软碳填充PTFE复合材料摩擦磨损性能研究

以不同含量的软碳为填料制备了PTFE基复合材料,测量了其机械性能,在M-2000型摩擦磨损试验机上研究其摩擦磨损行为,并探讨了其磨损机制.结果表明:软碳能提高PTFE复合材料的硬度,软碳/PTFE复合材料的耐磨性能优于纯PTFE,当软碳质量分数为7%时其耐磨性能最好.复合材料的摩擦因数随着软碳含量的增加而增加.摩擦表面的SEM观察发现:纯PTFE的摩擦表面分布着较明显的犁削和黏着磨损的痕迹,复合材料的摩擦表面均出现犁削,随着软碳含量的增加,犁削现象减轻,这表明以软碳作为填料可有效地抑制PTFE的磨损.     

Al2O3纤维填充PTFE复合材料摩擦磨损性能分析

利用M-200型摩擦磨损试验机考察了填料含量及载荷对粉状Al2O3纤维填充PTFE复合材料摩擦磨损性能的影响，采用扫描电子显微镜观察分析磨损表面形貌及磨损机理。结果表明：Al2O3纤维填料可提高PTFE的硬度，从而可提高PTFE的耐磨性，但复合材料中Al2O3含量较高时会导致磨粒磨损，且AL2O3含量越高相应的磨粒磨损越严重。在本试验条件下，当Al2O3的质量分数为20%左右时，PTFE复合材料的耐磨性最佳；PTFE复合材料同钢对磨时的摩擦系数比纯PTFE大，且随Al2O3含量的增加而增大。     

纳米Fe3O4填充聚四氟乙烯摩擦磨损性能的研究.doc

利用机械共混、冷压成型和烧结工艺制备不同含量的磁性纳米Fe3O4填充聚四氟乙烯(PTFE)复合密封材料,采用MM 200型摩擦磨损试验机考察其在干摩擦下与45#钢对磨时的摩擦磨损性能,借助扫描电子显微镜（SEM）对磨损表面形貌进行观察并分析磨损机制。结果表明：随磁性纳米Fe3O4含量的增加,复合材料的硬度显著提高,摩擦因数呈现先增大后减小再增大的变化趋势,耐磨性能得到明显改善;当Fe3O4质量分数为15%时,复合密封材料的摩擦因数较小,体积磨损率与纯PTFE相比降低两个数量级;随着Fe3O4含量的增加,磨损机制由纯PTFE的黏着磨损转变为黏着磨损与磨粒磨损共同作用。     

纳米Fe_3O_4磁性材料填充聚四氟乙烯的摩擦磨损性能

利用机械共混、冷压成型和烧结工艺制备不同含量的磁性纳米Fe3O4填充聚四氟乙烯(PTFE)复合密封材料,采用MM-200型摩擦磨损试验机考察其在干摩擦下与45#钢对磨时的摩擦磨损性能,借助扫描电子显微镜(SEM)对磨损表面形貌进行观察并分析磨损机制。结果表明:随磁性纳米Fe3O4含量的增加,复合材料的硬度显著提高,摩擦因数呈现先增大后减小再增大的变化趋势,耐磨性能得到明显改善;当Fe3O4质量分数为15%时,复合密封材料的摩擦因数较小,体积磨损率与纯PTFE相比降低两个数量级;随着Fe3O4含量的增加,磨损机制由纯PTFE的黏着磨损转变为黏着磨损与磨粒磨损共同作用。     

碳黑填充PTFE复合材料干摩擦磨损性能分析

以碳黑为填料制备了PTFE基复合材料,并研究了该复合材料在干摩擦条件下与不锈钢对摩时的摩擦磨损行为,并探讨其磨损机制。实验结果表明,碳黑/PTFE复合材料的摩擦因数随着碳黑含量的增加呈增加的趋势,其耐磨性能明显优于纯PTFE。当碳黑的质量分数为5%时,其抗磨性能最好。SEM观察发现纯PTFE的断面上分布着大量的带状结构,而填充了碳黑后,则未观察到这种带状结构,这说明碳黑有效地抑制了PTFE结构的破坏。对PTFE和碳黑/PTFE复合材料的摩擦表面的SEM观察发现,前者的摩擦表面分布着较明显的犁削和粘着磨损的痕迹,而后者的摩擦表面则平整光滑,这表明以碳黑作为填料可有效地抑制PTFE的磨损。     

硬碳填充PTFE复合材料摩擦磨损性能研究

以硬碳为填料制备了PTFE基复合材料,并研究了该复合材料在干摩擦条件下与不锈钢对摩时的摩擦磨损行为,并探讨其磨损机制.实验结果表明:硬碳能提高FIFE硬度,硬碳/PTFE复合材料的耐磨性能明显优于纯PTFE.其摩擦因数随着硬碳含量的增加而减小.复合材料的摩擦表面SEM观察发现:纯PTFE摩擦表面分布着较明显的犁削和粘着磨损的痕迹,硬碳/PTFE的磨痕较浅,表明硬碳作为填料可有效地抑制FTFE的磨损.     

