Helium-bubble-enhanced disordering of intermetallic phase under irradiation

Abstract

Abstract Understanding and controlling phase transformations in metals and alloys under irradiation is vital to the design of irradiation-tolerant materials. The L12-ordered intermetallic phase in nickel-based superalloys provides superior high-temperature mechanical properties and corrosion resistance. Here, we studied the order-disorder transformation kinetics of the L12-structured gamma-prime phase in nickel-based superalloy Rene N4 under irradiation and the effects of pre-implanted helium gas bubbles on the kinetics of phase transformation. The presence of pre-implanted helium gas bubbles significantly enhances the order-disorder transformation of L12-structured gamma-prime phase under irradiation at 300\u202f°C. The increase in helium gas bubble size under irradiation implies that the pre-implanted helium gas bubbles effectively trap irradiation-induced vacancies and impede the reordering of anti-site defects, leading to the acceleration of disordering under irradiation.