Effect of Zr, Ni and Zr7Ni10 alloy on hydrogen storage characteristics of TiFe alloy

• Remarkable improvements in activation behavior of TiFe+4wt% Zr7Ni10 system are due to positive influence of zirconium.
• Addition of nickel has negative influence on hydrogenation properties of TiFe alloy.
• Specific microstructure and Fe/Ti atomic ratio in intergranular phase is responsible for obtained results.
• The air resistant feature of TiFe alloy modified with pure Zr additive makes it a promising material for many applications.

The aim of this study is to understand the remarkable improvements achieved on the hydrogenation properties of TiFe alloy modified by Zr7Ni10 alloy. For this purpose, comparative effect of 4 wt% Zr, Ni and Zr7Ni10 alloy addition on hydrogenation, morphological and structural properties of TiFe alloy were investigated. Our results show that while zirconium addition has positive influence on hydrogen absorption capacity and kinetics of TiFe alloy, nickel addition has negative effect on these properties. Specific microstructure and Fe/Ti atomic ratio in intergranular phases are responsible for the obtained results. More specifically the present study shows that by zirconium addition, TiFe alloy could absorb hydrogen under moderate temperature-pressure conditions without any prior treatment. This modified system is also resistant to air exposure.