低含量磷片石墨填充改性PTFE复合材料的摩擦磨损性能

为了改善聚四氟乙烯高磨耗的缺点,通过冷压烧结成型工艺制备4种低含量鳞片石墨填充改性聚四氟乙烯(PTFE)复合材料,探究其在较高载荷(0.8 MPa)及不同转速下的摩擦磨损情况。采用三维视频显微镜观察样品的表面磨痕深度,借助扫描电镜观察摩擦表面形貌并分析磨损机制。结果表明:在较高载荷下石墨填充PTFE复合材料的摩擦因数和体积磨损率都较纯PTFE有一定程度的降低;且当石墨填充质量分数为5%时,复合材料的摩擦因数和体积磨损率降到最低,在载荷为0.8 MPa、转速为80 r/min时较纯PTFE分别降低了19.7%和84.25%;在较高载荷下,随着石墨含量的增大,复合材料的磨损机制逐渐由犁耕磨损向黏着磨损转变,且当石墨质量分数为10%时,出现轻微的疲劳磨损。     

有机填料填充聚四氟乙烯复合材料摩擦学及力学性能

采用共混-冷压-烧结-整形的工艺制备有机物填充聚四氟乙烯(PTFE)复合材料,考察相同含量的不同有机填料对PTFE复合材料力学性能和摩擦学性能的影响。结果发现,加入有机填料后,复合材料的拉伸强度降低,但硬度和压缩强度均提高;有机填料有效地改善了PTFE复合材料的摩擦学性能,其中,质量分数15%聚苯酯填充的PTFE复合材料减摩效果最好,质量分数15%聚酰亚胺填充的PTFE复合材料的耐磨损性能最优。相比之下,质量分数15%芳纶填充的PTFE复合材料摩擦磨损性能及力学性能最好,其耐磨损性能较纯PTFE提高了近400倍,而摩擦因数仅为纯PTFE的84%。其原因在于芳纶的加入有效地改变了摩擦机制,能形成均匀连续的转移膜,进而降低了磨损。     

Ekonol/石墨/MoS2填料对PTFE力学和摩擦磨损性能的影响

研究了Ekonol含量对Ekonol／石墨／MoS2／P，PTFE复合材料的力学性能、摩擦磨损性能的影响，以及滑动速度、载荷对材料摩擦磨损性能的影响；用扫描电子显微镜观察了复合材料磨损后的表面形貌，并探讨了其磨损机制。结果表明：加入填料降低了材料的拉伸强度和弯曲强度，但提高了弯曲模量和硬度；同时填料能提高材料的磨损性能，但使摩擦因数升高了；当Ekonol含量较低时，磨损机制为粘着磨损，随着填料含量的增加，Ekonol分散到基体中，起到了承载作用，阻止了PTFE基体的带状破坏，磨损机制为疲劳磨损和轻微的粘着磨损；摩擦因数随载荷的增大而减小，随滑动速度的增大而增大，在相同的滑动时间内，磨痕宽度随载荷和滑动速度的增大而增大。     

纳米粒子和聚四氟乙烯填充UHMWPE复合材料的摩擦磨损性能研究

以纳米氧化锌(ZnO)和纳米蒙脱土(MMT)及聚四氟乙烯(PTFE)作为复合填料,通过热压成型工艺制备了纳米ZnO-MMT及PTFE填充超高分子量聚乙烯(UHMWPE)复合材料,采用销-盘式摩擦磨损试验机考察了纳米粒子对复合材料摩擦磨损性能的影响,用扫描电子显微镜观察了复合材料磨损表面形貌。结果表明当PTFE和MMT的填充量均保持为质量分数6%,填充纳米ZnO质量分数为4%~6%时的复合材料可获得较好的摩擦磨损性能,与不含纳米ZnO的复合材料相比,其摩擦因数最低下降了11.1%,而磨损率下降了83.3%。当复合填料中纳米ZnO含量较低时,复合材料的磨损机制主要表现为不同程度的粘着磨损,但当复合填料中纳米ZnO含量较高时,复合材料的磨损机制主要表现不同程度的粘着磨损和磨粒磨损,同时其复合材料的摩擦磨损性能出现了恶化现象。     

