纳米SiO_2填充改性聚四氟乙烯复合材料的摩擦磨损性能研究

通过冷压烧结成型工艺制备了纳米二氧化硅(SiO_2)填充改性聚四氟乙烯(PTFE)复合材料,探究了不同添加比例的纳米SiO_2/PTFE复合材料在不同转速下摩擦磨损情况。采用三维视频显微镜观察了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理。结果表明,填充纳米SiO_2后的PTFE复合材料其摩擦因数虽有一定程度的升高,但其体积磨损率却大幅降低。且当纳米SiO_2填充质量分数为5%时,复合材料的体积磨损率降到最低,并在转速为80 r/min时较纯PTFE降低了89.5%。观察分析微观形貌发现,随着纳米SiO_2含量的增大,复合材料的磨损机理逐渐由犁耕磨损和黏着磨损向磨粒磨损转变,且当纳米SiO_2填充含量为10%时,出现轻微的疲劳磨损。     

碳纳米管改性PTFE复合材料摩擦磨损性能

以强酸氧化后不同含量的碳纳米管(CNTs)为填料制备了聚四氟乙烯(PTFE)/CNTs复合材料,研究其摩擦磨损情况。结果表明:CNTs填充质量分数为0,1%,3%,5%,7%时,PTFE/CNTs复合材料的摩擦系数随转速的增大而增大;20,40,60,80 r/min转速下,复合材料摩擦系数随碳纳米管填充质量分数的增加先增大后减小,当填充量为5%时,各转速下的摩擦系数均达到最大值。三维视频显微镜观察样品的表面磨痕深度并计算试样平均体积磨损率,发现填充CNTs可显著降低复合材料体积磨损率,当填充量大于5%后,复合材料体积磨损率增大。扫描电子显微镜观察发现:CNTs质量分数小于5%时,CNTs有效抑制PTFE的犁削,这种抑制作用随CNTs质量分数增大而增大,当质量分数为7%时,PTFE/CNTs复合材料犁削加剧,其原因为CNTs发生团聚,对PTFE分子链的约束作用弱化,使得分子链被拉出结晶区域。     

二硫化钼改性PTFE摩擦磨损性能

干燥过筛聚四氟乙烯(PTFE)、二硫化钼(MoS_2),模压烧结制备MoS_2/PTFE复合材料,研究其摩擦磨损情况。结果表明,MoS_2填充质量分数为0、5%、10%、15%、20%时,复合材料的摩擦因数随转速的增大而增大;在20、40、60、80 r/min转速下,复合材料摩擦因数随MoS_2填充质量分数的增加而增大,当填充量为20%时,各转速下的摩擦因数均达到最大值。填充MoS_2显著降低复合材料体积磨损率,体积磨损率随MoS_2填充质量分数的增加而减小。摩擦过程中,铝合金摩擦面并没有发生擦伤,试样被铝合金硬质微凸体挤压、犁削,MoS_2/PTFE复合材料的磨损机理为磨粒磨损。     

聚四氟乙烯/纳米氮化钛复合材料的摩擦磨损性能研究

利用摩擦磨损试验机考察了填料含量及载荷对纳米氮化钛(TiN)填充聚四氟乙烯(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,探讨了磨损机理。结果表明,纳米TiN可以提高PTFE的硬度和耐磨性,当纳米TiN质量分数为7%时,PTFE纳米TiN复合材料的磨损量最小;随载荷的增大,PTFE/TiN复合材料的磨损量增加。PTFE纳米TiN复合材料的摩擦因数比纯PTFE小。     

PHB与纳米Cu对PTFE/GF复合材料摩擦学性能的影响

考察了聚苯酯(PHB)与纳米铜(Cu)协同改性对聚四氟乙烯/玻纤(PTFE/GF)复合材料摩擦磨损性能的影响,探讨了复合材料的磨损表面形貌及磨损机理.结果表明,当PHB质量分数为6％时,PTFE/GF/PHB复合材料的摩擦因数最低,达到0.175,但磨损率较大,为6.84×10-6mm3/(N·m).在此基础上,采用PHB与纳米Cu复合改性PTFE/GF复合材料,当纳米Cu质量分数为0.3％和PHB质量分数为6％时,复合材料的摩擦学性能最佳,摩擦因数为0.194,磨损率仅为1.60×10-6mm3/(N·m).纳米Cu的加入使复合材料的摩擦因数能较早达到平稳阶段.SEM分析表明,PTFE/GF复合材料表现为严重的磨粒磨损,磨损表面出现深且宽的犁沟;与PTFE/GF复合材料相比,PTFE/GF/PHB复合材料磨粒磨损得到极大改善,磨粒磨损程度大大减小;PTFE/GF/6％ PHB/0.3％纳米Cu复合材料的磨损面更加光滑平整,表现为极轻微的磨粒磨损,耐磨性最好.     

