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采用M-2000 型摩擦磨损试验机考察纳米碳酸钙和石墨复合填充聚酰亚胺(PI) 润滑材料在不同速度和载荷下与GCr15 轴承钢对摩时的摩擦磨损性能,并利用扫描电子显微镜分析PI 材料及其对偶件磨损表面形貌。结果表明,单独填充纳米CaCO3时,聚酰亚胺摩擦因数轻微减小,体积磨损率显著增大,而单独填充石墨后,聚酰亚胺摩擦学性能有显著的改善;纳米CaCO3和石墨复合填充后,二者存在协同效应,减摩抗磨能力显著提高;PI材料的摩擦学性能与对偶钢环表面转移膜的性质紧密相关,纳米CaCO3能显著增强转移膜与对偶件的结合强度。 相似文献
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考察了添加少量纳米SiCp对铜基材料电学和摩擦学性能的影响。结果表明:添加少量纳米SiCp(体积分数为0.5%),轻微降低了铜基材料的导电率,显著提高了耐磨性,有效降低了铜/钢摩擦副之间的粘着作用和材料转移;130nm SiCp/Cu基复合材料的导电性和耐磨性都优于30nm SiCp/Cu基复合材料。 相似文献
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采用M-2000型摩擦磨损试验机考察单一纳米氧化锌(ZnO)和石墨以及二者复合填充聚酰亚胺(PI)复合材料在干摩擦下与GCr15轴承钢对摩时的摩擦磨损性能,并利用扫描电子显微镜分析PI复合材料及其对偶件磨损表面形貌状况。结果表明,填充纳米ZnO后,PI复合材料的摩擦学性能变差,填充石墨后,PI复合材料摩擦学性能显著改善;而复合填充纳米ZnO和石墨后PI复合材料的摩擦学性能最佳,即二者存在明显的协同效应。PI复合材料的摩擦磨损性能同其在偶件磨损表面形成的转移膜的性质密切相关,纳米ZnO能显著增强转移膜与对偶件的结合强度,不同PI复合材料呈现不同的磨损机制。 相似文献
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为研究石墨对铜基摩擦材料瞬时摩擦性能的影响,采用粉末冶金技术制备铜-SiO2和铜-石墨-SiO2烧结材料,通过干摩擦惯性试验,在始末速度不同的制动区间,测试材料的瞬时摩擦因数、瞬时磨损率,并观察摩擦表面形貌的变化。结果表明:在高速度制动区间,石墨的存在使得铜基摩擦材料摩擦因数的稳定性明显提高,磨损率降低,原因在于铜-石墨-SiO2材料剥落石墨颗粒的分隔和保护作用,减弱冲击波动,从而提高瞬时摩擦因数稳定性并降低磨损;但较低制动速度时,石墨的存在反而提高了磨损率,原因在于摩擦层对颗粒的包裹度和基体强度降低。 相似文献
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采用冷压-烧结-复压的方法在900℃下制备不同铝含量的铜基石墨复合材料,研究在干、湿2种摩擦条件下铝含量对复合材料摩擦学性能与磨损机制的影响。结果表明:铝含量增加,有利于提高复合材料的硬度和抗弯强度,但复合材料相对密度呈现先增后降的趋势;在干、湿摩擦条件下,较高的铝含量均使得复合材料耐磨性能得到极大提高,这是因为高铝含量的复合材料具有更高的强度,能有效抵抗微凸体犁削,并且能支撑保护更多石墨,避免金属基体与对偶件直接接触;在铜基石墨复合材料中添加铝后材料的强度增大,使剥落磨损和磨粒磨损减弱,氧化磨损逐渐加强,且湿摩擦时因水的作用使氧化磨损更加剧烈。 相似文献
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以PAO6润滑油为基础油,MoS2为纳米添加剂,制备质量分数为0.02%的纳米润滑油.通过自主研制的缸套-活塞环摩擦实验台,对添加不同浓度碳黑颗粒的MoS2纳米添纳米润滑油的摩擦学性能进行研究;通过电子扫描显微镜(SEM)对缸套表面磨痕进行观察.结果表明,低浓度的碳黑(0.01wt%和0.1wt%)可以进一步改善纳米润滑油的摩擦系数(降低7.7%和1.5%);任何浓度的碳黑都会导致纳米润滑油的抗磨性能恶化,甚至比未添加任何纳米颗粒的基础油的磨损量高约5~7倍;缸套的磨痕分析表明,碳黑通过破坏MoS2纳米润滑油在摩擦副表面形成抗磨损膜的稳定性,加剧零件磨损. 相似文献
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Hot wear properties of ceramic and basalt fiber reinforced hybrid friction materials 总被引:3,自引:0,他引:3
In the present study, hybrid friction materials were manufactured using ceramic and basalt fibers. Ceramic fiber content was kept constant at 10 vol% and basalt fiber content was changed between 0 to 40 vol%. Mechanical properties and friction and wear characteristics of friction materials were determined using a pin-on-disc type apparatus against a cast iron counterface in the sliding speeds of 3.2–12.8 m/s, disc temperature of 100–350 °C and applied loads of 312.5–625 N. The worn surfaces of the specimens were examined by SEM. Experiments show that fiber content has a significant influence on the mechanical and tribological properties of the composites. The friction coefficient of the hybrid friction materials was increased with increasing additional basalt fiber content. But the specific wear rates of the composites decreased up to 30 vol% fiber content and then increased again above this value. The wear tests showed that the coefficient of friction decreases with increasing load and speed but increases with increasing disc temperature up to 300 °C. The most important factor effecting wear rate was the disc temperature followed by sliding speed. The materials showing higher specific wear rates gave relatively coarser wear particles. XRD studies showed that Fe and Fe2O3 were present in wear debris at severe wear conditions which is indicating the disc wear. 相似文献
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E. N. Volnyanko S. F. Ermakov G. P. Okatova V. A. Smurugov 《Journal of Friction and Wear》2008,29(2):146-150
The results of triboengineering tests have revealed the effectiveness of β-sialon nanodispersed particles as an additive to lubricating materials oiling heavily loaded friction units. The method of X-ray structural analysis has established that use of β-sialon as an additive leads to the appearance of steel structures in the surface layer distinct in having a larger parameter of the crystalline lattice, reduced relative mean quadratic micro-deformation, and sparser dislocations, ensuring better triboengineering characteristics of friction couples. The main tribological effect of β-sialon in the lubricating material is that the mechanical energy of deformation converts into the chemical energy of formation of a new structure—an ordered surface layer. 相似文献
