含纳米CaCO3,Cu混合物添加剂润滑油的研究

采用纳米碳酸钙、纳米铜粒子混合物作为润滑油添加剂.选择合适的表面活性剂制备含纳米碳酸钙和纳米铜粒子混合物添加剂的润滑油.利用四球摩擦磨损试验机考察含纳米碳酸钙、纳米铜粒子添加剂的润滑油的摩擦学性能;用扫描电子显微镜(SEM)观察表面磨痕的形貌.用原子力显微镜和扫描电子显微镜(SEM)观察分析在磨损表面纳米粒子的形态与分布.研究结果表明,纳米碳酸钙、纳米铜的粒子混合物的最佳添加量为:纳米碳酸钙与纳米铜的总添加量的质量分数为0.6%,纳米碳酸钙与纳米铜的质量分数之比为1∶1;该润滑油具有最佳的摩擦学性能.研究还表明,润滑油中纳米碳酸钙、纳米铜粒子混合物添加剂的优良摩擦学性能与纳米粒子在表面存在形态相关.     

改性纳米Si_3N_4/环氧树脂复合材料的摩擦磨损特性

研究纳米氮化硅粒子(Si3N4)填充环氧树脂复合材料的滑动干摩擦磨损特性,着重探讨纳米粒子表面接枝共聚改性、粒子含量对复合材料摩擦磨损性能的影响。通过对复合材料磨损表面的粗糙度及形貌分析探讨复合材料的磨损机理。结果表明,纳米氮化硅粒子能在很低的含量下(0.18%(体积分数,下同))显著提高环氧树脂的耐磨性、并降低其摩擦系数,而经过接枝共聚改性的纳米Si3N4粒子填充的复合材料的上述性能改善更为明显,耐磨性比Si3N4/EP提高3倍,摩擦系数降低20%。这说明,在Si3N4纳米粒子表面进行接枝共聚后,有利于加强粒子与基体的界面结合,从而改善复合材料的摩擦学性能。     

石墨烯纳米片/聚四氟乙烯复合材料的制备及磨损性能研究

以石墨烯纳米片、聚四氟乙烯(PTFE)为原料,制备了石墨烯纳米片/聚四氟乙烯复合材料。研究了不同石墨烯纳米片含量(0,0.25%,0.50%,0.75%,1.00%,1.25%(质量分数))对复合材料导热性能、力学性能、摩擦磨损性能的影响。结果表明,随着聚四氟乙烯中石墨烯纳米片含量的增加,复合材料的微观结构趋于无序,其导热系数逐渐增大,导热性能逐步增强;当石墨烯纳米片含量为0.75%(质量分数)时,复合材料的抗拉强度和断裂伸长率最佳;当石墨烯纳米片含量为1.25%(质量分数)时,复合材料的摩擦系数最小,为0.195,磨损量最低,仅37 mg。磨损实验前后复合材料的碳结构发生了变化,磨损后复合材料的缺陷增大,石墨化程度大大降低,石墨烯纳米片/聚四氟乙烯复合材料具有良好的耐磨损性能。     

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%.     

纳米碳化硅填充环氧树脂复合材料的摩擦磨损特性

以提高环氧树脂的摩擦磨损性能为目的,研究了纳米碳化硅粒子填充环氧树脂复合材料的滑动干摩擦磨损特性,着重探讨纳米粒子表面接枝改性、纳米粒子含量、摩擦条件等对复合材料摩擦学性能的影响。通过对复合材料磨损表面的形貌分析,以及复合材料的热变形性能和表面硬度的测定,探讨了复合材料的磨损机理。结果表明,纳米碳化硅粒子能在很低的含量下提高环氧树脂耐磨性、并降低其摩擦系数,而经过接枝处理后的纳米碳化硅粒子填充复合材料的上述性能改善更为明显,耐磨性比环氧树脂提高近4倍,摩擦系数降低36%。这说明在SiC纳米粒子表面引入聚丙烯酰胺接枝链后,由于界面的强相互作用 ( 包括化学键合与链纠缠),有效地提高了复合材料的抵抗裂纹引发能力等性能,从而有利于改善其摩擦学性能。      

