A fracture model for hydride-induced embrittlement

Abstract

The presence of hydrides in the microstructure can substantially reduce the tensile ductility of Zr and Ti alloys. For treating hydride-induced embrittlement in these alloys, a fracture model has been developed by considering the hydrides to crack readily under tensile loading so that an array of microcracks form in the microstructure. Interaction of the plastic fields of the microcracks leads to fracture of the matrix ligaments, and a loss in the tensile ductility. Application of the proposed model to Zircaloys reveals that hydride-induced embrittlement depends on the hydride size, morphology, and distribution, as well as the continuity of the hydride network, in accordance with experimental observations.