水润滑下偶件表面粗糙度对PTFE复合材料摩擦学性能的影响

通过水润滑下的摩擦磨损实验,研究了偶件表面粗糙度对MoS2/PTFE复合材料摩擦学性能的影响,分析了在不同的偶件表面粗糙度下的摩擦学行为.实验结果表明:在水润滑下,一般存在着一个较佳的偶件表面粗糙度范围,在这个范围内可以取得较低的摩擦因数和磨损率;当偶件表面粗糙度高于这个范围时,摩擦磨损机制主要是机械作用;而当偶件表面粗糙度低于这个范围时,则主要是由于分子作用导致摩擦磨损.即当偶件表面粗糙度超出某一范围时,摩擦磨损行为将发生转变.     

凹凸棒土改性聚酰亚胺复合材料的摩擦磨损性能

采用原位聚合法制备凹凸棒土/聚酰亚胺纳米复合材料,考察纳米复合材料的力学性能及在干摩擦、水润滑和油润滑3种情况下的摩擦磨损性能,并利用扫描电子显微镜观察磨损表面形貌。结果表明:凹凸棒土质量分数为3%时,复合材料的拉伸强度最好,随着纳米颗粒含量的增加,复合材料的拉伸强度、断裂伸长率明显下降,而弹性模量一直呈现上升趋势;在干摩擦条件下,低含量的纳米颗粒有助于转移膜的形成,可以有效改善材料的摩擦性能;在水润滑下,由于水的溶胀和冷却作用,摩擦因数较干摩擦降低了一个数量级;在油润滑下,润滑油的流动性有助于纳米颗粒分布到整个摩擦表面,材料的摩擦因数及磨损率有明显降低,相比于干摩擦和水润滑的磨粒磨损,此时磨损机制以疲劳磨损为主。     

石墨填充聚四氟乙烯基复合材料的摩擦学性能

为了研制PTFE基粘弹-摩擦型阻尼材料,采用机械共混-冷压成型-烧结的工艺制备了石墨、聚苯硫醚、聚醚醚酮混合填充PTFE基复合材料,利用环-块式磨损试验机,在干摩擦条件下考察了复合材料的摩擦学性能,并用扫描电镜观察了磨损表面形貌,研究了复合材料的磨损机制。结果表明:PTFE含量不同的复合材料,随石墨填充量的增大,摩擦因数和磨损率的变化趋势不同,磨损主要由犁削、粘着和疲劳剥落中的一种或几种引起;适当配比的PTFE基复合材料具有较好的摩擦阻尼性能,能够满足粘弹-摩擦阻尼材料的要求。     

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。     

添加聚四氟乙烯微粉后聚醚醚酮复合材料的摩擦学性能

采用常温机械共混+高温模压方法制备了添加不同含量聚四氟乙烯(PTFE)微粉聚醚醚酮复合材料,研究了其力学性能、摩擦磨损性能及磨损形貌,并探讨了其摩擦磨损机理。结果表明:随PTFE微粉含量的增加,复合材料的洛氏硬度和压缩强度均降低,干摩擦条件下的摩擦因数减小,体积磨损量先降后升,当PTFE微粉质量分数5%时,体积磨损量最低;在油润滑和水润滑条件下复合材料的摩擦因数和体积磨损量均小于干摩擦条件下的,且随PTFE微粉含量的增加,油润滑条件下的体积磨损量下降,而水润滑条件下的增大;在干摩擦条件下复合材料的磨损机制以磨粒磨损为主,并伴有疲劳磨损,在油润滑条件下复合材料表面存在少量片状PTFE磨屑和碳纤维富集,在水润滑条件下复合材料表面被PTFE微片层覆盖,局部存在微裂纹和孔洞。     

纳米锌填充超高分子量聚乙烯复合材料微动摩擦磨损性能

利用热压烧结法制备不同含量纳米锌填充超高分子量聚乙烯(UHMWPE)复合材料,采用微动摩擦磨损试验机研究干摩擦条件下纳米锌含量对复合材料微动摩擦磨损性能的影响。利用场发射扫描电子显微对复合材料断面进行分析,采用扫描电子显微镜对材料磨损表面及钢球进行表征,探讨复合材料的磨损机制。研究结果表明:随着纳米Zn含量的增加,复合材料的摩擦因数和磨损率均表现为先降低后升高;当纳米Zn质量分数为1%时复合材料具有最低的摩擦因数和磨损率,且对偶钢球表面形成连续的转移膜;复合材料的磨损机制主要为黏着磨损和磨粒磨损。添加锌纳米颗粒,可以提高UHMWPE复合材料的微动摩擦磨损性能,当纳米锌质量分数为1%时,复合材料具有最低的摩擦因数和最优的耐磨损性能。     

