A novel Mg-Sn-Zn-Al-Mn magnesium alloy with superior corrosion properties

The corrosion behaviors of the hot-pressed Mg-Sn-Zn-Al-Mn magnesium alloys with the addition of Al in different proportions have been investigated. Paraffin coating technique was applied to Mg powders before production. After debinding at 300 °C, the sintering process was applied at 610 °C under 50 MPa pressure for 70 min. All of the alloys were immersed in Hank’s solution for 10-days. The results indicated that the corrosion properties of the alloys were affected by the production method (hot pressing) and alloying element addition. After immersion, magnesium hydroxide (Mg(OH)2), hydroxyapatite (HA), and Mg-Al hydrotalcite structures were determined by the X-ray diffraction (XRD) analysis on the surfaces of Mg-Sn-Zn-Al-Mn alloys. The Mg-Al hydrotalcite protective layer was effective in preventing corrosion. Superior corrosion properties (weight loss: 1.2%, total volume of evolved H2 gas: 4 ml/cm2, corrosion rate: 0.39 mm/year) were obtained from TZAM5420 alloy (5 wt.%Sn, 4 wt.%Zn, 2 wt.%Al, 0.2 wt.%Mn).