Corrosion behavior of heat treated Mg-xZn (x=0.5 – 3) alloys

The purpose of this study is to investigate the effects of zinc (0,5-1-2-3 wt.%) additions and heat treatment parameters on the microstructure, hardness and corrosion properties of magnesium zinc alloys. After the solution heat treatment at 400ºC, the samples subjected to 8 and 16 hours heat treatment. Microstructure studies showed that the grain size decreased with the increase of Zn content and the MgZn intermetallic phase was formed by the addition of 3 wt.% Zn. Hardness of the samples was increased with increase of Zn content before and after heat treatment. For the as-cast samples, as the amount of Zn increased, corrosion current density (Icorr) and corrosion rate (Pi) increased. As the amount of Zn increased, Icorr and Pi values decreased after 8 hours and 16 hours of heat treatment respectively. It can be suggested that in the galvanic couple of Mg-3Zn, α-Mg matrix phase behaves as an anode and MgZn intermetallic phase behaves as a cathode.