Temperature controls the competition between defect creation, diffusion, recombination, sink absorption and thermal vacancy emission. Consequently void swelling is normally largest in an intermediate temperature window, whose location depends on alloy, dose rate and exposure history.
At low temperature, many generated defects lack sufficient mobility to feed a growing cavity. Considerable irradiation hardening can still occur through small defect clusters, while large-scale void growth remains limited.
At intermediate temperature, vacancies and interstitials migrate sufficiently to establish the biased defect fluxes described above. Cavity nuclei can survive and receive a net vacancy flux, producing strong swelling.
At sufficiently high temperature, thermal vacancy emission, recombination, recovery and changes in sink populations compete more strongly with vacancy absorption. Stable nucleation and net cavity growth can become less favorable. This does not imply that every radiation effect disappears: material creep, precipitation, segregation and gas-bubble evolution can remain important.
For austenitic stainless steels, the relevant range is typically several hundred degrees Celsius; an alloy-independent peak temperature is not justified. Raising the displacement dose rate changes the balance between production and thermally activated processes and can shift both the temperature window and the incubation dose. Temperatures from accelerated ion or electron experiments should therefore be interpreted together with dose rate, implantation, specimen thickness and surface-sink effects.
Articles by others on the same topic
There are currently no matching articles.