It was noted that 1-dimensional motion of interstitial clusters was important for the microstructural evolution in metals. Here, the effect of 2at% alloying with elements Si (volume size factor to Ni: -5.81%), Cu (7.18%), Ge (14.76%) and Sn (74.08%) in Ni on the 1-dimensional motion of interstitial clusters and void growth was studied. In neutron-irradiated pure Ni, Ni–Cu and Ni–Ge, well-developed dislocation networks and voids in the matrix, and no defects near to grain boundaries were observed at 573K; irradiated to a dose of 0.4dpa by transmission electron microscopy. No voids were formed and only interstitial-type dislocation loops were observed near to grain boundaries in Ni–Si and Ni–Sn. The reaction kinetics analysis which included point defect flow into planar sinks revealed the existence of a 1-dimensional motion of interstitial clusters in Ni, Ni–Cu and Ni–Ge, and a lack of such motion in Ni–Si and Ni–Sn. In Ni–Sn and Ni–Si, the alloying elements would trap interstitial clusters and thereby reduce the cluster mobility, which led to the reduction in void growth.

One Dimensional Motion of Interstitial Clusters and Void Growth in Ni and Ni Alloys. T.Yoshiie, T.Ishizaki, Q.Xu, Y.Satoh, M.Kiritani: Journal of Nuclear Materials, 2002, 307-311[2], 924-9