Dislocation and grain boundary have great influence on helium behavior in materials. In this paper, the helium bubble coalescence in titanium with dislocations was simulated using molecular dynamics method. The results show that, when the second helium bubble nucleates near the slip plane, it grows toward the first helium bubble which lies at the dislocation core till they coalesce with each other. However, it is not easy for the coalescence to occur if the two helium bubbles lie in different atomic layers in (001) plane. If the second helium bubble is nucleated on the side of the slip plane with full atomic layers, the second helium bubble growth could lead to the movement of the first helium bubble toward the other sides of the slip plane. The growth rate and direction of the second helium bubble are closely related to the pressure around it.
References
[1]
Rowcliffe, A.F., Garrison, L.M., Yamamoto, Y., Tan, L. and Katoh, Y. (2018) Materials Challenges for the Fusion Nuclear Science Facility. Fusion Engineering and Design, 135, 290-301. https://doi.org/10.1016/j.fusengdes.2017.07.012
[2]
Rieth, M., Doerner, R., Hasegawa, A., Ueda, Y. and Wirtz, M. (2019) Behavior of Tungsten under Irradiation and Plasma Interaction. Journal of Nuclear Materials, 519, 334-368. https://doi.org/10.1016/j.jnucmat.2019.03.035
[3]
Fabritsiev, S.A. and Pokrovsky, A.S. (2003) The Effects of Grain Size and Helium Accumulation on Radiation Hardening and Loss of Ductility of Pure Copper for ITER Application. Fusion Engineering and Design, 65, 545-559.
https://doi.org/10.1016/S0920-3796(03)00314-4
[4]
Jeuland, H.L., Moll, S., Jourdan, T. and Legendre, F. (2013) Effect of Grain Microstructure on Thermal Helium Desorption from Pure Iron. Journal of Nuclear Materials, 434, 152-157. https://doi.org/10.1016/j.jnucmat.2012.11.025
[5]
Sakaguchi, N., Ohguchi, Y., Shibayama, T., Watanabea, S. and Kinoshitab, H. (2013) Surface Cracking on Σ3, Σ9 CSL and Random Grain Boundaries in Helium Implanted 316L Austenitic Stainless Steel. Journal of Nuclear Materials, 432, 23-27.
https://doi.org/10.1016/j.jnucmat.2012.08.019
[6]
Grigoreva, P., Bakaev, A., Terentyev, D., Oost, G.V., Noterdaeme, J.M. and Zhurkinc, E.E. (2017) Interaction of Hydrogen and Helium with Nanometric Dislocation Loops in Tungsten Assessed by Atomistic Calculations. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 393, 164-168. https://doi.org/10.1016/j.nimb.2016.10.036
[7]
Fu, J., Chen, Y.C., Fang, J.Z., Gao, N., Hu, W.Y., Jiang, C., Zhou, H.B., Lv, G.H., Gao, F. and Deng, H.Q. (2019) Molecular Dynamics Simulations of High-Energy Radiation Damage in W and W-Re Alloys. Journal of Nuclear Materials, 524, 9-20.
https://doi.org/10.1016/j.jnucmat.2019.06.027
[8]
Wang, J.C., Wang, W.J., Wei, R., Wang, X.L., Sun, Z.X., Xie, C.Y., Li, Q. and Luo, G.N. (2017) Effect of Ti Interlayer on the Bonding Quality of W and Steel HIP Joint. Journal of Nuclear Materials, 485, 8-14.
https://doi.org/10.1016/j.jnucmat.2016.12.024
[9]
Buzi, L., Yeh, M., Yeh, Y.W. and Donaldson, O.K. (2019) Deuterium and Helium Ion Irradiation of Nanograined Tungsten and Tungsten-Titanium Alloys. Nuclear Materials and Energy, 21, Article ID: 100713.
https://doi.org/10.1016/j.nme.2019.100713
[10]
Donnelly, S.E. and Evans, J.H. (1991) Fundamentals Aspects of Inert Gases in Solid. Plenum, New York. https://doi.org/10.1007/978-1-4899-3680-6
[11]
Cleri, F. and Rosato, V. (1993) Tight-Binding Potentials for Transition Metals and Alloys. Physical Review B, 48, 22. https://doi.org/10.1103/PhysRevB.48.22
[12]
Wang, J., Hou, Q., Sun, T.Y., Wu, Z.C., Long, X.G., Wu, X.C. and Luo, S.Z. (2006) Simulation of Helium Behaviour in Titanium Crystals Using Molecular Dynamics. Chinese Physics Letters, 23, 1666.
[13]
Zhang, B.L., Wang, J., Li, M. and Hou, Q. (2013) A Molecular Dynamics Study of Helium Bubble Formation and Gas Release near Titanium Surfaces. Journal of Nuclear Materials, 438, 178-182. https://doi.org/10.1016/j.jnucmat.2013.03.033
[14]
Wang, J., Hou, Q., Sun, T.Y., Long, X.G., Wu, X.C. and Luo, S.Z. (2007) Defect Behavior Induced by Helium Cluster Growth in Titanium Crystals. Journal of Applied Physics, 102, Article ID: 093510. https://doi.org/10.1063/1.2804110
[15]
Rodney, D. and Martin, G. (1999) Dislocation Pinning by Small Interstitial Loops: A Molecular Dynamics Study. Physical Review Letters, 82, 3272.
https://doi.org/10.1103/PhysRevLett.82.3272
[16]
Osetsky, N.Y. and Bacon, D.J. (2003) An Atomic-Level Model for Studying the Dynamics of Edge Dislocations in Metals. Modelling and Simulation in Materials Science and Engineering, 11, 427. https://doi.org/10.1088/0965-0393/11/4/302
[17]
Zhang, B.L., Wang, B.W., Su, X., Song, X.Y. and Li, M. (2018) Growth Mode of Helium Crystal near Dislocations in Titanium. Chinese Physics B, 27, Article ID: 060205.
https://doi.org/10.1088/1674-1056/27/6/060205
[18]
Hou, Q., Hou, M., Bardotti, L., Prével, B., Mélinon, P. and Perez, A. (2000) Deposition of Au N Clusters on Au(111) Surfaces. I. Atomic-Scale Modeling. Physical Review B, 62, 2825. https://doi.org/10.1103/PhysRevB.62.2825
[19]
Chen, M., Hou, Q., Wang, J., Sun, T.Y., Long, X.G. and Luo, S.Z. (2008) Anisotropic Diffusion of He in Titanium: A Molecular Dynamics Study. Solid State Communications, 148, 178-181. https://doi.org/10.1016/j.ssc.2008.08.025
[20]
Zhang, B.L., Wang, J. and Hou, Q. (2011) Molecular Dynamics Study of Helium Bubble Pressure in Titanium. Chinese Physics B, 20, Article ID: 036105.
https://doi.org/10.1088/1674-1056/20/3/036105
