A model describing neutron irradiation-induced segregation to grain boundaries in dilute alloys

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/BF02595431· OSTI ID:413274

Faulkner, R G; Song, S ^[1]; Flewitt, P E.J. ^[2]

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1. Loughborough Univ. of Technology (United Kingdom). Inst. of Polymer Technology and Materials Engineering
2. Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Technology Centre

A model describing neutron irradiation-induced grain boundary segregation at a given temperature is established for dilute alloys based on a complex diffusion mechanism and combined with McLean`s equilibrium segregation model. In the model, irradiation-enhanced solute diffusion is taken into consideration. The diffusion equations are more rigorously solved than in earlier models, so that an accurate definition of the grain boundary solute concentration is given as a function of time. The effect of the temperature dependence of dislocation density is accommodated and the estimation method for complex diffusion is reappraised. Theoretical predictions are made for segregation of phosphorus in neutron-irradiated {alpha}-Fe. There exists a transition temperature below which combined irradiation-induced nonequilibrium and irradiation-enhanced equilibrium segregation is dominant and above which thermal equilibrium segregation is dominant. The peaks in the temperature dependence of segregation shift to lower temperatures with decreasing neutron dose rate and/or increasing neutron dose. The combined radiation-induced nonequilibrium and radiation-enhanced equilibrium peak segregation temperature is about 150 C for P grain boundary segregation in neutron-irradiated {alpha}-Fe at dose rate = 10{sup {minus}6} dpa/s and dose = 1 dpa. The thermal equilibrium segregation peak is around 550 C for the same conditions. Comparison of some experimental and predicted results shows that the predictions are generally consistent with the observations.

• Sponsoring Organization: USDOE
• OSTI ID: 413274
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 11 Vol. 27; ISSN MMTAEB; ISSN 1073-5623
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL COMPOSITION
DIFFUSION
DISLOCATIONS
IRON
IRRADIATION
MATHEMATICAL MODELS
PHOSPHORUS
RADIATION DOSES
SEGREGATION
SOLUTES
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TRANSITION TEMPERATURE