Significantly improved corrosion resistance of Mg-15Gd-2Zn-0.39Zr alloys: Effect of heat-treatment
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2019年第8期
论文作者：Jing Liu Lixin Yang Chunyan Zhang Bo Zhang Tao Zhang Yang Li Kaiming Wu Fuhui Wang
文章页码：1644 - 1654
摘 要：The effects of heat-treatment on corrosion behavior of Mg-15Gd-2Zn-0.39Zr alloys were investigated through microstructure characterization, corrosion tests, and scanning Kelvin probe force microscope（SKPFM） analysis. In long-term corrosion experiments, the corrosion rates of Mg-Gd-Zn-Zr alloys were mainly determined by the effects of micro-galvanic corrosion. During heat-treatment, the β-（Mg,Zn）3Gd eutectic phase in as-cast alloys transformed into a long-period stacking ordered（LPSO） phase, coupled with the precipitation of small precipitates. As heat-treatment proceeded, the local potential and the volume fraction of the LPSO phases reduced gradually compared with the eutectic phase, which resulted in a remarkable decrease of the micro-galvanic effect between the second phase and Mg matrix. As a result, the corrosion resistance of heat-treated alloys improved significantly.
Jing Liu1，Lixin Yang2，Chunyan Zhang2，Bo Zhang2，Tao Zhang3，Yang Li3，Kaiming Wu1，Fuhui Wang3
1. The State Key Laboratory of Refractories and Metallurgy,Hubei Province Key Laboratory of Systems Science in Metallurgical Process,International Research Institute for Steel Technology,Wuhan University of Science and Technology2. Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences3. Shenyang National Laboratory for Materials Science,Northeastern University
摘 要：The effects of heat-treatment on corrosion behavior of Mg-15Gd-2Zn-0.39Zr alloys were investigated through microstructure characterization, corrosion tests, and scanning Kelvin probe force microscope（SKPFM） analysis. In long-term corrosion experiments, the corrosion rates of Mg-Gd-Zn-Zr alloys were mainly determined by the effects of micro-galvanic corrosion. During heat-treatment, the β-（Mg,Zn）3Gd eutectic phase in as-cast alloys transformed into a long-period stacking ordered（LPSO） phase, coupled with the precipitation of small precipitates. As heat-treatment proceeded, the local potential and the volume fraction of the LPSO phases reduced gradually compared with the eutectic phase, which resulted in a remarkable decrease of the micro-galvanic effect between the second phase and Mg matrix. As a result, the corrosion resistance of heat-treated alloys improved significantly.
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