Comparison of Electrochemical Corrosion Properties of Permanent Mold Casting GZ21 Alloy and AZ91 Alloy

금형 주조한 GZ21 합금과 AZ91 합금의 부식특성 비교

Kim, Dae Han;Kim, Byeong Ho;Park, Kyung Chul;Chang, In Ki

  • Received : 2016.01.05
  • Accepted : 2016.03.14
  • Published : 2016.04.30


In this study, comparison of corrosion properties of the Mg-1.5Ge-1Zn (GZ21) alloy and Mg-9Al-1Zn (AZ91) alloy were investigated. The studied alloys were fabricated by permanent mold casting method. And the potentiodynamic test, hydrogen evolution test, immersion test and A.C Impedance test were carried out in a 3.5% NaCl solution with pH7.2 at room temperature to measure the corrosion properties. The microstructure of GZ21 alloy was composed of ${\alpha}-Mg$ and $Mg_2Ge$ phases and AZ91 alloy was composed of ${\alpha}-Mg$ and $Mg_{17}Al_{12}$ phases. From the test results, the corrosion property was improved by adding Ge. It seemed that the corrosion mechanism was changed from galvanic corrosion (AZ91) to filiform corrosion (GZ21).


Magnesium alloy;Permanent mold casting;Microstructure;Corrosion property


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