WJNSE  Vol.4 No.2 , June 2014
Nano-Scale Modelling and Simulation of Metal Wiredrawing by Using Molecular Dynamics Method
ABSTRACT
In this paper, molecular dynamics (MD) simulations of nano-sized wiredrawing are performed. The wiredrawing is a traditional plastic working method, but there has not been any insight to develop it in a nano-sized scale. Therefore, to materialize the concept of the nano-sized wiredrawing, a numerical modelling is pursued at first in this paper, and the interatomic potential, a crystalline orientation, the drawing condition realized by a die geometry are thoroughly investigated. In particular, to reduce the friction between a wire and a die, a simple friction model for the MD analysis is newly proposed, where the interatomic interaction is adequately modified by a single factor ω. Then, the fruitful results are obtained by using ω = 0.1. We checked the availability of such nano-sized MD simulation by constructing a two-dimensional wiredrawing model, at first. The analysis of atomic stress during drawing is also assessed. It is useful to use invariant of the atomic stress tensor, such as hydrostatic stress (average stress, σm) or von Mises equivalent stress (σeq). The former is related to the phase transformation from the body-centered-cubic (bcc) structure to the face-centered-cubic (fcc) one, which is found in the present MD simulation. It is observed that an initial α-iron crystal with bcc structure changes partially into the fcc phase. It is recognized that the phase transformation is caused by the positive hydrostatic stress values, which is occurring especially inside the die region. We observed that a lot of dislocation core structures occur in wiredrawing process and their existence and evolution are well related to the equivalent stress values.

Cite this paper
Saitoh, K. , Sameshima, Y. and Daira, S. (2014) Nano-Scale Modelling and Simulation of Metal Wiredrawing by Using Molecular Dynamics Method. World Journal of Nano Science and Engineering, 4, 70-83. doi: 10.4236/wjnse.2014.42010.
References
[1]   Tang, Z. and Kotov, N.A. (2005) One Dimensional Assemblies of Nanoparticles: Preparation, Properties, and Promise. Advanced Materials, 17, 951-962.
http://dx.doi.org/10.1002/adma.200401593

[2]   Roters, F., Eisenlohr, P., Hantcherli, L., Tjahjanto, D.D., Bieler, T.R. and Raabe, D. (2010) Overview of Constitutive Laws, Kinematics, Homogenization and Multiscale Methods in Crystal Plasticity Finite-Element Modeling: Theory, Experiments, Applications. Acta Materialia, 58, 1152-1211.
http://dx.doi.org/10.1016/j.actamat.2009.10.058

[3]   Yoshida, T, Morita, Y and Nakamachi, E. (2013) Crystal Texture Evolution Analyses in Drawing Process by Using Multi-Scale Finite Element Method. Proceedings of JSME (88th Kansai Branch Annual Meeting), 134-1, (5-)23.

[4]   Nakatani, A. (2005) Plastic Deformation Analysis of Nanostructured Metal Using Molecular Dynamics. Proceedings of JSME (2005 Annual Congress), 8, 470-471.

[5]   Chu, C.-Y. and Tan, C.-M. (2009) Deformation Analysis of Nanocutting Using Atomistic Model. International Journal of Solids and Structures, 46, 1807-1814.
http://dx.doi.org/10.1016/j.ijsolstr.2008.11.017

[6]   Karthikeyan, S., Agrawal, A. and Rigney, D.A. (2009) Molecular Dynamics Simulations of Sliding in an Fe-Cu Tribopair System. Wear, 267, 1166-1176.
http://dx.doi.org/10.1016/j.wear.2009.01.032

[7]   Ngan, A.H.W. and Wen, M. (2001) Dislocation Kink-Pair Energetics and Pencil Glide in Body-Centered-Cubic Crystals. Physical Review Letters, 87, Article ID: 075505.
http://dx.doi.org/10.1103/PhysRevLett.87.075505

