Miniature impact test technique to evaluate the orientation dependence of impact toughness of hydrided Zr–2.5%Nb alloy

Miniature Impact test technique was used to investigate the plausible role of hydride platelet orientation relative to the crack plane on the fracture mechanism of the Zr–2.5%Nb alloy over a wide range of temperatures. Miniature impact samples were fabricated from spools of un-hydrided (UH), circumferential hydrided (C H ) and radial hydrided (R H ) materials with different combinations of crack plane normal and crack growth direction. The impact tests were carried out between − 50 to 300 °C. Both microstructural (microstructure, texture) and fractographic examinations were carried out. The extent of hydride embrittlement and temperature dependence of the impact toughness were explained in terms of the hydride platelet orientation with respect to the crack plane and solubility of hydrogen in the material at different test temperatures. Graphical abstract Variation of impact energy with test temperature for un-hydrided, circumferential and radial hydrided samples for a CA (Radial hydride lying parallel to the crack plane) and b AC (Both circumferential and radial hydride oriented normal to crack plane)