pISSN : 1598-706X / eISSN : 2288-8381
한국주조공학회지 (36권2호 60-66)
Comparison of Electrochemical Corrosion Properties of Permanent Mold Casting GZ21 Alloy and AZ91 Alloy
금형 주조한 GZ21 합금과 AZ91 합금의 부식특성 비교
Dae Han Kim, Byeong Ho Kim†, Kyung Chul Park and In Ki Chang
Defence Agency for Technology and Quality
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 p p p 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 α-Mg and Mg2Ge phases and AZ91 alloy was composed of α-Mg and Mg17Al12 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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