INHIBITION OF AZ91D BY SODIUM MOLYBDATE

摘要

The corrosion behavior of AZ91D magnesium alloy in ASTM D1384-87 corrosive water (pH 8.2) inhibited by sodium molybdate was investigated using electrochemical and surface analysis techniques. It was shown that inhibition of AZ91 by molybdates at ambient and high temperature of 82 C can be improved by buffering of the solution to higher pH values (pH>9). The protection afforded by the film formed at high temperature of 82 °C was low and the corrosion rate was accelerated. It was concluded that even molybdate can reduce the general corrosion of AZ91 at high pH and low temperature it can not prevent formation of micro-pits on the metal surface.