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TEM of Dislocations in AIN
Author(s) -
Seifert Andreas,
Berger Axel,
Müller Wolfgang Friedrich
Publication year - 1992
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.1151-2916.1992.tb04153.x
Subject(s) - slip (aerodynamics) , materials science , transmission electron microscopy , vickers hardness test , composite material , plasticity , critical resolved shear stress , scanning electron microscope , dislocation , shear (geology) , crystallography , ductility (earth science) , metallurgy , microstructure , chemistry , nanotechnology , thermodynamics , creep , physics , shear rate , viscosity
Sintered AIN specimens were deformed by Vickers hardness (HV) indentations. Compared with Al 2 O 3 the HV hardness values indicate a much higher plasticity of AIN at room temperature, but above 600°C a higher ductility for Al 2 O 3 . Deformed AIN specimens were examined by transmission electron microscopy. Basal and prismatic glide with the slip systems (0001) 〈1120〉 and {1 1 00}〈11 2 0〉 were frequently observed. This results in four linearly independent slip systems. The critical resolved shear stress for single prismatic slip seems to be even smaller than for basal slip. However, thermally activated dislocation reactions are frozen up to at least 1000°C. Thus, prismatic slip is suppressed as soon as more than one slip direction is activated.