腐蚀环境中纤维增强聚四氟乙烯复合材料的摩擦磨损性能研究

分别研究了不同含量碳纤维(CF)、玻璃纤维(GF)填充聚四氟乙烯（PTFE）复合材料在硫酸溶液中和干摩擦条件下的摩擦学性能,同时考察了PTFE复合材料在酸中的腐蚀行为,探讨了相关机理。结果表明,在酸中GF能够提高PTFE的耐磨性,比CF在提高PTFE耐磨性方面具有更好的优势。就酸溶液中的耐磨性和耐腐蚀性而言,15 %（质量分数,下同）是填料的最佳含量,此时GF和CF填充的PTFE,耐磨性分别较纯PTFE提高了7.7和4.4倍;当填料的含量超过15 %时,复合材料的耐磨性和耐腐蚀性均下降,主要是由于此时犁削和磨粒磨损是PTFE复合材料的主要磨损机制。由于酸溶液的冷却和润滑作用,硫酸溶液中PTFE复合材料的摩擦因数大幅降低,但酸溶液抑制了对磨面上转移膜的形成。     

纤维增强PTFE复合材料的摩擦磨损性能研究

分别以玻璃纤维(GF)与碳纤维(CF)作为增强体制备了纤维增强聚四氟乙烯(PTFE)复合材料。利用MM-200型摩擦磨损试验机研究了GF/PTFE和CF/PTFE复合材料的摩擦磨损性能,以及不同体积分数的纤维增强体、不同载荷与滑动速度对复合材料的摩擦磨损性能的影响。结果表明:GF与CF的引入有效地提高了复合材料的摩擦磨损性能,随纤维体积分数的增加,复合材料的摩擦因数逐渐增加;另外,随载荷的增加,复合材料的摩擦因数亦逐渐降低,但磨损率增大。     

不同玻璃纤维含量对PTFE增强PEEK复合材料摩擦学性能的影响

以聚四氟乙烯(PTFE)为增强相,加入不同含量的玻璃纤维(GF),通过注塑成型方式,制备PEEK/PTFE复合材料,使用力学试验机进行拉伸试验,利用摩擦试验机进行表面摩擦试验,利用白光仪对磨痕数据和三维形貌进行观测,使用扫描电子显微镜对磨痕进行观测与分析。结果表明：当GF含量越高,复合材料最大应力越高,应力增大的斜率越明显。当GF含量增至30%,复合材料的最大应力提高至183 MPa。当GF含量逐渐升高,复合材料表面的摩擦系数降低。当GF含量为30%,复合材料的摩擦系数降至0.08。当GF含量为0、15%、30%,复合材料磨损率分别为3.59×10^-6、2.30×10^-6、1.78×10^-6 mm³/(N·m)。GF含量越高,复合材料的硬度越高,耐磨损性能越好。     

酸性溶液中PTW增强PTFE复合材料的耐蚀性和摩擦磨损性能

分别研究了不同含量钛酸钾晶须(PTW)、碳纤(CF)填充聚四氟乙烯(PTFE)复合材料在硫酸溶液中和干摩擦条件下摩擦学性能以及酸中的耐蚀性能,借助SEM等分析探讨了相关机理。结果表明,酸中纯PTFE耐磨性较干摩擦条件下提高了2个数量级,摩擦系数也只有干摩擦的15.3%。与CF/PTFE相比,PTW/PTFE复合材料在酸中显示更好的耐蚀和耐磨性能。PTW可以进一步提高PTFE酸中耐磨性能、降低摩擦系数。含15%（质量）PTW时复合材料具有最低的磨损率,此时比纯PTFE酸中耐磨性提高13.8倍,是相同含量CF/PTFE耐磨性的3.2倍。由于酸溶液的冷却和润滑作用,复合材料的摩擦系数与干条件相比明显降低。然而,酸溶液阻止了转移膜的形成。不管是干摩擦还是在酸性溶液中,当填料含量超过15%（质量）时,犁削和磨粒磨损是PTFE复合材料的主要磨损机理。     

