.57 eV/atom, in good agreement with the fast diffusion of excess vacancies on the nonequilibrium surfaces and/or interfaces for Ni. The lattice contraction of Ni may result from a reduction in the grain boundary excess volume. The integral breadth of diffraction line profiles decreases with annealing time in an exponential manner, implying the gradual improvement of the lattice perfections during nanostructural relaxation. The microhardness evaluation demonstrates the initial invariance or slight softening and subsequent remarkable hardening of nanocrystalline Ni subjected to low-temperature annealing.

通过使用原位研究在 453-493 K 等温退火的电沉积纳米晶 Ni 中相当有限的微观结构演变X射线衍射技术。纳米结构弛豫具有大致线性的晶格收缩，基于此，动力学分析产生约 0.57 eV/原子的活化能，这与 Ni 的非平衡表面和/或界面上多余空位的快速扩散非常吻合。Ni的晶格收缩可能是由于晶界过剩体积的减少。衍射线轮廓的整体宽度随着退火时间以指数方式减小，这意味着在纳米结构弛豫期间晶格完美度的逐渐改善。显微硬度评估表明纳米晶镍在低温退火后的初始不变性或轻微软化以及随后的显着硬化。