微米和纳米SiO2改性聚四氟乙烯的摩擦磨损性能

使用超细及纳米SiO₂颗粒填充改性聚四氟乙烯塑料。测量其摩擦系数、磨损系数、结晶度,得到了填加量与复合材料摩擦系数、磨损系数和结晶度的关系曲线,并使用扫描电镜(SEM)对其表面形貌进行了分析。结果表明,无论微米或纳米SiO₂、表面处理后的纳米SiO₂,均使PTFE的摩擦系数有所提高,而耐磨损性能也有大幅度的提高。填充量小于6%时,填加未经偶联剂处理的纳米SiO₂的SiO₂/PTFE复合材料的磨损率降低98.5%;填充量大于6%以后,磨损率趋于稳定;填充量为6%时,摩擦系数仅从未加填料时的0.1提高为0.12。而偶联剂表面处理的纳米SiO₂复合材料的摩擦系数提高幅度最小。      

钛酸钾晶须增强聚四氟乙烯复合材料的摩擦磨损性能

研究了钛酸钾晶须(PTW)增强聚四氟乙烯复合材料(PTW-PTFE)的摩擦磨损性能。考察了PTW含量、摩擦温度、栽荷和滑行速度对其影响。结果表明，PTW-PTFE的磨损量仅是纯PTFE的1／10；负荷极限和滑行速度极限分别是纯PTFE的110％和160％；PTW的加入使摩擦系数更为稳定，但大小无明显改变；PTW的质量分数为5％时复合材料磨损量最小，拉伸强度最高；PTFE和PTW-PTFE在200℃的磨损量低于常温下的磨损量，但磨痕面积明显增加．观察磨损表面形貌发现，PTW的加入明显阻止了裂纹大规模的产生和扩展，提高了耐磨性。     

无机填料增强聚苯酯/聚四氟乙烯复合材料的力学和摩擦磨损性能

采用石墨/ 二硫化钼填充改性聚苯酯/ 聚四氟乙烯复合材料, 研究了复合材料的力学性能和摩擦磨损性能。研究表明, 石墨和MoS₂ 的加入不仅能够很好地改善Ekonol/ PTFE 复合材料的力学性能, 使复合材料的拉伸强度、弯曲强度和硬度均有所提高, 而且还使Ekonol/ PTFE 复合材料的摩擦系数增加, 磨损体积减小, 耐磨性能显著提高。当Ekonol 含量为5 % , 石墨/ 二硫化钼总含量为8 %时, 拉伸强度、弯曲强度分别提高了31 %和41 % ,硬度值约提高了713 %。SEM 分析表明, Ekonol/ 石墨/ MoS₂ / PTFE 复合材料的磨损主要以粘着磨损为主。      

Ti2SnC纳米片增强PTFE基复合材料的摩擦磨损性能

为探讨Ti2SnC纳米片含量对聚四氟乙烯(PTFE)基复合材料摩擦磨损性能的影响.采用超声剥离Ti2SnC块体材料的方法获得了Ti2SnC纳米片,并以此为原料通过冷压烧结的方法制备了Ti2SnC纳米片/PTFE复合材料.研究了Ti2SnC纳米片含量对复合材料硬度和相同载荷下摩擦磨损性能的影响,以及不同载荷对纯PTFE和...     

纳米蒙脱石填充PTFE和UHMWPE的摩擦磨损性能

用纳米蒙脱石(nano-MMT)对聚四氟乙烯(PTFE)和超高分子量聚乙烯(UHWMPE)进行填充改性,在往复式滑动摩擦试验机上进行摩擦磨损实验,用扫描电镜观察了材料摩擦表面形貌.结果表明:nano-MMT可以提高PTFE和UHWMPE材料的耐磨性,而PTFE基和UHWMPE基复合材料的摩擦系数无明显增大.与UHMWPE相比,nano-MMT更能提高PTFE基材料的耐磨性;nano-MMT/PTFE复合材料比nano-MMT/UHMWPE复合材料具有更低的摩擦系数和更好的导热性;纯PTFE、纯UHWMPE和10%nano-MMT/PTFE复合材料磨损机理主要为粘着和犁沟效应,而10%nano-MMT/UHWMPE复合材料表现为犁沟和疲劳机制.     

