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在液体石蜡中采用微波技术原位合成了油溶性环烷酸铅(LN)和十二烷基水杨酸铅(LAS).在高速低负荷(r=1500±10 rpm、 P=196~392 N)和低速高负荷(r=300±10 rpm、 P=800 N)两种条件下,用四球摩擦磨损试验对LN、 LAS和对应的羧酸进行了摩擦学性能评价,用往复式摩擦试验机考察了LN和LAS抗磨减摩性能.结果表明: LN具有良好的抗磨减摩性能和中等的极压性能,且各项摩擦学性能指标均好于LAS.为弄清其作用机理,从分子结构分析了产生摩擦学性能差异的原因,并用SEM及XPS研究了磨斑表面.结果发现: 摩擦过程中, LN和LAS都能在摩擦副表面形成吸附膜且部分吸附膜发生摩擦化学反应产生了铅氧化物转化膜,但所形成的吸附膜和转化膜厚度不同. 相似文献
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The influence of anti‐wear additive ZDDP on doped and undoped diamond‐like carbon coatings
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Louise Austin Tomasz Liskiewicz Ivan Kolev Hongyuan Zhao Anne Neville 《Surface and interface analysis : SIA》2015,47(7):755-763
Diamond‐like carbon (DLC) coatings are recognised as a promising way to reduce friction and improve wear performance of automotive engine components. DLC coatings provide new possibilities in the improvement of the tribological performance of automotive components beyond what can be achieved with lubricant design alone. Lubricants are currently designed for metallic surfaces, the tribology of which is well defined and documented. DLC does not share this depth of tribological knowledge; thus, its practical implementation is stymied. In this work, three DLC coatings are tested: an amorphous hydrogenated DLC, a silicone‐doped amorphous hydrogenated DLC and a tungsten‐doped amorphous hydrogenated DLC. The three coatings are tested tribologically on a pin‐on‐reciprocating plate tribometer against a cast iron pin in a group III base oil, and a fully formulated oil that consists of a group III base oil and contains ZDDP, at 100 °C for 6 h and for 20 h in order to determine whether a phosphor‐based tribofilm is formed at the contact. The formation of a tribofilm is characterised using atomic force microscopy and X‐ray photoelectron spectroscopy techniques. The main findings of this study are the formation of a transfer film at the undoped, amorphous hydrogenated DLC surface, and also the tungsten amorphous hydrogenated DLC having a significant wear removal during the testing. The three coatings were found to have differing levels of wear, with the tungsten‐doped DLC showing the highest, the silicon‐doped DLC showing some coating removal and the amorphous hydrogenated DLC showing only minimal signs of wear. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Youzhi Guo Peng Guo Lili Sun Xiaowei Li Peiling Ke Qiang Li Aiying Wang 《Surface and interface analysis : SIA》2019,51(3):361-370
Titanium-doped diamond-like carbon (Ti-DLC) coatings with Ti concentration of 4 at.% (Ti4at.%-DLC) and 27 at.% (Ti27at.%-DLC) were prepared by a hybrid ion beam deposition system for comparison. The tribological behaviors of Ti-DLC coatings under dry friction and boundary lubrication conditions were systematically investigated. Results showed that, under dry friction, the Ti4at.%-DLC coating displayed lower friction coefficient (0.07) and wear rate due to the continuous transfer film formed in the sliding interface, while Ti27at.%-DLC coating was worn out at initial stage due to severe abrasive wear. And under boundary lubrication, both the Ti4at.%-DLC and Ti27at.%-DLC coatings showed excellent tribological properties attributing to the formation of oil film between sliding interface. In particular, Ti27at.%-DLC performed the lowest wear rate of 1.12 × 10−16 m3 N−1 m−1 in this friction case. In conclusion, compared with Ti27at.%-DLC coating, Ti4at.%-DLC coating exhibited better tribological performances both under dry friction and boundary lubrication. The present result provides guidance for the selection of DLC coatings according to the realistic environment of starved-oil and rich-oil conditions. 相似文献
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利用X射线吸收精细结构光谱(XANES)研究了过碱硫化烷基酚钙与二烷基二硫代磷酸锌(ZDDP)复配使用时对ZDDP形成摩擦膜的表面化学行为的影响, 并提出了其和ZDDP的相互作用机制. 结果表明, 在ZDDP中加入过碱硫化烷基酚钙后完全改变了ZDDP单独使用时形成摩擦膜的结构, 摩擦膜中含有一定数量的钙离子, 其结构以磷酸钙为主; 对较高碱值的过碱硫化烷基酚钙, 在高浓度下使用时, 在摩擦膜形成的同时观测到碳酸钙颗粒的沉积. 此外, ZDDP和过碱硫化烷基酚钙共同使用时形成的摩擦膜厚度减小. 摩擦膜特性的改变是ZDDP和过碱硫化烷基酚钙复配体系抗磨性能变差的主要原因. 相似文献
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Ni-P-无机类富勒烯WS_2纳米材料化学复合镀层的制备及其摩擦学性能初步研究 总被引:6,自引:0,他引:6
用化学复合镀技术制备了含有无机类富勒烯硫化钨纳米材料的Ni-P-(IF-WS_2) 复合镀层。用环-块摩擦实验测试了Ni-P-(IF-SW_2)的摩擦学性能。研究结果表明 它比与Ni-P,Ni-P-(层状2H-WS_2)和Ni-P-石墨复合镀层具有更高的耐磨性能和更 低的摩擦系数。分析了无机类富勒烯纳米材料改善镀层摩擦学性能的机理。 相似文献
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油酸修饰CuS纳米颗粒的原位合成及其摩擦学性能 总被引:8,自引:0,他引:8
