目的 在保证膜层耐蚀性能的前提下，降低镁锂合金等离子电解氧化过程中的能量消耗。方法 分别使用常规NaOH-Na2SiO3电解体系与自研的NaOH-Na2SiO3-Na2B4O7-Na3C6H5O7.2H2O(柠檬酸钠)低能耗电解体系，对LA91型镁锂合金进行等离子电解氧化，并探究其放电过程。采用扫描电子显微镜(SEM)、能谱仪(EDS)、掠入射X射线衍射仪(GIXRD)，表征等离子电解氧化膜层的表面形貌、元素组成、物相组成。通过电化学极化曲线、盐雾试验，测试膜层的耐蚀性。结果 使用低能耗体系对镁锂合金进行等离子电解氧化处理，可将膜层的单位体积能耗降低至12.87 kJ/(dm².μm)，节约能耗约50.34%。在两个体系中制备的膜层表面均产生等离子电解氧化的特征性孔洞。低能耗体系膜层孔洞数量较少，但孔洞直径差异较大，孔隙率为14.21%;常规体系膜层孔洞大小均匀，但数量较多，孔隙率为13.93%。两个膜层表面的主要元素均为O、Mg、Na和Si。在低能耗体系中制备的膜层，主要物相为方镁石型MgO，而在常规体系中制备的膜层，物相组成较为复杂。盐雾试验和电化学极化曲线结果显示，在两种体系中进行等离子电解氧化，均能提升镁锂合金的耐蚀性。低能耗等离子氧化处理后，镁锂合金的腐蚀电流密度降低约3个数量级，腐蚀速率降低约2个数量级，自腐蚀电位正移0.261 V，有效地提升了镁锂合金的耐蚀性，并且耐蚀性的提升程度要优于常规体系。结论 使用低能耗体系电解液进行等离子电解氧化，能够形成孔洞特征不同于常规体系的等离子电解氧化膜层。与常规体系下制备的膜层相比，其厚度、孔隙率并无较大差异，但能够在节约较多能耗的情况下制备出耐蚀性能更好的等离子电解氧化膜层。

The work aims to reduce the energy consumption of plasma electrolytic oxidation of Mg-Li alloy under the premise of ensuring the corrosion resistance of the coating. The conventional NaOH-Na2SiO3 electrolysis system and the self-developed NaOH-Na2SiO3-Na2B4O7-Na3C6H5O.2H2O (sodium citrate) low energy-consumption electrolysis system were used, respectively, to conduct plasma electrolysis oxidation of LA91 Mg-Li alloy, and the discharge process was investigated separately. The surface morphology, elemental composition and phase composition of the plasma electrolytic oxide coating were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and GIXRD respectively. The corrosion resistance of the coating was tested by electrochemical polarization curve and salt spray test. The unit energy consumption of Mg-Li alloy was reduced to 12.87 kJ/(dm2.μm) by plasma electrolysis in low energy-consumption system, saving about 50.34%. Characteristic pores of plasma electrolysis oxidation were produced on the surface of the coating in both systems. The pores in the low energy-consumption system was small but the pore diameter was more different with a porosity of 14.21%, while the pores in the conventional system was uniform but with a large number, with a porosity of 13.93%. O, Mg, Na and Si were the main elements on the surface of both coatings. The main physical image of the coating prepared in the low energy-consumption system is the single phase of periclase MgO, while the phase composition of the coating prepared in the conventional system is more complex. Salt spray test and electrochemical results show that the corrosion resistance of Mg-Li alloy can be improved by plasma electrolytic oxidation in both systems. After low energy plasma oxidation treatment, the corrosion current density of magnesium lithium alloy is reduced by about 3 orders of magnitude, the corrosion rate is reduced by about 2 orders of magnitude and the self-corrosion potential positively shifts 0.261 V. The corrosion resistance of Mg-Li alloy is effectively improved and the corrosion resistance is better than that of conventional systems. The results show that the electrolyte plasma electrolytic oxidation with the use of low energy-consumption system can form the plasma electrolysis oxidation coating with a hole feature different from that under the conventional system. The thickness and the porosity of coating under the low energy-consumption system show little difference from that under the conventional one, the use of low energy-consumption system can fabricate plasma electrolysis oxidation coating with a better corrosion resistant performance as well as reduce energy-consumption.