微弧氧化处理对多孔Ti-15Mo合金显微结构、耐磨性和耐蚀性的影响

在铝酸盐电解液中对多孔Ti-15Mo合金进行微弧氧化表面改性。利用SEM和XRD研究多孔合金微弧氧化涂层的显微结构和相组成。采用显微硬度计、动电位极化曲线和球-盘摩擦磨损仪分析微弧氧化处理对多孔Ti-15Mo合金硬度、耐蚀性和耐磨性的影响。结果表明,微弧氧化处理未改变多孔Ti-15Mo合金原有的孔隙率和孔径,在合金表面和孔隙内壁呈现典型的粗糙多孔微弧氧化形貌。微弧氧化涂层主要由金红石TiO_2和Al_2TiO_5相组成。经微弧氧化处理后,多孔Ti-15Mo合金的表面显微硬度提高了32%,摩擦系数降低了近50%,磨损率大幅度下降,磨损机制由磨粒磨损转变为粘着磨损。微弧氧化处理后多孔Ti-15Mo合金的耐蚀性较基体提高了近1个数量级,微弧氧化陶瓷涂层的保护效率高达90.78%。

Influence of Micro-arc Oxidation Treatment on the Microstructure, Corrosion Resistance and Wear Resistance of the Porous Ti-15Mo Alloy

Porous Ti-15Mo alloys were modified by micro-arc oxidation (MAO) in the aluminate electrolyte. The microstructure and phase composition of the MAO coatings were investigated by SEM and XRD, respectively. The microhardness, corrosion resistance and wear resistance of the oxidized porous Ti-15Mo alloys were tested by microhardness tester, potentiodynamic polarization curve and ball-disk friction and wear tester, respectively. The results showed that the micro-arc oxidation treatment did not change the intrinsic porosity and pore size of the Ti-15Mo alloys, and the typical coarse and porous MAO morphology was formed on the surface and wall of pores. The MAO coating was composed of rutile TiO₂ and Al₂TiO₅ phases. The microhardness of coated Ti-15Mo alloys increased by 32% compared to the uncoated Ti-15Mo alloys. At the same time, the friction coefficient decreased by 50%, the wear rate greatly decreased and the wear mechanism changed from abrasire wear to adhesive wear. The corrosion resistance of the coated Ti-15Mo alloys was improved by one order of magnitude compared to the uncoated Ti-15Mo alloys, and the protective efficiency of the MAO coating was up to 90.78%.