目的 优化Ti2AlNb合金微弧氧化的电解液配方，提高Ti2AlNb合金微弧氧化膜的耐磨性。方法 借助SEM、EDS、XRD研究硅酸盐-磷酸盐电解液体系中Na2MoO4浓度对Ti2AlNb合金微弧氧化膜形貌、成分及相结构的影响。利用CFT-I型磨损试验机测试不同微弧氧化膜的摩擦磨损性能。结果 电解液中添加Na2MoO4后，微弧氧化膜的生长速率增加，膜层中出现了Mo元素且含量也逐渐增加。Na2MoO4的加入降低了Ti2AlNb合金微弧氧化膜的摩擦系数及比磨损率，但微弧氧化膜的耐磨性并非随Na2MoO4含量线性提高。含6 g/L Na2MoO4的体系中，微弧氧化膜摩擦系数低至0.25左右，比磨损率仅为1.20×10?3 mm3/(N?m)，表面呈轻微磨粒磨损特征。结论 电解液中的Na2MoO4参与了成膜过程，对Ti2AlNb合金微弧氧化膜的生长有显著的促进作用，有效地改善了Ti2AlNb合金微弧氧化膜的耐磨性。

The work aims to optimize micro-arc oxidation (MAO) electrolyte formula for Ti2AlNb alloy and improve wear resistance of MAO coatings on Ti2AlNb alloy. Effects of Na2MoO4 concentration on morphology, element composition and phase structure of MAO coatings on Ti2AlNb alloy were investigated in silicate-phosphate electrolyte system by virtue of SEM, EDS and XRD. Friction and wear properties of MAO coatings were tested with ball-disc wear tester. After the addition of Na2MoO4 in the electrolyte, growth rate of MAO coatings increased, Mo element appeared on the MAO coatings and Mo content increased gradually. Friction coefficient and volume wear rate of MAO coatings were reduced as Na2MoO4 was added in the electrolyte. However, the wear resistance of MAO coatings did not increase linearly with the increase of Na2MoO4 content. In the system with 6 g/L Na2MoO4, the friction coefficient of MAO coating reduced to nearly 0.25, and the volume wear rate was only 1.20×10?3 mm3/(N?m), and the surface featured in slight abrasive wear. Na2MoO4 in the electrolytes participates in the film-forming process, plays an important role in promoting growth of MAO coatings on Ti2AlNb alloy and can effectively improve its wear resistance.