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Reactions and microstructure evolution in A l 2 O 3 ‐ A l system in vacuum
Author(s) -
Feng Yue Bin,
Zhang Xiao,
Yang Bin,
Yang Bao Min,
Chen Zhen
Publication year - 2017
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.2144
Subject(s) - microstructure , scanning electron microscope , crystallography , materials science , atmospheric temperature range , transmission electron microscopy , diffraction , composite number , chemistry , analytical chemistry (journal) , nanotechnology , thermodynamics , composite material , physics , chromatography , optics
The reactions and microstructure evolution in Al 2 O 3 ‐Al system were researched through the experiments at a temperature range of 1,573–1,773 K in vacuum, along with thermodynamic analysis. The X‐ray diffraction and the scanning electron microscope were used to characterize the residues and the condensates. The results demonstrated that Al 2 O 3 and Al reacted to form gaseous Al 2 O, and then the gaseous Al 2 O disproportionated into Al 2 O 3 and Al with the decrease in temperature, which constituted the condensates together with the condensed Al from Al vapor. The residual Al 2 O 3 and Al were transformed into the composite powders consisting of the interconnected Al 2 O 3 flakes coated with Al, and the Al 2 O 3 in the condensates were not coated by Al even at the condensation temperature up to about 1,523 K. It was deduced that the reaction between Al 2 O 3 and molten Al should be the key factor leading to their bonding in vacuum.