The hydrogenation behavior of Cr-coated resistance upset welds (RUW) of E110 zirconium alloy was investigated at 360, 450 and 900 °C and a hydrogen pressure of 2 bar. The deposition of Cr coating, via magnetron sputtering, can decrease the hydrogen absorption rate of an RUW Zr alloy. The activation energy for the hydrogen absorption of Cr-coated specimens (84 kJ/mol) is higher in comparison with uncoated ones (71 kJ/mol), which indicates the deceleration of the hydriding of welded Zr alloys in the case of Cr coating deposition. A Cr coating can limit the formation of radially oriented hydrides and the hardening of RUW specimens at 360 and 450 °C. No significant difference in the hydrogen absorption rate was found at 900 °C. The application of Cr coating deposition to protect resistance-upset-welded Zr alloys in a hydrogen atmosphere is discussed.

This article describes the oxidation resistance of laser beam welds made from E110 zirconium alloy with a chromium coating obtained using multi-cathode magnetron sputtering. Oxidation tests of the welded Zr alloy without and with Cr coating were performed in an air atmosphere at 1100 °C for 2–90 min. Then, analysis of their cross-section microstructure in different regions (weld, heat-affected, and bulk zones) was done using optical microscopy. Hardness measurements and three-point bending tests demonstrated the hardening of the Cr-coated welded Zr alloy after the oxidation that is discussed in the article. Brittle fracture behavior was observed for uncoated Zr weld even after a short period of high-temperature oxidation.

Novel multicomponent Nb–Ni–Ti–Zr–Co alloys with 20–55 at.% Nb were synthesized from metal powders by arc melting. The resulting alloys consist primarily of Nb-rich and eutectic body-centered (BCC) phases. The content of the eutectic BCC phase is highest for an equimolar composition, while the content of the Nb-rich BCC phase increases with Nb content in the alloy. The content of secondary phases is the highest for the alloy with 32 at.% Nb. According to ab initio calculations, hydrogen occupies tetrahedral interstitial sites in the Nb-rich phase and octahedral sites in the eutectic BCC phase. For different Nb concentrations, hydrogen-binding energies were calculated. An increase in the Nb-rich phase leads to softening of multicomponent alloys. The alloys with 20 and 32 at.% Nb demonstrate high hydrogen permeability (1.05 and 0.96 × 10⁻⁸ molH₂m⁻¹s⁻¹Pa^−0.5, respectively) at 400 °C, making them promising for hydrogen purification membrane application. Multicomponent alloys with a high Nb content (55 at.%) have low resistance to hydrogen embrittlement.