润滑油添加剂对聚合物及其复事材料磨擦磨损性能的影响

利用ＭＨＫ－５００型环－块磨损试验机研究了二烷基二硫代磷酸锌（ＺＤＤＰ）对几种聚合物及其复材料－金属摩擦副油润滑摩擦磨损性能的影响。结果表明，液体石蜡中的ＺＤＤＰ对尼龙６６（ＰＡ６６）及聚酰亚胺（ＰＩ）－ＧＣｒ１５轴承钢摩擦副的摩擦系数影响不大，但却使聚四氟乙烯（ＰＴＦＥ）及其复合材料－ＧＣｒ１５轴承钢摩擦副的摩擦系数略有限低。ＰＴＦＥ及其复合材料－ＧＣｒ１５轴承钢摩擦副表面的ＺＤＤＰ吸附膜具有一     

铜层厚度和石墨粒度对铜包石墨-PTFE复合材料摩擦学性能的影响

作者采用化学还原法制备了铜包石墨（ＣＣＧ）粉，考察了石墨粒度和铜层厚度对铜包石墨－聚四氟乙稀复 合材料摩擦学性能的影响。摩擦学研究表明：随着填料粒度的增大，ＰＴＦＥ复合材料的摩擦系数逐渐降低，当填料平均 粒度为６６μｍ时，复合材料具有最佳的抗磨性；随着石墨表面铜镀层厚度的增加，ＣＣＧ－ＰＴＦＥ的摩擦系数逐渐升高，当 厚度超过３μｍ后，逐渐趋于稳定，材料的磨损率则随镀层厚度呈线性降低的趋势。研究还发现，铜包石墨改变了石墨 与ＰＴＦＥ的界面结合方式，且铜包石墨颗粒表面铜层在摩擦过程中易被磨掉，内部石墨颗粒暴露在摩擦表面，改善了 ＰＴＦＥ复合材料的摩擦性能；还原铜的硬度适中、颗粒细致，在摩擦过程中易在对偶表面的凹处嵌合，有助于连续、均 匀的转移膜的形成，从而提高了材料的耐磨性能。     

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。     

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。     

纳米金属粉填充Ekonol/PTFE复合材料的摩擦磨损性能研究

评价了分别用不同体积含量的纳米镍粉和纳米铜粉填充聚苯酯/聚四氟乙烯(Ekonol/PTFE)复合材料体系的力学性能,利用M-200型磨损试验机研究了纳米Ni、纳米Cu含量对Ekonol/PTFE复合材料摩擦学性能的影响,借助扫描电子显微镜和能谱分析手段考察试样磨损表面和磨屑,并探讨其摩擦磨损机制。结果表明,纳米Ni能在一定范围内增加Ekonol/PTFE复合材料的冲击强度;纳米金属粉填入量较小时均能增加复合材料的洛氏硬度。纳米Ni与纳米Cu均能增加Ekonol/PTFE复合材料的摩擦因数并降低磨损率。其原因在于纳米金属粉在复合材料摩擦表面富集,通过金属分子间的吸引作用,增大复合材料的摩擦因数。     

复合材料PZT—PVDF和PT—P（VDF／TeFE）的压电性

本文报道了两种压电陶瓷—聚合物复合材料ＰＺＴ－ＰＶＤＦ和ＰＴ—Ｐ（ＶＤＦ／ＴｅＦＥ）的制备工艺，利用ＸＲＤ、ＳＥＭ和ＤＳＣ分析了压电复合材料的结构、形貌与相变，用ＬＣＲ法和Ｂｅｒｌｉｎｃｏｕｒｔ法测试了压电复合材料的介电性和压电性，最后讨论了压电复合材料的应用。     

纳米HA增强PVA-H复合材料的摩擦学性能研究

利用四球试验机考察了纳米羟基磷灰石（HA）粉体增强PVA-H人工软骨材料与不锈钢球进行对磨时的摩擦磨损性能，采用扫描电子显微镜（SEM）观察并分析了磨损表面的微观形貌。试验结果表明：加入适量的纳米HA（质量分数1％）能有效地降低复合材料的摩擦因数，但更多的添加量反而增加复合材料的摩擦冈数；SEM图像表明，纯PVA-H的表面有较严重的磨损痕迹和磨屑，而HA粒子的加入可以降低复合材料表面的磨损情况。     

纳米晶粉末制备复合材料的摩擦磨损性能

本文研究了用机械合金化方法制备出Ｓｉ３Ｎ４／Ｆｅ基纳米晶复合粉末，用常规粉末冶金工艺烧结出试样，测试了复合材料的常温摩擦磨损性能，并对其显微组织进行了分析，认为纳米晶的界面确实机改善Ｓｉ３Ｎ４与Ｆｅ的结合强度。     