聚苯乙烯/纳米三氧化二镧复合材料的制备及性能研究

制备了聚苯乙烯/纳米三氧化二镧系列复合材料,考察了板材成型工艺条件对材料固化后综合性能的影响,对比了纯板材与复合材料板材在力学性能、硬度等方面的差异。结果表明,当表面有机化处理后的纳米La_2O_3质量分数为0.3%时,复合材料板材的冲击、弯曲性能均出现最高值,冲击强度比纯板材提高154.70%;弯曲强度比纯板材提高40.10%;邵氏强度在研究的质量分数范围内,随着纳米La_2O_3粒子质量分数的增加而线性上升。总结了复合材料板材性能得以提升的原因。     

酸性介质中不同聚醚醚酮纳微复合材料的耐蚀与耐磨性能

分别研究了不同质量分数的纳米SiC填充碳纤维/聚醚醚酮(CF/PEEK)和钛酸钾晶须/聚醚醚酮(PTW/PEEK)复合材料在pH=1的硫酸溶液中的耐蚀性能和摩擦学性能。采用电化学工作站评价复合材料的耐蚀性能,使用差热分析仪与扫描电镜分析了复合材料的玻璃化转变温度与磨损面的形貌,并讨论了复合材料的防腐和耐磨机理。结果表明,在腐蚀性介质中质量分数2.5%纳米SiC增强复合材料的耐蚀性最佳,此时纳米SiC增强PTW/PEEK复合材料的耐蚀性能优于纳米SiC增强CF/PEEK复合材料。在酸性环境下,2.5%纳米SiC增强复合材料的摩擦学性能最佳,在滑动摩擦过程中,PTW不但起到了承载的作用,而且暴露的PTW可以填充到对偶面的划痕之中,减小了纤维对复合材料的刮擦以及磨粒磨损程度,所以相同含量纳米SiC增强PTW/PEEK复合材料优于CF/PEEK的摩擦学性能,其耐磨性是CF/PEEK复合材料的5倍。     

纳米SiO2对聚醚砜酮复合材料摩擦学性能的影响

在MM-2000型摩擦磨损试验机上考察了不同载荷和速度下纳米SiO2含量对聚醚砜酮（PPESK）复合材料摩擦磨损性能的影响，并利用扫描电子显微镜（SEM）观察分析PPESK及纳米SiO2/PPESK复合材料磨损表面形貌及磨损机理，结果表明：纳米SiO2不但可以提高PPESK的耐磨性，而且还有较好的减摩作用，在本研究的试验条件下，当纳米SiO2的质量分数为25%时，填充PPESK复合材料具有最佳摩擦学性能。随着载荷的增大，填充PPESK的摩擦系数降低，填料含量在20%质量分数以下时随载荷增大其耐磨性提高较明显，而填料含量超过20%质量分数时载荷对复合材料耐磨性的影响不大。     

SiO2-竹纤维协同改性对环氧树脂基复合材料摩擦磨损性能的影响

为了提高环氧树脂（EP）基复合材料的摩擦磨损性能,制备低成本耐磨材料,选用纳米SiO₂粒子和竹纤维（BF）等作为填料,制备了纳米SiO₂-BF/EP复合材料。通过摩擦磨损测试仪、动态热机械分析仪和SEM研究了纳米粒子和纤维对复合材料的耐磨性能、热学性能及微观结构的影响。研究结果表明:单独加入BF后,BF/EP复合材料的体积磨损较同条件下的纯EP大幅度降低,最多可降低71%;同时加入SiO₂纳米粒子和BF后,对纳米SiO₂-BF/EP复合材料的玻璃化转变温度和体积磨损影响显著,玻璃化转变温度比纯EP提高了11℃,达到了124℃,体积磨损较同条件下的纯EP下降了约75.3%。      

