TY - GEN
T1 - Grain boundary sliding below ambient temperature in H.C.P. metals
AU - Sato, Eiichi
AU - Matsunaga, Tetsuya
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2010
Y1 - 2010
N2 - Hexagonal close-packed metals and alloys show significant creep behavior with extremely low activation energies at and below ambient temperature even below their 0.2% proof stresses. It is caused by straightly-aligned dislocation arrays in a single slip system without any dislocation cuttings. These dislocation arrays should, then, pile up at grain boundary (GB) because of violation of von Mises' condition in H.C.P. structure. The piled-up dislocations have to be accommodated by GB sliding. Electron back scatter diffraction (EBSD) analyses and atomic force microscope (AFM) observations were performed to reveal the mechanism of GB sliding below ambient temperature in H.C.P. metals as an accommodation mechanism of ambient temperature creep. EBSD analyses revealed that crystal lattice rotated near GB, which indicates the pile up of lattice dislocations at GB. AFM observation showed a step caused by GB sliding. GB sliding below ambient temperature in H.C.P. metals are considered to compensate the incompatibility between neighboring grains by dislocation slip, which is called slip induced GB sliding.
AB - Hexagonal close-packed metals and alloys show significant creep behavior with extremely low activation energies at and below ambient temperature even below their 0.2% proof stresses. It is caused by straightly-aligned dislocation arrays in a single slip system without any dislocation cuttings. These dislocation arrays should, then, pile up at grain boundary (GB) because of violation of von Mises' condition in H.C.P. structure. The piled-up dislocations have to be accommodated by GB sliding. Electron back scatter diffraction (EBSD) analyses and atomic force microscope (AFM) observations were performed to reveal the mechanism of GB sliding below ambient temperature in H.C.P. metals as an accommodation mechanism of ambient temperature creep. EBSD analyses revealed that crystal lattice rotated near GB, which indicates the pile up of lattice dislocations at GB. AFM observation showed a step caused by GB sliding. GB sliding below ambient temperature in H.C.P. metals are considered to compensate the incompatibility between neighboring grains by dislocation slip, which is called slip induced GB sliding.
KW - Ambient temperature creep
KW - Dislocation
KW - Grain boundary sliding
KW - H.c.p. metal
UR - http://www.scopus.com/inward/record.url?scp=84864764053&partnerID=8YFLogxK
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U2 - 10.4028/www.scientific.net/KEM.433.299
DO - 10.4028/www.scientific.net/KEM.433.299
M3 - Conference contribution
AN - SCOPUS:84864764053
SN - 9780878492831
T3 - Key Engineering Materials
SP - 299
EP - 303
BT - Superplasticity in Advanced Materials - ICSAM 2009
PB - Trans Tech Publications Ltd
T2 - 10th International Conference on Superplasticity in Advanced Materials, ICSAM 2009
Y2 - 29 June 2009 through 2 July 2009
ER -