Insight into the indium-related morphology transformation and application for hydrogen production of Al-rich alloys.

Al-Ga-In-(Sn) alloys with different indium (In) content were prepared by the traditional high-temperature melting technique. The compositions and microstructures of alloys are studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). We found that free indium presented in alloys plays vital role in morphology transformation of grain boundary (GB) phase particles and associated hydrogen production performance of alloys. As In dosage increasing, the numerous irregular bar-like particles instead of granular particles (mainly composed of In 3 Sn) were observed in alloys with GB phase which mainly composed of free indium (combined with XRD and EDS analysis). Meanwhile, the content and distribution of aluminum (Al) contained in GB phase particles have been somewhat neglected by the wider researchers. In this work, we provide a comprehensive study in relevant fields how Al atoms can contribute to morphology transformation process of GB phase particles. The hydrogen production performance tests were completed by gas mass flowmeter at 40 °C. The results show that the hydrogen release rate of the as-cast alloys gets significantly decreased with the increase of In dosage in alloys, which enables applications of effective on-demand hydrogen supply. • Free indium in alloys reduce the H 2 release rate compared with In 3 Sn. • Free indium leads to a morphology transformation of particles. • Al content of GB phase particles is increase as In dosage increasing. • Morphology transformation process relates to the distribution of Al in particles. [ABSTRACT FROM AUTHOR]