新型自润滑YBa_2Cu_3O_7/Cu复合材料的制备及性能

采用草酸盐共沉淀法制备了YBa2Cu3O7(YBCO)粉体,利用真空热压烧结法制备了不同质量分数的YBCO/Cu复合材料,测定了YBCO/Cu复合材料的密度、硬度和电导率,利用MMU-5GA磨损试验机对YBCO/Cu复合材料进行了摩擦磨损试验。采用XRD、SEM和TEM对YBCO粉体及YBCO/Cu复合材料的微观结构、磨损表面形貌及物相组成进行了表征。研究了YBCO质量分数对YBCO/Cu复合材料组织及性能的影响。结果表明:所制备的YBCO粉体物相为Y123相,其层状结构明显,粉体纯度高、杂质少,粒度达到纳米级;纳米YBCO可显著细化YBCO/Cu复合材料的基体组织,提高复合材料的摩擦学性能。随着YBCO质量分数增加,基体组织中纳米YBCO颗粒分布均匀度降低,逐渐出现团聚;YBCO/Cu复合材料的电导率和密度降低,硬度先升高后降低,摩擦系数逐渐减小。3%YBCO/Cu复合材料的摩擦磨损性能最好。YBCO/Cu复合材料强化机制为Orowan强化、热错配强化和细晶强化;其磨损机制主要为塑变磨损、磨粒磨损和疲劳剥落。     

三维编织复合材料在润滑条件下的摩擦性能

利用树脂传递模塑(RTM)工艺制备了三维编织炭纤维/环氧(C3D/EP)复合材料.采用MM-200型摩擦磨损试验机研究了该材料润滑条件下的摩擦磨损性能,探讨了载荷及滑动速度等外界因素的影响;并采用XL30 ESEM电子显微镜观察磨损表面形貌,分析了其磨损机理.结果表明,润滑条件下复合材料的摩擦磨损性能远优于干摩擦,且磨合期较短;随着载荷的增加,复合材料的摩擦系数和比磨损率降低,但滑动速度对摩擦磨损性能的影响很小;润滑条件下的磨损机理主要是磨粒磨损.     

Friction and wear behavior of three-dimensional braided carbon fiber/epoxy composites under lubricated sliding conditions

The friction and wear characteristics of three-dimensional (3D) braided carbon fiber-epoxy (C_3D/EP) composites under lubricated sliding conditions against a quenched medium-carbon steel counterface were studied. Wear tests were performed under different loads at two velocities. Comparative wear tests under dry conditions were carried out to investigate the influence of lubrication. Tribological properties of the C_3D/EP composites with various fiber loadings and two different fiber-matrix adhesion strengths were assessed. It was found that the lubricated contact promoted lower wear rates and friction coefficients. Compared to dry sliding, the tribological performance of the C_3D/EP composites under lubrication was less dependent on fiber content, fiber-matrix bonding, load, and velocity than dry sliding. The worn surfaces of the C_3D/EP composites were analyzed by scanning electron microscopy (SEM) to explore the relevant mechanisms.     

三维编织碳复合材料的制备及其力学性能研究

采用真空辅助RTM工艺制备了三维编织碳纤维增强环氧树脂(C3D/EP)复合材料,通过对树脂的粘度特性和固化特性的分析,确定了最佳的工艺参数.金相显微镜对复合材料微观结构的观察表明树脂对纤维的浸润良好.同时,还研究了该工艺制备的C3D/EP复合材料的力学性能,结果表明随着纤维体积比的增加,复合材料的硬度、弯曲强度和冲击强度均提高,断口的扫描电镜观察表明复合材料的破坏方式是以脆性断裂为主.     

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。     

Role of micro/nano fillers on mechanical and tribological properties of polyamide66/polypropylene composites

The objectives of this research article is to evaluate the mechanical and tribological properties of polyamide66/polypropylene (PA66/PP) blend, graphite (Gr) filled PA66/PP, nanoclay (NC) filled PA66/PP and NC plus short carbon fiber (NC + SCF) filled PA66/PP composites. All composites were fabricated using a twin screw extruder followed by injection molding. The mechanical properties such as tensile, flexure, and impact strengths were investigated in accordance with ASTM standards. The friction and sliding wear behaviour was studied under dry sliding conditions against hard steel on a pin-on-disc apparatus. Scanning electron micrographs were used to analyze the fracture morphologies. From the experimental investigation, it was found that the presence of NC and SCF fillers improved the hardness of PA66/PP blend. Further, the study reveals that the tensile and flexural strength of NC + SCF filled PA66/PP was higher than that of PA66/PP blend. Inclusion of micro and nanofillers reduced the wear rate of PA66/PP blend. The wear loss of the composites increased with increasing sliding velocity. The lowest wear rate was observed for the blend with nanoclay and SCF fillers. The wear rates of the blends with micro/nanofillers vary from 30–81% and lower than that of PA66/PP blend. The wear resistance of the PA66/PP composites was found to be related to the stability of the transfer film on the counterface. The results have been supplemented with scanning electron micrographs to help understand the possible wear mechanisms.     

