不同纳米材料填充聚四氟乙烯复合材料的力学性能研究

对不同纳米材料Si3N4、SiC、石墨、碳纳米管(CNTs)填充聚四氟乙烯(PTFE)复合材料进行了拉伸和硬度试验,观察了复合材料拉伸断面的微观结构。结果表明:几种填料均能不同程度地提高PTFE的硬度。不同填料对PTFE拉伸性能的影响不同,纳米SiC填充PTFE有较好的拉伸性能,碳纳米管的加入会使PTFE拉伸强度和断裂伸长率降幅较大,其复合材料呈脆性破坏。纳米SiC在PTFE基体中有较好的分散性,其与PTFE基体界面结合较好,而纳米Si3N4在PTFE中分散性不好,纳米石墨和碳纳米管与PTFE基体的界面结合不好。当SiC的质量分数为3%时,其综合性能最佳。     

偶联剂处理对PTFE/纳米TiC复合材料性能的影响

对纳米碳化钛(TiC)填充的聚四氟乙烯(PTFE)复合材料进行力学与摩擦学性能测试,研究纳米TiC质量分数、偶联剂处理对PTFE复合材料力学和摩擦磨损性能的影响,用扫描电子显微镜(SEM)对拉伸断口形貌进行观察,探讨复合材料增强机理.研究结果表明:纳米TiC的填充能提高PTFE复合材料的硬度、拉伸强度和耐磨性,但其冲击强度和减摩性能有所下降;偶联剂处理纳米TiC后,复合材料的拉伸强度、冲击强度、减摩性能有所提高.拉伸断口的微观分析表明:偶联剂处理纳米TiC在PTFE基体中有较好的分散性,与基体界面结合较好.     

纳米氮化物填充PTFE复合材料的性能研究

对纳米AlN、Si3N4、TiN填充的聚四氟乙烯(PTFE)复合材料进行了力学性能与摩擦磨损性能测试,研究了纳米粒子种类和含量对PTFE力学性能和摩擦磨损性能的影响,用扫描电子显微镜(SEM)对拉伸断面形貌进行观察,探讨了复合材料的相关机理。研究结果表明,纳米AlN、Si3N4、TiN的填充均能提高PTFE的硬度和耐磨性;PTFE纳米复合材料的拉伸强度和断裂伸长率均有所下降,PTFE/TiN复合材料的降幅最小;3种纳米填料均使PTFE的冲击强度下降,PTFE/TiN和PTFE/Si3N4复合材料冲击强度的降幅较小;SEM分析表明,纳米TiN在PTFE基体中有较好的分散性,与PTFE基体界面结合较好,纳米AlN、Si3N4在PTFE基体中的分散性较差。     

纳米粒子混合填充聚四氟乙烯复合材料的性能

采用模压成型法制备纳米Si3N4或SiC与纳米Al2O3混合填充的聚四氟乙烯(PTFE)复合材料,研究不同质量分数的纳米Si3N4或SiC与5%纳米Al2O3混合填充对PTFE复合材料力学与耐磨性能的影响,利用扫描电子显微镜(SEM)观察复合材料拉伸断面的微观结构,探讨其增强机理.结果表明:纳米SiN4或SiC与Al2O3混合填料均能使PTFE复合材料的硬度和耐磨性提高,且填充Si3N4/Al2O3的PTFE复合材料的硬度、拉伸性能、冲击强度和耐磨性均优于填充SiC/Al2O3的,其中5%Si3N4与Al2O3混合填充的PTFE复合材料有较好的综合性能.微观分析表明:Si3N4/Al2O3在PTFE基体中分散性较好,说明Si3N4与Al2O3具有较好的协同作用.     

不同粒径SiC改性PTFE复合材料的力学与摩擦学性能

以纳米碳化硅(SiC)、微米SiC及粉状SiC纤维填充聚四氟乙烯(PTFE)复合材料,对PTFE复合材料进行力学和摩擦学性能测试,分析对比不同粒径填料及其质量分数对PTFE复合材料力学和摩擦磨损性能的影响.用扫描电子显微镜(SEM)对拉伸断口形貌进行观察,探讨了复合材料增强机理.对比研究结果表明:不同粒径的SiC均能提高复合材料的硬度和耐磨性,SiC纤雏/PTFE复合材料有较高的拉伸强度和断裂伸长率,其综合性能最好.拉伸断口的微观分析表明:SiC纤维与PTFE界面粘结性能较好,对PTFE复合材料性能有一定的增强效果.     

