环氧树脂基碳纤维复合材料摩擦层的摩擦性能研究

为了提高碳纤维(CF)自行车轮毂的寿命,研究了以SiC颗粒改性的环氧树脂为基体,CF平纹布为增强体的复合材料在不同载荷、不同摩擦环境及不同SiC含量情况下的磨损量与摩擦系数。结果表明,增大载荷和湿态(水润滑)的摩擦环境会不同程度地增加复合材料的磨损量,同时随着SiC填料含量的增加,复合材料的耐磨损性能增加。     

纤维增强铝硅酸盐玻璃陶瓷复合材料的摩擦学特性研究

在UMT-2微观磨损试验机（USA）上研究了SiC纤维增强铝硅酸盐玻璃陶瓷复合材料的摩擦学特性,且对摩擦表面进行了SEM观察和分析。研究结果表明：随着SiC纤维含量的增加,摩擦系数逐渐降低,但变化幅度较小。而当纤维含量（体积）低于25％时,复合材料的磨损量明显降低,而显微硬度却有较大提高;超过25％时,继续增加纤维的含量会导致复合材料耐磨性下降。SiC纤维增强铝硅酸盐玻璃陶瓷复合材料的摩擦系数随着载荷的增大显现先增大后减小的趋势,并且在载荷140N时达到最大值,而磨损量随着载荷的增大而增加。复合材料的主要磨损失效形式为磨粒磨损。     

陶瓷颗粒在无规共聚聚丙烯改性中的应用

采用熔融共混法制备了陶瓷颗粒/聚丙烯复合材料,探讨了陶瓷颗粒用量对复合材料流动性及力学性能的影响。结果表明：经过硅烷偶联剂KH-550处理的陶瓷颗粒与聚丙烯之间的界面粘接性加强,使复合材料的流动性和加工性能得到提高;随着陶瓷颗粒用量的增加,复合材料的拉伸强度呈现先增大后减小的趋势,而冲击强度却一直下降,在陶瓷颗粒用量为15%时综合性能较好。     

MCPA6/改性聚硅氧烷复合材料的摩擦磨损性能

采用阴离子聚合法制备了浇铸尼龙6(MCPA6)/改性羟基封端聚二甲基硅氧烷(MHPDMS)原位复合材料,研究了不同MHPDMS含量对复合材料在水润滑及干摩擦条件下的摩擦磨损性能影响。结果表明,在干摩擦条件下,复合材料的摩擦系数随滑动时间增加先增大后减小最后达到平衡,随着MHPDMS含量的增加,复合材料在稳定阶段的摩擦系数变化不大,但是磨损量逐渐减小,MHPDMS质量分数为4%的复合材料磨损量仅为MCPA6的25%;在水润滑条件下,复合材料的摩擦系数随滑动时间增加先增大后平衡,随着MHPDMS含量的增加,复合材料的稳定摩擦系数基本没有变化,磨损量先减小后增大,当MHPDMS质量分数为2%时,磨损量最小,为MCPA6的50%左右。复合材料在水润滑条件下的稳定摩擦系数比干摩擦条件下的小,但磨损量比干摩擦条件下的大很多。复合材料在干摩擦条件下的磨损机理主要是粘着磨损和疲劳磨损,而在水润滑条件下主要为犁削磨损和磨粒磨损。     

硫酸钡填充聚四氟乙烯复合材料的摩擦磨损性能研究

用M 2000型摩擦磨损试验机研究了干摩擦条件下硫酸钡、载荷、对磨时间对聚四氟乙烯复合材料摩擦磨损性能的影响。结果表明:在本实验采用的条件下,硫酸钡/PTFE复合材料的摩擦因数随着硫酸钡含量的增加而增大,抗磨损能力则有一个最佳含量;随着载荷的增加,材料的摩擦因数、磨损量和磨痕宽度也随之增大;磨损量随着对磨时间的延长,波动变小并趋于稳定。     

