电镀铝−锰合金的耐人工汗液腐蚀性能

Corrosion resistance of electroplated aluminum-manganese alloy coating in artificial sweat

为解决可穿戴设备中镍镀层受到汗液腐蚀而产生镍释放的问题,提出以Al-Mn合金镀层替代镍镀层。采用扫描电镜(SEM)和能谱仪(EDS)分析了Al-Mn合金镀层的微观形貌、成分,测试了它的表面粗糙度、光泽和努氏硬度,通过静态浸泡腐蚀试验和动电位极化曲线测量研究了Al-Mn合金镀层在人工汗液中的耐蚀性。结果表明:电沉积所得Al-Mn合金镀层镜面光亮、平整、致密,与基体结合良好,努氏硬度高于光亮镍镀层。Al-Mn合金镀层在人工汗液中发生全面的均匀腐蚀,耐蚀性为2级。Al-Mn合金镀层在人工汗液中的腐蚀电流密度与光亮镍镀层相近,但腐蚀电位更负,对腐蚀电位较负的基体起牺牲阳极保护作用,可以替代镍镀层用于汗液腐蚀的环境中。

In order to deal with the nickel release problem on the surface of smart wearable devices caused by nickel corrosion in artificial sweat,Al-Mn alloy coating was recommended to replace nickel coating.The micromorphology and composition of Al-Mn alloy coating were analyzed using scanning electron microscope(SEM)and energy-dispersive spectrometer(EDS),its roughness,glossiness,and Knoop hardness were tested,and its corrosion resistance in artificial sweat was studied by static immersion testing and potentiodynamic polarization measurement.The results showed that the electroplated Al-Mn alloy coating was mirror-bright,smooth,and compact with strong adhesion to substrate and had a Knoop hardness higher than that of bright nickel coating.Al-Mn alloy coating suffered a uniform general corrosion in artificial sweat with a two-level corrosion resistance.The corrosion current density of Al-Mn alloy coating in artificial sweat was similar to that of bright nickel coating,but its corrosion potential was more negative.Al-Mn alloy coating has a protective effect on the substrates with relatively negative corrosion potentials as a sacrificial anode,and it is an alternative to nickel coating in corrosive sweat environments.