纳米Al2O3与青铜粉协同填充PTFE复合材料的性能研究

考察了不同含量的纳米Al2O3对青铜粉/聚四氟乙烯(PTFE)摩擦磨损性能和物理机械性能的影响,采用扫描电镜(SEM)观察了复合材料的磨损表面,并分析和探讨了磨损机理。研究发现,纳米Al2O3和青铜粉复合填充可以大大提高PTFE复合材料的耐磨性,表现出良好的协同作用,但会降低复合材料的拉伸强度和断裂伸长率。添加5%纳米Al2O3后,40%青铜粉/PTFE复合材料的磨痕宽度从12.0 mm降低为5.0 mm,体积磨损率从171.40×10-6mm3/(N.m)降低为12.11×10-6 mm3/(N.m)。     

不同介质中聚四氟乙烯复合材料的摩擦磨损性能

分别在碱液、水、油和干摩擦条件下考察了碳纤维和玻璃纤维填充聚四氟乙烯复合材料的摩擦磨损性能。利用SEM观察了不同介质中磨损面和对摩面的形貌，并探讨了其磨损机理。结果表明，不同介质中摩擦系数的大小关系是μ干>μ水或油>μ碱，磨损率是W水>W干>W碱或油。水、碱和油都不同程度地阻止了转移膜的形成。碱液和油具有很好的冷却与润滑作用，摩擦系数低，磨损小；然而水分子降低了填料和基体的界面粘接强度，造成犁削和磨粒磨损加重。     

GF及偶联剂改性PVC/稻壳木塑复合材料

采用模压成型的方式、通过实验探索玻璃纤维(GF)含量及偶联剂处理对聚氯乙烯(PVC)/稻壳木塑复合材料的力学特性和耐磨性的影响。实验结果表明:PVC/稻壳木塑复合材料的硬度随GF含量增加呈现先减小后增大的趋势。GF含量在15%以下时,随着GF用量的增大,木塑复合材料的拉伸强度与冲击强度总体上随之变大,超过15%则随GF含量增大而减小。而弯曲强度出现先减后增的趋势,弯曲弹性模量则与之相反。木塑复合材料的耐磨损性在GF含量为15%时最佳,摩擦系数在10%时最大。合适的偶联剂处理能增强木塑复合材料的力学性能和耐磨性。其中γ–氨丙基三乙氧基硅烷(KH550)的增强效果比较好,钛酸酯不能提高PVC/稻壳木塑材料的力学性能和耐磨性。     

聚四氟乙烯填充聚醚醚酮及其复合材料的研究

利用熔融共混工艺制备了ＰＥＥＫ／ＰＴＦＥ共混物及其复合材料,研究了ＰＴＦＥ对ＰＥＥＫ共混物及其复合材料力学性能和耐磨性的影响,结果表明,ＰＥＥＫ经１０％￣ＰＴＦＥ填充改性,玻纤／碳纤混杂增强后,由于磨损方式的改变,使该复合材料不仅保持了良好的物理力学性能,而且具有较低的摩擦系数,耐磨性也得到明显改善。     

聚四氟乙烯复合材料动态密封性能的研究

采用高速混合、冷压烧结成型法用玻璃纤维、二硫化钼填充改性制备聚四氟乙烯复合材料,探讨了填充料用量对PTFE复合材料拉伸性能和摩擦磨损性能的影响,经测试：当玻璃纤维含量为15％、二硫化钼含量为5％改性PTFE时,其改性复合材料的压缩回弹和耐磨损等综合性能最佳,适用于性能要求较高的动态密封场合。     

Effect of solid lubricants on tribological behavior of glass fiber reinforced polyamide 6

The tribological properties of glass fiber reinforced polyamide 6 (GF/PA6, 15/85 by weight) and its composites filled with solid lubricants were investigated. The main purposes of this article were to study the hybrid effect of solid lubricants with glass fiber as well as the synergism of combined solid lubricants, the wear mechanisms were studied by SEM. The results showed that graphite impaired the tribological properties of GF/PA6, but the tribology behavior of graphite filled GF/PA6 composite could be significantly improved by polytetrafluroethylene (PTFE) or/and ultrahigh molecular weight polyethylene (UHMWPE), and the GF/PA6 composite filled with 5 wt % graphite, 5 wt % PTFE together with 5 wt % UHMWPE exhibited the lowest friction coefficient and wear rate, which was almost a reduction in friction coefficient by 37% and in wear rate by 34% contrast to GF/PA6. The effect of load was also studied, and the results showed that the friction coefficient was virtually not affected by load, while the wear rate all increased with increasing load. POLYM. COMPOS., 34:1783–1793, 2013. © 2013 Society of Plastics Engineers     

