等离子体氟化改性丁腈橡胶表面涂层的减摩机理研究

采用四氟化碳作为反应气体,对丁腈橡胶试样表面进行等离子体氟化改性处理,以改善橡胶表面的摩擦性能,并初步探讨表面含氟涂层的减摩机理。结果表明:橡胶表面氟化处理后沉积上了含氟物质,摩擦因数较未改性试样明显降低;处理功率对改性试样表面的摩擦性能影响较大,处理功率太大或太小都会减小试样表面的氟含量;处理功率为140W时试样磨损后表面平整,涂层与基体具有良好的相互作用,氟分布均匀,减摩效果最优。     

减磨填料及表面处理对氟醚橡胶密封材料性能的影响

从橡胶密封材料减磨配合体系和表面减磨处理两个方面对氟醚橡胶密封材料性能进行了研究。试验结果表明,将石墨和聚四氟乙烯(PTFE)粉体作为减磨填料,可以提升氟醚橡胶材料的基础力学性能和摩擦磨损性能,但材料的压缩永久变形性能随填料用量增加而变差。试验同时还比较了表面氟化、表面沉积类金刚石涂层、表面喷涂PTFE涂层三种表面处理工艺的影响。研究发现,表面喷涂PTFE涂层可以显著减小材料的摩擦系数,且耐磨性较好,在试验范围内材料的摩擦特性较为稳定。     

水性聚四氟乙烯改性自润滑涂料的制备与应用

以水性聚氨酯树脂、水性丙烯酸树脂和氨基树脂为改性树脂,与水性聚四氟乙烯(PTFE)乳液复配,制备水性PTFE改性自润滑涂料,研究添加组分对涂料及其涂层性能和涂装工艺的影响。结果表明,水性PTFE改性自润滑涂料通过滚喷工艺喷涂在O形橡胶密封圈表面,经过热固化后形成的涂层表面附着性良好,摩擦因数小,具有良好的自润滑性。     

丁腈橡胶耐磨密封制品的关键性能优化

从胶料配方、表面处理和材料复合改性3个方面优化丁腈橡胶（NBR）耐磨密封制品的关键性能。结果表明：单 独使用4,4′ -二硫代二吗啉（DTDM）作硫化剂时,NBR胶料的硫化时间较长,压缩永久变形较大,硫黄与硫化剂DTDM并 用作硫化剂时,随着硫黄用量的增大,NBR胶料的硫化速度提高,交联密度增大,压缩永久变形先减小后增大,NBR胶料 的优化配方为NBR　100,氧化锌　5,硬脂酸　1,炭黑N330　60,促进剂TBBS　1. 5,硫化剂DTDM　1. 5,硫黄　0. 5; NBR胶料表面喷涂抗磨聚氨酯涂料无法在本质上减小其摩擦因数,但在NBR密封制品表面喷涂抗磨聚氨酯涂料可以降 低制品在装配初期磨损的风险;NBR胶料与聚酯帘布或粘胶纤维帘布复合均可以改善其耐磨性能,其中聚酯帘布/NBR 胶料复合材料的摩擦因数更小,较粘胶纤维帘布/NBR胶料复合材料减小44. 04%,较表面未喷涂抗磨聚氨酯涂料的NBR 胶料减小45. 72%。     

辐照交联GO/UHMWPE复合材料在人工海水润滑介质下的摩擦学性能研究

为改善超高分子量聚乙烯(UHMWPE)在海水润滑介质下的耐磨损性能,采用氧化石墨烯(GO)填充与辐照交联对UHMWPE进行改性处理。利用摩擦磨损试验机研究了辐照前后UHMWPE与GO/UHMWPE复合材料在人工海水润滑介质下的摩擦学性能,利用扫描电子显微镜(SEM)与三维表面轮廓仪扫描试样磨痕表面形貌,计算其磨损率,并分析了其摩擦磨损机理。结果表明,在人工海水润滑介质下,GO填充与辐照交联改性处理均略微增加了UHMWPE的摩擦因数,降低了磨损率;二者共同使用可以协同增强UHMWPE的耐磨性能,降低复合材料的摩擦因数与磨损率; GO填充显著提高了UHMWPE的抗磨粒磨损与抗疲劳磨损性能;辐照交联改性处理进一步提高了GO/UHMWPE复合材料的抗磨粒磨损性能。     

