聚合物及其复合材料微动摩擦学研究进展

综述了聚合物及其复合材料微动摩擦学研究的现状.介绍了几种常见的微动损伤机理及其在解释实验结论中的应用.基于目前聚合物及其复合材料微动摩擦学的研究现状和存在的问题,展望了其未来的研究方向.     

耐温聚合物基复合材料的摩擦学性能与磨损机理研究进展

本文综述了耐温聚合物基复合材料的种类、摩擦学性能和磨损机理。分析了聚合物基复合材料摩擦擦学性能和磨损机理现状与进展,从而指导耐温耐磨聚合物基复合材料的研究、开发应用。     

面向低温环境的聚合物摩擦学性能及其改性研究进展

聚合物及其复合材料具有力学性能好、摩擦系数低、耐磨性能强等优点,常被应用于制造摩擦副关键基础件,如密封圈、齿轮、轴承保持架、转子叶片、活塞等.但迄今针对低温工况的聚合物摩擦学研究甚少,主要工作集中在常温和高温工况.面向低温环境的聚合物及其复合材料的摩擦学应用与相关制备、改性工艺的相关理论并不完备,极端服役环境下聚合物的摩擦学损伤失效机理还尚未完全清楚.此外,聚合物材料虽然具有众多优良的性能,但是其表面硬度低、温度影响大、易变形等缺点也同样明显,限制了其在低温摩擦学领域的应用,为此,研究者通过填充填料、表面处理等方法对聚合物进行了改性研究,取得了一定的成果.目前,由于航空航天等前沿技术的不断发展,聚合物在真空低温环境下的摩擦学性能受到了广泛关注,聚四氟乙烯、聚酰亚胺、聚醚醚酮等聚合物自润滑材料已被应用于空间飞行器领域来制作润滑和密封部件.研究者利用石墨、石墨烯、二硫化钼、芳纶纤维、玻璃纤维等对聚合物进行改性,制备了在低温环境下具有低摩擦系数、高耐磨性的聚醚醚酮/石墨、聚四氟乙烯/芳纶纤维、聚四氟乙烯/超高分子量聚乙烯等复合材料,促进了聚合物在低温摩擦学领域的应用.本文系统分析了低温环境下温度、环境介质、滑动速度、载荷、滑动方向等因素对聚合物摩擦学性能的影响,对面向低温环境的聚合物摩擦学改性进行了简要总结,以期促进聚合物低温环境下摩擦学应用及其相关研究的进一步发展.     

耐温聚合物基复合材料的摩擦学性能与磨损机理研究进展

本文综述了耐温聚合物基复合材料的种类、摩擦学性能和磨损机理。分析了聚合物基复合材料摩擦学性能和磨损机理现状与进展 ,从而指导耐温耐磨聚合物基复合材料的研究、开发应用。     

聚合物复合材料摩擦学研究进展

综述了聚合物复合材料的摩擦学研究概况，分析了不同填充材料及其含量、纤维填充材料方向及环境等因素对聚合物复合材料摩擦学性能的影响，指出不同填充材料对提高基体耐磨性的影响不同，且其提高基体耐磨性的机理也不同。     

碳纤维增强复合材料的摩擦学研究进展

综述了碳纤维增强聚合物基、金属基、碳基等复合材料的研究和发展,分析了碳纤维的含量、碳纤维方向、纤维混杂、碳纤维的表面处理以及环境温度等因素对增强复合材料摩擦学性能的影响,并提出了今后需进一步深入研究的问题.     

颗粒填充环氧复合材料的摩擦学性能研究进展

阐述了近年来颗粒填充环氧树脂复合材料摩擦学性能方面的研究进展。分析了填充颗粒的种类、尺寸、含量及颗粒表面改性对填充环氧树脂复合材料摩擦学性能的影响;讨论了载荷、滑动速率及温度等摩擦外在条件对其摩擦学性能的影响规律;探讨了目前颗粒填充环氧复合材料摩擦磨损机理的研究现状,指出了计算机模拟仿真技术将是颗粒填充环氧复合材料摩擦磨损性能未来研究的重要方向。     

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.     

