聚苯硫醚复合材料摩擦性能的研究

考察了聚四氟乙烯（PTFE）、纳米无机粒子及不同含量和粒度的石墨填充改性聚苯硫醚（PPS）复合材料的摩擦磨损性能、力学性能；并采用扫描电镜（SEM）观测了磨损表面及对摩面的微观结构。结果表明：石墨的添加有利于在对摩面上形成转移物，而且随着石墨含量的增加，材料的摩擦系数明显降低，但磨耗量却有所升高，而石墨的粒度变化对材料的摩擦性能没有太大的影响；当PTFE和石墨两种固体润滑剂同时加入时，材料的力学强度有所降低，但其摩擦系数及磨耗量都得到明显改善，材料以疲劳磨损为主：纳米无机粒子的加入会使材料的磨耗量有所增大，其磨损机理转变为磨粒磨损。     

w(石墨)对NAO摩擦材料摩擦磨损性能的影响

采用热压固化方法制备了一种新型无石棉有机(Non-asbestos organic:NAO)摩擦材料,研究了w(石墨)对摩擦材料力学性能和摩擦磨损性能的影响。结果表明,随着w(石墨)的增加,材料密度逐渐降低;材料的冲击强度先增大后减小,当w(石墨)=4%时材料的冲击强度达到最大值4.15kJ/m~2。摩擦和磨损性能测试结果表明,w(石墨)对摩擦材料的低温摩擦系数影响较小,对高温摩擦系数影响较明显。当w(石墨)=4%时可以有效提高摩擦材料的高温摩擦系数和高温抗磨损性能,且w(石墨)越高,材料高温磨损率越低。     

芳纶浆粕对酚醛树脂基摩擦材料性能影响

以酚醛树脂为基体,使用高模量、高强度、吸附性好、热稳定性能优异的芳纶浆粕作为增强纤维,石墨、萤石、重晶石等作为填料,通过干法热压成型工艺制备酚醛树脂基摩擦材料。研究了芳纶浆粕含量对材料力学性能和摩擦磨损性能的影响。利用扫描电子显微镜观察磨损表面形貌,初步分析芳纶浆粕在摩擦材料中的作用机理。结果表明,芳纶浆粕可以使材料的冲击强度和硬度明显提高;当配方中芳纶浆粕含量较低时,材料的摩擦系数变化不大,随着含量进一步增加,材料的摩擦系数明显升高;适量的芳纶浆粕有助于形成致密均匀的摩擦层,进而提高材料的摩擦稳定性,同时降低磨损率。当配方中芳纶浆粕的质量分数为2%时,材料达到最佳的摩擦磨损性能。     

硅灰石与石墨对聚四氟乙烯摩擦磨损性能的影响

以针状的硅灰石和鳞片石墨为填料,采用冷压—烧结工艺制备了不同填料含量的聚四氟乙烯（PTFE）复合材料,考察了复合材料的摩擦磨损性能,并利用扫描电子显微镜对磨痕和转移膜进行了分析。结果表明,单独填充硅灰石和石墨时,PTFE的磨损率都会随填料含量的增加而降低,硅灰石的作用要强于石墨;但硅灰石会使PTFE的摩擦因数明显增大,而石墨会使PTFE的摩擦因数降低;2种填料提升PTFE耐磨性的作用机理不同,硅灰石在摩擦过程中会在滑动界面区域上逐渐堆积,起到优先承担载荷的作用;而石墨在摩擦过程中会发生片层的滑移与剥离,有助于转移膜的形成;适量的硅灰石（含量为20 %,质量分数,下同）与石墨（含量为5 %或10 %）复合填充能产生协同效应,使PTFE的磨损率进一步降低,耐磨性比未填充的PTFE提高200倍。     

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。     

氟醚橡胶摩擦磨损性能研究

研究了石墨、碳纤维和聚四氟乙烯不同用量和三者并用对氟醚橡胶摩擦磨损性能的影响,并用SEM对橡胶磨损表面形貌进行了分析。结果表明,石墨和聚四氟乙烯填充的氟醚橡胶以粘着磨损为主,磨损严重,而碳纤维填充的橡胶磨损主要是疲劳磨损,可显著提高氟醚橡胶的摩擦磨损性能。石墨和碳纤维并用可产生协同效应,两者用量均为15份时橡胶摩擦磨损性能较好,此时摩擦系数为0.378,磨损率为5.590×10-8mm3/Nm。     

SiC一石墨填充PTFE复合材料的摩擦磨损性能研究

在聚四氟乙烯（ＰＴＦＥ）中分别填充碳化硅（ＳｉＣ）,石墨及不同配比的ＳｉＣ－石墨混合物,制备了具有不同力学和摩擦学性能的ＰＴＦＥ基复合材料。探讨了填料组成对材料硬度及干摩擦条件下与不锈钢环对磨时摩擦磨损性能的影响,并研究了ＰＴＦＥ基复合材料的磨损表面和磨屑形貌。结果表明,填充适量的ＳｉＣ－石墨混合物既能增加ＰＴＦＥ的承载能力,又可保持良好的摩擦学性能;不同复合材料的磨损机理不同,磨损表面有磨屑形貌     

