We generalize a previous study of the atomic motions governing grain boundary migration to consider arbitrary misorientations of [0 0 1] tilt boundaries. Our examination of the nature of atomic motions employed three statistical measures of atomic motion: the non-Gaussian parameter, the ''dynamic en
Motion of [1 0 0]-tilt grain boundaries under cyclic stresses
β Scribed by Syed Badirujjaman; Xiao-Wu Li; Myrjam Winning
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 607 KB
- Volume
- 448
- Category
- Article
- ISSN
- 0921-5093
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β¦ Synopsis
The motion of planar symmetric [1 0 0]-tilt grain boundaries in high purity aluminium under cyclic elastic deformation conditions was investigated. Bicrystals were fabricated to obtain grain boundaries with different misorientation angles between 3.7 β’ and 42.5 β’ . They were deformed under cyclic tension and compression at elevated temperatures and maximum stresses of Β±0.5 MPa. Grain boundary displacements were measured by optical microscopy. After deformation activation parameters were calculated from an Arrhenius analysis of the displacements as a function of the temperature. Two regions can be distinguished; within each region the activation enthalpy was found to be constant. The misorientation angle which separates the two regions can be correlated with the transition angle between low and high angle grain boundaries. The mechanism of cyclic motion of [1 0 0]-boundaries is discussed in terms of migration and sliding. The results were compared with stress-induced grain boundary motion under the influence of a constant shear stress.
π SIMILAR VOLUMES
Stress-induced migration of planar grain boundaries in aluminum bicrystals was measured for both low-and high-angle symmetrical h1 0 0i tilt grain boundaries across the entire misorientation range (0-90Β°). Boundary migration under a shear stress was observed to be coupled to a lateral translation of
The grain structure of polycrystalline materials is controlled by recrystallization processes which are strongly affected by the character of moving interfaces. To elucidate an anisotropy of grain boundary motion, the temperature dependence of migration of a 45 β’ [1 0 0], {0 k l} symmetrical and a (
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