纳米SiC与PI填充改性PTFE复合材料的摩擦磨损性能

以纳米碳化硅(Nano-SiC)和聚酰亚胺(PI)为填料,经过机械共混、冷压成型和烧结等工艺制备Nano-SiC与PI共同填充改性聚四氟乙烯(PTFE)复合材料。利用MRH-3型环-块摩擦实验机研究不同实验条件下复合材料的摩擦磨损性能并记录磨损表面温度变化。通过扫描电镜观察试样磨损表面和转移膜形貌,分析其磨损机理。结果表明:纳米粒子含量、载荷和速度的变化会引起磨损表面温度发生变化,影响复合材料的摩擦磨损特性,复合材料磨损表面形貌和转移膜形貌也随之改变;随着纳米粒子含量增加,摩擦温升更快进入平稳阶段,有利于降低复合材料的磨损率;载荷由100N增加至400N,速度由1m/s增加至4m/s时,复合材料的摩擦磨损特性大幅下降,磨损表面形貌和转移膜形貌有显著变化,重载和高速条件下复合材料的磨损率高;环境温度在室温到135℃变化时复合材料的摩擦性能变化不明显。     

纳米TiO2与炭纤维协同填充PTFE复合材料的摩擦磨损性能

考察了不同含量的纳米二氧化钛对炭纤维/聚四氟乙烯复合材料摩擦磨损性能的影响,采用扫描电子显微镜、光学显微镜分析了磨损面、磨屑及对偶面转移膜形貌,并探讨了其磨损机理。结果表明,纳米TiO2与炭纤维能够很好地协同增强聚四氟乙烯,改变磨屑形成机理,有利于形成均匀致密的转移膜,明显提高CF/PTFE复合材料的耐磨性。当纳米TiO2含量为5%时,10?/PTFE复合材料表现出最佳的耐磨性,耐磨性又提高了2.77倍,而磨屑尺寸只有未加时的1/20。     

纳米Al_2O_3/聚苯硫醚改性聚四氟乙烯复合材料摩擦特性

使用MRH-3型环-块摩擦磨损试验机在不同实验条件下对纳米氧化铝(Nano-Al_2O_3)与聚苯硫醚(PPS)共混改性聚四氟乙烯(PTFE)复合材料的摩擦磨损状况进行了测试并在线测量了摩擦表层瞬时温度。采用扫描电镜对磨损表面形貌和转移膜形貌进行了观察与分析。结果表明,复合材料摩擦磨损特性与纳米粒子含量及摩擦表层温度有关;3%(体积分数)Nano-Al_2O_3/PPS/PTFE复合材料的耐磨性最佳;摩擦过程中表层瞬时温度呈现3个阶段:线性升温、温度缓慢变化和稳定阶段,且升温幅度随Nano-Al_2O_3含量的增加而增大;当载荷和速度分别超过200 N和2 m/s时,复合材料磨损率与摩擦表层温度均大幅上升,但摩擦热平衡所需时间却大幅缩短,此时摩擦表面形貌与转移膜形貌均发生明显变化;当环境温度在25~140℃变化时复合材料摩擦性能变化不显著。     

碳纤维改性聚四氟乙烯的摩擦及振动性能

文中研究了20%的碳纤维(体积分数)改性聚四氟乙烯在干摩擦和水润滑摩擦条件下的摩擦系数、磨损性能和摩擦振动性能。结果表明:(1)在干摩擦下,随着线速度增加,摩擦界面生成大量的热,黏着磨损和磨粒磨损严重,表面越来越粗糙,摩擦系数明显变大,摩擦振动加速度增加。而在水润滑条件下,随着线速度增加,摩擦界面间形成了一层水润滑膜,使摩擦系数降低,另外由于转速增加,使流噪声增加,从而使振动增加。(2)在干摩擦下,随着比压增加,摩擦系数和摩擦振动变化较大,而在水润滑条件下,随着比压增加,摩擦系数和摩擦振动变化较小。(3)干摩擦时,碳纤维增强聚四氟乙烯复合材料在不同比压下的磨损机理主要是磨粒磨损和黏着磨损;水润滑条件下,碳纤维增强聚四氟乙烯复合材料在高比压下的磨损机理主要是黏着磨损。因此,碳纤维改性聚四氟乙烯复合材料应该在水润滑条件下应用有利于提高耐磨性,降低摩擦系数和摩擦振动。     