MoO3-氧化碳纳米管改性玻璃纤维/环氧树脂复合材料的摩擦磨损性能

为改善玻璃纤维/环氧树脂(GF/EP)复合材料的耐摩擦磨损性能,采用真空抽滤法制备柔性MoO₃纳米带-氧化碳纳米管膜(m-MoO₃-OCNTs),并结合真空辅助树脂转移模塑(VARTM)工艺制备m-MoO₃-OCNTs改性GF/EP (m-MoO₃-OCNTs-(GF/EP))复合材料。结果表明,m-MoO₃-OCNTs显著提高了GF/EP复合材料的导热系数和自润滑性能,在干摩擦测试条件下,可在m-MoO₃-OCNTs-(GF/EP)复合材料与对偶面之间形成有效传递摩擦热的高质量连续转移膜;与GF/EP复合材料相比,m-MoO₃-OCNTs-(GF/EP)复合材料的耐摩擦磨损磨性能提高了约4倍。     

Study on the synergistic effect of carbon fiber and graphite and nanoparticle on the friction and wear behavior of polyimide composites

In this paper, the effect of short carbon fiber (SCF), graphite (Gr) and nano-Si₃N₄ on the friction and wear behavior of polyimide (PI) composites were studied using a block-on-ring arrangement. Experimental results revealed that single incorporation of SCF and Gr can improve the friction-reducing and anti-wear abilities of the PI composites significantly. However, nano-Si₃N₄ deteriorated the wear resistance of the PI composite drastically as single filler. A synergistic effect was found for the combination of nano-Si₃N₄ and SCF and Gr, which lead to the best tribological properties. It also can be found that the filled PI composites exhibited better tribological properties under higher PV product (the product of load and sliding speed). Moreover, the filled PI composites showed better tribological properties under oil lubrication and worse tribological properties under water lubrication compared with that under dry sliding condition.     

Tribological properties of MoS<Subscript>2</Subscript> and carbon fiber reinforced polyimide composites

The tribological properties of carbon fiber reinforced polyimide (PI) composites with different MoS₂ containing sliding against GCr15 steel were comparatively evaluated on an M-2000 model ring-on-block test rig. The wear mechanisms were also comparatively discussed, based on scanning electron microscopic examination of the worn surface of the PI composites and the transfer film formed on the counterpart. It was found that small incorporation of MoS₂ was harmful to the improvement of friction and wear behaviors of carbon fiber reinforced PI composites. However, it was found that the increasing filler of MoS₂ significantly improved the wear resistance and decreased the friction coefficient of carbon fiber reinforced PI composites. It was also found that the tribological properties of MoS₂ and short carbon fiber reinforced PI composites were closely related with the sliding condition such as sliding rate and applied load.     

Friction and wear studies of polyimide composites filled with short carbon fibers and graphite and micro SiO2

Polyimide (PI) composites filled with short carbon fibers (SCFs), micro SiO₂, and graphite (Gr) particles were prepared by means of hot press molding technique. The friction and wear properties of the resulting composites sliding against GCr15 steel were investigated on a model ring-on-block test rig. Experimental results revealed that single incorporation of graphite and SCF significantly improve the tribological properties of the PI composites, but micro SiO₂ was harmful to the improvement of the friction and wear behavior of the PI composite. It is found that a combinative addition of Gr, SCF and micro SiO₂ was the most effective in improving the friction-reducing and anti-wear abilities of the PI composites. Research results also show that the filled PI composites exhibited better tribological properties under higher PV-product.