石墨填充对均苯型聚酰亚胺材料性能的影响

以均苯四甲酸酐(PMDA)和4,4'-二氨基二苯醚(ODA)为原料,通过热亚胺化的方式,合成不同石墨填充量的均苯型聚酰亚胺模塑粉,并对其化学结构、比浓对数黏度和石墨含量进行测试表征。将聚酰亚胺模塑粉热模压成型,制备聚酰亚胺复合材料,测试石墨填充对其力学性能和摩擦性能的影响。结果表明,石墨的加入对聚酰亚胺树脂的化学结构没有明显影响。随着石墨质量分数的增大,聚酰亚胺材料的力学性能有所下降,但高温性能保持能力有所提升。石墨的加入显著改善了聚酰亚胺材料的摩擦磨损性能,摩擦系数和磨痕宽度明显降低。     

球形燃料元件基体石墨摩擦磨损性能的研究

利用OHT-1000E型摩擦磨损试验机系统研究了氦气中高温气冷堆球形燃料元件基体石墨在不同温度及载荷下的摩擦磨损性能,并与其摩擦磨损后的微观形貌相结合,对其摩擦磨损的机理进行分析。结果表明:在氦气中,不同温度下基体石墨的摩擦磨损性能差异很大,而且在不同载荷下,温度对基体石墨的摩擦磨损性能影响不同。在低载荷下,基体石墨在400~700℃温度范围的摩擦系数较大,在其他温度范围的摩擦系数都相对较小;在高载荷下,基体石墨在100~200℃和400~700℃温度范围的摩擦系数较大,在其他温度范围的摩擦系数都相对较小,载荷主要影响较低温度(100~200℃)下的摩擦磨损性能。基体石墨的摩擦系数、磨损量及其磨损机理有较好的对应关系:当基体石墨的摩擦系数大时,对应的磨损量较多,磨损机理主要为粘着磨损;当基体石墨的摩擦系数较小时,对应的磨损量也较小,磨损机理主要为磨粒磨损。     

弹性金属塑料复合材料摩擦系数的方程拟合及其应用

基于弹性金属塑料复合材料,对其摩擦系数的方程拟合及其应用进行了研究。结果表明,摩擦系数随摩擦时间的延长逐步趋于稳定,此时开始进入摩擦磨损的稳定阶段。如果将石墨添加到塑料工作层当中,将会构建层状结构,并与PPS、TPI、TLCP热塑性材料发生协同效应,从而促进金属表面均匀致密的自润滑转移膜的形成。增大复合材料的载荷和转速,此时能够确保以更短的时间进入到摩擦稳定阶段,也就是说增加转速和载荷以后,可以实现形成转移膜时间的前移。磨损体积和摩擦系数随塑料工作层材料配比的不同具有显著的变化,磨损量也有所不同。随着石墨和热塑性聚酰亚胺(TPI)的增加,在载荷增加时,复合材料摩擦系数变化量比其他配比要小。采用软件MATLAB7.0,根据复合材料的摩擦系数、结合强度和塑料工作层对数据进行拟合,从而获得塑料工作层配比和摩擦系数、结合强度间的拟合函数。     

抗辐照酚酞聚芳醚酮基自润滑复合材料的研制

采用二硫化钼、石墨、碳纤维和氟化镧研制了一种抗辐照的酚酞聚芳醚酮基自润滑复合材料。介绍了此材料的制备工艺和性能,研究了几种添加剂的配比对复合材料的影响。结果表明,在酚酞聚芳醚酮中添加二硫化钼和石墨可明显改善材料的摩擦磨损性能,加入碳纤维和氟化镧不仅可提高复合材料的机械强度,而且还使摩擦磨损性能在一定程度上得到改善。加入上述添加剂均可提高复合材料的抗辐照性。     

石墨改性超高分子量聚乙烯的性能研究

采用物理共混改性的方法,制备了具有不同性能的超高分子量聚乙烯／石墨合金。研究了填料含量对合金性能的影响,DSC分析结果表明UHMWPE的热分解温度在455℃而熔点超过140℃,拉伸强度随石墨的添加明显下降,当石墨含量为5％时其拉伸强度下降到O．24MPa,冲击强度和摩擦磨损性能的测试结果表明,石墨填料的加入可以一定程度的改善合金材料的冲击性能和耐磨性能,石墨含量为1％时合金的摩擦系数由原来的0．14下降到0．12,而石墨较少时其冲击强度亦有所提高。     

Effect of radiation on the friction-wear properties of polyetherketone with a cardo group

We studied the effect of radiation on the friction-wear properties of polyetherketone with a cardo group (PEK-C) with a MM-200 model friction and wear tester. We found that radiation could improve the friction-wear properties of PEK-C to a certain degree. The friction coefficient and wear rate of PEK-C decreased as the radiation dose increased from 5 × 10⁴ to 1 × 10⁷ Gy. Scanning electron microscopy results revealed that the size of wear debris of unirradiated PEK-C was larger than that of irradiated PEK-C. The worn surface of unirradiated PEK-C showed plough marks, whereas the worn surface of irradiated PEK-C did not show plough marks; its surface was quite smooth. With the frictional couple of a carbon steel ring and an irradiated PEK-C block, a relatively uniform and coherent 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 irradiated PEK-C. An IR spectrum showed that no significant chemical change took place when the PEK-C sample was irradiated. Thermal analysis results showed that radiation changed the thermal properties of PEK-C, therefore, its friction-wear properties changed at the same time. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 962–967, 2001     

