电解液pH值对镁合金表面灌注液体型光滑多孔表面耐腐蚀性能的影响

Influence of pH on corrosion resistance of slippery liquid-infused porous surface on magnesium alloy

在AZ31镁合金表面制备灌注液体型光滑多孔表面(SLIPS),从而为镁合金提供腐蚀防护。将粗糙多孔的层状双金属氢氧化物(LDH)作为纳米容器,用以盛放液体润滑液。通过调节电解液的pH值,获得用于构筑SLIPS的最佳LDH膜层。研究不同pH值对SLIPS表面形貌、表面润湿性和电化学行为的影响规律。结果表明,当pH值为10.5时,所制备的MgAl-LDH膜层厚度最大,为3.51μm,其可盛放最多的硅油,质量高达0.22mg/mm^(2),使得该MgAl-LDH膜层所构筑的SLIPS可为镁合金提供最优的腐蚀防护性能,腐蚀电流密度最低,为3.72×10^(-9)A/cm^(2)。另一方面,与超疏水表面相比,无论在电化学测试还是在长期浸泡试验中,SLIPS均可为AZ31镁合金基体提供更好的腐蚀防护。镁合金耐腐蚀性能的提高将进一步促进其在实践中的广泛应用。

A slippery liquid-infused porous surface(SLIPS)was developed on the AZ31 Mg alloy to provide corrosion protection.A layered double hydroxide(LDH)was applied to providing accommodation for liquid lubricants.The electrolyte pH was adjusted to obtain the best LDH film for the development of a SLIPS.The surface morphology,surface wettability,and electrochemical behavior of the SLIPS formed at different pH values were investigated.The results indicated that the MgAl-LDH film synthesized at a pH of 10.5 had a maximum thickness of 3.51μm to accommodate the most silicone oil,with a mass of 0.22 mg/mm^(2),which provided the best corrosion protection,with the lowest corrosion current density of 3.72×10^(-9) A/cm^(2).On the other hand,compared with the superhydrophobic surface,the SLIPS imparted better corrosion resistance for the AZ31 substrate in both electrochemical behavior and long-term immersion test.The improved corrosion resistance of the SLIPS can further accelerate the application of Mg alloys in practice.