Hydrogenation properties and structure of Ti–Cr alloy prepared by mechanical grinding

The C14 intermetallic TiCr1.9 compound was prepared by arc melting, annealed at 1623 K in helium atmosphere for 8 h, and then quenched in water. The X-ray diffraction profiles showed that the crystal structure transformed from C14 to bcc after mechanical grinding for 18 h. The hydrogenation properties of the sample were examined by pressure–composition isotherm measurements. This sample with bcc structure reacted with hydrogen by maintaining the bcc structure. The maximum hydrogen content was found to be about 0.5 H/M at 273 K and 10 MPa, where H/M means the atomic ratio of hydrogen to metal. This hydrogen content was smaller than that of other bcc structure alloys. The sample prepared by MG consists of nanosized grains of polycrystalline TiCr1.9 and amorphous-like structure regions, judging from the bright field image and the corresponding selected area diffraction pattern. The hydrogen storage capacity is reduced due to the amorphous-like structure.