Effect of Mn addition on the microstructure, mechanical properties and corrosion resistance of a biodegradable Mg–Gd–Zn alloy
| Autor: | F. Abdiyan, Reza Mahmudi, Hamid M. Ghasemi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Alloy 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Grain size 0104 chemical sciences Corrosion Dielectric spectroscopy Phase (matter) Volume fraction engineering Pitting corrosion General Materials Science Composite material 0210 nano-technology |
| Zdroj: | Materials Chemistry and Physics. 271:124878 |
| ISSN: | 0254-0584 |
| Popis: | The effect of 0.5 and 1 wt% Mn additions on the microstructure, mechanical properties, and biocorrosion resistance of an extruded Mg–3Gd–1Zn (GZ31) alloy was investigated. Mn addition refined the grain structure so that the grain size decreased from 3.7 μm for the GZ31 alloy, to 2.3 μm for GZ31–1Mn alloy. Hardness measurements and shear punch tests (SPT) revealed that by adding 1 wt% Mn, the hardness, shear yield stress (SYS) and ultimate shear strength (USS) increased from 61 to 66 Hv, 102.0 to 128.5 MPa, and 142.8 to 152.4 MPa, respectively. The main mechanisms responsible for the improvement of mechanical properties were grain refinement and higher volume fraction of the second phase particles formed by Mn addition. Electrochemical impedance spectroscopy showed that the addition of 1 wt% Mn increased the overall corrosion resistance from about 515.4 Ω cm2 to 5883.6 Ω cm2. In addition, initiation of the inductive loop in the Nyquist diagrams of the Mn-containing alloys, in the lower frequencies in comparison to the base alloy, can be a sign of retarding the onset of pitting corrosion. The improved corrosion resistance of these alloys was due to the refined microstructure and formation of a more stable protective layer on the surface. |
| Databáze: | OpenAIRE |
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