Study on the Friction and Wear Behaviors of Modified PA66 Composites

The wear-resistant polyamide 66 (PA66) composites were prepared and the mechanical properties, friction and wear properties were inspected. Results show that GF, PTFE and MoS₂ can improve the mechanical, friction and wear properties of PA66 composites. PTFE is more effective on the friction and wear properties than MoS₂ when GF is 30%wt. The best effect of the modification is 35%wt GF when both PTFE and MoS₂ were added. Friction coefficient first increase, then reduce to be stable as sliding time increases. Friction coefficient and wear mass loss increase as load increases. The main wear mechanisms are fatigue and abrasion wears.     

Influence of solid lubricant reinforcement on wear behavior of Kevlar fabric composites

The friction and wear behavior of Kevlar fabric composites reinforced by PTFE or graphite powders was investigated using a Xuanwu‐III friction and wear tester at dry sliding condition, with the unfilled Kevlar fabric composite as a reference. The worn surfaces were analyzed by means of scanning electron microscope, and X‐ray photoelectron spectroscopy. It was found that PTFE or graphite as fillers could significantly improve the tribological behavior of the Kevlar fabric composites, and the Kevlar fabric composites filled with 20% PTFE exhibited the best antiwear and antifriction ability among all evaluated cases. The transfer films established with two lubricants in sliding wear of composites against metallic counterparts made contributions to reducing friction coefficient and wear rate of Kevlar fabric composites. In particular, FeF₂ generated in the sliding of Kevlar fabric composites filled with PTFE against counterpart pin improved the bonding strength between the transfer film and counterpart surface, which accounted for the lowest friction coefficient and wear rate of the Kevlar fabric composites filled with PTFE measured in the testing. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.     

Tribological behaviors of polytetrafluoroethylene composites under dry sliding and seawater lubrication

The composites of polytetrafluoroethylene (PTFE) filled with expanded graphite (EG), poly(p‐oxybenzoyl) (POB), and basalt fiber (BF) were prepared by heating compression and sintering molding. The tribological behavior of PTFE composites was investigated with a pin‐on‐disk tester under dry conditions and seawater lubrication. The worn surface of PTFE composites and the transfer film on the counterface were observed with a scanning electron microscope. The results indicated that the incorporation of EG and POB improved the hardness of PTFE composites, and addition of BF led to greater load‐carrying capacity. Compared to pure PTFE, the coefficients of friction of PTFE composites slightly increased, but the wear rates were significantly reduced (the wear rate of composite with 3% EG being only 10.38% of pure PTFE). In addition, all the composites exhibited a lower coefficient of friction (decreases of about 0.03–0.07) but more serious wear under seawater lubrication than under dry sliding. The wear mechanism changed from serious abrasive wear of pure PTFE to slight adhesion wear of PTFE composites under both conditions. A transfer film was obviously found on the counterface in seawater, but it was not observed under dry conditions. Among all the materials tested, the PTFE‐based composite containing 20% POB (mass fraction), 2% EG, and 3% BF exhibited the best comprehensive performance. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2523–2531, 2013     

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。     

纳米Si3N4及其混杂填料改性PTFE的性能研究

采用模压成型的方法制备了纳米氮化硅(Si3N4)与二硫化钼(MoS2)、玻璃纤维(GF)、纳米三氧化二铝(Al2O3)混合填充的聚四氟乙烯(PTFE)复合材料,研究了PTFE复合材料的力学性能和摩擦学性能。采用扫描电子显微镜(SEM)观察分析了拉伸断面形貌及增强机理。结果表明：Si3N4及其混杂填料均使复合材料表面硬度增大;PTFE/Si3N4/Al2O3纳米复合材料具有较好的拉伸性能;混杂填料均可以显著改善PTFE复合材料的耐磨性能,其中5 %的Si3N4与10 %的Al2O3混杂填充复合材料的耐磨性最好,填料对复合材料摩擦因数影响不大。SEM分析表明,纳米Si3N4、Al2O3与PTFE基体界面结合较好。