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     

Tribological behaviour of powder metallurgy-processed aluminium hybrid composites with the addition of graphite solid lubricant

The tribological behaviour of powder metallurgy-processed Al 2024–5 wt% SiC–x wt% graphite (x=0, 5, and 10) hybrid composites was investigated using a pin-on-disc equipment. An orthogonal array, the signal-to-noise ratio and analysis of variance were employed to study the optimal testing parameters using Taguchi design of experiments. The analysis showed that the wear loss increased with increasing sliding distance and load but was reduced with increased graphite content. The coefficient of friction increased with increasing applied load and sliding speed. The composites with 5 wt% graphite had the lowest wear loss and coefficients of friction because of the self-lubricating effect of graphite. Conversely, due to the effect of the softness of graphite, there was an increase in wear loss and the coefficient of friction in composites with 10 wt% graphite content. The morphology of the worn-out surfaces and wear debris was examined to understand the wear mechanisms. The wear mechanism is dictated by the formation of both a delamination layer and mechanically mixed layer (MML). The overall results indicated that aluminium ceramic composites can be considered as an outstanding material where high strength and wear-resistant components are of major importance, particularly in the aerospace and automotive engineering sectors.     

矿井筒表面用石墨-环氧树脂复合涂层的性能研究

为了考查石墨对环氧树脂涂层磨蚀性能的影响,研究了石墨含量分别为0、2%和8%的环氧树脂复合涂层的摩擦磨损性能和腐蚀性能。采用MM-200试验机进行摩擦磨损试验,在自配pH为2.97的模拟矿井水中进行腐蚀实验,通过电化学工作站考查涂层的电化学特性。结果显示:加入2%石墨和8%石墨,随着石墨的增加,石墨环氧树脂复合涂层摩擦系数和磨损量均减小;在5%NaCl溶液中浸泡10 d后,涂层摩擦系数也有所减小;石墨的加入使环氧树脂涂层在腐蚀介质中腐蚀电位变正、腐蚀电流减小,涂层耐腐蚀性能得到提高;同时,涂层相位角Q值随着石墨的增加而减小,涂层的防水性有所提高。     

Synthesis and properties of polyurethane/graphite elastomer by in situ technique

Elastomeric polyurethane (PU) was mixed with 0, 10, 15, 20, 25, and 30 wt% of graphite to obtain PUE‐based composites. The structure of PU/graphite elastomer was characterized by scanning electron microscopy. It was found that the polyurethane elastomer (PUE) molecular chains were intercalated into the graphite layers and evenly distributed in the matrix. When the graphite content was lower it could make full use of its strength with some loss of plasticity; when the graphite content was too high, the friction between graphite and PUE increased and hence it is more difficult for the macromolecular chain reaction. The polymer was more unstable as a whole. Furthermore, the thermal and mechanical properties of the obtained products were investigated in detail. The result showed that the thermal stability of PUE was improved by the introduction of the graphite. The softening temperature of the PUE/graphite containing 10% graphite was 11°C higher than that of pure PUE. At the same time, the hardness, tensile strength, elongation, 300% tensile modulus, tearing strength of PU/graphite elastomer were also investigated. POLYM. COMPOS., 37:1318–1322, 2016. © 2014 Society of Plastics Engineers     

PPESK/TK/石墨复合材料的摩擦磨损性能研究

以含二氮杂萘联苯型聚醚砜酮(PPESK)树脂为基体,以石墨和钛酸钾晶须(TK)为填料,采用物理混合、热压模塑的方法制备了PPESK/TK/石墨复合材料。研究了石墨和TK含量对复合材料摩擦磨损性能的影响,利用扫描电镜观察了磨面的形貌。结果表明,石墨和TK均能显著改善聚合物材料的摩擦磨损性能,并具有明显的协同作用。石墨对降低材料的摩擦系数起主导作用,仅以石墨为填料,材料的摩擦系数可降低至纯树脂的1/3;而TK对复合材料的磨损性能起到了明显的改善作用,当TK和石墨比例为3∶1时,材料的磨损率可降至最低,比纯树脂降低了两个数量级。扫描电镜观察结果表明材料的磨损机理主要为磨粒磨损、粘着磨损和轻微的疲劳磨损。     

石墨/铜粉改善双马来酰亚胺复合材料摩擦性能

采用层压成型制备了2类改性双马来酰亚胺纤维复合材料,分别考察了石墨、铜粉的用量对纤维复合材料摩擦性能(摩擦系数,磨损率)和力学性能的影响,并用扫描电镜对复合材料的磨损表面形貌进行了分析。结果表明:石墨对改善双马来酰亚胺的摩擦磨损性能较铜粉更有效。石墨的质量分数为3%时,复合材料的摩擦磨损性能和力学性能达到最佳。