Corrosion Behavior of Pb-Free Sn-1Ag-0.5Cu-XNi Solder Alloys in 3.5% NaCl Solution
Corrosion Behavior of Pb-Free Sn-1Ag-0.5Cu-XNi Solder Alloys in 3.5% NaCl Solution
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DOI：
10.1007/s11664-012-2452-4
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发表时间：
2013-02
影响因子：
2.1
通讯作者：
U. S. Mohanty;Kwang-Lung Lin
中科院分区：
文献类型：
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作者：
U. S. Mohanty;Kwang-Lung Lin
采用动电位极化法研究了无铅Sn-1Ag-0.5Cu-XNi钎料合金在3.5%NaCl溶液中的腐蚀行为。极化研究表明，Ni含量从0.05 wt.%至1重量%在焊料合金中，使腐蚀电位（Ecorr）向更负的值移动，并增加线性极化电阻。将Ni的添加量增加至1重量%导致外表面上Sn和Ni氧化物的浓度显著增加。二次离子质谱和俄歇深度剖面分析表明，锡的氧化物主要有助于在含0.05wt.%和1重量%倪扫描电子显微镜（SEM）和能量色散X-射线光谱（EDX）建立了锡晶须附近的钝化区域的焊料合金从极化曲线的形成。Sn晶须的形成是由于外表面上形成的Sn和Ni的氧化物的体积增加所产生的压应力的积累。Cl−的存在导致钝化膜的破坏，极化实验后Sn-1Ag-0.5Cu-0.5Ni钎料合金发生了明显的点蚀。
Potentiodynamic polarization techniques were employed in the present study to investigate the corrosion behavior of Pb-free Sn-1Ag-0.5Cu-XNi solder alloys in 3.5% NaCl solution. Polarization studies indicated that an increase in Ni content from 0.05 wt.% to 1 wt.% in the solder alloy shifted the corrosion potential (Ecorr) towards more negative values and increased the linear polarization resistance. Increased addition of Ni to 1 wt.% resulted in significant increase in the concentration of both Sn and Ni oxides on the outer surface. Secondary-ion mass spectrometry and Auger depth profile analysis revealed that oxides of tin contributed primarily towards the formation of the passive film on the surface of the solder alloys containing 0.05 wt.% and 1 wt.% Ni. Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) established the formation of a Sn whisker near the passive region of the solder alloy obtained from the polarization curves. The formation of Sn whiskers was due to the buildup of compressive stress generated by the increase in the volume of the oxides of Sn and Ni formed on the outer surface. The presence of Cl−was responsible for the breakdown of the passive film, and significant pitting corrosion in the form of distinct pits was noticed in Sn-1Ag-0.5Cu-0.5Ni solder alloy after the polarization experiment.