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Atomic‐scale microstructure of Hf 2 Al 4 C 5 ceramic synthesized by spark plasma sintering
Author(s) -
Song Kepeng,
Zhang Hui,
Du Kui,
Qi Dongqing,
Chen Houwen,
Wang Xiaohui,
Nie JianFeng,
Ye Hengqiang
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.14812
Subject(s) - spark plasma sintering , microstructure , materials science , transmission electron microscopy , stacking , scanning electron microscope , crystallography , stacking fault , ternary operation , carbide , niobium , analytical chemistry (journal) , ceramic , atomic units , composite material , metallurgy , nanotechnology , chemistry , physics , quantum mechanics , computer science , programming language , organic chemistry , chromatography , dislocation
A layered ternary carbide phase, Hf 2 Al 4 C 5 , was successfully synthesized by spark plasma sintering method. Detailed (atomic‐scale) microstructure of the ternary carbide was investigated by aberration‐corrected scanning transmission electron microscopy and atomic‐resolution energy dispersive X‐ray spectroscopy. Hf 2 Al 4 C 5 crystal grains have elongated morphologies and are characterized with a high density of stacking faults with the insertion of additional (Al 4 C 3 ) or (HfC) units. Periodic stacking of Hf 2 Al 4 C 5 and HfAl 4 C 4 units along the [0001] direction is frequently observed in the Hf 2 Al 4 C 5 crystal, and it leads to the formation of Hf 4 Al 12 C 13 , which consists of 2/3 Hf 2 Al 4 C 5 unit cell and 1/2 HfAl 4 C 4 unit cell. In addition, Z‐shaped planar defects are observed in Hf 2 Al 4 C 5 grains, and the formation mechanism of the Z‐shaped defects was proposed as blocking effects of the Hf diffusion in Al 4 C 3 by pre‐existing {1‐101} pyramidal stacking faults in Al 4 C 3.