Combined effects of crystallographic orientation, stacking fault energy and grain size on deformation twinning in fcc crystals
- 21 August 2008
- journal article
- research article
- Published by Informa UK Limited in Philosophical Magazine
- Vol. 88 (24), 3011-3029
- https://doi.org/10.1080/14786430802438168
Abstract
The combined effects of crystallographic orientation, stacking fault energy (SFE) and grain size on deformation twinning behavior in several face-centred cubic (fcc) crystals were investigated experimentally and analytically. Three types of fcc crystals, Al single crystals, Cu single crystals and polycrystalline Cu–3% Si alloy with different SFEs and special crystallographic orientations, were selected. The orientations of the Al and Cu single crystals were designed with one of the twinning systems just perpendicular to the intersection plane of equal-channel angular pressing (ECAP). For Al single crystals, no deformation twins were observed after a one-pass ECAP, although a preferential crystallographic orientation was selected for twinning. For Cu single crystals, numerous deformation twins were found even when strained at room temperature and at low strain rate. For Cu–3% Si alloy, deformation twins were only observed in some grains; however, others with different orientations were full of dislocations, although it has the lowest SFE value of the three fcc crystal types. The experimental results provide evidence that SFE and crystallographic orientation have a remarkable influence on the behavior of deformation twinning in fcc crystals. The observations were subsequently analyzed based on fundamental dislocation mechanisms and the grain-size effect. The deformation conditions required for twinning and the variation in twinning stress with SFE, crystallographic orientation and grain size in fcc crystals are also discussed.Keywords
This publication has 44 references indexed in Scilit:
- Effect of equal channel angular pressing on tensile properties and fracture modes of casting Al–Cu alloysMaterials Science and Engineering: A, 2006
- Grain Boundary-Mediated Plasticity in Nanocrystalline NickelScience, 2004
- Advances in Materials Plasticity 10–12 June 2002, CracowPhilosophical Magazine, 2004
- Dynamic Processes for Nanostructure Development in Cu after Severe Cryogenic Rolling DeformationMATERIALS TRANSACTIONS, 2003
- Deformation twinning in nanocrystalline Al by molecular-dynamics simulationActa Materialia, 2002
- Nucleation and growth of deformation twins: A perspective based on the double-cross-slip mechanism of deformation twinningPhilosophical Magazine A, 2002
- Length-scale effects in the nucleation of extended dislocations in nanocrystalline Al by molecular-dynamics simulationActa Materialia, 2001
- Effect of grain size and pressure on twinning and microbanding in oblique shock loading of copper rodsActa Materialia, 1997
- The effect of stacking fault energy on the microstructural development during room temperature wire drawing in Cu, Al and their dilute alloysJournal of Materials Science, 1996
- Materials processing by simple shearMaterials Science and Engineering: A, 1995