In order to evaluate the electrochemical properties of aluminum alloy anode under high current densities in alkaline electrolyte, the galvanostatic discharge, potentiodynamic polarization and hydrogen evolution tests of three experimental Al?Mg?Sn?In?(Ga) alloys were performed. The results show that the alloying element gallium improves the working potentials of experimental Al?Mg?Sn?In alloys under different discharge current densities. The average working potentials of the alloys containing gallium can reach?1.3 V under current density ranging from 650 to 900 mA/cm2, while those of alloy without Ga are only?1.0 V. Such phenomenon is attributed to the solid solution which can form amalgam with aluminum matrix. Such an amalgam can form the hydrolyzed species during the discharge process and lead to the corrosion infiltrating into aluminum matrix.
Al？50%SiC （volume fraction） composites containing different sizesofSiC particles （average sizesof 23, 38 and 75 μm） were prepared by powder metallurgy. The influences of SiC particle sizes and annealing on the propertiesof the compositeswere investigated. The results show that SiC particles are distributed uniformly in the Al matrix. The coarse SiC particles result in higher coefficient of thermal expansion （CTE） and higher thermal conductivity （TC）, while fine SiC particles decrease CTE and improve flexural strength of the composites. The morphology and size of SiC particles in the composite are not influenced by the annealing treatment at 400℃for 6h. However, the CTE and the flexural strength of annealed composites are decreased slightly, and the TCis improved. The TC, CTE and flexural strength of the Al/SiC composite with averageSiC particlesize of75 μm are 156 W/（m·K）, 11.6×10^-6K^-1 and 229 MPa, respectively.
Mg-Al-Sn alloy is one of the new developed anode materials for seawater activated batteries. The potentiodynamic polarization, galvanostatic discharge and electrochemical impedance spectroscopy of Mg-6%Al-1%Sn and Mg-6%Al-5%Sn(mass fraction) alloys in seawater were studied and compared with the commercial AZ31 and AP65 alloys. The results show that the Mg-6%Al-1%Sn alloy obtains the most negative discharge potential of average-1.611V with a electric current density of 100 mA/cm2. EIS studies reveal that the Mg-Al-Sn alloy/seawater interfacial electrochemical process is determined by an activation controlled reaction. The assembled prototype batteries with Mg-6%Al-1%Sn alloy as anodes and Ag Cl as cathodes exhibit a satisfactory integrated discharge properties.
