纳米材料填充改性PTFE力学性能的研究

利用四种纳米粒子填充改性聚四氟乙烯(PTFE),并研究了改性PTFE复合材料的物理机械性能。结果表明:纳米粒子会使PTFE的力学性能发生变化,提高了复合材料的硬度;但会使复合材料的拉伸强度和断裂伸长率降低。     

纳米Al_2O_3改性PTFE复合保持架材料性能研究

制备了纳米Al_2O_3改性PTFE复合保持架材料,研究了不同纳米Al_2O_3含量对复合材料硬度、压缩强度、拉伸强度及摩擦性能的影响。通过对复合保持架材料摩擦磨损机理分析认为,纳米Al_2O_3质量分数为5%时,复合保持架材料结构最稳定,对比了该配方复合材料常温、液氮、液氢下力学性能。结果表明:与常温相比,液氮和液氢温度下复合保持架材料的拉伸强度和弹性模量有所增加,冲击强度有所下降,断裂伸长率显著下降,呈典型脆性材料特性。     

纳米及微米石墨/聚四氟乙烯复合材料的力学与耐磨性能

用热压成型法分别制备了纳米、微米石墨填充聚四氟乙烯(PTFE)的复合材料,对纯PTFE和复合材料进行了硬度、耐磨性和拉伸试验,用SEM观察了拉伸断口形貌.结果表明:纳米和微米石墨均能提高复合材料的硬度和耐磨性,而复合材料的抗拉强度和断后伸长率均有所下降;纳米石墨/PTFE复合材科的硬度、耐磨性、抗拉强度和断后伸长率均比微米石墨/PTFE复合材料的高;当纳米石墨质量分数为7%时,复合材料的综合性能较好,当质量分数大于7%后,复合材料的断后伸长率迅速下降;纳米石墨与PTFE相容性较好,在PTFE中的分布均匀.     

表面处理纳米Si3N4/PTFE复合材料的力学与摩擦学性能

用热压成型法制备了纳米Si3N4填充的聚四氟乙烯(PTFE)复合材料,研究了纳米Si3N4质量分数、表面处理对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,分析了复合材料增强机制.结果表明:未处理纳米Si3N4能提高复合材料的硬度和耐磨性,但拉伸强度和冲击强度有所降低;表面处理纳米Si3N4后,PTFE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,表面处理Si3N4在PTFE基体中有较好的分散性,与PTFE基体界面结合较好.     

碳纤维增强酚醛树脂/石墨复合材料双极板的性能

研究了碳纤维表面处理方法及其含量对碳纤维增强酚醛树脂／石墨复合材料导电性能与力学性能的影响。结果表明：空气氧化处理碳纤维表面形成微孔和刻蚀沟槽，容易形成应力集中，复合材料的强度不高；空气加液相氧化处理填充了碳纤维表面的微裂纹，对复合材料有一定的补强作用；液相氧化处理有利于提高碳纤维表面活性以及碳纤维的均匀分散性，使材料表现出较好的力学性能与导电性能；随碳纤维含量增多，材料电导率变小，材料强度开始增大，达到最大值后材料强度下降。对碳纤维进行液相氧化处理，碳纤维含量在3％～4％时复合材料的力学性能与导电性能最好。     

钛酸钾晶须增强聚四氟乙烯复合材料摩擦磨损机制的研究

研究了钛酸钾晶须(PTW)对聚四氟乙烯(PTFE)复合材料力学及摩擦学性能的影响,并与碳纤维(CF)和玻璃纤维(GF)的填充效果进行了比较.结果表明:加入PTW后,PTFE的硬度、冲击强度、拉伸强度、弯曲强度、压缩强度及耐磨性能比纯PTFE的分别约提高了10%、30%、20%、15%、20%和300倍;PTW/PTFE的耐磨性能要优于GF/PTFE及CF/PTFE.SEM研究表明: PTW/PTFE的内部结构比GF/PTFE及CF/PTFE的均匀致密,具有显微增强效果;PTW/PTFE的磨损面比GF/PTFE及CF/PTFE的要平整,其转移膜也较GF/PTFE及CF/PTFE的更为均匀、连续、致密.     