利用原位合成法室温下直接在基础油中成功制备了油酸修饰CuS 纳米颗粒, 将其长时间静置, 不会发生纳米颗粒的团聚. TEM 研究表明, 该方法制备的纳米颗粒粒径大约为30 nm. 红外光谱结果表明, 由于油酸的羧基与无机CuS纳米颗粒表面发生了化学吸附,使无机纳米颗粒的表面有一层有机修饰层, 从而增强了其油溶性.摩擦磨损试验结果表明,该添加剂在基础油中能起到抗磨减摩的效果.随着添加剂浓度的增大, 摩擦系数和磨斑直径都呈现下降趋势,当添加剂浓度为0.1%(w)时, 摩擦系数和磨斑直径都达到最小值,但是进一步增加添加剂浓度, 摩擦系数与磨斑直径又都开始增大. SEM 研究结果表明, 油酸修饰CuS 纳米颗粒能起到抗磨减摩作用的原因是因为其有利于在摩擦副表面形成牢固的润滑膜. 相似文献
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The tribological properties of Si3N4 ball sliding against diamond‐like carbon (DLC) films were investigated using a ball‐on‐disc tribometer under dry friction and oil lubrications, respectively. The influence of nano boron nitride particle as lubricant additive in poly‐α‐olefin (PAO) oil on the tribological properties of Si3N4/DLC films was evaluated. The microstructure of DLC films was measured by Raman spectroscopy and X‐ray photoelectron spectroscopy. The experimental results show coefficient of friction (COF) of Si3N4/DLC films was as low as 0.035 due to the formation of graphite‐like transfer films under dry friction condition. It also indicates that the tribological properties of Si3N4/DLC films were influenced significantly by the viscosity of oil and the content of nano boron nitride particle in PAO oil. COF increases with the viscosity of PAO oil increasing. Si3N4/DLC films exhibit the superlubricity behaviors (μ=0.001 and nonmeasurable wear) under PAO 6 oil with 1.0 wt% nano boron nitride particle lubrication, indicating that the improved boundary lubrication behaviors have indeed been responsible for the significantly reduced friction. Nano boron nitride additive is used as solid lubricant‐like nano scale ball bearing to the pointlike contact and a soft phase bond with the weak van der Waals interaction force on the contact surface to improve the lubrication behaviors of Si3N4/DLC films. The potential usefulness of nano boron nitride as lubricant additive in PAO oil for Si3N4/DLC films has been demonstrated under oil lubrication conditions. The present work will extend the wide application of nano particle additive and introduce a new approach to superlubricity under boundary lubrication in future technological areas. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Oil‐Soluble Polymer Brush Grafted Nanoparticles as Effective Lubricant Additives for Friction and Wear Reduction
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Roger A. E. Wright Dr. Kewei Wang Dr. Jun Qu Prof. Dr. Bin Zhao 《Angewandte Chemie (International ed. in English)》2016,55(30):8656-8660
The development of high performance lubricants has been driven by increasingly growing industrial demands and environmental concerns. Herein, we demonstrate oil‐soluble polymer brush‐grafted inorganic nanoparticles (hairy NPs) as highly effective lubricant additives for friction and wear reduction. A series of oil‐miscible poly(lauryl methacrylate) brush‐grafted silica and titania NPs were synthesized by surface‐initiated atom transfer radical polymerization. These hairy NPs showed exceptional stability in poly(alphaolefin) (PAO) base oil; no change in transparency was observed after being kept at ?20, 22, and 100 °C for ≥55 days. High‐contact stress ball‐on‐flat reciprocating sliding tribological tests at 100 °C showed that addition of 1 wt % of hairy NPs into PAO led to significant reductions in coefficient of friction (up to ≈40 %) and wear volume (up to ≈90 %). The excellent lubricating properties of hairy NPs were further elucidated by the characterization of the tribofilm formed on the flat. These hairy NPs represent a new type of lubricating oil additives with high efficiency in friction and wear reduction. 相似文献
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Wensheng Li Dongqing He Wei Ren Liping Wang Lunling Shang Guangan Zhang 《Surface and interface analysis : SIA》2020,52(7):396-406
Tribological behaviors of three typical kinds of diamond-like carbon (DLC) films (a-C, a-C:Cr, and a-C:H) in sulfuric acid and sodium hydroxide solutions were investigated. The a-C film showed the lowest stable coefficients of friction (COF) in both sulfuric acid and sodium hydroxide solutions but the worst wear resistance in sulfuric acid solution. The a-C:H film showed the highest COF in sulfuric acid solution and the best wear resistance in both sulfuric acid and sodium hydroxide solutions. The a-C:Cr film exhibited superior comprehensive tribological performance in sulfuric acid solution, while in sodium hydroxide solution, high COF and very poor wear resistance was observed. What is more, friction and wear mechanism was revealed by investigating the friction-induced material evolutions on the sliding surface. 相似文献