PTFE/BaSO4复合材料摩擦磨损性能研究

用M-2000型摩擦磨损试验机研究了干摩擦条件下BaSO4用量，载荷，对磨时间对聚四氟乙烯（PTFE）复合材料摩擦磨损性能的影响。在本实验条件下，PTFE/BaSO4复合材料的摩擦系灵敏随着BaSO4含量的增加而增大，抗磨损能力则有一个最佳含量；随着载荷的增加，材料的摩擦系数，磨损量和磨痕宽度也随之增大，磨损量随着对磨时间的延长而波动变小并趋于稳定。     

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。     

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。     

干摩擦条件下Ti（CN）—Al2O3复合陶瓷与金属摩擦副的摩擦学特性研究

为了模拟陶瓷刀具的磨损过程，对干摩擦条件下Ｔｉ（ＣＮ）－Ａｌ２Ｏ３复合陶瓷与纯铝、纯铁和不锈钢３种金属的摩擦、磨损特性进行了研究。结果表明：随着速度或载荷的增加，摩擦副中金属与陶瓷的磨损量均很快增大。金属的磨损量比对摩的陶瓷的磨损量大得多。３种金属中，铝的磨损量最大，铁和不锈钢的磨损量较小。与铝与摩的陶瓷的磨损量小是由于：（１）铝的硬度小，易剪切，不会对陶瓷造成较大损伤；（２）在摩擦过程中，金属和     

改性硫酸钙晶须填充PP/EPDM复合材料的制备和性能研究

采用钛酸酯偶联剂对硫酸钙晶须(CSW)表面进行有机化处理,得到改性硫酸钙晶须(OCSW),然后通过熔融挤出法制备了聚丙烯(PP)/三元乙丙橡胶(EPDM)/OCSW三元复合材料。采用红外光谱(IR)和扫描电子显微镜(SEM)对OCSW及PP/EPDM/OCSW复合材料进行了表征,同时考察了复合材料的力学性能及摩擦性能。结果表明:CSW表面产生了有机官能团,该有机化CSW在聚合物基体中能够均匀分散;随着OCSW含量的增加,复合材料的冲击强度不断降低,而拉伸强度则先增大后减小,其中当OCSW含量为15%时,复合材料的拉伸强度达到最大值。另外,OCSW的引入提高了PP/EPDM复合材料的耐磨性。随着OCSW含量的增加,复合材料的摩擦系数呈下降趋势,而磨损量则先减小后增大。     

Investigation on thermal stability and tribological properties of ZrB2 particles filling cyanate ester resin composites by experiments and numerical simulation

The thermal stability and tribological properties of cyanate ester (CE) composites filled with Zirconium boride (ZrB₂) particles were investigated by experimental and numerical simulation. The results of thermogravimetric analysis and differential scanning calorimetry showed that the thermal stability of composites was improved by introduction of ZrB₂ particles. The tribological properties of composites including friction coefficient and wear rate measured by pin‐on‐disk friction and wear tester were enhanced. Friction coefficient and wear rate of composites were decreased significantly with an increase of ZrB₂ particles content under dry and oil sliding conditions. The 5 wt% ZrB₂ particles reinforced CE resin composite presented optimal thermal stability and tribological performance due to good dispersion of ZrB₂ particles. The worn surfaces of composites were observed by scanning electron microscopy to explore wear mechanism, indicating that the dominant wear mechanism of composites was transformed from adhesive wear to abrasive wear after incorporation of ZrB₂ particles. Finite element model was established to study the distribution of friction stress. The results revealed that filling ZrB₂ particles in the friction process of composites could bear more friction stress than CE resin matrix, which further illustrated that abrasive wear is main wear mechanism of ZrB₂/CE resin composites. POLYM. ENG. SCI., 59:602–607, 2019. © 2018 Society of Plastics Engineers     

Friction and wear characteristics of ceramic particle filled polytetrafluoroethylene composites under oil-lubricated conditions

