Radiation response of Ti2AlC MAX phase coated Zircaloy-4 for accident tolerant fuel cladding

A Ti2AlC MAX phase material was deposited on Zircaloy-4 substrate using the cold spray process, with the goal of enhancing the accident tolerance of zirconium-alloy fuel cladding in light water reactors. The samples were annealed up to 923 K to study the intermetallic phase formation between the coating and Zircaloy-4 substrate. Three interface compounds, ZrAl2, ZrAl, and Zr3Al, were identified and the activation energy of the interfacial intermetallic compound growth was determined. The radiation response of the coating material and interfacial intermetallic compounds after 3.5 MeV Zr2+ ion irradiation was investigated by transmission electron microscopy and nanoindentation. Ion irradiation disrupted the nanolamellar structure of the Ti2AlC coating while amorphization was observed some of the intermetallic compounds. Nanoindentation revealed overall hardening of the Ti2AlC coating and Zr3Al phase, with no significant change observed in the ZrAl2 and ZrAl phases.