PTFE复合材料高温摩擦磨损性能研究

研究了高温条件下不同填料填充的PTFE复合材料的摩擦磨损性能,并与常温下的摩擦磨损性能进行了比较.结果表明青铜粉、纤维填充的复合材料在高温下表现出与常温相反的摩擦磨损规律;碳类填充复合材料在不同温度下则表现出较为稳定的规律;特种塑料改性的PTFE复合材料,具有极好的综合性能.     

碳纳米管增强PTFE复合材料摩擦磨损性能研究

以不同含量的CNTs(碳纳米管)为填料制备了PTFE基复合材料,测量其硬度,在M-2000型摩擦磨损试验机上研究其摩擦磨损行为。结果表明,CNTs能提高PTFE的硬度,CNTs/PTFE复合材料的耐磨性能明显优于纯PT-FE,当CNTs的质量分数为3%时,复合材料的耐磨性能大幅度提高。其摩擦因数随着CNTs含量的增加而加大,当CNTs的质量分数为1%时,摩擦因数随载荷的增加而减少,CNTs的质量分数为3%和5%时,摩擦因数随载荷的增加而增大。SEM观察发现:纯PTFE的断面上分布着大量的带状结构,而填充CNTs后,摩擦表面较平整光滑,表明CNTs作为填料可有效地抑制PTFE的犁削和粘着磨损。     

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。     

PTFE、石墨与玻璃纤维填充聚甲醛的摩擦磨损特性研究

用聚四氟乙烯(PTFE)、玻璃纤维(GF)和石墨填充聚甲醛(POM),采用热模压成型制备出4种复合材料。在往复式滑动摩擦试验机上进行摩擦磨损实验。实验条件为正压力5.8 MPa,往复频率1 Hz,对摩面粗糙度Ra0.8μm。结果表明:经填充的POM复合材料的摩擦因数和比磨损率均有不同程度的降低,其中POM 20%(质量分数)PTFE的摩擦因数最低,POM 20%PTFE 10%GF的耐磨性最好。扫描电镜分析表明POM材料的磨损机制以粘着磨损为主。     

SiC颗粒增强PTFE基复合材料磨损图的研究

研究了SiC颗粒增强PTFE基复合材料(PTFE／SiCp)在干摩擦条件下的磨损特性。对磨损表面进行了观察分析，建立了复合材料磨损机制转变图，对在不同磨损条件下的磨损机制进行了概括。结果表明，SiC颗粒增强PTFE基复合材料发生轻微磨损的主要机制是显微切削，发生严重磨损的主要机制是粘着磨损。     

高速摆动下PTFE编织复合材料干摩擦研究

利用高速摩擦试验机对PTFE编织复合材料进行干摩擦试验,研究不同条件(载荷、速度和湿度)下PTFE编织复合材料干摩擦磨损性能;并利用扫描电子显微镜对不同条件下的磨屑形貌进行分析。结果表明:单因素变化条件下,摩擦因数随载荷和相对湿度的增大而减小,随摩擦速度的增大而增大;磨损量随载荷和速度的增大而增大,但相对湿度的增加可降低磨损;载荷及速度的增加显著影响材料磨损状况。     

短玻璃纤维和石墨填充PTFE的摩擦磨损特性研究

利用自主研制的往复式摩擦试验机对短玻璃纤维(SGF)及石墨填充聚四氟乙烯(PTFE)复合材料的摩擦磨损特性进行了研究,探讨了共混材料对PTFE摩擦学性能的影响。利用扫描电子显微镜对材料的磨损表面进行了观察和分析。研究结果表明,短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,在较高载荷下,短玻璃纤维和石墨填充的PTFE复合材料表现出优异的抗磨性能。     

PTFE与纳米高岭土填充PPS复合材料的摩擦磨损性能研究

通过模压的方法制备了聚四氟乙烯(PTFE)和纳米高岭土填充的聚苯硫醚(PPS)复合材料。摩擦磨损实验在往复式滑动摩擦试验机上完成进行,对摩面为硬度值HRC 38、表面粗糙度Ra0.8μm的45#钢。用扫描电镜观察了试样磨损表面形貌。实验结果表明:填料的加入降低了PPS的摩擦因数和磨损率,且PTFE和纳米高岭土共同填充的PPS复合材料比单一PTFE填充的PPS复合材料具有更好的摩擦磨损性能;其中试样PPS 15%PTFE 15%(质量分数)纳米高岭土具有最低的稳定摩擦因数0.20~0.23和最小的磨损率1.9×10-6mm3/(N.m)。PTFE和纳米高岭土的加入使PPS的主要磨损方式由粘着磨损转变为磨粒磨损。     

高速条件下PTFE编织复合材料的摩擦磨损性能

将PTFE编织复合材料与9Cr18Mo钢组成摩擦副,在高速压摆摩擦磨损试验机上进行干摩擦磨损试验,研究了循环次数和摩擦温度对摩擦因数的影响,用扫描电镜观察了不同阶段摩擦表面及磨屑的形貌,并分析了PTFE编织复合材料的磨损机理。结果表明:PTFE复合材料的摩擦因数随着循环次数的增加先迅速降低,后在一定范围内达到动态平衡,随着摩擦的继续进行,摩擦因数急剧上升,PTFE复合材料发生磨损失效;摩擦温度是影响PTFE复合材料摩擦磨损机制一个重要因素,摩擦温度的急剧升高将加剧PTFE复合材料的磨损;随着磨损的加剧,磨屑也表现为相应的恶化趋势;磨损机理以疲劳磨损为主。     

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.     