纳米TiO2/PTFE复合材料的干摩擦磨损性能

利用磨损试验机、扫描电子显微镜等方法研究了表面处理与未处理纳米TiO2(质量分数为6％)填充聚四氟乙烯(PTFE)复合材料的干摩擦性能。结果表明，纳米TiO2能明显提高：PTFE耐磨性并改变其磨屑形成机理。表面处理纳米TiO2在PTFE中能较均匀分散。纳米TiO2填充PTFE复合材料的摩擦系数比PTFE稍大，纳米TiO2表面处理与否对PTFE复合材料的摩擦系数影响不大，但表面处理纳米TiO2填充聚四氟乙烯耐磨性比PTFE有显著提高，表面处理与表面未处理纳米TiO2填充PTFE复合材料的耐磨性比PTFE可分别提高7倍和3倍左右。导致PTFE磨损的重要机理是粘着磨损。     

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。     

纳米SiC及其与石墨、二硫化钼填充PTFE基复合材料摩擦磨损性能研究

用摩擦磨损试验机对纳米碳化硅（SiC）及其与石墨、二硫化钼（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,用洛氏硬度计对PTFE及其复合材料的硬度进行了测量,用扫描电子显微镜对PTFE复合材料磨损表面进行了观察。结果表明,纳米SiC的加入能提高PTFE复合材料的硬度和耐磨性,纳米SiC与MoS2混合填充会使PTFE复合材料的耐磨性提高更多,特别是在载荷增大时其耐磨效果更好。纳米SiC填充PTFE复合材料的摩擦因数比纯PTFE大,且随载荷增加有所减小, MoS2、石墨的加入可降低PTFE的摩擦因数。     

纳米氮化硅复合树脂的制备及性能研究

采用硅烷偶联剂(HG-560)对纳米氮化硅进行表面处理,选择超声波和高速剪切分散制备复合材料.运用TEM、FT-IR对复合材料进行研究,结果表明:纳米氮化硅处理后,在有机溶剂中分散性良好,改性剂包覆在其表面.并与其发生了化学作用.研究了纳米氮化硅粒子对其填充的环氧树脂6101力学性能,结果发现纳米Si3N4/EP复合材料的拉伸强度和耐冲击性都随纳米氮化硅不同的添加量有相应的提高.经偶联剂改性后,提高的幅度更大.TG表征,在120-380℃之间,纳米Si3N4复合材料的热失质量较空白基体的热失质量小;复合材料的热稳定性略有提高.     

PTFE/纳米SiC复合材料的摩擦磨损性能研究

利用冷压烧结法制备了不同含量的聚四氟乙烯/纳米碳化硅(PTFE/纳米SiC)复合材料。采用MM-200型摩擦磨损试验机在干摩擦条件下考察了纳米SiC含量及载荷对PTFE/纳米SiC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,并探讨了其磨损机理。结果表明,纳米SiC能够提高PTFE/纳米SiC复合材料的硬度和耐磨性,当纳米SiC质量分数为7%时,PTFE/纳米SiC复合材料的磨损量最小,摩擦系数也最小;随纳米SiC含量的增加,其摩擦系数有所增大;随着载荷的增大,PTFE/纳米SiC复合材料的磨损量增加。     

混杂填料增强聚四氟乙烯复合材料的摩擦学性能研究

采用MM-200型摩擦磨损试验机对纳米SiC、MoS2和石墨填充聚四氟乙烯(PTFE)复合材料在干摩擦条件下与45#钢对摩时的摩擦磨损性能进行了研究,探讨了MoS2、石墨及纳米SiC的协同效应。认为纳米SiC的加入大大提高了复合材料的承载能力,石墨、MoS2的加入减少PTFE复合材料的摩擦因数。利用扫描电子显微镜(SEM)对PTFE复合材料的摩擦面进行了观察。结果表明:实验中5%nano-SiC和3%MoS2填充PTFE复合材料的摩擦磨损性能最好,且在高载荷下的摩擦磨损性能尤为突出,具有一定的应用价值。     

Tribological and mechanical properties of carbon‐nanofiber‐filled polytetrafluoroethylene composites

The effects of various filler concentrations (0.1, 0.5, 1, 1.5, 2, 2.5, and 3 wt %) on the tribological and mechanical properties of carbon‐nanofiber (CNF)‐filled polytetrafluoroethylene (PTFE) composites were studied. Moreover, the influence of various loads (50, 100, 150, and 200 N) and sliding velocities (0.692 and 1.39 m/s) on the friction and wear behaviors of the PTFE composites was investigated. The results showed that the friction coefficients of the PTFE composites decreased initially up to a 0.5 wt % filler concentration and then increased, whereas the antiwear properties of the PTFE composites increased by 1–2 orders of magnitude in comparison with those of pure PTFE. The composite with a 2 wt % filler concentration had the best antiwear properties under all friction conditions. The friction coefficients of the CNF/PTFE composites decreased with increases in the load and sliding velocity, whereas the wear volume loss of the PTFE composites increased. At the same time, the results also indicated that the mechanical properties of the PTFE composites increased first up to a 1 wt % filler concentration and then decreased as the filler concentration was increased above 1 wt %. In comparison with pure PTFE, the impact strength, tensile strength, and elongation to break of the PTFE composites increased by 40, 20, and 70%, respectively, at a 1 wt % filler concentration. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2430–2437, 2007     

Friction and wear characteristics of PTFE composites filled with metal oxides under lubrication by oil

Four kinds of polytetrafluoroethylene(PTFE)-based composites, such as pure PTFE, PTFE+30%(v)PbO, PTFE+30%(v)Pb₃O₄, and PTFE+30%(v)Cu₂O composite, were prepared. The friction and wear properties of these metal oxides filled PTFE composites sliding against GCr15 bearing steel in both dry and lubricated conditions were studied by using an MHK-500 ring-block wear tester. Then the worn surfaces of these PTFE composites and the transfer films of these PTFE composites formed on the surface of GCr15 bearing steel were examined by using a Scanning Electron Microscope (SEM) and an Optical Microscope, respectively. Experimental results show that the friction and wear properties of these metal oxide-filled PTFE composites can be greatly improved by liquid paraffin lubrication, and the friction coefficients can be decreased by one order of magnitude. Meanwhile, the interactions between liquid paraffin and metal oxide-filled PTFE composites, especially the absorption of liquid paraffin into the surface layers of these PTFE composites, reduce the mechanical strength and the load-carrying capacity of these metal oxide-filled PTFE composites. This leads to the deterioration of the friction and wear properties of these PTFE composites. Investigations of the frictional surfaces show that Pb₃O₄, Cu₂O, and PbO enhance the adhesion of the transfer films to the surface of GCr15-bearing steel, and thus promote the transfer of the PTFE composites onto the surface of GCr15-bearing steel. Therefore, they greatly reduce the wear of the PTFE composites. However, the transfer of these PTFE composites onto the counterfaces can be greatly reduced by lubrication with liquid paraffin. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 85–93, 1997     

纳米碳化硅改性聚四氟乙烯复合材料的摩擦磨损性能

采用不同偶联剂对纳米碳化硅进行表面处理后,制备了聚四氟乙烯/纳米碳化硅复合材料,考察了偶联剂种类和含量随载荷变化对复合材料摩擦磨损性能的影响,并利用扫描电子显微镜观察和分析了复合材料磨损表面形貌及其磨损机理。结果表明,经表面处理的纳米碳化硅填充后的复合材料硬度和摩擦磨损性能均有提高,以钛酸酯偶联剂（NDZ101）处理效果最好;随着偶联剂含量的增大,钛酸酯偶联剂（NDZ101）处理的复合材料的磨损量和摩擦因数均增大,偶联剂最佳含量为填料质量的1 %;偶联剂处理后的纳米碳化硅与基体之间形成了良好的界面,复合材料的磨损以黏着磨损和磨粒磨损为主。     

Mechanical and tribological properties of polyoxymethylene modified with nanoparticles and solid lubricants

Polyoxymethylene (POM) composites modified with nanoparticles, polytetrafluoroethylene (PTFE) and MoS₂ were prepared by a twin‐screw extruder. The effect of nanoparticles and solid lubricant PTFE/MoS₂ on mechanical and tribological properties of the composites were studied. Tribological tests were conducted on an Amsler friction and wear tester using a block‐on‐ring arrangement under dry sliding and oil lubricated conditions, respectively. The results showed that generally speaking POM nanocomposites had better stiffness and tribological properties than corresponding POM composites attributed to the high surface energy of nanoparticles, except that the tensile strength of three composites and dry‐sliding tribological properties of POM/3%Al₂O₃ nanocomposite decreased due to the agglomeration of nanoparticles. Tribological properties differed under dry sliding and oil lubricated conditions. The friction coefficient and wear volume of POM nanocomposites under oil lubricated condition decreased significantly. The increased deformation resistance supported the increased wear resistance of POM nanocomposites. POM/PTFE/MoS₂/3%Al₂O₃ nanocomposite had the best mechanical and tribological properties of all three composites, which was attributed to the synergistic effect of nanoparticles and PTFE/MoS₂. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Tribological behaviors of carbon series additions reinforced CF/PTFE composites at high speed

The tribological, mechanical, and thermal properties of carbon series additions reinforced CF/PTFE composites at high speed were investigated. In this work, carbon fiber (CF) filled polytetrafluoroethylene (PTFE) composites, which have excellent tribological properties under normal sliding speed (1.4 m/s), were filled with some carbon materials [graphene (GE), carbon nanotubes (CNTs) and graphite (Gr)] respectively to investigate the tribological properties of CF/PTFE composites at high sliding speed (2.1 and 2.5 m/s). The results reveal that the carbon series additions can improve the friction and anti‐wear performances of CF/PTFE, and GE is the most effective filler. The wear rate of 0.8 wt % GE/CF/PTFE was decreased by 50 ? 55%, 55 ? 60%, 40 ? 45% at 1.4, 2.1, and 2.5 m/s compared with CF/PTFE. SEM study shows GE could be helpful to form smooth and continuous transfer film on the surface of counterparts. Meanwhile, GE can improve its tensile strength and elastic modulus obviously. Thin layer structure of GE could enhance the thermal conductivity, which can be helpful to dissipate heat of CF/PTFE composites wear surface. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43236.