Micro-scale fracture experiments on zirconium hydrides and phase boundaries

作者：Chan H; Roberts S G; Gong J

来源：Journal of Nuclear Materials, 2016, 475: 105-112.

DOI：10.1016/j.jnucmat.2016.03.026

Fracture properties of micro-scale zirconium hydrides and phase boundaries were studied using microcantilever testing methods. FIB-machined microcantilevers were milled on cross-sectional surfaces of hydrided samples, with the most highly-stressed regions within the delta-hydride film, within the alpha-Zr or along the Zr-hydride interface. Cantilevers were notched using the FIB and then tested in bending using a nanoindenter. Load-displacement results show that three types of cantilevers have distinct deformation properties. Zr cantilevers deformed plastically. Hydride cantilevers fractured after a small amount of plastic flow; the fracture toughness of the delta-hydride was found to be 3.3 +/- 0.4 MPam(1/2) and SEM examination showed transgranular cleavage on the fracture surfaces. Cantilevers notched at the Zr-hydride interface developed interfacial voids during loading, at loads considerably lower than that which initiate brittle fracture of hydrides.

• 出版日期2016-7