scholarly journals Estimation of Grain Boundary Sliding During Ambient-Temperature Creep in Hexagonal Close-Packed Metals Using Atomic Force Microscope

10.5772/35640 ◽  
2012 ◽  
Author(s):  
Tetsuya Matsunaga ◽  
Eiichi Sato
Keyword(s):  
Grain Boundary ◽  
Ambient Temperature ◽  
Atomic Force Microscope ◽  
Grain Boundary Sliding ◽  
Hexagonal Close Packed ◽  
Temperature Creep ◽  
Atomic Force ◽  
Boundary Sliding

Grain Boundary Sliding Below Ambient Temperature in H.C.P. Metals

2010 ◽  
Vol 433 ◽  
pp. 299-303 ◽  
Author(s):  
Eiichi Sato ◽  
Tetsuya Matsunaga
Keyword(s):  
Grain Boundary ◽  
Ambient Temperature ◽  
Grain Boundary Sliding ◽  
Electron Back Scatter Diffraction ◽  
Dislocation Slip ◽  
Hexagonal Close Packed ◽  
Atomic Force ◽  
Dislocation Arrays ◽  
Pile Up ◽  
Von Mises

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.

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