【作者】 易敬华；

【导师】 朱旻昊；

【作者基本信息】 西南交通大学 ， 材料科学与工程， 2012， 硕士

【摘要】 扭动微动是指在法向载荷作用下接触副间发生的往复的微小幅度的相对扭动。作为四种基本微动运行模式之一的扭动微动,对其的相关研究极少,尤其是在微动腐蚀条件下。因此,本研究具有探索未知的科学意义,不仅丰富和发展了微动摩擦学的基本理论,而且对于认识人工关节的损伤失效机理,也有一定的参考价值。本论文选用Ti6A14V与Zr02球、CoCrMo合金与CoCrMo球配副作为研究对象,在小牛血清溶液中对其进行了的扭动微动腐蚀试验研究。通过对动力学特性和腐蚀电化学行为分析,结合表面轮廓仪、三维轮廓仪、光学显微镜(OM)、扫描电子显微镜(SEM)和电子能谱(EDX)等手段,系统地研究了Ti6A14V和CoCrMo合金的扭动微动腐蚀的运行与损伤行为。获得的主要结论如下：1. Ti6A14V合金分别在纯水、血清溶液(?) CoCrMo合金在血清溶液中的T-O曲线随着扭动角位移幅值的增大分别呈现直线型、椭圆型和平行四边形型,分别对应部分滑移区、混合区和滑移区；结合磨痕OM形貌分析,建立了Ti6A14V合金和CoCrMo合金在血清溶液中的扭动微动运行工况图。在相同法向载荷和扭动角位移幅值情况下,Ti6A14V合金在纯水溶液中产生的塑性变形最大,损伤最严重,CoCrMo合金在血清溶液中的损伤最轻微。2.在相同法向载荷和扭动角位移幅值情况下,Ti6A14V合金在纯水溶液中的摩擦扭矩最大,Ti6A14V合金在血清溶液中的次之,CoCrMo合金在血清溶液中的摩擦扭矩最小。3.在相同法向载荷和扭动角位移幅值情况下,Ti6A14V合金在血清溶液中的腐蚀电位在扭动试验阶段产生的负移和腐蚀电流值上升幅度,比CoCrMo合金在血清溶液中产生的大,产生的电化学腐蚀要严重。4.在部分滑移区,Ti6A14V合金分别在纯水、血清溶液以及CoCrMo合金在血清溶液中的损伤机理均为轻微的磨粒磨损。在混合区,Ti6A14V合金在纯水溶液中的损伤机理为磨粒磨损、剥落以及轻微的氧化磨损；Ti6A14V合金在血清溶液中的损伤机理为磨粒磨损、氧化磨损、剥落以及一定的材料转移,伴随电化学腐蚀,CoCrMo合金在血清溶液中的损伤机理主要是磨粒磨损、氧化磨损和剥层,还伴有一定的材料转移与轻度电化学腐蚀。在滑移区,Ti6A14V合金在纯水溶液中的损伤机理为磨粒磨损、氧化磨损、剥落以及一定的材料转移；Ti6A14V合金在血清溶液中的损伤机理为磨粒磨损、氧化磨损、剥落与一定的材料转移,伴随明显的电化学腐蚀现象；CoCrMo合金在血清溶液中的损伤机理为严重的磨粒磨损、氧化磨损与剥落,并伴随有一定的材料转移与电化学腐蚀。更多还原

【Abstract】 Torsional fretting can be defined as a relative angular motion which is induced by reciprocating torsion in an oscillatory vibratory environment. As one of four basic motion modes of fretting wear, torsional fretting wear has been rarely studied up to now, especially under the condition of fretting corrosion. Therefore, this research has scientific significance to explore the unknown. At the same time, it will not only enrich and develop the basic theory of fretting tribology, but also has some practical reference values for understanding the failure mechanism of the artificial joints.In this paper, the counter-pairs of Ti6A14V flats verus ZrO2ball and CoCrMo flats verus CoCrMo ball were selected as the objects of study, and the torsional fretting corrosion tests were carried out in the serum solution. Based on the analyses of torsional dynamics and electrochemical corrosion behaviors and combined with surface profile-meter,3D surface profilometry, optical microscope (OM), scanning electron microscopy (SEM) and electron energy dispersive X-ray spectroscopy (EDX), and so on, the torsional fretting corrosion running and damage behaviors were investigated systematically. The main conclusions were obtained as follows:1. T-θ curves of Ti6A14V alloy in the pure water, serum solution and CoCrMo alloy in the serum solution appeared three basic shapes:linear, elliptical and parallelogram as the function of the increase of torsional angle displacement amplitude, corresponding to the partical slip regime, mixed regime and slip regime. Combining with OM morphology analyses of wear scars, the running condition fretting maps of Ti6A14V and CoCrMo alloys in the serum solution have been set up. Under the same normal load and tortional angle displacement amplitude, the extend of plastic deformation and damage for the Ti6A14V alloy in pure water were the most serious, and the CoCrMo alloy in the serum solution presented the slightest damage.2. Under the same normal load and tortional angluar displacement amplitude, the friction torque of Ti6A14V alloy in the pure water was topest, the next was Ti6A14V alloy in the serum solution, and the friction torque of CoCrMo alloy in the serum solution was the lowest.3. Under the same normal load and tortional angluar displacement amplitude, the corrosion potential negative shift and corrosion current of Ti6A14V alloy were higher than that of the CoCrMo alloy in the serum solution during the tortional fretting tests. As a result the electrochemical corrosion of Ti6A14V alloy was more serious relatively.4. In the partical slip regime, the damage mechanisms of Ti6A14V alloy in the pure water, serum solution and CoCrMo alloy in the serum solution were slight abrasive wear. In the mixed regime, the wear mechanisms of Ti6A14V alloy in the pure water were abrasive wear, delamiantion and slight oxidation wear; the wear mechanisms of Ti6A14V alloy in the serum solution were abrasive wear, delamiantion, certain oxidation wear accompanied with a little material transfer at the contact zone and electrochemical corrosion; the wear mechanisms of CoCrMo alloy in the serum solution were abrasive wear, delamiantion, certain oxidation wear zone, accompanied with a little material transfer at the contact and slight electrochemical corrosion at the same time. In the slip regime, the damage mechanisms of Ti6A14V alloy in the pure water were serious abrasive wear, oxidation wear and delamiantion, accompanied with some material transfer; the damage mechanisms of Ti6A14V alloy in the serum solution were serious abrasive wear, oxidation wear and delamiantion combined with some material transfer and serious electrochemical corrosion; the damage mechanisms of CoCrMo alloy in the serum solution were serious abrasive wear, oxidation wear and delamiantion accompanied with some material transfer and electrochemical corrosion.更多还原