On grain boundary influence on void distribution in molybdenum irradiated with neutrons at 800 deg. C

It has been established that in commercially pure heat treated (1100 deg/C, 2 h) molybdenum after high temperature (800 deg.C) neutron irradiation (WWR-K, 2·1019 n/cm2, E>0.4 MeV) voids were found with the application of transmission electron microscopy. The radiation defect structure morphology observation brought to light that near grain boundaries form a region in which the void density is much less than that in matrix. Void size distribution alteration near the grain boundaries and in the matrix depending on increasing the post-irradiation isochronal annealing temperature over the range of 800-1100 deg.C has been investigated. A thesis of voids-grain boundary interaction to be significant for the refractory metals radiation swelling has been developed. (author)