Electrochemical behavior and localized corrosion associated with Al3 Sc intermetallic compounds in AlSc15 alloy
The electrochemical behavior of Al3 Sc intermetallic compounds in 0.1 mol/L NaCl solutions with varying pH and their effects on localized corrosion susceptiblity with were investigated using micro-capillary electrochemical cell and scanning Kelvin probe force mi-croscopy(SKPFM).Firstly,the hypereutectic AlSc15 alloy was heated to liquid state and cooled at 10℃/h to obtain millimeter-sized Al3 Sc imtermetallic compounds.The results show that Al3 Sc intermetallic compounds is spontaneously passive and has passivation regions in alkaline environments.The electrochemical behavior of Al3 Sc varies markedly with pH.With the increase of pH,the corrosion potential of the intermetallic compounds decreases gradually,and the corrosion rate of Al3 Sc in neutral and alkaline solutions is lower than that in acidic solution.The Volta potential difference between the Al3 Sc intermetallic compounds and the matrix is about 40 mV.In aluminum alloys,it may act as a weak local cathode and has little effect on galvanic corrosion.
Al3 Sc intermetallic compoundsmicro-capillary cellscanning Kelvin probe force microscopylocalized corrosion
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