(1. Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology, Wuhan 430068, China) (2. School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China) (3. The State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China)
A highly activated aluminum alloy for portable in-situ hydrogen production was prepared using melt-casting method. The results showed that the addition of a proper amount of AlTi5B to Al-3Ga-3In-3Sn aluminum alloy can significantly improve the hydrogen production performance of aluminum alloy. When the water temperature is 20 ℃, 1 g Al-3Ga-3In-3Sn aluminum alloy reacts for 230 min to produce 980 mL of hydrogen and get a conversion rate of 79.3%, while 1 g Al-3Ga-3In-3Sn-0.1%AlTi5B aluminum alloy reacts 230 min, hydrogen production is 1200 mL, and the conversion rate is 97.1%. The reason that the hydrogen production properties of Al-3Ga-3In-3Sn alloy are improved can be ascribed to the following three factors. Firstly, with adding AlTi5B, the average grain sizes of the aluminum alloy are refined from columnar crystals with an average size of 70 μm to equiaxed crystals with an average size of 30 μm. The grain boundary areas increase significantly， which results in the increase of volume fraction of Ga-In-Sn eutectic alloy (GIS) phase. Secondly, a low melting point GIS grain boundary phase was present in Al-3Ga-3In-3Sn-0.1% AlTi5B due to the addition of AlTi5B. When the reaction temperature of the aluminum alloy is higher than the melting point of the GIS phase, the GIS phase changes to the liquid state. The liquid GIS phases not only provide a channel for the reaction of aluminum atoms with water, but also protect the aluminum atoms from oxidation, thereby promoting the reaction of aluminum alloy and water. Thirdly, the open circuit voltage of aluminum alloy decreased with adding 0.1% AlTi5B, which indicates that the activity of Al-3Ga-3In-3Sn-0.1% AlTi5B alloy is improved. The reduction of open circuit voltage is beneficial to the reaction of aluminum alloy with water.