微弧氧化处理对钛铌合金力学及摩擦磨损性能的影响

采用微弧氧化的方法于磷酸盐电解液中在二元β型TiNbx(x=5,10,15,20,25)合金表面制备了微弧氧化涂层。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)表征各合金表面微弧氧化涂层的物相组成和微观形貌。采用纳米压痕仪、球-盘摩擦磨损实验仪分析了微弧氧化处理对钛铌合金力学性能、耐磨性的影响。结果表明,通过微弧氧化处理可以有效的在各基体表面制备出氧化涂层,表面微孔数目及大小无明显差别,拥有相似的致密度,氧化涂层主要由TiO₂相组成。随着基体Nb含量的增加,各基体表面微弧氧化涂层的硬度值与弹性模量表现出相同的变化趋势,Ti-15Nb合金表面微弧氧化涂层的硬度值和弹性模量值最大。经过微弧氧化处理后,Ti-5Nb和Ti-15Nb表面摩擦系数与基体相近,并无减摩效果;Ti-10Nb、Ti-20Nb和Ti-25Nb表面摩擦系数下降了55%以上,主要磨损机制由磨粒磨损变为粘着磨损,改善了合金的耐磨性能。

Effects of microarc oxidation treatment on mechanical and wear properties of Ti-Nb alloys

Microarc oxidation coatings are fabricated on the surface of binaryβTiNbx(x=5,10,15,20,25)alloys by microarc oxidation(MAO)method in phosphate electrolyte.The phase composition and microstructure of the microarc oxidation coatings are characterized by XRD and SEM.The hardness,elastic modulus and wear properties of the oxidized TiNbx(x=5,10,15,20,25)alloys are investigated by nanoindentation method and ball-disk friction and wear tester,respectively.The results show that the oxide coatings can be effectively fabricated on the surface of each substrate through microarc oxidation treatment,with no significant difference in the number and size of micropores and the density is similar.The microarc oxidation coatings are composed of rutile TiO₂ phase.As the Nb content increases in the substrates,the hardness and elastic modulus of microarc oxide coatings show the same trend.The hardness and elastic modulus of the Ti-15Nb coating are the largest.After microarc oxidation treatment,the surface friction coefficient of Ti-5Nb and Ti-15Nb are close to the substrate,and there is no antifriction effect.The surface friction coefficient of Ti-10Nb,Ti-20Nb and Ti-25Nb have decreased by more than 55%,and the main wear mechanism changes from abrasive wear to adhesive wear,which improves the wear resistance of the alloy.