Hydrogenation behaviour, neutron diffraction studies and microstructural characterisation of boron oxide-doped Zr-V alloys

Compositions in the range Zr3V3B0.12-0.40O0.18-0.60 from the Zr-V-B2O3 syst em have been subjected to metallographic characterisation, microprobe analy sis and powder neutron diffraction. On melting, boron was found to be reduc ed from its oxide and in the annealed condition, it was identified as a con stituent of two phases, eta-oxyboride Zr3V3(B,O) and vanadium boride V3B2. Hydrogen absorption-desorption properties were studied and related to the p hase and structural composition of the alloys. A redistribution of the ligh t atoms (oxygen, boron) within the eta-oxyboride Zr3V3(B,O) matrix and, als o, between the constituent phases of the alloys takes place during high tem perature cycling in hydrogen which could indicate increased lattice mobilit y of these non-metallic elements in the hydride material. (C) 1999 Elsevier Science S.A. All rights reserved.