填料对聚合物基复合材料摩擦学行为的影响

本文综述了用于聚合物填充增强改性的填料种类、对摩擦学性能的影响以及填料的作用机理，同时讨论了填料的表面改性以及填料的选择标准。提出了今后研究填料对聚合物改性研究应注意的问题，从而对研究、开发、应用性能优异的聚合物基复合材料具有指导意义。     

Effect of size refinement and distribution of lubricants on friction coefficient of high temperature self-lubricating composites

IS304 high temperature self-lubricating composites were prepared by ball milling and induction sintering with embedded BaF₂/CaF₂ and Ag particles as lubricants. In comparison to PM304 composites with the same composition, the friction coefficient of IS304 is slight lower than that of PM304 in the temperature range from 20 to 250 °C. However, the friction coefficient of IS304 dramatically decreases at 260–280 °C while the friction coefficient of PM304 dramatically decreases at 330–350 °C under the same test condition. The improved friction coefficient of IS304 composites in the temperature range from 260 to 340 °C is due to the formation of self-lubricating fluoride films. The existence of fluoride film on the worn surface of IS304 is attributed to the refinement of lubricants from 30–70 μm to less than 2 μm and the appropriate distribution of fluorides, which can lead to a higher temperature rise (flash temperature) at the instantaneous contacting surface in comparison to that of the PM304 under the same test condition. It is this considerably higher superficial temperature rise at the contacting surface that can effectively activate the self-lubrication property of the fluoride phase and subsequently induce the formation the lubricating film.     

新型填料对高摩复合材料摩擦磨损性能影响及机制

采用干法热压成型工艺制备高摩复合材料,研究了基体材料腰果壳油改性酚醛树脂(CPR)与丁晴橡胶(NR)的质量比和新型高性能填料(主要成分为石墨粉Al2O3、MoS2、Fe粉)含量对高摩复合材料摩擦磨损性能的影响规律。在摩擦磨损试验机上测试了高摩复合材料的摩擦磨损性能,利用激光共聚焦显微镜、扫描电镜对摩擦表面形貌、磨屑进行观察和分析,借助EDS测定摩擦表面成分的变化。结果表明,随着CPR与NR质量比的增加,高摩复合材料的耐热性能、结合性能大幅提高,且具有较好的摩擦磨损性能。当高性能填料含量较低时,磨损表面出现大量连续的真实接触面,磨损机制为磨粒磨损和黏着磨损;当高性能填料含量较高时,真实接触面积减少,磨损表面剥落严重,并出现较多的裂纹,其主要磨损形式转变为磨粒磨损和疲劳磨损。随着高性能填料含量的增加,摩擦表面的元素从均匀分布逐渐转变为局部富集,磨粒的尺寸逐渐变大。     

Comparative study of high temperature composites

Two classes of composite made using either ceramic matrix with high temperature fibers or carbon/carbon have been used for various applications that require high temperature resistance, over three decades. However, their use has been limited to special applications because of the high costs associated with fabrication. Typically the composites are cured at more than 1000°C, and in most instances the heating has also to be carried out in controlled environments. In addition, because of the high processing temperature, only certain type of expensive fibers can be used with the ceramic matrices. A recently developed inorganic matrix, called polysialate can be cured at temperatures less than 150°C, making it possible to use carbon and glass fibers. Composites made using carbon, glass and combinations of carbon and glass fibers have been tested in bending and tension. This paper presents the comparison of processing requirements and mechanical properties of carbon/carbon composites, ceramic matrix composites made with silicon carbide, silicon nitride and alumina fibers and carbon/polysialate composites. The results indicate that carbon/polysialate composite has mechanical properties comparable to both carbon/carbon and ceramic matrix composites at room and high temperatures. Since the polysialate composites are much less expensive, the authors believe that it has excellent potential for more applications in aerospace, automobile and naval structures.     

