电解液中Li_2SO_4含量对Ti6Al4V微弧氧化膜特性的影响

Effects of Li_2SO_4 Content in the Electrolyte on Characteristics of Coating on Ti6Al4V by Micro-Arc Oxidation

在硅酸盐电解液体系中加入Li2SO4,对Ti6Al4V合金进行微弧氧化。采用SEM、AFM对试样表面所获得的氧化膜的微观形貌进行表征。结果表明:随着电解液中Li2SO4加入量从0增加到4.0g/L,试样表面氧化膜的厚度由87下降至57μm,表面粗糙度降低;氧化膜表面存在的蜂窝状孔洞直径由约30μm逐渐减小到约5μm,孔的外壁变得光滑;氧化膜表面由于熔体喷射产生的陶瓷颗粒数目由416减少为145,但陶瓷颗粒平均直径由350增大至597nm。XRD分析表明,随着Li2SO4加入量的增加,锐钛矿相TiO2的含量逐渐减少,金红石相TiO2的含量增加。

The oxide coatings were obtained on Ti6Al4V alloy in Na2SiO3 electrolyte system containing Li2SO4 by micro-arc oxidation（MAO）.The thickness of coatings was measured and their surface micromorphology and roughness were analyzed by SEM and AFM,respectively.The results show that the thickness of coatings decreases from 87 μm to 57 μm and the roughness also decrease with the increasing of Li2SO4 content from 0 to 4.0 g/L in the electrolyte.Meantime,the diameter of cellular microholes on the surface of coatings decreases from 30 μm to 5 μm and the wall of microholes becomes smoother.The number of individual particles by melt spraying reduces from 416 to 145 but the average particle diameter increases from 350 nm to 597 nm.It is found by X-ray diffraction that the amount of rutile TiO2 in the coatings is increased and that of anatase TiO2 is reduced gradually with increasing of Li2SO4 content in the electrolyte.