人造摩擦层对TC11合金干滑动摩擦磨损性能的影响

发布时间：2018-10-18 16:22

【摘要】：钛合金因其优异的综合性能而在诸多领域得到广泛应用,但较差的摩擦磨损性能却限制了钛合金的应用。人造摩擦层可显著提高钛合金的耐磨性,但对其破坏、作用机理及不同结构人造摩擦层对钛合金摩擦磨损性能的影响缺乏深入、系统的研究。本文在TC11合金/GCr15钢滑动界面添加不同混合方式的Fe_2O_3、多层石墨烯、MoS2纳米材料,以制备不同人造摩擦层。研究人造摩擦层对TC11合金在不同载荷、速度下摩擦磨损行为的影响,采用XRD、Raman、SEM、EDS等手段对二次磨损前后TC11合金的磨面和剖面物相、形貌及成分进行了分析,基于摩擦层的特征变化探索了其破坏过程,并探讨了不同人造摩擦层的作用机理及其对TC11合金摩擦磨损性能的影响。此项研究为钛合金的摩擦学设计提供了科学依据,具有重要的理论意义和工程应用价值。结果表明,添加Fe_2O_3时,无论何种载荷或速度下,TC11合金的磨损失重与平均摩擦系数均较高,且与未添加时的相当。添加多层石墨烯/Fe_2O_3、MoS2+Fe_2O_3时,磨损失重与平均摩擦系数在一定载荷或速度范围内较低,而后呈线性增长。而添加多层石墨烯+Fe_2O_3时,在全部载荷、速度内,磨损失重及平均摩擦系数几乎均保持极低值。研究发现,滑动界面上添加不同纳米材料,诱导TC11合金表面形成结构相异的人造摩擦层。添加Fe_2O_3时形成单层摩擦层,因其欠缺润滑性而极易破坏,磨面呈粘着、撕裂痕迹及犁沟,且亚表层发生变形。含MoS2和Fe_2O_3的机械混合摩擦层及含多层石墨烯和Fe_2O_3的双层摩擦层因同时具有润滑、承载能力而易于保留至二次磨损结束。然而,机械混合摩擦层和分层不明显的双层摩擦层中所含组分较均匀分布限制了其润滑作用的发挥,导致其在较高载荷或速度下发生破坏,磨损表面及亚表面呈现犁沟、粘着痕迹及塑性变形。添加多层石墨烯+Fe_2O_3时形成的双层摩擦层因分层更明显而润滑性能极佳,所有条件下几乎均稳定存在而不破坏。单层人造摩擦层不能改善TC11合金的摩擦磨损性能,相比于机械混合人造摩擦层和分层不明显的双层人造摩擦层,分层明显的双层人造摩擦层可更显著地提高TC11合金的耐磨性和减摩性。
[Abstract]:Titanium alloys are widely used in many fields because of their excellent comprehensive properties, but the poor friction and wear properties limit the application of titanium alloys. The wear resistance of titanium alloy can be improved obviously by artificial friction layer, but the failure, the mechanism of action and the influence of artificial friction layer of different structure on the friction and wear properties of titanium alloy are not thoroughly studied. In this paper, Fe_2O_3, multilayer graphene and MoS2 nanomaterials with different mixing modes were added to the sliding interface of TC11 alloy / GCr15 steel to prepare different artificial friction layers. The effect of artificial friction layer on the friction and wear behavior of TC11 alloy under different loads and speeds was studied. The wear surface, profile phase, morphology and composition of TC11 alloy before and after secondary wear were analyzed by means of XRD,Raman,SEM,EDS. Based on the characteristic change of friction layer, the failure process was investigated, and the action mechanism of different artificial friction layer and its influence on the friction and wear properties of TC11 alloy were discussed. This study provides a scientific basis for the tribological design of titanium alloys and has important theoretical significance and engineering application value. The results show that the wear weight loss and the average friction coefficient of TC11 alloy are higher when Fe_2O_3 is added under any load or velocity, and is similar to that of the alloy without adding TC11. When the multilayer graphene / Fe_2O_3,MoS2 Fe_2O_3 was added, the wear weight loss and the average friction coefficient were lower in a certain range of load or velocity, and then increased linearly. However, the wear weight loss and the average friction coefficient are almost kept very low at all loads and speeds when adding multilayer graphene Fe_2O_3. It is found that different nano-materials are added to the sliding interface to induce the formation of artificial friction layer with different structure on the surface of TC11 alloy. A single layer friction layer is formed when Fe_2O_3 is added, which is easy to destroy because of its lack of lubricity. The abrasive surface is adhesive, tearing marks and furrows, and the subsurface layer is deformed. The mechanical mixed friction layer containing MoS2 and Fe_2O_3 and the double friction layer containing multilayer graphene and Fe_2O_3 are easy to be retained until the end of secondary wear due to their lubricating capacity and bearing capacity. However, the more uniform distribution of the components in the mechanical mixed friction layer and the stratified double-layer friction layer limits its lubricating function, resulting in its failure at higher load or velocity, and the ploughing of the worn surface and the sub-surface. Adhesion marks and plastic deformation. The double-layer friction layer formed by adding multilayer graphene Fe_2O_3 has excellent lubricating performance because of its obvious delamination, and almost all of the layers exist stably without destruction under all conditions. The friction and wear properties of TC11 alloy can not be improved by single layer artificial friction layer, compared with mechanical mixing layer and double layer artificial friction layer. The wear resistance and friction reduction of TC11 alloy can be improved more obviously by the layer of double layer artificial friction layer.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

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