Journal
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
Volume 41A, Issue 2, Pages 421-430Publisher
SPRINGER
DOI: 10.1007/s11661-009-0097-6
Keywords
-
Funding
- National Science Foundation (North Arlington, VA) [DMR-0710570]
- Deutsche Forschungsgemeinschaft [EI 681/2-1]
Ask authors/readers for more resources
The role of strain transfer in the activation of deformation twinning at grain boundaries has been characterized in commercially pure titanium deformed in bending. Two different orientations of a textured polycrystal were deformed in bending and were analyzed using electron backscattered diffraction (EBSD) to determine the active slip and twinning systems in the surface tensile region. Prismatic slip and {10 (1) over bar2}<(1) over bar 011 > twinning were the most widely observed deformation modes in both orientations. Nonprismatic slip systems were also activated, most likely to accommodate local strain heterogeneities. A slip-stimulated twin nucleation mechanism was identified for soft/hard grain pairs: dislocation slip in a soft-oriented grain can stimulate twin nucleation in the neighboring hard grain when the slip system is well aligned with the twinning system. This alignment was described by a slip-transfer parameter m'.([24]) Twins activated by this mechanism always had the highest m' value among the six available {10 (1) over bar2}<(1) over bar 011 > twinning systems, while the Schmid factor, based on the global (uniaxial tensile) stress state, was a less significant indicator of twin activity. Through slip transfer, deformation twins sometimes formed despite having a very low global Schmid factor. The frequency of slip-stimulated twin nucleation depends strongly on the texture and loading direction in the material. For grain pairs having one grain with a large Schmid factor for twinning, nonparametric statistical analysis confirms that those with a larger m' are more likely to display slip-stimulated twinning.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available