不同碳材料对耐磨涂层的改性研究

将不同碳材料石墨和石墨烯分别掺杂在聚四氟乙烯耐磨涂料中,制备了由石墨和石墨烯分别改性的聚四氟乙烯耐磨涂料,采用喷涂的方式将耐磨涂料在斯特林制冷机的关键部件—活塞表面进行成膜,并对改性的耐磨涂层进行性能研究。结果表明,石墨烯改性的耐磨涂层摩擦系数能够达到0.13,表面较为光滑,均匀一致,比聚四氟乙烯耐磨涂层的摩擦系数降低了0.03,附着力为0级,具有较好的改善效果。     

辐照交联及老化对GO/UHMWPE复合材料生物摩擦学性能的影响

采用改良Hummer法制备了氧化石墨烯(GO),通过热压成型工艺制备了GO/超高分子量聚乙烯(UHMWPE)复合材料,在真空环境下采用γ射线对其进行辐照交联处理,并将部分样品置于80℃环境下加速老化处理21d。利用摩擦磨损实验机研究了复合材料在小牛血清润滑介质下的摩擦学性能;利用扫描电子显微镜(SEM)和三维表面轮廓仪观察试样表面磨痕并计算相应的磨损率。结果表明,在小牛血清润滑介质下,GO填充与辐照交联改性处理可以降低UHMWPE的摩擦因数和磨损率,协同提高其耐磨性,但对摩擦因数的影响并不显著。加速老化处理显著增加辐照UHMWPE及辐照GO/UHMWPE复合材料的摩擦因数和磨损率,降低了其摩擦磨损性能。GO填充降低了辐照UHMWPE在加速老化处理后摩擦因数和磨损率,增强了其摩擦学性能。     

改性膨胀石墨在POE中的分散及其对性能的影响

将膨胀石墨分别经过超声波、酸化和表面活性剂处理,得到的改性产物添加到聚烯烃热塑性弹性体(POE)中,采用扫描电子显微镜(SEM)对改性膨胀石墨在POE中的分散状况进行了分析,并对复合材料的力学性能和电学性能进行了评价,研究结果表明,膨胀石墨在POE中呈现出团聚状态,团聚的膨胀石墨仍具有孔状结构,膨胀片层分散不均匀,改性...     

超细石墨/HNBR复合材料的性能研究

采用机械共混法制备超细石墨/氢化丁腈橡胶(HNBR)复合材料,研究超细石墨用量对超细石墨/HNBR复合材料性能的影响.结果表明,超细石墨用量对复合材料的硫化特性影响不大;随着超细石墨用量的增大,复合材料的邵尔A型硬度变化不大,100%定仲应力增大,拉伸强度和拉断伸长率减小,撕裂强度有所降低,体积磨耗量先增大后减小;当超细石墨用量达到40份时,复合材料的摩擦因数明显减小.     

摩擦对胎面材料单轴压缩力学行为的影响

为获取摩擦因数对胎面材料压缩力学行为的影响规律,进行了准静态单轴压缩试验,并采用ABAQUS有限元分析软件对不同摩擦因数下胎面胶的压缩行为进行研究。结果表明:随着摩擦因数的增大,胎面材料单轴压缩弹性模量增大;橡胶试样上表面的膨胀半径随摩擦因数的增大而减小,而中性面的膨胀半径先增大后减小;接地压力在摩擦因数为0.4左右时趋于最大。     

Structures and tribological performances of PEEK (poly-ether-ether-ketone)-based coatings designed for tribological application

Driven by economical and ecological reasons, thermoplastic-based coatings become a potential solution for anti-wear purpose. Two coating design concepts, flame spraying and printing PEEK (poly-ether-ether-ketone)-based coatings on Al substrate, were introduced in this paper. An amorphous PEEK coating was obtained by these two techniques. After being annealed, the coating presents a semi-crystalline structure. The friction and wear behaviors of PEEK-based coatings were investigated by means of ball-on-disc tests. The results show that PEEK coatings exhibit an excellent tribological performance with a relatively low coefficient of friction and wear rate. The semi-crystalline PEEK coating exhibits a lower friction coefficient and wear rate than the amorphous one. The additions of micron-sized particles such as SiC and graphite in PEEK coating can improve significantly the coating wear resistance.     

