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- Zetterström, P., et al.
(författare)
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Nanoscale defect clusters in metallic glasses
- 2007
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 19:37, s. 376217-
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Tidskriftsartikel (refereegranskat)abstract
- The reverse Monte Carlo method was used to obtain three-dimensional discrete distributions of constitutional atoms in melt-spun CuZr and CuZrTi metallic glasses from neutron and x-ray diffraction data. It was found that the icosahedral short-range order is less stable in the CuZr binary alloy than in the Ti-doped ternary alloy. The present investigation also provides evidence on the medium-range order, characterized by some nanoscale clusters of defects, in the metallic-glassy state.
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| 2. |
- Cong, D Y, et al.
(författare)
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Crystal structures and textures in the hot-forged Ni-Mn-Ga shape memory alloys
- 2006
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Ingår i: Metallurgical and Materials Transactions. A. - 1073-5623 .- 1543-1940. ; 37A:5, s. 1397-1403
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Tidskriftsartikel (refereegranskat)abstract
- Three ferromagnetic shape-memory alloys with the chemical compositions of Ni53Mn25Ga22, Ni48Mn30Ga22, and Ni48Mn25Ga22Co5 were prepared by the induction-melting and hot-forging process. The crystal structures were investigated by the neutron powder diffraction technique, showing that Ni53Mn25Ga22 and Ni48Mn25Ga22Co5 have a tetragonal, I4/mmm martensitic structure at room temperature, while Ni48Mn30Ga22 has a cubic, L2(1) austenitic structure at room temperature. The development of textures in the hot-forged samples shows the in-plane plastic flow anisotropy from the measured pole figures by means of the neutron diffraction technique. Significant texture changes were observed for the Ni48Mn25Ga22Co5 alloy after room temperature deformation, which is due to the deformation-induced rearrangements of martensitic variants. An excellent shape-memory effect (SME) with a recovery ratio of 74 pct was reported in this Ni48Mn25Ga22Co5 polycrystalline alloy after annealing above the martensitic transformation temperature, and the "shape-memory" influence also occurs in the distributions of grain orientations.
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| 3. |
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| 4. |
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| 5. |
- Jia, N, et al.
(författare)
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Micromechanical behavior and texture evolution of duplex stainless steel studied by neutron diffraction and self-consistent modeling
- 2008
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 56:4, s. 782-793
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Tidskriftsartikel (refereegranskat)abstract
- Microscopic incompatibility-induced stresses in a duplex stainless steel undergoing plastic deformation are elucidated using a visco-plastic self-consistent model. The model considers not only the grain-orientation-dependent stresses and phase-to-phase interactions, but also texture evolution during deformation. The parameters used for describing the micromechanical behavior of the two-phase polycrystalline material are directly derived from the neutron diffraction data. A reliable prediction of the evolution of grain orientation distributions for both phases at small deformations is achieved after considering various micromechanical interactions of the studied material. © 2007 Acta Materialia Inc.
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| 6. |
- Peng, Ru, 1960-, et al.
(författare)
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Interactions between the phase stress and the grain-orientation-dependent stress in duplex stainless steel during deformation
- 2006
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 54:15, s. 3907-3916
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Tidskriftsartikel (refereegranskat)abstract
- The development of phase stress and grain-orientation-dependent stress under uniaxial compression was investigated in a duplex stainless steel consisting of austenite and ferrite. Using in situ neutron diffraction measurements, the strain response of several h k l planes to the applied compressive stress was mapped as a function of applied stress and sample direction. Analysis based on the experimental results and elastoplastic self-consistent simulations shows that phase stresses of thermal origin further increase during elastic loading but decrease with increased plastic deformation. Grain-orientation-dependent stresses become significant in both austenite and ferrite after loading into the plastic region. After unloading from the plastic regime, a considerable intergranular stress remains in the austenitic phase and dominates over the phase stress. This study provides fundamental experimental inputs for future micromechanical modeling aiming at the evaluation and prediction of the mechanical performance of multiphase materials. © 2006 Acta Materialia Inc.
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