CRYSTAL-STRUCTURE AND PHASE-COMPOSITION OF ALLOYS ZR1-XTIX(MN1-YVY)(2)

The crystal structure and morphology of the Laves-phase alloys Zr1-xTi x(Mn1-yVy)(2), have been studied by X-ray powder diffraction and trans mission electron microscopy (TEM). Hydriding properties were analyzed from pressure-composition (PC) isotherms. Most of the alloys were mult iphase, with up to four phases simultaneously present in one alloy. Th e identified phases were: hexagonal C14 and cubic C15 Laves phases, bc c solid solution, alpha-ZrO2, and eta-carbide type oxide. A qualitativ e phase map of the system was constructed. TEM measurements indicated that the Laves phase C14 and the bcc solid solution have preferential atomic composition. To clarify this result, the alloys Zr0.6Ti0.4Mn1.1 V0.9 and Ti0.2Mn0.2V0.6 were prepared and analyzed by X-ray powder dif fraction. The hydrogen capacity on the system Zr1-xTixMnV by PC measur ements agreed with the value calculated by the capacity and abundance of each end member phase.