Impact of Viscoelasticity on the Tribological Behavior of PTFE Composites for Valve Seals Application

In this article, we studied and explored the impact of viscoelasticity on the friction and wear behavior of pure polytetrafluoroethylene (PTFE), carbon–graphite PTFE composite, and glass fiber–MoS₂ PTFE composite. Tests were carried out using a specific reciprocating tribometer for valve seal application. The worn surfaces of the PTFE composites and the transfer films formed on the counterface were examined with a scanning electron microscope (SEM). Experimental results revealed that the addition of filler materials was effective in reducing the wear volume in all composites studied. In addition, the friction coefficient and wear resistance showed high sensitivity to the viscoelastic behavior of the PTFE seal. SEM investigation showed that the incorporation of particulate fillers into the PTFE matrix could dramatically reduce and stabilize the transfer films to the counterface, so they largely decreased the wear of the PTFE composites.     

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。     

硫酸钙晶须填充PTFE复合材料的摩擦学性能研究

用硫酸钙晶须(CSW )填充改性聚四氟乙烯(MVE),采用模压成型工艺制备不同硫酸钙晶须含量的PTFE/CSW复合材料;利用摩擦磨损试验机研究硫酸钙晶须对PTFE/CSW复合材料摩擦学性能的影响,利用扫描电子显微镜对PM复合材料的磨损表面进行微观分析.结果表明:填充硫酸钙晶须提高PTFE复合材料的耐磨损性能,但复合材料的摩擦因数略高于纯PTFE;纯PTFE的磨损机制为黏着磨损,而PTFE/CSW复合材料的磨损机制为轻微磨粒磨损和黏着磨损共同作用.当硫酸钙晶须质量分数大于10%时,PTFE/CSW复合材料的磨损机制逐渐转变为严重的磨粒磨损.     

油介质对聚四氟乙烯纤维织物自润滑复合材料摩擦学性能的影响

采用栓-盘式摩擦磨损试验机研究航空煤油和液压油介质对聚四氟乙烯纤维织物自润滑复合材料的摩擦磨损性能的影响;利用扫描电子显微镜(SEM)观察和分析复合材料磨损表面形貌,并分析探讨摩擦磨损机制。结果表明,油介质的存在可明显降低复合材料的耐磨性能和极限承载能力,其中液压油的影响更为显著;介质浸泡处理的复合材料在摩擦过程中,磨损形式由黏着磨损逐步过渡到疲劳磨损,并且界面结合强度降低,导致材料耐磨性能下降。     

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.     

石英粉填充聚四氟乙烯复合材料的蠕变性能

以石英粉为填料,通过机械混合和冷压烧结的方法制备石英粉填充改性聚四氟乙烯复合材料,研究复合材料的硬度、抗拉强度、压缩与回复性能和长期压缩蠕变性能.借助SEM探讨拉伸断面的微观结构.结果表明:加入适量的石英粉可以提高复合材料的硬度、抗蠕变性能,改进PTFE压缩与回复性能;但由于存在相界面缺陷,复合材料的抗拉强度降低.当粉石英质量分数在20%-30%之间时,其综合性能能够满足密封材料的要求.     

聚醚醚酮填充聚四氟乙烯摩擦学性能

采用共混-冷压-烧结的工艺制备聚醚醚酮（PEEK）填充聚四氟乙烯（PTFE）复合材料,考察 PEEK 含量对 PTFE /PEEK 复合材料的力学性能和摩擦学性能的影响,用扫描电子显微镜（SEM）观察其磨损表面和对偶表面形貌,并探讨磨损机制。结果表明：复合材料的拉伸强度随着 PEEK 含量的增加而降低,在一定范围内,冲击强度随着PEEK 含量的增加而增大;随着 PEEK 含量的增多,摩擦因数呈现先减小后增大的趋势,体积磨损率则逐渐减小。当PEEK 质量分数为20％时,复合材料耐磨性较纯 PTFE 提高了近700倍,其原因在于 PEEK 的加入改变了磨屑形成机制,并能形成均匀连续的转移膜,进而降低了磨损。     

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.     

Friction and wear of PTFE composites at cryogenic temperatures

This paper presents investigations on the tribological behaviour of PTFE composites against steel at cryogenic temperatures. The results showed that the friction coefficient decreases with temperature down to 77 K, but did not follow a linear evolution further down to extreme low temperatures. It can be stated that the cryogenic environment has a significant influence on the tribological performance of the polymer composites. The effect of low temperatures was more clearly detected at low sliding speed, where friction heat is reduced. A change in wear mechanism from adhesive to abrasive was observed in this case. SEM and AFM analyses showed that the PTFE matrix composites investigated under these experimental conditions have transferred material onto the disc down to very low temperatures. Chemical analyses indicate the presence of iron fluorides.