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A model is presented for the sliding friction of multiphase materials in abrasion. The friction is described in terms of the load distribution between the phases. Different load distribution modes are used with Amontons' first law of friction to derive both the friction force and the coefficient of friction as functions of the area fractions of the phases, their individual coefficients of friction and their wear resistance. It is shown that the coefficient of friction of a multiphase material should depend on the load distribution mode and that the upper and lower limits for the coefficient of friction expected from composites or multiphase materials can be identified. For most pressure distribution modes, the friction depends on the wear resistance of the phases. The model is compared with results from abrasion tests on a silicon carbide reinforced aluminium alloy (AlSi7Mg) over a wide range of loads and with different fixed abrasive particles. The experimental results are described and interpreted in terms of the model. 相似文献
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Results are presented of studies on the influence of the carbon nanotube concentration on the tribological behavior of composite powder materials based on copper matrix obtained by electrocontact sintering. The tribological characteristics of materials based on the powder copper-carbon nanotube and copper-graphite systems are compared. 相似文献
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Adhesive wear and thermal degradation are the main aging mechanisms of paper-based friction materials. However, how these aging mechanisms affect the tribological characteristics of such materials is not fully understood. In this paper, the respective influences of the two aging mechanisms on the tribological characteristics of the friction materials are investigated through simulation. It is assumed that adhesive wear pre-dominantly affects the surface topography, while thermal degradation significantly affects the mechanical properties of the friction material. The simulation results show that the static friction coefficient and both normal and tangential contact stiffnesses increase due to adhesive wear, but decrease due to thermal degradation. These trends are qualitatively in agreement with experimental observations reported in the literature and our previous work. 相似文献
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混杂纤维含量对汽车制动摩擦材料性能的影响 总被引:2,自引:0,他引:2
研究了不同混杂纤维含量对汽车制动摩擦材料性能的影响.结果表明,随着坡缕石纤维和钢纤维含量的增加,摩擦材料的冲击强度均增加;坡缕石含量的变化对磨损率影响不大,Kevlar含量较高时,混杂纤维摩擦材料200 ℃时磨损率增加,250 ℃和350 ℃时磨损率降低;Kevlar纤维随着其含量的增加,混杂纤维摩擦材料高温摩擦性能(250~350 ℃)有所降低. 相似文献
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To investigate and understand the tribological behaviour of high-frequency tribosystems such as ultrasonic motors, a specific test method is necessary. This work reports on the construction of a test machine to evaluate the friction and wear behaviour of friction materials under ultrasonic fretting conditions, as well as giving some representative experimental results. Hard/soft (steel/polymer) and hard/hard (steel/alumina, alumina/alumina) couples were studied with respect to their application as contact materials in ultrasonic motors. Investigation of friction behaviour at high frequencies showed that friction-induced vibrations lead to friction forces of much lower magnitude than predicted by quasistationary friction coefficients obtained for sliding friction. The wear behaviour is characterised by abrasive, adhesive, fatigue and oxidative mechanisms, depending on the mating materials. For polymeric friction materials, the influence of fibre reinforcement and the incorporation of PTFE as a solid lubricant were evaluated. The presence of PTFE resulted in a strong improvement of both friction and wear behaviour. 相似文献