摘要
The microstructure evaluation, surface morphology, chemical compositions and phase analysis of the biomedical Mg-6Zn-IMn-4Sn-1.5Nd/0.5Y （ZMT614- 1.5Nd/0.5Y） alloys were investigated by means of optical microscopy, EPMA, X-ray EDS, XRD and FTIR. The corrosion behavior was evaluated using weight-loss measurement, hydrogen evolution, electrochemical and pH measurements, The results demonstrate that the microstructure for both ZMT614-1,5Nd alloy and ZMT614-0.5Y alloy is characterized by α-Mg and intermetallic compounds, most of which are distributed along the grain boundaries. These second phases contain Mg2Zn, Mg2Zn11, Mg2Sn and single metal Mn, together with Mg12Nd phase for the ZMT614-1.5Nd alloy, and with Mg24Y5 phase for the ZMT614-0.5Y alloy. Honeycomb-like corrosion product layers form. The corrosion resistance of the ZMT614-0.5Y alloy is higher than that of the ZMT614-1.5Nd alloy, which is ascribed to the addition of the element Y into the alloy delaying the corrosion initiation in comparison to that of Nd element in the alloy.
The microstructure evaluation, surface morphology, chemical compositions and phase analysis of the biomedical Mg-6Zn-IMn-4Sn-1.5Nd/0.5Y （ZMT614- 1.5Nd/0.5Y） alloys were investigated by means of optical microscopy, EPMA, X-ray EDS, XRD and FTIR. The corrosion behavior was evaluated using weight-loss measurement, hydrogen evolution, electrochemical and pH measurements, The results demonstrate that the microstructure for both ZMT614-1,5Nd alloy and ZMT614-0.5Y alloy is characterized by α-Mg and intermetallic compounds, most of which are distributed along the grain boundaries. These second phases contain Mg2Zn, Mg2Zn11, Mg2Sn and single metal Mn, together with Mg12Nd phase for the ZMT614-1.5Nd alloy, and with Mg24Y5 phase for the ZMT614-0.5Y alloy. Honeycomb-like corrosion product layers form. The corrosion resistance of the ZMT614-0.5Y alloy is higher than that of the ZMT614-1.5Nd alloy, which is ascribed to the addition of the element Y into the alloy delaying the corrosion initiation in comparison to that of Nd element in the alloy.
基金
Acknowledgements This research was financially supported by the National Natural Science Foundation of China （Grant No. 5124 1001 ）, the Natural Science Foundation of Shandong Province （Grant No. ZR2011EMM004）, the Open Foundation of State Key Laboratory for Corrosion and Protection （Grant No. SKLCP21012KF03）, SDUST Research Fund and Taishan Scholarship Project of Shandong Provincc （Grant No. TS20110828）.
