Stress fields and geometrically necessary dislocation density distributions near the head of a blocked slip band

By T. Ben Britton, A. Wilkinson. 2012

249 citations recorded by the source corpus.

Abstract We have examined the interaction of a blocked slip band and a grain boundary in deformed titanium using high-resolution electron backscatter diffraction and atomic force microscopy. From these observations, we have deduced the active dislocation types and assessed the dislocation reactions involved within a selected grain. Dislocation sources have been activated on a prism slip plane, producing a planar slip band and a pile-up of dislocations in a near screw alignment at the grain boundary. This pile-up has resulted in activation of plasticity in the neighbouring grain and left the boundary with a number of dislocations in a pile-up. Examination of the elastic stress state ahead of the pile-up reveals a characteristic “one over the square root of distance” dependence for the shear stress resolved on the active slip plane. This observation validates a dislocation mechanics model given by Eshelby, Frank and Nabarro in 1951 and not previously directly tested, despite its importance in underpinning our understanding of grain size strengthening, fracture initiation, short fatigue crack propagation, fatigue crack initiation and many more phenomena. The analysis also provides a method to measure the resistance to slip transfer of an individual grain boundary in a polycrystalline material. For the boundary and slip systems analysed here a Hall–Petch coefficient of K  = 0.41 MPa m ½ was determined.

Subfields: Electrical and Electronic Engineering, Materials Chemistry, Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/52d34c8b9abba0ddaf5838030b9c5c3ba17f9985

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Electrical and Electronic Engineering

1. F. Dunne
2. A. Wilkinson
3. T. Ben Britton
4. Yi Guo
5. Yuntian Zhu
6. Y. Liu

In Materials Chemistry

1. T. Ben Britton
2. A. Wilkinson
3. F. Dunne
4. Yuntian Zhu
5. Yi Guo
6. Yonghao Zhao
7. Yang Cao
8. Hao Zhou

In Mechanical Engineering

1. F. Dunne
2. T. Ben Britton
3. A. Wilkinson
4. Yuntian Zhu
5. Yi Guo
6. Yonghao Zhao
7. Yang Cao
8. Hao Zhou

Citations in the corpus

• On the mechanistic basis of deformation at the microscale in hexagonal close-packed metals (2015, methodology): “More recent work by Britton & Wilkinson [106] in single-phase commercially pure titanium has quantified the stress concentration generated by a slip band impinging on a GB using high-resolution EBSD.”
• Critical microstructures and defects in heterostructured materials and their effects on mechanical properties (2020, background): “12b and c), the plastic deformation is still inhomogeneous at microscale, because of the presence of GBs and textures [5,49,52].”
• Slip band–grain boundary interactions in commercial-purity titanium (2014, methodology): “finite rotation tensor were used to estimate 6 infinitesimal rotation gradients using procedures documentented in [23].”