Abstract
A model for the effects of low applied stress on grain boundary segregation/dilution of solute has been suggested in the present paper. This model is based on the following assumptions: (1) The grain boundary is a weaker region on strength than the perfect crystalline in the interior of gain and will preferentially be deformed when a polycrystalline is exerted by an low applied stress. (2) Grain boundaries will work as sources of vacancies to emit vacancies when a compression stress is exerted on them and as sinks to absorb vacancies when a tension stress is exerted; (3) Oversaturated vacancies induced by the applied stress will be combined with the solute atoms to form vacancy-solute atom complexes, the diffusion rate of which is far greater than that of solute atoms in matrix; (4) The effects of applied stress on grain boundary segregation/dilution of solute will be controlled by the balance between the complex diffusion and the reverse solute atom diffusion. According to this model, there will be a critical time during stress aging, at which a maximum level of grain-boundary segregation/dilution will occur. This model can be corroborated by Shinoda and Nakamura's observation for phosphorus and Misra's observation for sulfur in steels. It can be expected that a new basis for understanding the low ductility intergranular fracture induced by applied stress will result from this new model.
Similar content being viewed by others
References
T. SHINODA and T. NAKAMURA, Acta metall. 29 (1981) 1631.
Idem., ibid. 29 (1981) 1637.
J. SHIN and C. J. McMAHON, ibid. 32 (1984) 1535.
Idem., Met. Sci. 18 (1984) 403.
C. A. HIPPSLEY, J. F. KNOTT and B. C. EDWARDS, Acta Metall. 28 (1980) 869.
J. F. KNOTT and B. C. EDWARDS Idem., ibid. 30 (1982) 641.
J. F. KNOTT and B. C. EDWARDS Idem., ibid. 32 (1984) 1381.
P. BOWEN, C. A. HIPPSLEY and J. F. KNOTT, ibid. 32 (1984) 637.
J. J. LEWANDOWSKI, C. A. HIPPSLEY, M. B. D. ELLIS and J. F. KNOTT, ibid. 35 (1987) 593.
J. J. LEWANDOWSKI, C. A. HIPPSLEY and J. F. KNOTT, ibid. 35 (1987) 2081.
C. A. HIPPSLEY, ibid. 35 (1987) 2399.
C. A. HIPPSLEY, D. BUTTLE and C. B. SCRUBY, ibid. 36 (1987) 441.
R. D. K. MISRA, Acta Mater. 44 (1996) 885.
J.-R. LEE and Y.-M. CHIANG, Materials. Science. Forum 207-209 (1996) 129.
C. HERRING, Jr. Appl. Phys. 21 (1950) 437.
R. L. COBLE, ibid. 34 (1963) 1679.
D. BIKA, J. A. PFAENDTNER, M. MENYHARD and C. J. MCMAHON JR, Acta. Metall. Mater. 43 (1995) 1895.
D. BIKA and C. J. McMAHON JR, ibid. 43 (1995) 1909.
XU TINGDONG, J. Mater. Sci. 22 (1987) 337.
Idem., J. Mater. Sci. Lett. 7 (1988) 241.
XU TINGDONG and SONG SHENHUA, Acta Metall. 37 (1989) 2499.
R. G. FAULKNER, J. Mater. Sci. 16 (1981) 373.
G. SEIBEL, Mem. Sci. Rev. Met. 60 (1964) 413.
R. D. K. MISRA and T. V. BALASUBRAMANIAN, Acta Metall. 37 (1989) 1475.
P. BOWEN and C. A. HIPPSLEY, Acta Metall. 36(2) (1988) 425.
I-WEI CHEN, ibid. 34(7) (1986) 1335.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Tingdong, X. A model for intergranular segregation/dilution induced by applied stress. Journal of Materials Science 35, 5621–5628 (2000). https://doi.org/10.1023/A:1004877601914
Issue Date:
DOI: https://doi.org/10.1023/A:1004877601914