Novel coalescence-driven grain-growth mechanism during annealing/spark plasma sintering of NiO nanocrystals

作者:Akkiraju K; Kashyap S; Srivastav Ajeet K; Chawake Niraj; Bichler L; Murty B S*
来源:Journal of the European Ceramic Society, 2017, 37(15): 4973-4977.
DOI:10.1016/j.jeurceramsoc.2017.05.057

摘要

A novel oriented attachment growth mechanism of nanograins has been suggested for spark plasma sintering and annealing of NiO nanopowder. A hierarchical microstructure built by cube-shaped nanograins was observed during pressure-less spark plasma sintering at temperatures above 1000 degrees C and when the powders were annealed in ambient atmosphere at and above 700 degrees C. Irrespective of the processing method used, a rotation assisted grain attachment of irregularly shaped nanocrystals results in such a microstructure with parallel epitaxy, twinning or line defects at the grain interface. The unique microstructural features and the governing factors for the attachment process have been discussed.

  • 出版日期2017-12
  • 单位MIT