Defect formation by order coalescence in vermicular grains during alumina phase transformation. (October 2015)

• Record Type: Journal Article
• Authors: Wang, Ling; Hu, Jianfeng; Cheng, Yao; Fu, Zhengyi; Shen, Zhijian; Xiong, Yan
• Is Part Of: Scripta materialia. Volume 107(2015)
• Page Start: 59
• Page End: 62
• Publication Date: 2015-10
• Subjects: Defects -- Phase transformation -- Alumina -- Oriented coalescence (OC); Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2015.05.020
• Languages: English
• ISSNs: 1359-6462

Abstract

Graphical abstract: Abstract: Vermicular α-Al2 O3 grains obtained from γ- to α-phase transformation were investigated. X-ray diffraction patterns showed a left-shifting shoulder in all diffraction peaks of transformed α-Al2 O3 . High-resolution transmission electron microscopy results confirmed large amounts of defects inside the vermicular α-Al2 O3 single-crystal. Combined with grain-growth discontinuity, the authors proposed that the defects inside vermicular grains resulted from assembly of nanosized α-crystallites by an ordered coalescence mechanism directly after phase transformation, by which the orientation alignment was thermodynamically favored in the solid-state sintering.