Novel coalescence-driven grain-growth mechanism during annealing/spark plasma sintering of NiO nanocrystals. Issue 15 (December 2017)

• Record Type: Journal Article
• Authors: Akkiraju, K.; Kashyap, S.; Srivastav, Ajeet K.; Chawake, Niraj; Bichler, L.; Murty, B.S.
• Is Part Of: Journal of the European Ceramic Society. Volume 37:Issue 15(2017)
• Page Start: 4973
• Page End: 4977
• Publication Date: 2017-12
• Subjects: Spark plasma sintering -- Grain growth -- Annealing -- Densification -- Nanoparticles; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2017.05.057
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: 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 °C and when the powders were annealed in ambient atmosphere at and above 700 °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.