New advances with EBSD strain mapping (as reviewed recently in Materials Today) enable for the first time to systematically characterize the effect of different grain boundaries properties on the propagation of slip in engineering materials. Slip underpins how materials deform and such insights are crucial to advancing our understanding of the mechanical behaviour of materials.
In this paper published in Acta Materialia, Yi Guo (Oxford Materials), Ben Britton (Imperial Materials) and Angus Wilkinson (Oxford Materials) present three classes of slip band-grain boundary interactions: (1) blocked slip bands with a large stress concentration at their tip, with no obvious long range slip features in the neighbour grain; (2) connected slip bands between neighbouring grains without associated stress concentration in both neighbouring grains; (3) blocked slip bands with no stress concentration at their tip, and no obvious long range slip features.
Schematic showing the geometric configurations between two slip systems intersecting a grain boundary. L is the line of intersection between the slip plane and grain boundary, n is plane normal, and the Burgers vector b is used to represent the slip direction g.This study rationalizes their behaviour in terms of grain morphology and crystallography. This work opens up a new realm of understanding of the behaviour of polycrystalline materials with quantitative microstructural characterisation using HR-EBSD and understanding of microstructural mechanisms. Developments of this kind are required to realise new alloys and advance microstructural development, as explored within the HexMat programme grant (http://www.imperial.ac.uk/hexmat), to improve future Ti alloys for jet engines and Zr alloys for nuclear fuel technologies.
This paper was originally published in Acta Materialia Volume 76, 1 September 2014, Pages 1–12
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