大变形纯钛微弧氧化膜层的生物摩擦学性能研究

采用微弧氧化法在纯钛及大变形纯钛表面制备多孔氧化膜层，研究微弧氧化膜层在干摩擦、模拟体液和小牛血清不同润滑介质条件下的生物摩擦学性能，探讨钛基材组织细化对其膜层表面摩擦磨损性能的影响。结果表明：与纯钛微弧氧化膜层相比，大变形纯钛微弧氧化膜层耐磨性能更优的原因在于钛基材晶粒的细化使得晶体缺陷增多，为微弧氧化膜层的形核提供了更多的能量，反应生成的TiO2膜层硬度更强，膜层表面更致密均匀光滑，提高了其摩擦磨损性能所致。大变形纯钛微弧氧化膜层在小牛血清润滑时的摩擦系数和磨损程度都优于干摩擦和模拟体液润滑条件下的摩擦系数与磨损情况。这归因于小牛血清于摩擦表面形成的化学反应膜及物理吸附膜，起到了更有效的润滑、冷却与承载作用。

Bio-tribological Properties of Micro-arc Oxidation Coating on Large Plastic Deformed Titanium

This paper reports the use of micro-arc oxidation(MAO) to prepare porous oxide coatings on the surface of titanium and large plastic deformed titanium. The bio-tribological properties of the MAO coatings were evaluated under different lubrication medium conditions, namely dry friction, stimulated body liquid, and calf serum. The effect of structure refinement of the titanium substrate on the friction wear properties of the coating surface was also investigated. The MAO coating obtained from large plastic deformed titanium exhibits higher abrasion resistance than the MAO coating on titanium because of improved friction wear properties. To be more specific, the structure refinement of the titanium substrate results in more crystal defects and provides more energy for nucleation on the MAO coating,which makes the TiO2 coating formed through the reaction harder, the coating surface more compact, uniform, and smooth.The friction coefficient and degree of wear of the MAO coating formed from large plastic deformed titanium under calf serum lubrication are better than those under dry friction and stimulated body liquid. This finding could be attributed to more effective lubrication and cooling, as well as to the roles of the coatings formed on the friction surface through chemical reaction and physical adsorption under calf serum lubrication.