Skip to main content Accessibility help
×
Home

An Atomistic Study of Hydrogen Effects on the Fracture of Tilt Boundaries in Nickel.

  • N. R. Moody (a1) and S. M. Foiles (a1)

Abstract

In this study, molecular dynamics simulations were used to fracture Σ9 tilt boundaries in nickel lattices containing a range of trap site hydrogen concentrations. These lattices were created in a previous study using Monte Carlo simulations and the Embedded Atom Method to duplicate room temperature exposure to a hydrogen environment. The molecular dynamics simulations were run at absolute zero to immobilize the hydrogen distributions for determination of trap site occupancy effects on grain boundary fracture. In all lattices, fracture began by the breaking of bonds next to polyhedral defect sites that characterize the boundary structure followed by rapid failure of the remaining bonds. The effect of hydrogen was to lower the stress for fracture from 18 GPa to a lower limiting value of 8 GPa as the trap sites along the boundary plane filled. The simulations showed that the atoms at these sites were the only atoms involved in the fracture process. Within the constraints imposed on these calculations, the results of this study showed that the ‘inherent’ effect of hydrogen in the absence of plastic deformation is to reduce the cohesive force between atoms across the boundary.

Copyright

References

Hide All
1. Moody, N. R., Robinson, S. L., and Perra, M. W., Hydrogen Effects on Material Behavior. edited by Moody, N. R. and Thompson, A. W. (TMS, Warrendale, PA, 1990) pp. 625–35.
2. Moody, N. R., Robinson, S. L., and Garrison, W. M., Res Mechanica 30, 143 (1990).
3. Moody, N. R., Perra, M. W., and Robinson, S. L., Scripta Metallurgica 22, 1261 (1988).
4. Perra, M. W., in Environmental Degradation of Engineering Materials in Hydrogen, edited by Louthan, M. R. Jr, McNitt, R. P., and Sisson, R. D. Jr (VPI Press, Blacksburg, VA, 1981) pp. 321–33.
5. Mutschele, T. and Kirchheim, R., Scripta Metall. 21, 135 (1987).
6. Fukushima, H. and Birnbaum, H. K., Acta Metall. 22, 851 (1984).
7. Hirth, J. P., Metall. Trans. A 11A, 861 (1980).
8. Daw, M. S., Baskes, M. I., Bisson, C. L., and Wolfer, W. G., in Modeling Environmental Effects on Crack Growth Processes, edited by Jones, R. H. and Gerberich, W. W., (TMS-AIME, Warrendale, PA 1986) pp.99124.
9. Daw, M. S. and Baskes, M. I., Phys. Rev. Lett. 50, 1285 (1983).
10. Moody, N. R. and Foiles, S. M., in Structure/Property Relationships for Metal/Metal Interfaces, edited by Romig, A. D., Fowler, D. E., and Bristowe, P. D., (Mater. Res. Symp. Proc, 229, Pittsburgh, PA 1991) pp. 179185.
11. Lassila, D. H. and Birnbaum, H. K., Acta Metall. 34, 1237 (1986).
12. Windle, A. H. and Smith, G. C., J. Metal Science, 4, 136 (1970).
13. Daw, M. S. and Baskes, M. I., Phys. Rev. B 29, 6443 (1984).
14. Mills, M. J. and Daw, M. S., in High Resolution Electron Microscopy of Defects in Materials, edited by Sinclair, R., Smith, D. J., and Dahmen, U., (Mater. Res. Symp. Proc, 183, Pittsburgh, PA 1991) pp. 1926.
15. Daw, M. S. and Foiles, S. M., Phys. Rev. B 21, 2128 (1987).
16. Foiles, S. M., in Surface Segregation Phenomena, edited by Dowbert, P. A. and Miller, A., (CRC Press, Boca Raton, 1990) p.79.
17. Foiles, S. M., Baskes, M. I., Melius, C. F., and Daw, M. S., J. of the Less Common Metals 130. 465 (1987).
18. Foiles, S. M., Baskes, M. I. and Daw, M. S., Phys. Rev. B 33, 7983 (1986).
19. Foiles, S. M., in High-Temperature Ordered Intermetallic Alloys II. edited by Stoloff, N. S., Koch, C. C., Liu, C. T., and Izumi, O., (Mater. Res. Symp. Proc, 81, Pittsburgh, PA 1987) pp. 5156.
20. Beeler, J. R. Jr, in Radiation Effects Computer Simulations, Defects in Solids (series), 13. edited by Amelinckx, S., Gevers, R., and Nihoul, J., (North-Holland Publishing Co., New York, NY, 1983).
21. Baskes, M. I. and Vitek, V., Metall. Trans. A 16A, 1625 (1985).

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed