Hydrogen absorbing properties of a Ti-Zr-Mn eutectic alloy

Chem. Met. Alloys 1 (2008) 133-136

https://doi.org/10.30970/cma1.0044

V. IVANCHENKO, T. PRYADKO, V. DEKHTYARENKO, T. KOSORUKOVA

Hydrogen storage properties of Ti-Zr-Mn eutectic alloys with the formula Ti_0.475Zr_0.3Mn_0.225 were evaluated at ambient temperature and 565 °C using a Sieverts-type device. The initial alloys were studied by means of SEM-EDS technique, X-ray diffraction and DTA. The phase compositions and the crystal structures of the hydrogenation products were determined. The hydrogenation product obtained at room temperature consisted of an e-hydride with a tetragonal crystal structure of ThH₂ type (a = 0.455 nm, c = 0.469 nm) and a Laves phase-based hydride with MgZn₂-type crystal structure (a = 0.5587±0.0005 nm, c = 0.9135±0.0007 nm) and had the composition 0.634(Ti_0.64Zr_0.29Mn_0.066)H_1.96 + 0.366(Ti_0.18Zr_0.32Mn_0.5)H_1.3. The phase composition of the hydrogenation products obtained at 565 ۜ°C was estimated to 0.55(Ti_0.71Zr_0.285Mn_0.005)H_1.85 + 0.45(Ti_0.19Zr_0.32Mn_0.5)H_1.35 and consisted of a d-hydride with a cubic crystal structure of CaF₂ type (a = 0.4597 nm) and a Laves phase-based hydride with MgZn₂-type crystal structure (a = 0.5598±0.0006 nm, c = 0.9192±0.0008 nm).

Microstructure of the 47.5Ti-30Zr-22.5Mn (at.%) eutectic alloy (electron back scattering image).

Keywords

Laves phase / Ternary alloy system / Crystal structure / Hydrogen storage