Insights on high temperature friction mechanism of multilayer ta-C films

In this work,the high temperature friction mechanism of the tetrahedral amorphous carbon(ta-C)film was elucidated.The multilayer ta-C film with alternating hard...     

珍珠母及其仿生复合材料力学行为的研究进展

珍珠母是由天然文石晶片和有机基质构成的一种两相生物复合材料.其中,文石晶片通过典型交错层叠方式镶嵌在连续的有机基质中,形成高度有序的分级结构,使珍珠母呈现出远优于其组份材料的力学性能.因此,受到力学、材料学和生物学领域研究学者们的广泛关注.本文首先介绍了珍珠母材料的微结构特征及其基本变形机制和力学性能,然后分别从理论分...     

The effect of temperature on the nanoscale adhesion and friction behaviors of thermoplastic polymer films

Adhesion and friction tests were carried out in order to investigate the effect of temperature on the tribological characteristics of poly(methylmethacrylate) (PMMA) film using AFM. The pull-off and friction forces on the PMMA film were measured under a high vacuum condition (below 1 × 10(-4)?Pa) as the temperature of the PMMA film was increased from 300 to 420?K (heating) and decreased to 300?K (cooling). Friction tests were also conducted in both high vacuum and air conditions at room temperature. When the temperature was 420?K, which is 25?K higher than the glass-transition temperature (T(g)) of PMMA, the PMMA film surface became deformable. Subsequently, the pull-off force increased in proportion to the maximum applied load during the pull-off force measurement. In contrast, when the temperature was under 395?K, the pull-off force did not depend on the maximum applied load. The friction force began to increase when the temperature rose above 370?K, which is 25?K lower than the T(g) of PMMA, and rapidly increased at 420?K. Decrease of the PMMA film stiffness and plastic deformation of the PMMA film were observed at 420?K in force-displacement curves. After the heating to 420?K, the coefficient of friction was measured under air condition at room temperature and was found to be lower than that measured before the heating. Additionally, the RMS roughness increased as a result of heating.     

高温处理对炭/炭复合材料摩擦性能的影响

利用热梯度化学气相沉积工艺制备了炭/炭复合材料,研究了热处理温度对炭/炭复合材料石墨化度、硬度和摩擦性能的影响.结果表明:随着热处理温度的升高,炭/炭复合材料的石墨化度增加,石墨片层的间距d002逐渐减小,石墨微晶的厚度LC逐渐增大,炭/炭复合材料的硬度降低.随石墨化度的增加,有更多的石墨微品碎片参与摩擦而形成摩擦表面膜,这些石墨碎片会填充摩擦表面的犁沟,使凹凸不平的摩擦面变得平整光滑,从而使摩擦系数减小、刹车力矩降低,刹车时间延长.     

高阻尼铝基复合材料的研究

采用包套挤压法制备了高阻尼6061Al/SiCp/ 石墨混杂金属基复合材料,并对所制备的复合材料的金相组织、力学和阻尼特性进行了初步分析。包套挤压法制备的6061Al/SiCp/石墨混杂金属基复合中增强增阻颗粒分布均匀,其体积分数可精确控制。SiC颗粒作为增强剂能够增大复合材料的强度和刚度,而石墨粉作为增阻剂可以提高复合材料的阻尼特性。试验结果表明,能够应用包套挤压法制备力学性能和阻尼特性符合定要求的新型结构－功能材料－6061Al/SiCp/石墨混杂金属基复合材料。     

Interfacial ageing of high temperature carbon/bismaleimide composites

Ageing studies were performed on a carbon fibre–bismaleimide (CBR320/328) system developed by the CSIRO in Australia, with a fibre volume fraction of 55%. This material has a glass transition temperature of 302 °C and the effect of ageing at 204 and 250 °C on the interfacial region was studied. A variety of test techniques were employed to characterise interfacial property changes (mode I delamination, SEM, Raman); chemical changes due to ageing (Raman, FTIR); changes in glass transition temperature (DMTA) and weight loss. The results showed that both interfacial and resin degradation mechanisms differed between the two temperatures. It can, therefore, be concluded that accelerated ageing is not applicable to this system.