Five kinds of polytetrafluoroethylene (PTFE)-based composites were prepared: PTFE, PTFE + 30 vol % SiC, PTFE + 30 vol % Si₃N₄, PTFE + 30 vol % BN, and PTFE + 30 vol % B₂O₃. The friction and wear properties of these ceramic particle filled PTFE composites sliding against GCr15 bearing steel under both dry and liquid paraffin lubricated conditions were studied by using an MHK-500 ring-block wear tester. The worn surfaces and the transfer films formed on the surface of the GCr15 bearing steel of these PTFE composites were investigated by using a scanning electron microscope (SEM)and an optical microscope, respectively. The experimental results show that the ceramic particles of SiC, Si₃N₄, BN, and B₂O₃ can greatly reduce the wear of the PTFE composites; the wear-reducing action of Si₃N₄ is the most effective, that of SiC is the next most effective, then the BN, and that of B₂O₃ is the worst. We found that B₂O₃ reduces the friction coefficient of the PTFE composite but SiC, Si₃N₄, and BN increase the friction coefficients of the PTFE composites. However, the friction and wear properties of the ceramic particle filled PTFE composites can be greatly improved by lubrication with liquid paraffin, and the friction coefficients of the PTFE composites can be decreased by 1 order of magnitude. Under lubrication of liquid paraffin the friction coefficients of these ceramic particle filled PTFE composites decrease with an increase of load, but the wear of the PTFE composites increases with a load increase. The variations of the friction coefficients with load for these ceramic particle filled PTFE composites under lubrication of liquid paraffin can be properly described by the relationship between the friction coefficient (μ) and the simplified Sommerfeld variable N/P as given here. The investigations of the frictional surfaces show that the ceramic particles SiC, Si₃N₄, BN, and B₂O₃ enhance the adhesion of the transfer films of the PTFE composites to the surface of GCr15 bearing steel, so they greatly reduce the wear of the PTFE composites. However, the transfer of the PTFE composites onto the surface of the GCr15 bearing steel can be greatly reduced by lubrication with liquid paraffin, but the transfer still takes place. Meanwhile, the interactions between the liquid paraffin and the PTFE composites, especially the absorption of liquid paraffin into the surface layers of the PTFE composites, create some cracks on the worn surfaces of the ceramic particle filled PTFE composites; the creation and development of these cracks reduces the load-supporting capacity of the PTFE composites. This leads to the deterioration of the friction and wear properties of the PTFE composites under higher loads in liquid paraffin lubrication. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2611–2619, 1999     

Preparation of interpenetrating alumina–copper composites

To prepare interpenetrating alumina–copper composites, alumina foams were activated with titanium coating by chemical vapor deposition and then were infiltrated with molten copper by expendable casting process. The microstructure and phase composition of the composites were analyzed, and bending strength, electrical conductivity, friction and wear properties were tested. The results showed that the bonding between ceramic and metal was fine in the composites while no reactions took place between them because of the undissolved titanium coating. With increase of ceramic fraction, the electrical conductivity of the composite decreased, whereas the bending strength increased. The composite failure occurred by ductile fracture of the metal followed by fracture of the ceramic. The wear rate of the composites decreased with increase of ceramic fraction. And the wear of the composites was featured with ceramic struts peeling compared with ploughing and adhering wear for pure copper.     

聚苯硫醚复合材料摩擦性能的研究

考察了聚四氟乙烯（PTFE）、纳米无机粒子及不同含量和粒度的石墨填充改性聚苯硫醚（PPS）复合材料的摩擦磨损性能、力学性能；并采用扫描电镜（SEM）观测了磨损表面及对摩面的微观结构。结果表明：石墨的添加有利于在对摩面上形成转移物，而且随着石墨含量的增加，材料的摩擦系数明显降低，但磨耗量却有所升高，而石墨的粒度变化对材料的摩擦性能没有太大的影响；当PTFE和石墨两种固体润滑剂同时加入时，材料的力学强度有所降低，但其摩擦系数及磨耗量都得到明显改善，材料以疲劳磨损为主：纳米无机粒子的加入会使材料的磨耗量有所增大，其磨损机理转变为磨粒磨损。     

CE／TiO2复合材料的固化及摩擦磨损性能

采用纳米二氧化钛(TiO2)粒子改性氰酸酯树脂(CE),研究了复合材料的固化性能及摩擦磨损性能,分析微观形貌与性能变化之间的关联,总结出复合材料性能得以改善的微观机理。结果表明,少量TiO2粒子(质量分数≤4%)引入,可改善CE的固化性能及摩擦性能。纳米TiO2粒子经偶联剂处理并表面乳液接枝后,其质量分数为4%时,复合材料的摩擦系数降低约43.5%,磨损降低68.1%,耐磨性得到提高。     

