A multi-scale model for texture development in Zr/Nb nanolayered composites processed by accumulative roll bonding

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Ardeljan, M.^1 ; Knezevic, M.^1 ; Nizolek, T.^2 ; Beyerlein, I.J.^3 ; Zheng, S.J.^4 ; Carpenter, J.S.^5 ; McCabe, R.J.^5 ; Mara, N.A.^4 ; Pollock, T.M.^2

Department of Mechanical Engineering, University of New Hampshire, Durham, NH 03824, United States^1

Materials Department, University of California at Santa Barbara, Santa Barbara, CA 93106, United States^2

Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States^3

Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States^4

Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States^5

关键词: Accumulative roll bonding;    Crystal plasticity finite element;    Deformation mechanism;    Dislocation densities;    Multi-scale Modeling;    Severe plastic deformations;    Submicron and nanoscale;    Texture measurement;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012170/pdf
DOI  :  10.1088/1757-899X/63/1/012170

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Recently it has been demonstrated that nanolayered hcp/bcc Zr/Nb composites can be fabricated with a severe plastic deformation technique called accumulative roll bonding (ARB) [1]. The final layer thickness averaged to approximately 90 nm for both phases. Interestingly, the texture measurements show that the textures in each phase correspond to those of rolled single-phase rolled Zr and Nb for a wide range of layer thickness from the micron to the nanoscales. This is in remarkable contrast to fcc/bcc Cu/Nb layered composites made by the same ARB technique, which developed textures that strongly deviated from theoretical rolling textures of Cu or Nb alone when the layers were refined to submicron and nanoscale dimensions. To model texture evolution and reveal the underlying deformation mechanisms, we developed a 3D multiscale model that combines crystal plasticity finite element with a thermally activated dislocation density based hardening law [2]. For systematic study, the model is applied to a two-phase Zr/Nb polycrystalline laminate and to the same polycrystalline Zr and polycrystalline Nb as single-phase metals. Consistent with the measurement, the model predicts that texture evolution in the phases in the composite and the relative activities of the hcp slip modes are very similar to those in the phases in monolithic form. In addition, the two-phase model also finds that no through-thickness texture gradient develops. This result suggests that neither the nanoscale grain sizes nor the bimetal Zr/Nb interfaces induce deformation mechanisms different from those at the coarse-grain scale.