He-cavity accumulation at oxide particle-matrix interface in Ni-base ODS superalloy

Ni-based ODS superalloy is found to be an effective candidate for a core material of Gen. IV nuclear reactors by means of a Fe/He dual-ion bombardment simulation technique. It accumulates He cavities at the dispersed oxide particle/matrix interface, and avoids the aggregation of the cavities at the other sinks even after the irradiation up to 100.1 dpa at 1000°C. Swelling was reduced less than 1%. Cavity growth and sink strengths were estimated based on TEM observation and the rate theory. The estimations support the capability of the oxide particles for trapping the He cavities and suppressing their accumulation at grain boundaries.