Tribological Behavior of Carbon-Nanotube-Filled PTFE Composites

Carbon nanotube/polytetrafluoroethylene (CNT/PTFE) composites with different volume fractions were prepared and their friction and wear properties were investigated using a ring-on-block under dry conditions. It was found that CNTs signifi-cantly increased the wear resistance of PTFE composites and decreased their coefficient of friction. PTFE composites with 15–20 vol.% CNTs exhibited very high wear resistance. The significant improvements in the tribological properties of CNT/PTFE composites are attributed to the super-strong mechanical properties and the very high aspect ratio of CNTs. The CNTs greatly reinforce the structure of the PTFE-based composites and thereby greatly reduce the adhesive and plough wear of CNT/PTFE composites. The CNTs are released from the composite during sliding and transferred to the interface of the friction couples. They thus serve as spacers, preventing direct contact between the mating surfaces and thereby reducing both wear rate and friction coefficient.     

Friction and wear properties of metal powder filled PTFE composites under oil lubricated conditions

Four kinds of polytetrafluoroethylene (PTFE)-based composite, pure PTFE, PTFE+30vol.%Cu, PTFE+30vol.%Pb and PTFE+30vol.%Ni composite, were prepared. The friction and wear properties of these metal powder filled PTFE composites sliding against GCr15 bearing steel under both dry and lubricated conditions were studied using an MHK-500 ring-block wear tester. The worn surfaces of the PTFE composites and the transfer films formed on the surface of GCr15 bearing steel were examined using scanning electron microscopy (SEM) and optical microscopy respectively. Experimental results show that the friction and wear properties of the PTFE composites can be greatly improved by liquid paraffin lubrication. The wear of these PTFE composites can be decreased by at least 1 to 2 orders of magnitude compared with that under dry friction conditions, while the friction coefficients can be decreased by 1 order of magnitude, SEM and optical microscopy investigations of the rubbing surfaces show that metal fillers of Cu, Pb and Ni not only raise the load carrying capacity of the PTFE composites, but also promote transfer of the PTFE composites onto the counterfaces, so they greatly reduce the wear of the PTFE composites. However, the transfer of these PTFE composites onto the counterfaces can be greatly reduced by liquid paraffin lubrication, but transfer still takes place.     

Friction and wear characteristics of lead and its compounds filled polytetrafluoroethylene composites under oil lubricated conditions

The friction and wear properties of Pb, PbO, Pb₃O₄, or PbS filled polytetrafluoroethylene (PTFE) composites sliding against GCr15 bearing steel under both dry and liquid paraffin lubricated conditions were studied by using an MHK-500 ring-block wear tester. The worn surfaces and the transfer films of these PTFE composites formed on the surface of GCr15 bearing steel were then investigated by using a scanning electron microscope (SEM) and an optical microscope, respectively. Experimental results show that filling Pb, PbO, Pb₃O₄ or PbS to PTFE can greatly reduce the wear of the PTFE composites, but the wear reducing action of Pb₃O₄ is the most effective. Meanwhile, PbS increases the friction coefficient of the PTFE composite, but Pb and Pb₃O₄ reduce the friction coefficients of the PTFE composites. However, the friction and wear properties of lead or its compounds filled PTFE composites can be greatly improved by lubrication with liquid paraffin, and the friction coefficients of the PTFE composites can be decreased by one order of magnitude. Optical microscope investigation of transfer films shows that Pb, PbO, Pb₃O₄ and PbS enhance the adhesion of the transfer films to the surface of GCr15 bearing steel, so they greatly reduce the wear of the PTFE composites. However, the transfer of the PTFE composites onto the surface of GCr15 bearing steel can be greatly reduced by lubrication with liquid paraffin, but the transfer still takes place. SEM examination of worn surfaces shows that the interaction between liquid paraffin and the PTFE composites creates some cracks on the worn surfaces of the PTFE composites; the creation and development of the cracks reduces the load-carrying capacity of the PTFE composites, and this leads to deterioration of the friction and wear properties of the PTFE composites filled with lead or its compounds under higher loads in liquid paraffin lubrication.     