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。     

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。     

碳纤维增强杂萘联苯聚醚砜酮复合材料的摩擦学性能研究

利用MRH-03型环-块摩擦磨损试验机研究不同碳纤维含量的聚醚砜酮(PPESK)基复合材料的摩擦磨损性能,讨论载荷、速度及润滑介质对质量分数10%碳纤维增强复合材料摩擦磨损性能的影响,并用SEM观察材料的断面形貌和磨损表面形貌。结果表明：适量碳纤维的加入可以明显提高材料的摩擦磨损性能,并使得复合材料干摩擦条件下的磨损机制由严重的磨粒磨损和黏着磨损转变为黏着磨损和轻微的磨粒磨损。以质量分数10%碳纤维增强的复合材料为例,随着载荷的增加复合材料在干摩擦条件下的摩擦因数降低,而磨损率先降低后增加,在高滑动速度下复合材料的摩擦因数降低而磨损率增加;而海水润滑介质的加入大大降低了材料的摩擦因数和磨损率,并使得复合材料的磨损机制由干摩擦条件下的黏着磨损和轻微的磨粒磨损转变为轻微的磨粒磨损。     

碳纤维增强杂萘联苯聚醚砜酮复合材料的摩擦学性能

利用MRH-03型环-块摩擦磨损试验机研究不同碳纤维含量的聚醚砜酮(PPESK)基复合材料的摩擦磨损性能,讨论载荷、速度及润滑介质对质量分数10%碳纤维增强复合材料摩擦磨损性能的影响,并用SEM观察材料的断面形貌和磨损表面形貌。结果表明:适量碳纤维的加入可以明显提高材料的摩擦磨损性能,并使得复合材料干摩擦条件下的磨损机制由严重的磨粒磨损和黏着磨损转变为黏着磨损和轻微的磨粒磨损。以质量分数10%碳纤维增强的复合材料为例,随着载荷的增加复合材料在干摩擦条件下的摩擦因数降低,而磨损率先降低后增加,在高滑动速度下复合材料的摩擦因数降低而磨损率增加;而海水润滑介质的加入大大降低了材料的摩擦因数和磨损率,并使得复合材料的磨损机制由干摩擦条件下的黏着磨损和轻微的磨粒磨损转变为轻微的磨粒磨损。     

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.     

PTFE复合材料的摩擦磨损性能研究

用机械共混、冷压成型烧结的方法制备了纳米SiO2/石墨/玻璃纤维/PTFE复合材料试样。用MM-200型磨损试验机测试了在干摩擦条件下不同载荷时各试样的摩擦磨损性能;用扫描电镜对磨损后试件表面进行观察和分析。研究结果表明：纳米SiO2和玻璃纤维有效提高了PTFE的承载能力,石墨的加入起到了减小摩擦的作用;在本试验条件下,在摩擦过程中三元混合填充PTFE复合材料在偶件表面形成了转移膜,减少了复合材料与偶件的直接接触,因而表现出优异的抗磨性。     

Tribological Behavior of Micrometer- and Submicrometer-Size Cenosphere Particulate-Filled Glass Fiber–Reinforced Vinylester Composites Under Dry and Water-Lubricated Sliding Conditions

In this work, the tribological behavior of micrometer and submicrometer cenosphere particulate–filled E-glass fiber–reinforced vinylester composites have been investigated on a pin-on-disc tester under dry sliding and water-lubricated sliding conditions. Three different uniform sizes of cenosphere particles (2 μm, 900 nm, 400 nm) were used as fillers in the glass fiber–reinforced vinylester composites. The weight fraction of cenosphere particles has been varied in the ranges from 5, 10, 15, to 20 wt%. The experimental results show that all of the composites exhibited lower coefficient of friction and lower wear resistance under water-lubricated sliding conditions than under dry sliding. It has been noted that the submicrometer size (400 nm) cenosphere particulates as fillers contributed significantly to improve the wear resistance. It has also been noted that 10 wt% of the cenosphere particles is the most effective in reducing the wear rate and coefficient of friction. Effects of various wear parameters such as applied normal loads, sliding speeds, particle size, and particle content on the tribological behavior were also discussed. In order to understand the wear mechanism, the morphologies of the worn surface were analyzed by means of scanning electron microscopy (SEM) for composite specimens under both dry and water-lubricated sliding conditions.     

