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通过控制球磨时间制备粗晶Ag-25Cu合金粉末和纳米Ag-25Cu合金粉末,采用真空热压法制备出纳米晶Ag-25Cu块体合金,对比研究不同晶粒尺寸的Ag-25Cu合金的化学稳定性。通过PAR273与5210电化学工作站测定Ag-25Cu合金在中性Na2SO4溶液中动电位极化曲线和交流阻抗谱等研究了晶粒尺寸对其腐蚀电化学行为的影响。由动电位极化曲线可以看出在中性Na2SO4溶液中,两种Ag-25Cu合金均发生活性溶解,且机械合金化法制备的纳米Ag-25Cu合金得腐蚀电流密度明显大于粗晶Ag-25Cu合金;从阻抗谱中可以看出两种工艺的合金均呈现单容抗弧,且粗晶Ag-25Cu合金的容抗弧曲率半径大于机械合金化法制备的纳米晶Ag-25Cu合金的曲率半径。
The Ag-25Cu alloy powders and nano-Ag-25Cu alloy powders were prepared by controlling the ball milling time. The nanocrystalline Ag-25Cu bulk alloys were prepared by vacuum hot pressing. The chemical stability of Ag-25Cu alloy with different grain sizes was compared Sex. The effects of grain size on the electrochemical behavior of Ag-25Cu alloy were investigated by means of the potentiodynamic polarization curves and AC impedance spectra of Ag-25Cu alloy in neutral Na2SO4 solution by using PAR273 and 5210 electrochemical workstations. It can be seen from the potentiodynamic polarization curve that both Ag-25Cu alloys are active dissolved in neutral Na2SO4 solution, and the corrosion current density of the nano-Ag-25Cu alloy prepared by mechanical alloying is obviously larger than that of the coarse Ag-25Cu Alloy. It can be seen from the impedance spectra that the alloys of the two processes exhibit single capacitive arc resistance, and the capacitive radius of curvature of the coarse-grained Ag-25Cu alloy is larger than the radius of curvature of the nanocrystalline Ag-25Cu alloy prepared by mechanical alloying .