纳米ZrO2改性热塑性聚酰亚胺复合材料的摩擦磨损性能

采用热模压工艺制备了纳米ZrO2改性热塑性聚酰亚胺(PI)纳米复合材料,考察了复合材料的力学性能、在干摩擦和油润滑条件下的摩擦磨损性能,并利用扫描电子显微镜观察了冲击断面和磨损表面形貌.结果表明:纳米ZrO2在低含量下对PI复合材料的力学性能影响不大,随着其含量的增大,材料的弯曲性能下降,刚性增大.在干摩擦条件下,较低的纳米颗粒含量有助于转移膜的形成,从而降低材料的摩擦因数及磨损率.纳米ZrO2体积分数为1%时,材料的摩擦磨损性能较纯PI分别下降了50%和15%;在油润滑条件下,润滑油的流动性有助于纳米颗粒分布到整个摩擦界面,PI复合材料的摩擦因数及磨损率有明显降低,此时磨损机制以疲劳磨损为主.     

Friction and Wear of Hybrid PTFE/Kevlar Fabric Composite Filled with ZnO Nanoparticles Sliding against Steel,Copper, and Aluminum

ZnO nanoparticles were incorporated into phenolic resin and the effect of the ZnO content on tribological properties of hybrid polytetrafluoroethylene (PTFE)/Kevlar fabric/phenolic composite was investigated. Fabric composite filled with 5 wt.% ZnO nanoparticles sliding against steel, copper, or aluminum was investigated in detail. Friction and wear tests showed that fabric composite/steel exhibited lower friction coefficient and wear rate with varied loads and speeds. It is believed that the coherent transfer film and tribochemical reactions involved in fabric composite/steel contributed to the reduced friction coefficient and wear rate of the fabric composite.     

The friction and wear properties of nanometre SiO2 filled polyetheretherketone

Nanometre SiO₂ filled-polyetheretherketone (PEEK) composite blocks with different filler proportions were prepared by compression moulding. Their friction and wear properties were investigated on a block-on-ring machine by running a plain carbon steel (AISI 1045 steel) ring against the composite block. The morphologies of the wear traces and the transfer film were observed by scanning electron microscopy (SEM). It was found that nanometre SiO₂ filled-PEEK exhibited considerably lower friction coefficient and wear rate in comparison with pure PEEK. The lowest wear rate was obtained with the composite containing 7.5 wt.% SiO₂. The SEM pictures of the wear traces indicated that with the frictional couple of carbon steel ring/composite block (fillec with 7.5 wt.% filler), a thin, uniform, and tenacious transfer film was formed on the ring surface. It was inferred that the transfer film contributed largely to the decreased friction coefficient and wear rate of the filled PEEK composites.     

Reduction in wear of metakaolinite-based geopolymer composite through filling of PTFE

Metakaolinite-based geopolymer composite containing 5-30% (volume fraction) polytetra-fluoroethylene (PTFE) was synthesized using compound activator composed of aqueous NaOH and sodium silicate at room temperature. Flexural strength, compressive strength and elastic modulus of the composite were measured. Tribological behaviour of the composite sliding against AISI-1045 steel was investigated on an MM-200 friction and wear tester. SEM, EDS and XPS analysis were conducted on worn surfaces and wear debris. The results show that mechanical strength of the composite was lower than corresponding geopolymer while the wear model became mild. The friction process was stable and the wear rate was dramatically reducted by 86-99.4%. The improvement of tribological properties of the composite was attributed to form a brown soft thin layer on the worn surface of the composite containing Fe₂O₃ came from tribochemical reaction. EDS analysis on the worn surfaces indicate the content of Fe increase along with the increase of volume content of PTFE in the composite. Furthermore, the counterpart, the steel ring was also protected from terrible wear as occurred when friction with geopolymer without any filling of solid lubricant. There is a brown thin layer mainly composed of Fe₂O₃ on the steel ring.     

Wear-Resistant PTFE/SiO2 Nanoparticle Composite Films

Polytetrafluoroethylene (PTFE) is a polymer that is well known for its exceptional tribological properties and, as such, it is commonly used to reduce the coefficient of friction between surfaces. In recent years it has also been established that by incorporating nanoparticle fillers in PTFE, it is possible to extend the polymer's life by reducing its wear rate. Although much study has been placed on bulk PTFE, very little study has been focused on thin films. This article demonstrates that SiO ₂ nanoparticles can be used as a filler to significantly reduce the wear of PTFE thin films while also maintaining a low coefficient of friction. The wear resistance and coefficient of friction of PTFE/SiO ₂ composite films on stainless steel substrates were tested using a linear reciprocating tribometer and compared to pure PTFE films and bare stainless steel to evaluate the benefit of incorporating the SiO ₂ filler in the film. The composite films showed a significant improvement in wear resistance when compared to pure PTFE films. The coefficient of friction for the composite film remained low and stable during a 50 g normal load friction test for a duration of approximately 300 cycles, whereas that of PTFE showed an increasing trend at onset. In addition, of 1.7 and 3.3 wt% SiO ₂ concentrations in solution, 3.3 wt% SiO ₂ showed better performance, with a much higher wear resistance than that of 1.7% SiO ₂ after being subjected to a 1,000-cycle abrasive wear test.     