纤维/Ekonol/PTFE复合材料的力学与摩擦学性能研究

对比考察了碳纤维(CF)、六钛酸钾晶须(PTW)分别与聚苯酯(Ekonol)混合填充对聚四氟乙烯(PTFE)复合材料的力学与摩擦学性能的影响,并探讨了内部机理.结果表明:PTW相比于传统纤维CF,尺寸细微,具有微区增强特性,PTW的填充提高了Ekonol/PTFE复合材料的致密程度,协助形成更为均匀、致密的转移膜,相比于CF/Ekonol/PTFE复合材料,有着较好的力学性能、摩擦稳定性、耐磨性,进一步改善了Ekonol/PTFE复合材料的综合性能.纤维、Ekonol混合填充PTFE,二者表现出协同润滑与减磨效应.纤维协助均匀、致密的转移膜的形成;而硬质Ekonol颗粒在纤维和对偶之间可能起到了一种第三体滚动效应,避免了纤维受到较为严重的磨损,从而提高复合材料的摩擦磨损性能.     

Friction and wear behavior of polytetrafluoroethene composites filled with Ti3SiC2

In this work, polytetrafluoroethylene (PTFE) composites filled with Ti₃SiC₂ or graphite were prepared through powder metallurgy. The effects of different filling components, loads and sliding velocities on the friction performance of Ti₃SiC₂/PTFE composites were studied. Ti₃SiC₂/PTFE composites exhibit better wear resistance than graphite/PTFE composites due to the better mechanical properties of Ti₃SiC₂. The wear resistance was found to improve around 100× over unfilled PTFE with the addition of 1 wt.% Ti₃SiC₂. In addition, the 10 wt.% sample had the lowest wear rate of K = 2.1 × 10⁻⁶ mm³/Nm and the lowest steady friction coefficient with μ = 0.155 at the condition of 90 N–0.4 m/s. Ti₃SiC₂ was proved to promote the formation of a thin and uniform transfer film on counterpart surface and a protection oxide film on worn surface, which are the key roles for improving wear resistance.     

Evaluation of the friction and wear properties of PTFE composites filled with glass and carbon fiber

The aim of the research article is to study the mechanical and two‐body abrasive wear behaviour of glass/carbon fiber reinforced PTFE composites. The measured wear volume loss increases with increase in abrading distance. The results showed that the highest specific wear rate is for glass fiber reinforced PTFE composite with a value of 8.1×10^–6 mm³/Nm and the lowest wear rate is for carbon fabric reinforced vinyl ester composite with a value of 7.2×10^–6 mm³/Nm. Mechanical properties were evaluated and obtained values are compared with the wear behaviour. The worn surface features have been examined using scanning electron microscope (SEM). Photomicrographs of the worn surfaces revealed higher percentage of broken glass fiber as compared to carbon fiber.     

Tribological properties of PTFE composites filled with surface-treated carbon fiber

Carbon fibers (CF) were surface treated with concentrated HNO₃, silane coupling agent, rare earth solution and rare earth sol, respectively. The friction and wear behavior of polytetrafluoroethylene (PTFE) filled with differently surface treated CF were studied. The worn surfaces of CF/PTFE composites were then examined with scanning electron microscope (SEM). It is found that the wear volume loss of the rare earth sol treated CF filled PTFE composites reaches the lowest value when the modifier concentration is 10 wt%. It is only about 65% of the wear volume loss of the PTFE filled with untreated CF. Among all the treatments to CF, rare earth sol treatment is the most effective and the lowest friction and wear volume loss of CF/PTFE composite is exhibited.     