聚四氟乙烯及其石墨填充复合材料的摩擦磨损特性

对聚四氟乙烯（PTFE）及石墨填充PTFE复合材料在不同载荷、不同润滑条件下,以及在不同对磨时间内的摩擦磨损性能进行了研究。结果表明,石墨填充PTFE的耐磨性比纯PTFE提高很多,不同的润滑条件对PTFE和石墨填充PTFE的磨损量及摩擦系数的影响不一样,对纯PTFE,其磨损量在水润条件下较小,而对石墨填充PTFE,其磨损量在油润滑条件下较小。     

Tribological behavior of the polyamide composite coating filled with different fillers under dry sliding

The polyamide (PA) composite coating filled with the particles of microsized MoS₂, microsized graphite, and nano‐Al₂O₃, respectively, were prepared by flame spraying. The friction and wear characteristics of the PA coating and composite coating filled with the varied content of filler under dry sliding against stainless steel were comparatively investigated using a block‐ring tester. The morphologies of the worn surfaces and transfer films on the counterpart steel ring were observed on a scanning electron microscope. The result showed that the addition of fillers to the composite coatings changed significantly the friction coefficient and wear rate of the coatings. The composite coatings filled with a low level content of fillers showed lower wear rate than did pure PA coating under dry sliding; especially the MoS₂/PA composite coating had the lowest wear rate among these composite coatings. The composite coatings with a high level content of fillers had higher wear rate than did pure PA coating, except of the Al₂O₃/PA composite coating. The bonding strengths between the polymer matrix and fillers changed with the content of the fillers, which accounted for the differences in the tribological properties of the composite coatings filled with the varied content fillers. On the other hand, the difference in the friction and wear behaviors of the composite coatings and pure coating were attributed to the difference in their worn surface morphologies and transfer film characteristics. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Mechanical and tribological properties of glass–epoxy composites with and without graphite particulate filler

The objectives of this research article is to evaluate the mechanical and tribological properties of glass‐fiber‐reinforced epoxy (G–E) composites with and without graphite particulate filler. The laminates were fabricated by a dry hand layup technique. The mechanical properties, including tensile strength, tensile modulus, elongation at break, and surface hardness, were investigated in accordance with ASTM standards. From the experimental investigation, we found that the tensile strength and dimensional stability of the G–E composite increased with increasing graphite content. The effect of filler content (0–7.5 wt %) and sliding distance on the friction and wear behavior of the graphite‐filled G–E composite systems were studied. Also, conventional weighing, determination of the coefficient of friction, and examination of the worn surface morphological features by scanning electron microscopy (SEM) were done. A marginal increase in the coefficient of friction with sliding distance for the unfilled composites was noticed, but a slight reduction was noticed for the graphite‐filled composites. The 7.5% graphite‐filled G–E composite showed a lower friction coefficient for the sliding distances used. The wear loss of the composites decreased with increasing weight fraction of graphite filler and increased with increasing sliding distance. Failure mechanisms of the worn surfaces of the filled composites were established with SEM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2472–2480, 2007     

Preparing SiC/diamond coatings via chemical vapor deposition of SiC on diamond-coated graphite and their frictional properties

SiC/diamond coatings with excellent frictional properties were successfully prepared using graphite as substrate. Diamond particles with size of 25–38 μm were firstly bonded on graphite substrate through PVA glue, followed by chemical vapor deposition (CVD) of SiC with varied MTS flow on the diamond-coated graphite substrate to enhance the adhesion of diamond particles. The influence of the MTS flow on the SiC coatings was investigated. The results showed that polycrystalline SiC coating with good crystallinity has been obtained. With MTS flow increasing, the SiC grains feature increased surface roughness and greater sizes of the SiC crystallite resulting from the co-deposition of SiC and carbon with increased carbon containing species. Reciprocating sliding wear tests were conducted to investigate the coefficient of friction. With increasing applied load, while the low-flow specimens showed a remarkable increase in the friction coefficient resulting from degradation of the SiC coatings, the high-flow specimens maintained a relatively low friction coefficient during wear tests indicating strong holding force to diamond particles of the SiC coatings. The reason for low friction coefficient of the high-flow specimens was that GCr15 steel ball was wearing by the SiC/diamond coatings with good affinity to the substrate resulting in a flat–flat contact on the contact area.     

