A novel method to prepare Al–Ga alloy with intergranular penetrating

•A new method to prepared Al–Ga alloy utilizes penetration without any stress.•The penetration process relies on energy of grain boundary.•The cold-rolling treatment favor to increase the passes for the penetration of liquid Ga.•Excessive cold-rolling can reduce the driving force of GBP.

A novel method to prepare Al–Ga alloy used to produce hydrogen by reacting with water was established. In this method, liquid gallium (Ga) is penetrated into grain boundaries (GB) of the pure aluminum (Al). It is found that both high angle grain boundaries (HAGB) and low angle grain boundaries (LAGB) can be penetrated by liquid Ga. Moreover, HAGB prefer to be penetrated because of their higher GB energy. The cold-rolled treatment can introduce LAGB as the passes for the penetration of liquid Ga. However, excessive cold-rolling reducing HAGB is not benefit for the penetrating of liquid Ga.