Study On Preparation And Hydrogen Generation Performance Of Active Soluble Aluminum Alloy

With the rapid development of the global economy,industry,science and technology,energy and environmental problems in countries around the world have become increasingly serious.Therefore,vigorously developing new clean energy has become one of the important means for countries to solve environmental problems.many researchers have begun to work on the hydrogen generation technology of soluble aluminum alloys in recent years.Researchers have designed the composition of aluminum alloys from the original design of Al-Ga,Al-In and Al-Sn binary alloys,to Al-In-Sn and Al-Ga-In ternary alloys,and then to Al-Ga-In-Sn quaternary alloys,and they found that Al-Ga-In-Sn quaternary alloys have higher hydrogen generation volume and faster hydrogen generation rate than binary and ternary alloys.Moreover,as the Al content in the alloy gradually increases,the hydrogen generation performance of the alloy also gradually improves.Regarding the mechanism of the aluminum-water reaction,researchers believe that it is not only related to the Ga-In-Sn eutectic phase existing in the alloy,but also to the InSn₄ phase and In₃Sn phase existing in the alloy.However,at present,no researchers have prepared the alloys with the ratio of In:Sn to1:4 and 3:1 to study the effects of the content and distribution on the alloy properties.The first-principles calculation methods can predict and analyze the electronic structure,mechanical properties,and various defect properties of materials by simulating the microscale of the material.At present,many scholars have applied this method to the study of element composition and content ratio of alloy materials,so as to provide theoretical guidance for the preparation of alloy materials.Therefore,in this study,under the premise of ensuring that the aluminum content in the alloy is maximized as much as possible,the active soluble aluminum alloy is prepared by adjusting the alloy distribution ratio,and the effect on the hydrogen generation performance is studied,while using the first-principles calculation method to simulate the properties of the solid solution and the second phase formed in the alloy.The effects of solid solution and second phase content and distribution in alloys on various properties are explored and analyzed by combining theoretical calculation results with experimental results,and a new method for improving the hydrogen generation performance of soluble alloys is provided.In this paper,two sets of Al-Ga-In-Sn（In:Sn=3:1）series and Al-Ga-In-Sn（In:Sn=1:4）series alloys with different element content are prepared by melting and casting.X-ray diffraction,Scanning electron microscope with energy spectrometer,Differential scanning calorimeter,Nano-indenter were used to analyze the microstructure,phase composition,melting point and mechanical properties of the alloy.The hydrogen generation volume and hydrogen generation rate of the alloy were tested by using the aluminum-water reaction test device system.The effects of different element ratios,secondary phase distribution,aluminum grain size,and reaction temperature on hydrogen production performance were studied,and the mechanism of aluminum-water reaction in the alloy was analyzed;The first-principles calculation method is used to calculate and analyze the electronic structure,thermodynamic properties,and mechanical properties of the solid solution and the second phase formed in the aluminum alloy.At the same time,the experimental results were combined with the theoretical calculation results to explore the effects of the content and distribution of the solid solution and the second phase on the properties of the Al-Ga-In-Sn quaternary soluble aluminum alloy.The main research results of the paper are as follows:Al（Ga）solid solution and In₃Sn phase are formed in Al-Ga-In-Sn（In:Sn=3:1）series alloys,and the Al-5Ga-3.75In-1.25Sn alloy has relatively good hydrogen generation performance;Al（Ga）solid solution and InSn₄ phase are formed in Al-Ga-In-Sn（In:Sn=1:4）series alloys,the Al-3Ga-1.4In-5.6Sn alloy has relatively good hydrogen generation performance;the smaller the aluminum grain size in the alloy,the better the hydrogen generation performance of the alloy;Too little Ga,In,and Sn content in the alloy will cause the hydrogen generation volume and hydrogen generation rate of the alloy to decrease;lowering of the aluminum-water reaction temperature will cause the alloy’s hydrogen generation volume and hydrogen generation rate decreases;Sn has a higher reactivity than In,and the content of Sn in the alloy composition is higher than In,which will increase the activity of the alloy when it reacts with water and accelerate the reaction rate.The first-principles calculation and analysis of the crystal properties of the Al_0.95Ga_0.05solid solution and the In₃Sn phase show that the solid solution of Ga in Al reduces the stability,toughness,and anisotropy of alloys.However,the hardness,compression resistance,shear strain and deformation resistance of the alloy are improved.The In₃Sn phase is brittle,and there is a possibility of brittle fracture along the direction of the weak bond.Meanwhile,it also has obvious anisotropy.Its mechanical properties are inferior to that of Al_0.95Ga_0.05.05 solid solution.And the hardness and elastic modulus of the In₃Sn phase in the nanoindentation test result are lower than those of the Al（Ga）solid solution;At the same time,it was verified that the alloys become more brittle due to the presence of low melting point phases,and their mechanical properties became worse.