电解抛光法制备铝合金EBSD试样方法研究

目的 为在导电单相金属中获得高质量EBSD试样表面，研究电解抛光法制备铝合金试样的方法，并提供理论支持。方法 基于Jacquet黏膜模型和金属阳极原理，提出利用阳极极化曲线、电流-时间曲线和扫描电镜二次电子图像获得电解抛光工艺参数，批量制备铝合金EBSD试样的理论方法。采用恒电位法中的静态法记录稳定的电压-电流走势，以获得电流稳定的实验时间，在90 s内进行各电压下的电解抛光实验，获得电压与稳定电流的对应关系，并绘制阳极极化曲线。电流由持续稳定转至持续上升后的斜率与电压横坐标相交处为理论最低分解电压值。结合扫描电镜二次电子图像在最低分解电压以上观察抛光表面。结果 获得最优抛光电压值为31 V。利用电流随时间的变化曲线，结合黏膜模型分析，并通过扫描电镜二次电子图像验证，最优电压下的最佳抛光时间为12 s，该值是电流-时间曲线中的电流最低点。此工艺使制备的铝合金EBSD样品标定率为97%，是理想的电解抛光工艺。结论 采用阳极极化曲线获得的最优电压和最优电压下的最小电流规律由Jacquet黏膜模型支持，其所获得的电解抛光工艺能够制备出优质的样品表面，也能够为其他金属块体导电材料和其他需要电解抛光的实验类型提供获得最佳电解抛光工艺值的理论方法。

Preparation of Aluminum Alloy EBSD Specimens by Electropolishing

The work aims to obtain high quality EBSD sample surfaces in conductive single-phase metals, so as to study the method of preparing aluminum alloy samples by electropolishing and provide theoretical support. Based on the Jacquet visous film model and anode dissolution electrochemistry principle, the anodic polarization curve, the current versus time curve and the secondary electron image of scanning electron microscope were used to obtain electropolishing parameters and theoretical method for batch preparation of aluminum alloy EBSD samples. The static method in the potentiostatic method was adopted to obtain the time with stable current through a stable voltage-current trend. Electropolishing experiments at various voltages within 90 seconds were conducted to obtain the relationship between voltage and stable current and plot the anodic polarization curve. The anodic polarization curve was applied to analyze the slope after the current switched from stable to upward trend and the theoretical minimum decomposition voltage value at the horizontal coordinate of voltage. The polishing surface was observed above the minimum decomposition voltage combined with the secondary electron image of scanning electron microscope. An optimum polishing voltage value of 31 V was obtained. By using the curve of current changing with time and combining the Jacquet visous film model, it was verified that the best polishing time under the optimal voltage was 12 s through the secondary electronic image of SEM, which was the lowest point of current in the current-time curve. The calibration rate of the aluminum alloy EBSD sample prepared under this process reached 97% and the ideal electropolishing process was realized. The optimal voltage obtained by anodic polarization curve and the minimum current rule under the optimal voltage are supported by Jacquet visous model. The electropolishing process obtained by Jacquet visous model can prepare high quality sample surfaces, and can also provide theoretical methods for obtaining the optimal electropolishing process value for other metal block conductive materials and other experimental types requiring electropolishing.