Solidification Cooling Rate, The Heat Treatment Process On The Organization And Performance Of The Magnesium Alloy Anode Materials

The object of this thesis is Mg-Hg-X magnesium alloy anode. The influence of different preparation and heat treatment for microstructure and performance of Mg-Hg-X alloy has been investigated , and the relation and disciplinarian of structure-performance-application of the alloy has been investigated by metallography, electrochemical testing, SEM in present thesis.At different solidified velocity, the change of microstructure and performance on magnesium alloy anode has been studied. The result indicate that solidified velocity is more fast, the grains and the second-phase compound of alloy is more fine , and the solubility of solute-atom in Mg matrix increase. The grains of magnesium alloy anode using rapid solidification is very fine, and the appearance of interphase is like branch, there is not remarkable second-phase also. Furthermore, solidified velocity being more fast, discharge's voltage decline, but the corrosion resistance improve.At different heat treatment, change of microstructure and performance has been studied. The result indicate that the temperature of homogenization is higher, structure of alloy and second phase is more homogeneous. At 450°C homogenize, discharge's voltage of the sample is highest, but the corrosion resistance is bad. The time of homogenization is longer, structure of alloy and second phase is more homogeneous, and the corrosion resistance improve, but discharge's voltage have not too changed. As the temperature of final anneal improving, the structure of alloy transform into recrystallization grain, and discharge's voltage decline a little, but corrosion resistance decline.The corrosion mechanism of Mg-Hg-X alloy has been studied. It is mainly pits and aperture, which intervein together and accelerate each other.Alloy elements on activation of magnesium alloy anode has been discussed. It is studied that in the initial stages of dissolve, alloy elements and Mg-based form micro-battery and arose pits. In the course of discharge, alloy elements is reduced and deposits the surface of the alloy, which block corrosive product to adhibit and destroy oxide film, so as to the voltage increase.