Wear behavior of Al(OH)<Subscript>3</Subscript>-GF/epoxy composites in low velocity

Effects of fiber content, size, and weave form, and addition of particles on wear behaviors of epoxy composites are studied widely, while little investigation is paid on thermal effect in friction. In this study, effects of Al(OH)₃ powder on wear behavior of glass fiber reinforced epoxy composites are investigated. The experimental results show that within 6 wt%, the addition of Al(OH)₃ powder could decrease the friction surface temperature, friction coefficient, and wear mass loss of the composites. The decrease is attributed to the heat absorption when Al(OH)₃ powder decomposes. However, when the content of Al(OH)₃ powder increases to 9 wt%, the temperature, the friction coefficient, and the wear mass loss increase to nearly equal to those of pure epoxy resin-based composites. It is considered resulting from the decrease in mechanical property, which could lead to more serious fatigue wear. In a word, within a proper content, the addition of Al(OH)₃ powder in epoxy could increase the resistance to wear and friction.     

Tribological behaviour of powder metallurgy-processed aluminium hybrid composites with the addition of graphite solid lubricant

The tribological behaviour of powder metallurgy-processed Al 2024–5 wt% SiC–x wt% graphite (x=0, 5, and 10) hybrid composites was investigated using a pin-on-disc equipment. An orthogonal array, the signal-to-noise ratio and analysis of variance were employed to study the optimal testing parameters using Taguchi design of experiments. The analysis showed that the wear loss increased with increasing sliding distance and load but was reduced with increased graphite content. The coefficient of friction increased with increasing applied load and sliding speed. The composites with 5 wt% graphite had the lowest wear loss and coefficients of friction because of the self-lubricating effect of graphite. Conversely, due to the effect of the softness of graphite, there was an increase in wear loss and the coefficient of friction in composites with 10 wt% graphite content. The morphology of the worn-out surfaces and wear debris was examined to understand the wear mechanisms. The wear mechanism is dictated by the formation of both a delamination layer and mechanically mixed layer (MML). The overall results indicated that aluminium ceramic composites can be considered as an outstanding material where high strength and wear-resistant components are of major importance, particularly in the aerospace and automotive engineering sectors.     

Thermal conductivity and tribological properties of POM‐Cu composites

The polyoxymethylene (POM) composites with different copper contents were prepared by extrusion. The thermal conductivity and tribological behavior of POM‐Cu composites with various contents of copper particles were investigated by a hot disk thermal analyzer and an M‐2000 friction and abrasion testing machine, respectively. The effect of copper particles on the thermal conductivity of POM composites was negligible when copper content was below 10 wt %. As the copper content increased, the thermal conductivity of composites increased and reached 0.477 W m^?1 K^?1 for POM‐25 wt % Cu composite, which increased by 35.9% compared with that of unfilled POM. The incorporation of copper particles into POM reduced the friction coefficient of POM composites. The wear mechanisms of POM‐Cu composites were adhesive and abrasive wear. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Tribological behavior of graphene nanoplatelet reinforced 3YTZP composites

The tribological behavior of graphene nanoplatelet (GNP) reinforced 3 mol% yttria tetragonal zirconia polycrystals (3YTZP) composites with different GNP content (2.5, 5 and 10 vol%) was analyzed and discussed. Their dry sliding behavior was studied using a ball-on-disk geometry with zirconia balls as counterparts, using loads between 2 and 20 N at ambient conditions and compared to the behavior of a monolithic 3YTZP ceramic used as a reference material. The composites showed lower friction coefficients and higher wear resistance than the monolithic 3YTZP. An outstanding performance was achieved at 10 N, where the friction coefficient decreased from 0.6 to 0.3 and the wear rates decreased 3 orders of magnitude in comparison with the monolithic ceramic. A layer adhered to the worn surface was found for all the composites, but it did not acted as a lubricating film. The composites with the lowest GNP content showed an overall improved tribological behavior.