[8]   Saitoh, K. and Liu, W.K. (2009) Molecular Dynamics Study of Surface Effect on Martensitic Cubic-to-Tetragonal Transformation in Ni-Al Alloy. Computational Materials Science, 46, 531-544.
http://dx.doi.org/10.1016/j.commatsci.2009.04.025

[9]   Dan, T. and Saitoh, K. (2012) Microstructure Evolution in Polycrystalline Metal under Severe Plastic Deformation by Strain-Controlled Molecular Dynamics. Journal of Solid Mechanics and Materials Engineering, 6, 48-60.
http://dx.doi.org/10.1299/jmmp.6.48

[10]   Pei, Q.X., Lu, C., Liu, Z.S. and Lam, K.Y. (2007) Molecular Dynamics Study on the Nanoimprint of Copper. Journal of Physics D: Applied Physics, 40, 4928-4935.
http://dx.doi.org/10.1088/0022-3727/40/16/026

[11]   Saitoh, K., Sameshima, Y., Takuma, M. and Takahashi, Y. (2014) Atomistic Simulation of Crystal Change and Carbon Diffusion in Nano-Sized Wiredrawing of Pearlitic Steel. Technische Mechanik, 32, in press.

[12]   Nakagiri, A., Yamano, T., Konaka, M., Yoshida, K. and Asakawa, M. (2000) Chevron Crack and Optimum Drawing Condition in the Diagram of Mean Stress and Die-Wire Contact Length Ratio by FEM Simulation. 2000 Conference Proceedings of the Wire Association International, Inc., 75-82.

[13]   Atienza, J.M., Martinez-Perez, M.L., Ruiz-Hervias, J., Mompean, F., Garcia-Hernandez, M. and Elices, M. (2005) Residual Stresses in Cold Drawn Ferritic Rods. Scripta Materialia, 52, 305-309.
http://dx.doi.org/10.1016/j.scriptamat.2004.10.010

[14]   McAllen, P.J. and Phelan, P. (2007) Numerical Analysis of Axisymmetric Wire Drawing by Means of a Coupled Damage Model. Journal of Materials Processing Technology, 183, 210-218.
http://dx.doi.org/10.1016/j.jmatprotec.2006.10.014

[15]   Wright, R.N. (2009) Center Bursts—A Review of Criteria. Wire Journal International, 42, 80-84.

[16]   Yoshida, K. and Koyama, R. (2012) Reduction of Residual Stress of Drawn Wires. Wire Journal International, 45, 56- 60.

[17]   Finnis, M.W. and Sinclair, J.E. (1984) A Simple Empirical N-Body Potential for Transition Metals. Philosophical Magazine A, 50, 45-55.
http://dx.doi.org/10.1080/01418618408244210
(Erratum: ibid., 1986, 53, 161.http://dx.doi.org/10.1080/01418618608242815)


[18]   Saitoh, K., Daira, S. and Sameshima, Y. (2012) Nano-Scale Modelling and Simulation of Metal Wiredrawing by Using Molecular Dynamics Method. Proceedings of International Conference on Materials Processing and Technology 2012 (MAPT2012), Hawaii, 28-29 June 2012, 211-216.

[19]   Wright, R.N. (2010) Wire Technology “Process Engineering and Metallurgy”. Butterworth-Heinemann, Oxford.

[20]   Honeycutt, J.D. and Andersen, H.C. (1987) Molecular Dynamics Study of Melting and Freezing of Small Lennard-Jones Clusters. The Journal of Physical Chemistry, 19, 4950-4963.
http://dx.doi.org/10.1021/j100303a014

[21]   Tsuzuki, H., Branicio, P.S. and Rino, J.P. (2007) Structural Characterization of Deformed Crystals by Analysis of Common Atomic Neighborhood. Computer Physics Communications, 177, 518-523.
http://dx.doi.org/10.1016/j.cpc.2007.05.018

 
 
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