不同填料增强Ekonol/PTFE复合材料力学性能和摩擦学性能的研究

研究了不同的无机填料对Ekonol/PrFE复合材料的力学性能和摩擦学性能的影响,用扫描电子显微镜观察了复合材料磨损后的表面形貌,并探讨了其磨损机制.结果表明:无机填料的加入改善了Ekonol/PTFE复合材料的力学性能和抗磨损性能.添加石墨与MoS2的Ekonol/PrFE复合材料的力学性能最好,当石墨与MoS2的质量分数为5%和3%时.复合材料的力学性能达到最佳值,拉伸强度提高了34%,弯曲强度提高了62%,弯曲模量提高了75%;添加石墨的Ekonol/PTFE复合材料的抗磨损性能最好,磨损体积最大减少了42%,且受外界条件变化的影响较小.SEM分析表明:在低速低载荷下,复合材料主要以粘着磨损为主;在高速高载荷下,主要以磨粒磨损为主.     

PVC／ABS复合材料的力学性能研究

应用冲击试验机、材料试验机和其它一些相关仪器对PVC／ABS复合材料的力学性能进行了测试和研究,结果表明,该复合材料的性能是组分的函数,ABS的加入改善了其力学性能。随着ABS含量的增加,复合材料PVC／AnS的冲击强度和断裂仲长率明显提高,而拉伸强度和拉伸模量几乎随ABS含量的增加而单调地下降。     

不同纤维增强和不同固体润滑剂改性PTFE复合材料的摩擦磨损性能

以碳纤维或玻璃纤维为增强纤维,二硫化钼(MoS_2)或石墨为固体润滑剂,制备了不同配方的聚四氟乙烯(PTFE)复合材料;在干摩擦和油润滑条件下对复合材料进行了摩擦磨损试验,观察了其磨损形貌,并分析了不同增强纤维和固体润滑剂对复合材料摩擦磨损性能的影响。结果表明:在干摩擦条件下,当固体润滑剂相同时,与玻璃纤维增强的相比,碳纤维增强PTFE复合材料的磨痕宽度更小、摩擦因数更大,而当增强纤维相同时,MoS_2改性PTFE复合材料的磨痕宽度比石墨改性的小,摩擦因数比石墨改性的大;在油润滑条件下,当固体润滑剂相同时,碳纤维增强PTFE复合材料的磨痕宽度比玻璃纤维增强的小,摩擦因数比玻璃纤维增强的大,当增强纤维相同时,MoS_2改性PTFE复合材料的磨痕宽度比石墨改性的略低,摩擦因数比石墨改性的大。     

环氧树脂对玻纤增强尼龙6力学性能的影响

本文对玻纤增强尼龙6复合材料(GFPA)的力学性能进行研究,结果表明随着玻纤含量的增加,玻纤增强尼龙6复合材料的各项力学性能逐渐提高。同时得出加入少量环氧树脂可明显提高GFPA的力学性能,通过对拉伸测试断口分析得出这主要是由于环氧树脂的加入提高了GF与PA6的粘接强度。     

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。     

填料对聚四氟乙烯工程塑料改性的影响

研究了MoS2、PbS、石墨、玻璃纤维、碳纤维等填料对聚四氟乙烯（PTFE）工程塑料抗磨损、摩察系数、表面硬度、耐冲击强度等性能的影响。结果表明：填料可将PTFE的磨损量降低2个数量级，石墨和适量硬质填料的协同作用对PTFE的改性效果比较理想，既降低了PTFE的磨损量，增大了表面硬度，又提高了耐冲击强度。对其作用机理进行了分析和探讨，为材料的性能优化提供理论依据。     

纤维改性聚四氟乙烯密封材料的制备及性能研究

以碳纤粉、短玻纤为主要增强纤维,采用冷压成型和自由烧结工艺制备改性聚四氟乙烯(PTFE)密封复合材料.分析了增强纤维含量以及不同纤维表面处理工艺对材料抗拉强度和压缩回弹率、应力松弛率等密封性能的影响.结果表明:增强纤维含量对材料密封性能具有显著影响,而表面处理工艺的影响则不甚明显;碳纤粉对PTFE的改性效果明显好于短玻纤;具有适当填充量的PTFE密封复合材料可满足200 ℃下长期使用的要求.     

Effect of rare earths on mechanical and tribological properties of carbon fibers reinforced PTFE composite

The effect of a rare earth (RE) surface treatment on the mechanical and tribological properties of carbon fiber (CF) reinforced polytetrafluoroethylene (PTFE) composites was experimentally investigated. The tensile properties of the CF reinforced PTFE (CF/PTFE) composites treated with air oxidation and RE modifier were superior to those of untreated CF/PTFE composites, while RE treatment was most effective in promoting the tensile strength and strain at break of the CF/PTFE composite. The bending strength of the RE treated CF/PTFE composite was improved by about 16% compared with that of untreated composites, while 2% improvement was achieved by air oxidation. Under oil-lubricated conditions, RE treatment was more effective than air oxidation to reduce the friction coefficient and wear of PTFE composite. RE treatment effectively improved the interfacial adhesion between CF and PTFE. The strong interfacial coupling of the composite made CF not easy to detach from the PTFE matrix, and prevented the rubbing-off of PTFE, accordingly improved the friction and wear properties of the composite.     

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.     

Fiber Traction Printing: A 3D Printing Method of Continuous Fiber Reinforced Metal Matrix Composite

A novel metal matrix composite freeform fabrication approach, fiber traction printing(FTP), is demonstrated through controlling the wetting behavior between fibers and the matrix. This process utilizes the fiber bundle to control the cross-sectional shape of the liquid metal, shaping it from circular to rectangular which is more precise. The FTP process could resolve manufacturing diffculties in the complex structure of continuous fiber reinforced metal matrix composites. The printing of the first layer monofilament is discussed in detail, and the effects of the fibrous coating thickness on the mechanical properties and microstructures of the composite are also investigated in this paper. The composite material prepared by the FTP process has a tensile strength of 235.2 MPa, which is close to that of composites fabricated by conventional processes. The complex structures are printed to demonstrate the advantages and innovations of this approach. Moreover, the FTP method is suited to other material systems with good wettability, such as modified carbon fiber, surfactants, and aluminum alloys.     

A correlation between the tribological and mechanical properties of short carbon fibers reinforced PEEK materials with different fiber orientations

In this work the effect of fiber orientation on the mechanical and tribological properties of SCF (short carbon fibers)/PTFE (poly-tetra-fluor-ethylene)/graphite filled PEEK (poly-ether-ether-keton) composites was studied. The composites were manufactured by using injection molding technique. Mechanical and tribological experiments were conducted to measure the compression modulus, compression strength and wear resistance. A correlation of the tribological and mechanical properties considering different fiber orientations was studied. Additionally to the fiber orientation influence, the wear resistance under low and high pressures was examined. The results analyses, based on scratch experiments and scanning electron microscope (SEM) inspections explain how the fiber orientation influences the mechanical performance and the tribological properties of the considered materials.     

短玻纤填充PTFE复合材料磨损性能研究

用机械共混、冷压成型和烧结的方法制备了不同质量分数(10％～40％)的短玻纤填充PTFE复合材料样品。用MM-200型磨损试验机评价了不同样品在于摩擦定载荷条件下的磨损性能；用扫描电子显微镜(SEM)对试样的磨损表面进行了观察分析。结果表明：在所采用的实验条件下，随短玻纤含量的增加，抗磨损性能先增大后减小，在含量为30％取得最佳抗磨损性能。     

真空导入树脂模塑工艺对EKB1100/430LV复合材料纤维含量及力学性能的影响

通过真空导入树脂模塑工艺制备了EKB1100/430LV复合材料,研究了不同工艺参数对复合材料中玻璃纤维含量及力学性能的影响。结果表明:纤维含量随真空度的增大而增加,靠近树脂注入口区域的纤维含量较低,而真空抽口附近的纤维含量最高;复合材料的拉伸强度和压缩强度也随真空度的增大而增大;充模前对预成型体实施压缩可提高纤维含量;充模过程中溢流一定的树脂可提高弯曲强度和层间剪切强度。     

纳米ZnO填充PTFE复合材料的力学及摩擦学性能

通过机械搅拌和超声分散制备纳米ZnO填充PTFE复合材料,研究纳米ZnO填充量对复合材料力学及摩擦磨损性能的影响。结果表明:当ZnO质量分数小于3%时,复合材料的拉伸强度与纯PTFE相比略有增高;复合材料的密度、硬度、摩擦因数随ZnO填充量的增加而逐渐增大;当ZnO填充质量分数为1%～3%时,复合材料的磨耗量大幅下降,但若继续增加ZnO填充量,复合材料的磨耗量却变化不大。