PEEK与纳米TiO_2填充PTFE复合材料的摩擦磨损性能研究

采用高速机械搅拌的方式充分混合原料,然后用模具将混合好的材料冷压成型,再通过一定的烧结程序制备不同体积含量的聚醚醚酮(PEEK)和纳米TiO2协同填充改性的聚四氟乙烯(PTFE)复合材料试样。利用MRH-3摩擦磨损实验机在不同实验条件下对试样进行摩擦学性能的测试。磨损后用QuantaFEG450扫描电镜对钢环表面的摩擦形貌进行观察与分析。实验结果表明,填充PEEK可大幅降低PTFE复合材料的体积磨损率,但复合材料的摩擦系数却随PEEK含量的增加而表现出逐渐上升的趋势。用不同含量的纳米TiO2填充10%PEEK/PTFE,摩擦系数和体积磨损率都表现出随纳米TiO2含量的增加而逐步上升的趋势,其中2%Nana-TiO2/10%PEEK/PTFE复合材料的摩擦系数和体积磨损率最小。当滑动速度和载荷分别超过2m/s和200N后对复合材料的磨损率有显著地影响,而环境温度在25~120℃范围内变化对磨损率和摩擦系数的影响均不明显。     

石墨、MoS2填充PTFE的摩擦学转移特性研究

利用改装的MM - 2 0 0型磨损试验机 ,评价了石墨、MoS2 填充的PTFE的摩擦学性能 ,实验表明 ,MoS2 填充的复合材料在上下两个试验环上形成转移膜的能力较强 ,且转移膜寿命较长。EDS、XPS等分析测试结果显示 ,MoS2 填充的PTFE复合材料形成的转移膜与底材金属之间发生了以S的氧化为特征的摩擦化学反应。认为 ,二硫化钼与底材表面由于摩擦引发的活性中心的化学反应提供了转移膜与底材间的牢固结合 ,导致体系具有较高的耐摩性     

Friction and wear properties of UHMWPE composites reinforced with carbon fiber

The artificial joint acetabular material ultrahigh molecular weight polyethylene (UHMWPE) was reinforced with carbon fibers (CF) in different contents. The effects of CF content on hardness and tribological properties of the materials were studied. The morphologies of wear surfaces were examined with a Scanning Electron Microscope (SEM). The results show that the hardness and wear resistance of CF-reinforced UHMWPE composites increased with CF content; the friction coefficients under distilled water lubrication were decreased greatly by the addition of CF; that adherence, plowing, plastic deformation and fatigue wear are dominant for the UHMWPE under dry sliding, and that abrasive wear and drawing out of CF from the wear surface of the composites are dominant for the CF-UHMWPE composites under both dry and distilled water lubrication conditions.     

三维网络Al2O3增强球墨铸铁基复合材料摩擦磨损性能

采用SRV摩擦磨损试验机研究了球墨铸铁及三维网络Al2O3增强球墨铸铁基复合材料的干摩擦磨损性能,测量了球墨铸铁和复合材料在不同摩擦频率及载荷下的摩擦系数和磨损率;用扫描电镜观察磨损表面形貌,并分析了三维网络Al2O3对复合材料磨损机制的影响.结果表明:陶瓷与金属基体之间具有良好界面结合的三维网络Al2O3/球墨铸铁复合材料,其摩擦系数随载荷和摩擦频率的变化保持稳定;复合材料的耐磨性能远优于球墨铸铁,而且随着摩擦频率和载荷的增加,复合材料的抗磨损性能明显提高.这是由于复合材料中陶瓷与金属相之间三维空间结构和良好的界面结合有利于摩擦载荷的传递;金属基体中的石墨减摩作用保持摩擦系数的稳定;三维陶瓷骨架在磨损表面形成硬的微突体并起承载作用,制约了基体的塑性变形和高温软化,有利于磨损表面氧化膜的留存.