Improvement of Wear, Pitting Corrosion Resistance and Repassivation Ability of Mg-Based Alloys Using High Pressure Cold Sprayed (HPCS) Commercially Pure-Titanium Coatings
Improvement of Wear, Pitting Corrosion Resistance and Repassivation Ability of Mg-Based Alloys Using High Pressure Cold Sprayed (HPCS) Commercially Pure-Titanium Coatings
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DOI：
10.3390/coatings11010057
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发表时间：
2021-01-01
期刊：
影响因子：
3.4
通讯作者：
Gupta, Rajeev K.
中科院分区：
文献类型：
--
作者：
Daroonparvar, Mohammadreza;Kasar, Ashish K.;Gupta, Rajeev K.
采用高压冷喷涂（HPCS）系统在镁合金表面沉积了致密的冷喷涂（CS） Ti涂层。比较了CS Ti涂层与CS Al涂层和裸镁合金的磨损和腐蚀行为。与Al涂层和镁合金相比，Ti涂层的磨损率较低。电化学阻抗谱（EIS）和循环动电位极化（CPP）测试表明，与CS Al涂层相比，CS Ti涂层可以显著降低AZ31B在含氯溶液中的腐蚀速率。有趣的是，ti包覆的镁合金表现出负的迟滞回线，描述了凹坑的再钝化，而AZ31B和al包覆的AZ31B则表现出正的迟滞回线，腐蚀电位(E-corr) >再钝化电位（E-rp）；表明凹坑的不可逆生长。AZ31B和al包覆的AZ31B最容易发生点蚀，而ti包覆的镁合金在3.5 wt % NaCl溶液中表现出明显的抗点蚀性。与Al涂层相比，在11天的长期浸泡试验中，Ti涂层较好地将AZ31BMg合金表面与腐蚀性电解液分离。
In this study, a compact cold sprayed (CS) Ti coating was deposited on Mg alloy using a high pressure cold spray (HPCS) system. The wear and corrosion behavior of the CS Ti coating was compared with that of CS Al coating and bare Mg alloy. The Ti coating yielded lower wear rate compared to Al coating and Mg alloy. Electrochemical impedance spectroscopy (EIS) and cyclic potentiodynamic polarization (CPP) tests revealed that CS Ti coating can substantially reduce corrosion rate of AZ31B in chloride containing solutions compared to CS Al coating. Interestingly, Ti-coated Mg alloy demonstrated negative hysteresis loop, depicting repassivation of pits, in contrast to AZ31B and Al-coated AZ31B with positive hysteresis loops where corrosion potential (E-corr) > repassivation potential (E-rp); indicating irreversible growth of pits. AZ31B and Al-coated AZ31B were most susceptible to pitting corrosion, while Ti-coated Mg alloy indicated noticeable resistance to pitting in 3.5 wt % NaCl solution. In comparison to Al coating, Ti coating considerably separated the AZ31BMg alloy surface from the corrosive electrolyte during long term immersion test for 11 days.