KINETICS OF RADIATION-INDUCED SEGREGATION OF IMPURITIES IN FCC METALS AT THE THERMAL STAGE OF THE COLLISION CASCADE

The behaviour of heavy impurity replacement in a f.c.c. metal at the thermal stage under radiation is studied by the molecular dynamics technique. It is shown that vacancies formed as a result of collision cascade diffuse preferentially towards the cascade region centre at the initial stage because of the presence of enormous temperature gradients and form a void. At the second stage impurity atoms are adsorbed by the surface, while at the third one a void transforms into a dislocation loop. Impurity concentration near its plane increases strongly by tenths to hundredths times and formation of a new phase becomes significantly easier. The results are compared with the experimental data received during the investigation of the radiation heredity phenomenon. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA