纳米Si3N4及其与石墨、MoS2混合填充PTFE摩擦磨损性能研究

用M-2000型摩擦磨损试验机对纳米Si3N4及其与石墨、MoS2混合填充聚四氟乙烯(PTFE)复合材料在干摩擦条件下与45#钢对磨时摩擦磨损性能进行了研究,用洛氏硬度仪对其进行了测量,用扫描电子显微镜对磨损表面进行了观察.结果表明:纳米Si3N4的加入能提高PTFE复合材料的硬度和耐磨性,纳米Si3N4与MoS2混合填充会使PTFE复合材料的耐磨性能提高更多,特别是在载荷增大时其耐磨效果更好.纳米Si3N4能阻止PTFE复合材料中磨损微裂纹的产生,在纳米Si3N4的富聚区,磨损微裂纹较少,在纳米Si3N4的贫聚区,磨损的微裂纹较多.纳米Si3N4填充PTFE复合材料的摩擦系数比纯PTFE大,且随着载荷增加有所减小,石墨的加入可降低PTFE的摩擦系数.     

Si-C-Nnp/Si3N4复合材料的室温和高温显微结构与力学性能

以 Si- C- N纳米微粉为增强相 ,Si3N4 为基相 ,采用热压的方法制备了 Si Cp/ Si3N4 纳米复相陶瓷。应用扫描电镜 (SEM)、高分辨透射电镜 (HRTEM)对其结构进行了观察 ,并讨论了结构与性能之间的关系。结果表明 ,所得的 Si Cp/ Si3N4 复相陶瓷的室温力学性能比氮化硅单相陶瓷有较大的提高 ,而 135 0℃断裂韧性达 14 .6 6 MPa· m1 / 2 。Si C微晶在晶粒内和在晶界玻璃相内的钉扎作用是材料高温性能提高的主要因素。     

纳米SiC改性PTFE复合材料的力学与摩擦磨损性能

评价了用不同含量纳米SiC改性聚四氟乙烯（PTFE）复合材料的力学性能,利用MM-200型摩擦磨损试验机研究了纳米SiC含量对PTFE复合材料摩擦磨损性能的影响。借助于扫描电子显微镜观察分析了试样磨损表面形貌,并探讨其磨损机理。结果表明：纳米SiC能够提高PTFE复合材料的硬度,但复合材料的拉伸强度有所降低。纳米SiC能够增加PTFE复合材料的摩擦系数,降低其磨损量,当其质量分数为7％时,PTFE复合材料的耐磨损性能最佳。纳米SiC可以阻止PTFE带状结构的大面积破坏,以及在摩擦过程中于偶件表面能够形成转移膜并隔离复合材料与偶件的直接接触是减摩耐磨的主要原因。     

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。     

纳米陶瓷颗粒填充PTFE基复合材料的干摩擦磨损性能

利用MM-200型环-块摩擦磨损试验机研究了纳米陶瓷颗粒SiC、Si3N4、AlN和TiN对聚四氟乙烯(PTFE)复合材料在干摩擦条件下与45#钢对磨时的摩擦磨损性能的影响,借助于扫描电子显微镜观察分析了试样磨损表面形貌,并探讨了磨损机理。结果表明:添加纳米TiN减少了PTFE的摩擦系数,而添加纳米SiC、Si3N4增大了PTFE的摩擦系数。与纯PTFE相比,PTFE复合材料的耐磨性能显著提高,其中以纳米AlN的减磨效果最好,纳米Si3N4的减磨效果最差。纯PTFE的磨损机制主要表现为粘着磨损和疲劳磨损,而纳米粒子填充PTFE基复合材料的磨损机制主要表现为不同程度的粘着磨损、犁沟效应和塑性变形特征。     

纳米SiC与石墨填充PTFE复合材料的摩擦磨损性能

考察了不同含量的纳米SiC对石墨/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分析了磨损表面,并探讨了其磨损机理。结果表明:纳米SiC与石墨能够很好地协同增强聚四氟乙烯,纳米SiC的加入大大提高了复合材料的承载能力,石墨的加入减少了纳米SiC与对偶面的摩擦系数,从而降低了纳米SiC的脱落趋势,提高了复合材料的耐磨性。当纳米SiC含量为5%时,5%石墨/PTFE复合材料表现出最佳的耐磨性,具有一定的应用价值。     

双马来酰亚胺复合材料摩擦学性能的研究

采用浇铸成型法制备了两类双马来酰亚胺复合材料,分别考察了石墨、纳米Si3N4的添加量对复合材料摩擦学性能和力学性能的影响,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:纳米Si3N4对改善双马来酰亚胺的摩擦磨损性能方面比石墨更有效,尤其是当纳米Si3N4的添加量为1.5%(质量分数)时,复合材料的摩擦磨损性能最佳,摩擦系数降为0.25,磨损率下降72%.     

