Effects of B addition on the hydrogen absorption–desorption property of Ti0.32Cr0.43V0.25 alloy

The effects of boron addition on the hydrogen absorption–desorption properties of the Ti0.32Cr0.43V0.25Ti0.32Cr0.43V0.25 alloy were studied. Boron was added either directly or indirectly through a mother alloy Ti0.75B0.25Ti0.75B0.25. Direct boron addition caused the decrease in the titanium content of the BCC matrix through formation of Ti–B phases, resulting in the decrease in the lattice constant. Conversely, mother alloy addition increased the titanium content and the lattice constant of the matrix, for it contained enough titanium to contribute to the matrix even after forming the second phase TiB. Such lattice constant changes caused by boron addition resulted in drastic changes in hydrogen plateau pressure and great decrease in effective hydrogen storage capacity.