电子手刹按键表面镀层呈中部薄、端部和边缘厚,不仅影响外观和触感,甚至存在镀层起壳的风险.采用金相显微镜、二次元投影仪和X射线荧光测厚仪对汽车手刹按键镀铬端部堆镀现象进行研究.在设计初期,适当增大倒圆角可从根本上改善上述堆镀现象;而在造型设计冻结后,施镀时在端部增加阴极保护框可有效屏蔽部分阴极电场,调节不同区域的电流密度分布,使镀层厚度均匀分布.%The coating on surface of electronic handbrake button is thin at the center while thick at the tip and on the edge,which not only influences the appearance and tactility,but also has a peeling risk of coating.The over-electrodeposition phenomenon at the tip of chromium-electroplated automotive handbrake button was studied using metallographic microscope,binary optical projector and X-ray fluorescence coating thickness tester.The over-electrodeposition phenomenon mentioned above can be improved fundamentally by enlarging the rounded comer at the early design stage.After the modeling design is determined,the coating with a uniform thickness distribution can be obtained by adding an auxiliary cathodic frame near the tip during the electroplating process,which plays a role in adjusting the current density distribution at different parts of the substrate due to its efficient shielding to partial electric field around the cathode.
展开▼
