High energy microarc alloying on ZM2 Mg base alloy by ZM2 alloy.

Magnesium and its alloys are susceptible to corrosion, which has limited their use in automotive and aerospace industries. In the present study, ZM2 electrode was coated on ZM2 magnesium alloy using high energy microarc alloying (HEMAA) technique, and the influence of the coatings on the corrosion behaviour of the ZM2 alloy was examined. A potentiostat for electrochemical corrosion tests, X-ray diffractometer (XRD) for phase analysis, energy dispersive analysis (EDX) for compositional analysis of coating, scanning electron microscopy (SEM) for cross-section and a microhardness tester for microhardness were used. It was found that the material transfer depended on the voltage and the effective output power. It was determined that ZM2 HEMAA coatings on ZM2 magnesium alloy increased the corrosion resistance of the alloy. However, it was observed that, in the coating layers, small structural defects, e.g. pores, pinholes and cracks that could arise from the coating process or substrate and get the ability of protection from corrosion worsened were present. Microhardness of the alloyed layer was improved to 130 HV as compared with 100 HV of the as received ZM2. The phases in the coating layers were the same as those in the ZM2 alloy. [ABSTRACT FROM AUTHOR]