Journal ArticleDOI
Fracture toughness and brittle-ductile transition controlled by grain boundary character distribution (GBCD) in polycrystals
L.C. Lim,T. Watanabe +1 more
TLDR
In this article, the authors evaluate quantitatively the effect of different types, frequencies and configurations of grain boundaries, so-called the grain boundary character distribution (GBCD), on the toughness of a 3D polycrystals.Abstract:
The structural dependence of intergranular fracture processes in bicrystals and polycrystals of metals and alloys is first reviewed. It is shown that even in polycrystals, grain boundary structure plays a significant role in controlling the fracture properties of the material. Next, we evaluate quantitatively the effect of different types, frequencies and configurations of grain boundaries, so-called the grain boundary character distribution (GBCD), on the toughness of a three-dimensional (3D) polycrystals. The results show that the toughness of a polycrystals increases monotonically with increasing overall fraction of fracture-resistant low-energy boundaries in the material. A brittle-ductile transition, corresponding to a change of fracture mode from predominantly intergranular with low toughness to predominantly transgranular with high toughness, is observed when the overall fraction of low-energy boundaries reaches a critical value. For a 3D polycrystals with a non-random GBCD such that the fraction of low-energy boundaries on the inclined boundary facets is maximised, a smaller critical overall fraction of low-energy boundaries is needed to bring about the brittle-ductile transition. Similar effect is also found if the grains are made elongated and aligned with the stress axis. The results are discussed in relation to the concept of grain boundary design for strong and tough polycrystals proposed by one of the present authors (T.W.).read more
Citations
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Journal ArticleDOI
Current issues in recrystallization: a review
Roger D. Doherty,D.A. Hughes,F.J. Humphreys,John J. Jonas,D. Juul Jensen,Michael E. Kassner,Wayne E. King,Terry R. McNelley,H.J. McQueen,Anthony D. Rollett +9 more
TL;DR: The current understanding of the fundamentals of recrystallization is summarized in this paper, which includes understanding the as-deformed state, nucleation and growth, the development of misorientation during deformation, continuous, dynamic, and geometric dynamic recystallization, particle effects, and texture.
Journal ArticleDOI
Atomistic modeling of the fracture of polycrystalline diamond
TL;DR: A series of molecular-dynamics simulations using a many-body interatomic potential has been performed to investigate the behavior under load of several symmetrical tilt grain boundaries in diamond.
Journal ArticleDOI
The control of brittleness and development of desirable mechanical properties in polycrystalline systems by grain boundary engineering
TL;DR: Grain boundaries can be effectively controlled to produce or enhance their beneficial effects and also to diminish or reduce their detrimental effects on bulk properties in polycrystalline materials as mentioned in this paper, which remains a serious problem of material processing and development.
Journal ArticleDOI
Grain boundary engineering: historical perspective and future prospects
Tadao Watanabe,Tadao Watanabe +1 more
TL;DR: A brief introduction of the historical background of grain boundary engineering for structural and functional polycrystalline materials is presented in this article, where a new approach in terms of the grain boundary and interface engineering is discussed for the design and development of high performance materials with desirable bulk properties.
Book
The measurement of grain boundary geometry
TL;DR: A survey of grain boundary geometry investigations can be found in this paper, where the authors discuss the importance of grain boundaries in polycrystals grain boundary structure and "special" boundaries.
References
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High-temperature ordered intermetallic alloys
TL;DR: In this article, the authors describe the behavior of grain boundaries in a two-dimensional model ordered alloy and the effects of elastic anisotropy on the anomalious yield behavior of cubic ordered alloys.
Journal ArticleDOI
Grain boundaries in rapidly solidified and annealed Fe-6.5 mass% Si polycrystalline ribbons with high ductility
TL;DR: The electron channelling pattern (ECP) technique for crystallographic orientation determination was applied in this article to determine the type and frequency of grain boundaries in rapidly solidified and subsequently annealed ribbons of Fe-6.5 mass% Si alloy polycrystalline ribbons.
Journal ArticleDOI
The Hall–Petch relation in aluminium and its dependence on the grain boundary structure
J.W. Wyrzykowski,M.W. Grabski +1 more
TL;DR: In this paper, the mechanical properties of aluminium polycrystals exhibiting differences in grain boundary (GB) properties have been studied by means of the Hall-Petch analysis and the results obtained indicate that th...
Journal ArticleDOI
Grain boundary sliding and stress concentration during creep
TL;DR: In this paper, the effect of grain boundary structure on creep intergranular fracture on metal bicrystals and polycrystals is discussed on the basis of the effect on sliding, the contribution of sliding to the overall creep deformation and a sliding-fracture diagram.