Void Swelling of Ferritic Alloys Bombarded with Nickel Ions

Abstract

Listen

Translate article

The dependence of swelling on temperature, dose and composition of simple ferritic alloys bombarded with 5 MeV Ni ions has been investigated. The peak swelling temperature of 550°C (1022°F) is 125°C (257°F) lower than forlow nickel austenitic alloys. The swelling in ferritic alloys is at least an order of magnitude less than in the high swelling, low Ni, austenitic alloys. However, the swelling of simple ferritic alloys at 116 dpa overlaps that in about 40% of the austenitic phase field. The variation of swelling with temperature is due to changes in both void size and void density. The increase in swelling with dose, and the variation with Cr content, are due to the variation in void size. However, the reduction of swelling with Ni addition is due to a reduction in void density, so there is a major qualitative difference in the way Ni and Cr affect the swelling. The voids in ferritic alloys are cube-shaped in contrast to the truncated octahedra in austenitic alloys. The sharp reduction in swelling by Ni indicates that, at high doses, the implanted Ni will lead to errors in the swelling data. It is judged that the semi-quantitative conclusions drawn from the present work are not seriously compromised by the effects of implanted nickel.