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Slip and Twinning in Polycrystalline Alumina (α‐Al 2 O 3 ) Deformed under Hydrostatic Pressure between 600° and 1000°C
Author(s) -
Korinek Sylvie Lartigue,
Castaing Jacques
Publication year - 2003
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/j.1151-2916.2003.tb03342.x
Subject(s) - crystal twinning , slip (aerodynamics) , materials science , crystallite , hydrostatic pressure , grain boundary , microstructure , composite material , dislocation , crystallography , metallurgy , mineralogy , chemistry , thermodynamics , physics
The microstructure of polycrystalline alumina deformed under hydrostatic pressure and at low temperature is investigated by transmission electron microscopy. Deformation occurs mainly by prism plane slip and rhombohedral twinning. Introduction of hydrogen leads to a significant decrease in the yield stress. In large grain size alumina deformed with hydrogen, accommodation of twinning involves dislocation reactions in the twin boundary and in the grains rather than by cracking. Prism plane dislocations decompose into basal dislocations by cross slip probably due to a decrease of Peierls stress for basal slip in the presence of hydrogen.