金属硫化物及石墨填充PTFE 复合材料的摩擦磨损性能研究

利用MHK-500 型环-块磨损试验机, 对MoS₂、CuS、PbS 及石墨(添加量均为30 vo l% )填充的聚四氟乙烯(PTFE) 复合材料在干摩擦条件下与GCr15 轴承钢对摩时的摩擦磨损性能进行了较为系统的研究, 并利用扫描电子显微镜(SEM ) 和光学显微镜对PTFE 复合材料的磨屑和摩擦磨损表面进行了观察。结果表明, 添加石墨降低了PTFE 的摩擦系数, 而添加MoS₂、CuS 及PbS则增大了PTFE 的摩擦系数; 同时, 添加MoS₂、CuS、PbS 及石墨均可将PTFE 的磨损量降低2 个数量级, 其中以PbS 的减磨效果为最好, 而MoS₂ 的减磨效果则最差。      

PTFE复合材料的摩擦学性能及力学性能

利用MM-200型磨损试验机,对不同填料填充PTFE复合材料的摩擦磨损性能进行了研究,并探讨了淬火处理对PTFE复合材料摩擦学性能及力学性能的影响.研究发现,几乎所有填料均可大大降低PTFE复合材料的磨损,但其对PTFE复合材料性能的影响差别较大.聚苯脂填充PTFE复合材料虽然具有良好的摩擦磨损性能,但是其拉伸强度较小.PI增大了PTFE复合材料的摩擦系数,随着PI含量的增加,PTFE复合材料的拉伸强度增大,而其伸长率则减小.CdO填充PTFE复合材料虽具有良好的摩擦性能,但其伸长率较大.淬火处理使PTFE复合材料的结晶度下降,从而导致PTFE复合材料的硬度减小、耐磨性变差.     

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     

Effect of oil and oil with graphite on tribological properties of glass filled PTFE polymer composites

Present work deals with the experimental investigation of tribological properties of GF-filled polymer composites considering three velocities, i.e. 0.5, 1 and 2.0 m/s and loads ranging from 15.7 N to 45.13 N keeping rest of the parameters constant. The test has been carried out for three materials, PTFE + 15% GF, PTFE + 25% GF and PTFE + 35% GF in wet (oil) and adding additive as graphite (5% wt) in oil. SAE 20W40 oil is used for the test. Friction and wear tests of PTFE composite against a counter surface of EN8 with surface finish of 0.56 μm are carried out at ambient conditions using pin-on-disc tribometre (TR-20), Ducom make, Bangalore. The results are tabulated and graphs are plotted. It has been found that load and wet conditions have significant effect on coefficient of friction and specific wear rate of the materials. Where as sliding velocity also plays little role in wear mechanism of the material. It is concluded from the experimental study that the specific wear rate in wet condition as well as by adding additives in lubricating oil with 5% (by wt.) has been declined. Also the specific wear rate decreases with normal load and sliding velocity. Wear of PTFE + GF composite decreases with increase in glass percentage. Microscopic analysis of pin and disc surface is made with optical microscope. The mathematical models has been developed by using regression analysis and found to be valid for the above tested parameters.     

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.     

微细锡青铜粉填充聚四氟乙烯的性能及应用

介绍了微细锡青铜粉ZQSn6 6 3对其填充聚四氟乙烯复合材料的物理机械性能、摩擦磨损性能的影响 ,简要介绍该复合材料在液压气动密封等方面的应用     

Wear and friction of aramid fibre and PTFE filled composites

The most widespread reinforcements and lubricants used for wear applications include polytetrafluoroethylene (PTFE), silicone, glass fibre, carbon fibre and aramid fibre. Of these, PTFE and aramid fibre play a key role in the production and performance of a huge variety of seal components. This article describes work undertaken at LNP Engineering Plastics to optimise the aramid fibre loadings in systems with and without PTFE. Mechanical properties, tribological performance and cost were all considered, and in addition the transfer film formed when these composites are wearing was examined.     

MgTiO3 filled PTFE composites for microwave substrate applications

MgTiO₃ filled PTFE composite substrates were fabricated for microwave circuit applications. The filler content in the PTFE matrix was varied from 30 to 70 wt%. Low loss MgTiO₃ ceramic powder was prepared by the solid state ceramic route. The phase formation of MgTiO₃ was studied by powder X-ray diffraction analysis. Morphology of the composites and dispersion of filler in the PTFE matrix was studied using scanning electron microscopy. Microwave dielectric properties of the composites with respect to filler loading were measured by stripline resonator method using Vector Network Analyzer. Different theoretical modeling approaches were used to predict the dielectric constant of PTFE ceramic composites with respect to filler loading. The linear coefficient of thermal expansion of the composites was investigated. Moisture absorption of the composites was found out conforming to IPC-TM-650 2.6.2.     

Ekonol和nano-TiO2改性聚四氟乙烯的摩擦磨损性能

采用纳米TiO2和Ekonol填充改性聚四氟乙烯,研究了复合材料的摩擦磨损性能,并讨论了磨损机理.研究表明:Ekonol含量为20%时,磨损率最低,仅为0.98×10-6mm3/(N·m).纳米TiO2的存在能够很好地改善10%Ekonol/PTFE复合材料的耐磨性能,纳米TiO2含量为6%时,复合材料的磨损率大大降低...     

石墨混凝土复合材料敏感特性基础研究

作为石墨混凝土复合材料机敏特性探索,从材料的表观密度、吸水率、抗压强度、体积电阻率等性能、特殊功能(电热、温敏、湿敏、压敏等)方面进行了基础性能研究,研究表明,随石墨掺量增加表观密度、体积电阻率、抗压强度降低,吸水率提高。     

液体羧基丁腈橡胶对纳米Si3N4粉体表面处理研究

用液体羧基丁腈橡胶作表面处理剂处理纳米氮化硅(Si3N4)粉体.结果表明:液体羧基丁腈橡胶包覆在纳米Si3N4粉体的表面,并与其发生了化学作用,有效地阻止了纳米Si3N4粉体的团聚;处理过的Si3N4粉体粒径明显减小,在有机溶剂中的分散性良好;亲水性减小,亲油性增加,表面自由能明显降低,处理后的纳米Si3N4粉体更容易在聚合物中分散.