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《先进技术聚合物》2018,29(2):896-905
The tribological characteristics of PEEK composites fretting against GCr 15 steel were investigated by a SRV‐IV oscillating reciprocating ball‐on‐disk tribometer. In order to clarify the effect of type and size of fillers on the properties of PEEK composites, nano‐sized and micro‐sized CF and PTFE fillers were added to the PEEK matrix. The thermal conductivity, hardness, and fretting wear properties of PEEK composites reinforced by CF or PTFE were comparatively studied. The results showed that the type and size of the fillers have an important effect on both the friction coefficient and wear rate, by affecting their thermal conductivity, hardness, as well as the surface areas of their transfer films. In comparison, the effect on improving the tribological properties of micro‐sized CF was superior to that of nano‐sized CF, while the effect of nano‐sized PTFE was superior to that of micro‐sized PTFE. Considering the acceptable friction coefficient and wear rate of the composite under the fretting wear test, it seemed that 4% nCF, 20% mCF, 2% nPTFE and 10% mPTFE were desired additive proportions. And it also can be found that during the fretting wear test, the abrasive and adhesive wear resulted in accumulative debris at the contacting surface. The transfer films made of debris were formed on the counterfaces. 相似文献
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Glass fiber (GF) is becoming one of the most popular reinforcement materials used in many fields. However, it still has some disadvantages such as brittleness and poor wear resistance. In order to improve its tribological property, the GF was modified and use high-density polyethylene (HDPE) as the matrix material to verify it. In this work, friction tests of HDPE samples with seven different compositions of modified GF were carried out. Different working conditions were applied to determine the tribological properties and service life as used in water-lubricated bearings. Their friction coefficient, surface morphology, wear scar, wear quality and wear mechanism were investigated. The results showed that the modified GF could significantly improve the HDPE tribological properties. Moreover, the wear mechanism of pure HDPE was mainly adhesive wear and slight fatigue wear, and the composite material was mainly abrasive wear. The 30% GF composite material had the best wear resistance, its friction coefficient was reduced by 51.56% under 0.4 MPa and 500 r/min. The findings from this experiment will provide a new method for reducing friction and wear of water-lubricated bearings. 相似文献
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Selecting the best brake friction composite composition amongst a set of natural fibres reinforced composites using hybrid optimization method - ELECTRE (elimination and choice translating priority) II - entropy is discussed in this article. Three sets of natural fibres containing different amounts of banana, hemp, and pineapple reinforced brake friction composites were tested according to IS 2742 (part-4) regulations on a chase friction testing machine. The experimental results have been discussed in terms of seven performance defining attributes such as coefficient of friction, fade, wear, friction stability coefficient, friction recovery, friction fluctuations, and friction variability coefficient. The composite containing 5 wt% pineapple fiber exhibit the highest coefficient of friction, whereas wear performance and friction stability remain highest for 5 wt% hemp fiber based composites. The recovery performance remains highest for the composite containing 15 wt% banana fiber, while fade, friction variability, and fluctuations remain lowest for 10 wt% banana fiber reinforced composites. The tribological results indicate that the inclusion of disparate natural fibers in varying amounts may differently affect the tribological performances and therefore to choose the best brake friction composite satisfying the maximum beneficial criteria hybrid ELECTRE II- entropy optimization technique is used. Brake friction composite containing ~10 wt% banana fibers was ranked first, in meeting the desired performance tribological properties. A comparison of this optimization approach with other multi-criteria decision-making techniques is also made for validating the performance ranking of these composites. 相似文献