Friction and wear properties of bronze–graphite composite under water lubrication

Bronze–graphite composite was prepared using powder metallurgy. The friction and wear behaviors of the resulting composites in dry- and water-lubricated sliding against a stainless steel were comparatively investigated on an MM-200 friction and wear tester in a ring-on-block contact configuration. The wear mechanisms of the bronze–graphite composite were discussed based on examination of the worn surface morphologies of both the composite block and the stainless steel ring by means of scanning electron microscopy equipped with an energy dispersion spectrometry and on determination of some typical elements on the worn surfaces by means of X-ray photoelectron spectroscopy. It was found that the friction coefficient was higher under water lubrication than that under dry sliding and it showed margined change with increasing load under the both sliding conditions. A considerably decreased wear rate of the bronze–graphite composite was registered under water-lubricated sliding than under dry sliding, though it rose significantly at a relatively higher load. This was attributed to the hindered transfer of the composite onto the counterpart steel surface under water-lubricated sliding and the cooling effect of the water as a lubricant, while its stronger transfer onto the steel surface accounted for its higher wear rate under dry sliding. Thus, the bronze–graphite composite with much better wear-resistance under water-lubricated sliding than under dry sliding against the stainless steel could be a potential candidate as the tribo-material in aqueous environment.     

聚苯酯填充聚四氟乙烯复合材料摩擦学行为研究

采用聚苯酯（Ekonol）、Ekonol／PAB纤维增强聚四氟乙烯（PTFE）制备利用转移膜润滑的摩擦副材料，并研究了两组材料在于摩擦条件下与9Cr18轴承钢对摩时的摩擦学性能；运用扫描电镜分析了两组材料磨损表面形貌和磨损机理。结果表明：随着Ekonol含量的增大，Ekonol填充PTFE复合材料的摩擦因数逐渐增大，当Ekonol质量分数超过25％时摩擦因数略有下降，磨损方式由以犁削磨损为主转变为以疲劳磨损为主；而Ekonol／PAB纤维填充门FE复合材料的摩擦因数，随Ekonol含量的增大而增大，磨损方式由以粘着磨损为主转变为以疲劳磨损为主。Ekonol／PAB纤维填充PTFE复合材料的摩擦学性能优于Ekonol填充PTFE复合材料。     

聚四氟乙烯复合材料的摩擦学二次转移行为研究

采用冷压成型、自由烧结工艺分别制备了青铜粉、聚酰亚胺、二硫化钼和石墨填充改性的聚四氟乙烯复合材料,在改装的M-2000型摩擦磨损试验机上考察了材料的二次转移摩擦学性能;用扫描电子显微镜对磨损表面进行观察和分析。结果表明:增加载荷有利于提高转移膜与基底的结合强度;填料种类对PTFE复合材料二次转移膜的摩擦学性能有影响,在本实验条件下(干摩擦、室温、滑动速度为0.42m/s、接触载荷为30N),以PTFE复合材料作为润滑剂提供源使用时,PTFE/MoS2、PTFE/Graphite复合材料形成的二次转移膜最好,PTFE/Bronze复合材料二次转移膜次之,PTFE/PI复合材料形成二次转移膜的能力最差。     

纳米ZnO填充的PTFE基复合材料摩擦学性能研究

得胜０００型摩擦磨损试验机研究了不同体积含量的纳米氧化锌（ＺｎＯ）填充的ＰＴＦＥ基复合材料在于摩擦条件下与不风对摩时的摩擦学性能,并利用扫描电子微镜（ＳＥＭ）对ＰＴＦＥ及纳米ＺｎＯ／ＰＴＦＥ复合材料的微观结构、磨损表面和转移膜进行了观察和分析。结果表明,纳米ＺｎＯ／ＰＴＦＥ复合材料的摩擦性能与纯ＰＴＦＥ基本相当,但耐磨性明显优于后者,纳米ＺｎＯ在复合材料中的最佳含量为１５ｖｏｌ．％左右。     

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.     

聚酰亚胺复合材料与不同金属间干滑动时的摩擦学性能

采用MPX-2000型摩擦磨损试验机研究了聚四氟乙烯和二硫化钼填充聚酰亚胺复合材料在干滑动摩擦条件下与45钢、镍铬合金、铜和铝对磨时的摩擦磨损性能,并利用扫描电子显微镜和光学显微镜分析了复合材料及对偶件的磨损表面形貌。结果表明:复合材料与铝对磨时的摩擦因数和磨损率最低,分别约为与钢摩擦时的43%和49%;摩擦后铝表面形成均匀连续的转移膜,45钢、镍铬合金和铜的表面没有形成有效转移膜,因此复合材料的摩擦因数较大;复合材料与不同金属材料摩擦时的磨损机理主要是粘着磨损与疲劳磨损。