Effect of temperature on initial corrosion of AZ91 magnesium alloy under cyclic wet-dry conditions

The effect of temperature on the initial corrosion of an as cast AZ91 magnesium alloy with surface deposition of salt particles in a water-vapour atmosphere under cyclic wet-dry conditions was studied using an environmental scanning electron microscope (ESEM). The results showed that the corrosion on the surface accelerated with increase in temperature and wetting time. The corrosion rates at various temperatures were a function of time, which expressed as M = At-n with A representing the initial corrosion rate and n, usually in a range of 0 to 0.5, the exponent for the protective ability of corrosion products.