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片状MoS2/MoS1.5Se0.5纳米复合材料的制备及其摩擦学性能研究 总被引:2,自引:2,他引:0
将钼粉与升华硫和硒粉的混合粉末按一定化学计量比混合,通过固相反应法成功制备出了均匀的片状纳米颗粒。分别使用X射线粉末衍射仪(XRD)、扫描电子显微镜(SEM)以及透射电子显微镜(TEM)对该纳米粉体进行结构表征和分析,发现该粉体为MoS2/MoS1.5Se0.5混合晶相,晶粒尺寸在300~600 nm,厚度约为5 nm的片状结构。将该MoS2/MoS1.5Se0.5纳米片作为润滑油添加剂添加到基础油中,使用UMT-2型摩擦磨损试验机对其摩擦学性能进行测试,并对摩擦机理进行了解释,结果表明MoS2/MoS1.5Se0.5纳米片作为润滑油添加剂具有良好的减摩抗磨性能。 相似文献
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The interface issue of two-dimensional (2D) nanomaterials has seriously restricted their applications in the past. To date, there have been few reports on the friction behavior of 2D MOFs. Herein, 2D Zn(Bim)(OAc) metal–organic framework structure nanosheets with a thickness of ca. 4 nm were successfully prepared via convenient ultrasonic-assisted exfoliation in solvents. For the first time, we probed the dispersion performance of the as-obtained 2D Zn(Bim)(OAc) in different oils, and intensively investigated the tribological behavior. The results indicated that the as-obtained 2D Zn(Bim)(OAc) used as an additive showed the preferable friction reducing performance and wear resistance in liquid paraffin, and showed the better dispersivity in glycerol. 相似文献
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Effect of temperature on friction and wear behaviors of polyimide (PI)‐based solid–liquid lubricating materials
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The tribological properties of polyimide (PI) under four oils (including two perfluoropolyether oils and two silicon oils) lubricated conditions were comparatively investigated at room temperature in vacuum and Fomblin M30 and chlorine‐containing silicon oil were selected to study the friction and wear behaviors of PI‐based solid–liquid lubricants against steel at different temperatures in vacuum. Significant improvement in tribological performance of PI was found under oil‐lubricated conditions. The friction coefficient increased as the test temperature decreased for the mobility of liquid lubricant was limited at lower temperatures, while the wear rate exhibited distinct rule. Besides, no tribochemical reaction was detected at the contact surface of PI and chlorine‐containing silicon oil. However, the –CF3 and fluorinated C? O groups were detected on the worn tracks of PI/Fomblin M30 by X‐ray photoelectron spectroscopy, which indicated that tribochemical reaction happened to PI and Fomblin M30 under high temperature as well as the simulation of friction heat. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Zhuang Xu Wenjing Lou Gaiqing Zhao Qin Zhao Nan Xu Junying Hao 《Journal of Dispersion Science and Technology》2019,40(5):737-744
A novel biomimetic surface modification method utilizing mussel-inspired chemistry was used to prepare tungsten disulfide (WS2) nanocomposites, which enhanced the dispersion stability and tribological performance of WS2 in polyalkylene glycol (PAG). Herein, WS2-polydopamine-methoxypolyethylene glycol amine (WS2-PDA-MPGA) was first synthesized via mussel-inspired chemistry and used as a lubricant additive in PAG. After modification, the dispersion stability of WS2 nanosheets in PAG was obviously improved. Moreover, the tribological performance of WS2-PDA-MPGA in PAG at high temperature was evaluated by the oscillating reciprocating tribometer. Compared to pure PAG, the lubricant composition containing WS2-PDA-MPGA exhibited excellent performance in friction reduction and anti-wear properties at high temperature. The optimal tribological performance could be obtained when the percentage of additives was 0.9?wt%. The tribological results indicate that WS2-PDA-MPGA, with its good dispersion stability, has better friction reduction and anti-wear properties than does WS2 in PAG base oil. The chemical composition analysis of the wear surface indicated that a stable protective film had been formed by physical adsorption and tribo-chemical reactions. Therefore, the surface modification strategy is an effective way to improve the dispersion stability of WS2 in PAG, which can be expanded application of WS2 in the tribological field. 相似文献