Effects of Bi composition on microstructure and Al-water reactivity of Al-rich alloys with low-In

Bi-bearing Al-Ga-In-Sn quinary alloys were prepared by a high-temperature melting technique. The alloys primarily consist of Al(Ga) matrix and Ga, In, Sn, Bi (GISB) grain boundary phase, mainly in the form of Ga-InSn4-InBi. The microstructure of GISB particles was obviously equiaxed with the increasing Bi dosage. Al-water reaction was tested at 40 °C. Owing to the Bi-doping, the hydrogen generation yields of alloys with InSn4 intermetallic compound are obviously improved and hydrogen release rates gradually tend to be stable, which show great potential in applications. At the dosage of 2.53 wt% Bi, the hydrogen generation performance of alloys was more prominent in Al-water reaction, including a theoretical hydrogen generation yield and hydrogen released extremum rate to ∼0.076 L/min·g Al alloy. Furthermore, the Al-water reaction mechanism of Bi-bearing Al-rich low-In quinary alloys has been put forward.