NSUF 24-4893: Phase stability of partially-stabilized-zirconia under irradiation

Yittria-stabilized-zirconia (YSZ) is a promising ceramic material for applications in the inert matrix fuels and nuclear waste forms. They can burn minor actinides and plutonium and immobilize the high-level nuclear waste. There are three major variants of YSZs (monoclinic, tetragonal, and cubic), depending on the sintering conditions and yttria stabilizer concentration. The application of the monoclinic (m) variant is limited by the phase transformation-induced volume expansion during cooling, while the tetragonal (t) and cubic (c) variants have attracted more attention due to their high temperature stability and excellent mechanical properties. The use of 10 mol% yttria stabilized zirconia with a single cubic phase have shown outstanding phase stability under swift heavy ion irradiation. In YSZ solid solution, anion diffusivity is predominated as its activation energy (~0.5 eV) is 10 times lower than that of cation diffusion. Such sluggish diffusion behaviors ensure the phase stability during irradiation-induced displacement damage. When the concentration of yttria reduces to 3–5 mol%, the tetragonal phase is retained, leading to the formation of multiphase materials known as partially-stabilized zirconia. The retention of the fine-scale tetragonal phase increases the fracture toughness and fracture strength due to the increase in the resistance to crack propagation that caused by the stress-induced t->m phase transformation [5], thus it is anticipated that the partially-stabilized-zirconia has broad applications in nuclear structural components. To date, while the irradiation effects of fully stabilized zirconia have been reported, the evolution of partially stabilized zirconia under irradiation remains unclear, especially the effect of displacement damage on the phase evolution and mechanical properties of two-phase zirconia (tetragonal and cubic) is not understood. In this project, we aim to study the phase stability of yttria partially stabilized zirconia subjected to ion irradiation and their irradiation-induced hardening behaviors.

추가 정보

필드	값
Award Announced Date	2024-02-02T12:36:50.88
Awarded Institution	Clemson University
Facility Tech Lead	Lin Shao, Yaqiao Wu
Irradiation Facility	Accelerator Laboratory
PI	Cheng Sun
PI Email	[email protected]
Project Type	RTE
RTE Number	None