Effect of solid lubricants on tribological behavior of glass fiber reinforced polyamide 6

The tribological properties of glass fiber reinforced polyamide 6 (GF/PA6, 15/85 by weight) and its composites filled with solid lubricants were investigated. The main purposes of this article were to study the hybrid effect of solid lubricants with glass fiber as well as the synergism of combined solid lubricants, the wear mechanisms were studied by SEM. The results showed that graphite impaired the tribological properties of GF/PA6, but the tribology behavior of graphite filled GF/PA6 composite could be significantly improved by polytetrafluroethylene (PTFE) or/and ultrahigh molecular weight polyethylene (UHMWPE), and the GF/PA6 composite filled with 5 wt % graphite, 5 wt % PTFE together with 5 wt % UHMWPE exhibited the lowest friction coefficient and wear rate, which was almost a reduction in friction coefficient by 37% and in wear rate by 34% contrast to GF/PA6. The effect of load was also studied, and the results showed that the friction coefficient was virtually not affected by load, while the wear rate all increased with increasing load. POLYM. COMPOS., 34:1783–1793, 2013. © 2013 Society of Plastics Engineers     

混杂填料增强聚四氟乙烯复合材料的摩擦学性能研究

采用MM-200型摩擦磨损试验机对纳米SiC、MoS2和石墨填充聚四氟乙烯(PTFE)复合材料在干摩擦条件下与45#钢对摩时的摩擦磨损性能进行了研究,探讨了MoS2、石墨及纳米SiC的协同效应。认为纳米SiC的加入大大提高了复合材料的承载能力,石墨、MoS2的加入减少PTFE复合材料的摩擦因数。利用扫描电子显微镜(SEM)对PTFE复合材料的摩擦面进行了观察。结果表明:实验中5%nano-SiC和3%MoS2填充PTFE复合材料的摩擦磨损性能最好,且在高载荷下的摩擦磨损性能尤为突出,具有一定的应用价值。     

载荷对汽车活塞环表面Ni-W-SiC镀层摩擦性能的影响

以摩擦因数和摩擦失重量为指标,并参照磨损形貌,研究了载荷对表面镀有Ni-W-SiC镀层的汽车发动机活塞环的摩擦性能的影响。结果表明:随着载荷的增大,摩擦因数降低,而摩擦失重量升高。当载荷为5N时,稳定时摩擦因数约为0.43,摩擦失重量约为1.83 mg;当载荷增至10N和20N时,稳定时摩擦因数分别为0.37和0.32,摩擦失重量分别为2.14mg和2.37mg。载荷变化未影响活塞环表面Ni-W-SiC镀层的摩擦机制。     

Influence of solid lubricant reinforcement on wear behavior of Kevlar fabric composites

The friction and wear behavior of Kevlar fabric composites reinforced by PTFE or graphite powders was investigated using a Xuanwu‐III friction and wear tester at dry sliding condition, with the unfilled Kevlar fabric composite as a reference. The worn surfaces were analyzed by means of scanning electron microscope, and X‐ray photoelectron spectroscopy. It was found that PTFE or graphite as fillers could significantly improve the tribological behavior of the Kevlar fabric composites, and the Kevlar fabric composites filled with 20% PTFE exhibited the best antiwear and antifriction ability among all evaluated cases. The transfer films established with two lubricants in sliding wear of composites against metallic counterparts made contributions to reducing friction coefficient and wear rate of Kevlar fabric composites. In particular, FeF₂ generated in the sliding of Kevlar fabric composites filled with PTFE against counterpart pin improved the bonding strength between the transfer film and counterpart surface, which accounted for the lowest friction coefficient and wear rate of the Kevlar fabric composites filled with PTFE measured in the testing. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.     

聚氨酯涂层的合成及其吸声性能研究

以聚氨酯为涂层基体,研究了石墨作为填料对涂层吸声性能的影响。试验结果表明,石墨改变了涂层的密度,提高了涂层的吸声系数。合成的高性能聚氨酯涂层随着水压的增大,涂层的吸声系数增加,水压在3 MPa时,平均吸声系数达87.6%。