School of Chemistry and Chemical Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, 200240 Shanghai, China.
Institute of Functional Textiles and Advanced Materials, College of Textiles & Clothing, Qingdao University, 266000 Qingdao, Shandong, China.
J Mech Behav Biomed Mater. 2019 Feb;90:460-471. doi: 10.1016/j.jmbbm.2018.10.031. Epub 2018 Oct 29.
Titanium alloys (Ti-6Al-4V) are promising materials as bone implants in clinical surgeries owing to their excellent performances. However, wear debris caused by the tribological behavior of the cortical bone and titanium alloy interface were found to be paramount for implant stability. The contact environment between the cortical bone and Ti-6Al-4V in vivo has been considered to affect the tribological behavior. Currently, the tribological behaviors of bone and Ti-6Al-4V in different biolubricants remain elusive. Therefore, in this work, the tribological behaviors of Ti-6Al-4V plates sliding against bovine cortical bone were investigated in dry sliding and in biolubricants of physiological saline (PS), simulated body fluids (SBF), and fetal bovine serum (FBS). Results show that the friction coefficient and wear rate of the bovine cortical bone and Ti-6Al-4V interface exhibit the same sequence as follows: FBS > SBF > PS > dry sliding. These results are attributed to bone hardness variation and corrosion of different biolubricants. Meanwhile, the effects of normal load and velocity on the tribological behavior of bone and Ti-6Al-4V interface were also investigated in dry sliding and three different biolubricants. Results show that as the normal load is increased and the sliding velocity is decreased, the friction coefficient decreases in dry condition, adhering to the Hertz contact theory. However, according to the boundary lubrication theory, the friction coefficient in three biolubricants correlates positively to the normal load and negatively to the sliding velocity. Moreover, the wear rates of the bone samples increase with the increase in normal load and sliding velocity under dry and biolubrication conditions. Finally, the characterization results indicate that the wear mechanisms of the cortical bone and Ti-6Al-4V interface in dry friction are primarily adhesive and abrasive wear. Further, corrosive wear occurs in biolubrications, apart from adhesive and abrasive wear.
钛合金（Ti-6Al-4V）由于其优异的性能，作为骨植入物在临床手术中具有广阔的应用前景。然而，在皮质骨和钛合金界面的摩擦学行为中产生的磨屑被认为是影响植入物稳定性的主要因素。体内皮质骨和 Ti-6Al-4V 之间的接触环境被认为会影响摩擦学行为。目前，不同生物润滑剂中皮质骨和 Ti-6Al-4V 的摩擦学行为仍不清楚。因此，在这项工作中，研究了 Ti-6Al-4V 板在干滑动和生理盐溶液（PS）、模拟体液（SBF）和胎牛血清（FBS）三种生物润滑剂中的滑动与牛皮质骨之间的摩擦学行为。结果表明，牛皮质骨和 Ti-6Al-4V 界面的摩擦系数和磨损率具有相同的顺序：FBS>SBF>PS>干滑动。这些结果归因于骨硬度的变化和不同生物润滑剂的腐蚀。同时，还研究了在干滑动和三种不同生物润滑剂中，法向载荷和速度对骨和 Ti-6Al-4V 界面摩擦学行为的影响。结果表明，在干条件下，随着法向载荷的增加和滑动速度的降低，摩擦系数减小，符合赫兹接触理论。然而，根据边界润滑理论，三种生物润滑剂中的摩擦系数与法向载荷呈正相关，与滑动速度呈负相关。此外，在干摩擦和生物润滑条件下，骨样的磨损率随法向载荷和滑动速度的增加而增加。最后，表面形貌和成分分析表明，干摩擦条件下皮质骨和 Ti-6Al-4V 界面的磨损机制主要为粘着磨损和磨粒磨损。此外，在生物润滑条件下，除了粘着磨损和磨粒磨损外，还发生了腐蚀磨损。
