Electrochemical properties of intermetallic phases and common impurity elements in magnesium alloys

摘要

The electrochemical properties of the key intermetallic particles that form in commercial Mg alloys are presented. Results were collected via microcapillary electrochemical testing upon bulk intermetallic analogs in dilute chloride solution. The intermetallics investigated were Mg_(17) Al _(12), Mg_2 Al_3, Mg_2 Ca, Mg_(12) Ce, Mg_(12) La, Mg_3 Nd, Mg_2 Si, Mg_(24) Y_5, and MgZn_2. It was found that the intermetallic phases, with the exception of Mg_2 Ca, were more noble than Mg, supporting increased levels of cathodic kinetics; however, the variation in electrochemical response between intermetallics was large in terms of corrosion potential, presence of a passive window, and currents sustained over a range of potentials.