Hydrogen sorption properties of Ti-Cr alloys synthesized by ball milling and cold rolling

摘要

Three Ti-Cr alloys with nominal compositions of TiCr_x (x = 2,1.8 and 1.5) were synthesized by cold rolling and ball milling of as-cast ingots, and their microstructures and hydrogenation properties were studied. X-ray diffraction showed that TiCr_x transformed from a mixture of C14 and C15 Laves phases to a metastable BCC phase after 5 h of ball milling under argon. Cold rolling did not lead to the formation of a metastable BCC phase but only to the reduction of TiCr_x size particles under 20 nm. Surprisingly, the hydrogen absorption/desorption curves of cold rolled and ball milled samples at 323 K were quite similar. This result proves that hydrogen storage properties do not depend only on microstructure and that cold rolling could be an interesting method to synthesize hydrogen storage materials.