多因素影响的格莱圈材料摩擦磨损试验研究*

格莱圈由聚四氟乙烯(PTFE)矩形滑环和丁腈橡胶(NBR)O形圈组成。为了研究不同因素对于格莱圈密封材料摩擦磨损性能的影响,利用UMT-3多功能摩擦磨损试验机,通过改变往复频率、粗糙度、润滑状态研究格莱圈材料与45钢配副时的摩擦磨损性能,利用SEM对试块试验前后表面形貌进行观测,并对摩擦磨损机制进行分析。试验结果表明:在干摩擦和滴油润滑条件下PTFE材料相比NBR材料具有更为优异的摩擦磨损性能;NBR材料表面粗糙度过高或过低都会导致摩擦因数升高,表面粗糙度对具有自润滑性能的PTFE材料的摩擦因数影响不大;高往复频率会使NBR材料摩擦因数降低,过高或过低的往复频率都会使PTFE材料摩擦因数降低;NBR材料的磨损形式以磨粒磨损和黏着磨损为主,PTFE材料以黏着磨损和疲劳磨损为主。     

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.     

A study on friction and wear characteristics of nanometer Al2O3 /PEEK composites under the dry sliding condition

The friction and wear properties of the polyetheretherketone (PEEK) based composites filled with 5 mass% nanometer or micron Al₂O₃ with or without 10 mass% polytetrafluroethylene (PTFE) against the medium carbon steel (AISI 1045 steel) ring under the dry sliding condition at Amsler wear tester were examined. A constant sliding velocity of 0.42 m s⁻¹ and a load of 196 N were used in all experiments. The average diameter 250 μm PEEK powders, the 15 or 90 nm Al₂O₃ nano-particles or 500 nm Al₂O₃ particles and/or the PTFE fine powders of diameter 50 μm were mechanically mixed in alcohol, and then the block composite specimens were prepared by the heat compression moulding. The homogeneously dispersion of the Al₂O₃ nano-particles in PEEK matrix of the prepared composites was analyzed by the atomic force microscopy (AFM). The wear testing results showed that nanometer and micron Al₂O₃ reduced the wear coefficient of PEEK composites without PTFE effectively, but not reduced the friction coefficient. The filling of 10 mass% PTFE into pure PEEK resulted in a decrease of the friction coefficient and the wear coefficient of the filled composite simultaneously. However, when 10 mass% PTFE was filled into Al₂O₃/ PEEK composites, the friction coefficient was decreased and the wear coefficient increased. The worn scars on the tested composite specimen surfaces and steel ring surfaces were observed by scanning electron microscopy (SEM). A thin, uniform, and tenacious transferred film on the surface of the steel rings against the PEEK composites filled with 5 mass% 15 nm Al₂O₃ particles but without PTFE was formed. The components of the transferred films were detected by energy dispersive spectrometry (EDS). The results indicated that the nanometer Al₂O₃ as the filler, together with PEEK matrix, transferred to the counterpart ring surface during the sliding friction and wear. Therefore, the ability of Al₂O₃ to improve the wear resistant behaviors is closely related to the ability to improve the characteristics of the transfer film.     

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.     

Tribology of selectively irradiated PTFE surfaces

Selectively irradiated polytetrafluoroethylene (PTFE) surfaces combining the low friction and non-abrasive attributes of an unirradiated polymer with the enhanced wear resistance of wholly irradiated PTFE are demonstrated. Augmented wear resistance, similar to that of filled PTFE composites, is obtained without the accompanying counterface abrasion typical of hard particulate fillers. Friction of these ‘composite’ irradiated/unirradiated surfaces can be less than that of unirradiated PTFE, as irradiated regions limit transfer morphology to only thin oriented films. Spatially distributed irradiated and unirradiated surface regions are patterned by masking 225 keV incident electrons. Under the given contact conditions (6.5 MPa nominal pressure against polished stainless steel) such self-lubricating, wear-resistant composite surfaces had lifetimes of several kilometers sliding distance before giving way to rapid wear of the underlying unmodified PTFE. This revised version was published online in June 2006 with corrections to the Cover Date.