MoS2、CdO及聚全氟乙丙烯填充改性聚四氟乙烯复合材料的摩擦磨损性能

用机械共混、冷压成型自由烧结的方法制备了MoS2、CdO和聚全氟乙丙烯填充聚四氟乙烯复合材料;用MM-2000型摩擦磨损试验机测试了在干摩擦条件下该复合材料的摩擦磨损性能;用扫描电镜(SEM)对磨损试样的表面形貌进行观察和分析.结果表明:未添加聚全氟乙丙烯的复合材料其摩擦磨损性能比添加的好;当CdO的体积分数为22.5%,MoS2的体积分数为7.5%时,复合材料的摩擦因数最小,抗磨性强,复合材料的摩擦磨损性能最佳.     

填料对聚四氟乙烯工程塑料改性的影响

研究了MoS2、PbS、石墨、玻璃纤维、碳纤维等填料对聚四氟乙烯（PTFE）工程塑料抗磨损、摩察系数、表面硬度、耐冲击强度等性能的影响。结果表明：填料可将PTFE的磨损量降低2个数量级，石墨和适量硬质填料的协同作用对PTFE的改性效果比较理想，既降低了PTFE的磨损量，增大了表面硬度，又提高了耐冲击强度。对其作用机理进行了分析和探讨，为材料的性能优化提供理论依据。     

表面改性硅灰石纤维填充PTFE复合材料的摩擦学性能

用KH550硅烷偶联剂表面改性的硅灰石纤维(WF)填充PTFE,在MPX-2000型磨损试验机上研究复合材料的摩擦磨损性能,并与经典的炭纤维(CF)填充PTFE复合材料进行比较。采用SEM对磨损面和对偶面进行分析。结果表明:较高载荷(200和300 N)下复合材料摩擦因数随WF含量变化的幅度不大,较稳定地维持在较低值;细小尺寸WF填充PTFE复合材料的耐磨性能较好,在WF质量分数为10%时,复合材料的磨损量只有相同含量CF填充PT-FE复合材料的81%;细小尺寸WF填充PTFE复合材料的磨损面较为平整,存在轻微黏着磨损,其对偶面转移膜平整光滑、结构致密;而CF/PTFE复合材料磨损面存在许多裸露和碎断的CF,犁削和磨粒磨损是主要的磨损形式。     

聚四氟乙烯及其石墨和MoS2填充复合材料的摩擦学性能研究

利用往复式摩擦磨损实验机,对聚四氟乙烯(PTFE)及石墨和MoS2填充的PTFE复合材料的摩擦磨损性能进行了实验,考察了载荷、速度以及对摩时间的影响,并利用光学显微镜对PTFE复合材料的摩擦磨损表面进行了观察。结果表明,填加了石墨和MoS2的PTFE,由于石墨和MoS2一方面起到了润滑作用,另一方面阻止了PTFE带状大面积破坏,因而使得PTFE的摩擦因数降低,耐磨性提高。加入石墨和MoS2后PTFE的磨损机制由以犁沟效应和粘着磨损为主变为以磨粒磨损为主。     

Tribological Properties of PTFE and PTFE Composites at Different Temperatures

The friction and wear properties of polytetrafluoroethylene (PTFE) and its composites with fillers such as bronze, glass fiber, carbon fiber, carbon, graphite, and polymer were studied at ambient temperature and high temperature. The wear resistance and hardness were enhanced by the fillers. Results showed that the wear resistance of all composites was much higher than that of pure PTFE. Pure PTFE has the lowest friction coefficient at ambient temperature (temperature: 23 ± 2°C, humidity: 50 ± 10%) but highest friction coefficient at high temperature (above 100°C). The PTFE composite filled with bronze showed the best wear resistance at ambient temperature but the poorest wear resistance at high temperature. The carbon-graphite- or polymer-filled PTFE composite showed a lower friction coefficient and moderate wear resistance at both ambient and high temperature.     

Tribological behaviour of PTFE modified cotton polyester composites

Abstract

An attempt on modification of tribological behaviour of cotton polyester composite was done with polytetrafluoroethylene (PTFE). PTFE modified polyester–cotton composites were developed and studied for their friction and sliding wear behaviour at different applied loads. The sliding wear tests of composites were conducted against EN-31 steel counter face. The coefficient of friction μ as well as the sliding wear rate of cotton–polyester composites reduced significantly on addition of PTFE. The reduction in wear rate of PTFE modified polyester–cotton composite has been discussed with the help of SEM observations of worn surfaces and coefficient of friction.