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经济型汽车干摩擦式离合器的磨损及影响因素 总被引:2,自引:0,他引:2
磨损是经济型汽车干摩擦离合器损坏的主要原因.通过分析经济型汽车干摩擦式离合器在滑动摩擦条件下磨损的基本类型及其影响因素,得出磨粒磨损、粘着磨损和疲劳磨损是其磨损的基本类型,摩擦材料、温度和滑动速度是磨损的主要影响因素;通过分析经济型汽车干摩擦离合器磨损过程三个阶段的磨损类型和磨损量,得出缩短磨合磨损阶段、延长稳定磨损阶段和推迟剧烈磨损阶段可以提高离合器的使用寿命;通过摩擦学性能试验和耐磨损性试验,得出提高离合器摩擦副的材料性能、降低离合器摩擦副的表面粗糙度和改善离合器工作条件(温度、滑动速度和工作载荷)等措施,有助于增强干摩擦式离合器的摩擦性能和耐磨性,从而降低经济型汽车干摩擦式离合器的磨损. 相似文献
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本文通过磨损试验得出气门和导管摩擦副各影响因素在不同水平下的摩擦系数,以此分析出各因素对气门和导管摩擦副的影响权重。通过本研究总结了气门和导管之间的摩擦行为规律,为在实际设计中减小摩擦系数、降低导管磨损提供了一定的指导和参考。 相似文献
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为了研究电场对摩擦副摩擦磨损性能的影响,在自行设计的高速摩擦磨损试验装置上,进行了WC-Co/Ti6Al4V摩擦副的摩擦磨损试验。结果表明:断开摩擦副热电回路可以有效地减小热电流对WC-Co/Ti6Al4V摩擦副摩擦磨损的影响,静电冷却环境下形成的强电场的效果更加明显,在抑制摩擦副磨损的同时还可以改善
Ti6Al4V磨损表面质量。通过扫描电镜及EDS能谱分析可知,静电冷却条件下的列宾捷尔效应削弱了钛合金的黏着能力,从而有效地减小了WC-Co的黏着磨损;WC-Co在高速摩擦时主要以黏着磨损、氧化磨损为主,同时伴有微裂纹的产生。
相似文献
Ti6Al4V磨损表面质量。通过扫描电镜及EDS能谱分析可知,静电冷却条件下的列宾捷尔效应削弱了钛合金的黏着能力,从而有效地减小了WC-Co的黏着磨损;WC-Co在高速摩擦时主要以黏着磨损、氧化磨损为主,同时伴有微裂纹的产生。
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针对干摩擦机械密封在高速运转工况下密封端面的摩擦磨损而导致密封失效问题,通过试验分析几种典型摩擦副材料组对在干摩擦下的摩擦磨损性能。选择浸锑石墨M106D和浸树脂石墨M106K分别与38CrMoAlA以及喷涂Cr2O3、Al2O3的38CrMoAlA硬环组对,采用Plint摩擦磨损试验机,监测摩擦副在高速干摩擦条件下的摩擦因数,分析轴向载荷及线速度对摩擦因数的影响,通过白光干涉仪观测试验前后端面形貌。结果表明:干摩擦下,喷涂的硬环表面石墨转移附着较少,其更耐磨、磨损程度小,浸锑石墨较浸树脂石墨磨损少;6组配对试验主要磨损形式为磨粒磨损,其中浸锑石墨/喷涂Al2O3的38CrMoAlA摩擦副摩擦因数最小;由于石墨的自润滑性,适当增加转速和轴向载荷均有利于降低端面摩擦因数。 相似文献
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盘式制动器摩擦磨损热动力学研究进展 总被引:3,自引:0,他引:3
摩擦磨损热动力学是制动器失效分析和设计的重要理论依据,对选择摩擦副材料也有指导作用.因此从分析摩擦热对制动器摩擦副的影响着手,总结了盘式制动器摩擦磨损热动力学的数学、物理模型,并对制动摩擦表面温度场和应力场的计算方法进行分析比较,评述了盘式制动器摩擦磨损热动力学的研究进展,并对今后主要研究工作进行了展望. 相似文献
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J. Campa-Molina† O. Blanco† A. Correa-Gomez M. Czank‡ & A. G. Castellanos-Guzman 《Journal of microscopy》2002,208(3):201-211
The domain structures of Zn3B7O13Cl, Zn3B7O13Br and Zn3B7O13I boracite single crystals were studied by means of polarized light in conjunction with electron microscopy. Single crystals of the three compositions were grown by chemical transport reactions in closed quartz ampoules, at a temperature of 900 °C and were examined by polarizing optical microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For both PLM and SEM, the same as‐grown samples were used without having to resort to metallization of the crystal faces. For TEM the single crystals were crushed and mounted on holey carbon films. Comparative electron microscope images were useful for revealing the domain structure of these ferroelectric/ferroelastic materials previously observed between the crossed polars of an optical microscope. X‐ray diffraction analysis of the pulverized crystals was performed for this triad of halogen boracites containing zinc as a common metal. 相似文献
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本文研究了在B2O3-La2O3-BaO-Nb2O5四元系统中当B2O3含量分别为25、30、35wt%时,该系统的玻璃生成范围和它们的光性、密度等变化规律。结果表明,随着B2O3含量的增加,系统的玻璃生成范围向贫Nb2O5边界扩充,富Nb2O5边表现收缩。工作中得出了该系统分别以SiO2代B2O3、Al2O3代BaO后的析晶、折射率、色散及密度等性质的变化规律。最后应用该系统研制定型了713/538玻璃。 相似文献
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本文首次系统地研究了Na2O—B2O3—Ta2O5。三元新系统的红外光谱,分析了B2O3、Ta2O5含量的变化对玻璃结构的影响。结果表明:随着Na2O/B2O3比值的减小,结构中:[BO4]四面体减小,[BO3]三角体增加。随着Ta2O5含量的增加,[BO4]四面体的数量增多,非桥氧的数量减少,表明Ta5+可以连结非桥氧,形成网络。 相似文献
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Al2O3/(Ag72Cu28)97Ti3/Ti-6Al-4V界面反应 总被引:1,自引:0,他引:1
《机械工程学报》2002,38(2):31-34
在1.8 ks、1
073~1 173 K条件下对Al2O3/(Ag72Cu28)97Ti3/Ti-6Al-4V进行了钎焊试验.通过扫描电镜、波谱、能谱和X射线衍射对界面反应产物进行了测试,确定了界面结构,并讨论了这些反应产物形成的可能性.结果表明,温度小于1
123 K的界面结构为Al2O3/Cu2Ti4O/Cu4Ti3+Cu固溶体/Ag-Cu共晶 + 富Ag相;温度1 173
K的界面结构为Al2O3/Cu3TiO5 + CuAl2O4/Cu4Ti3/富Ag相+ Cu4Ti3. 相似文献
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光开关是集成光路上一个重要的元器件。提出了一种用在L和C波段基于硫系相变材料(Ge2Sb2Se4Te1)的片上2×2定向耦合器式的可重构光开关,可通过改变相态切换开关。利用仿真软件Lumerical中的Mode Solutions和FDTD Solutions模块设计器件,得到在1500 ~1625 nm内耦合长度为24.9 μm的Ge2Sb2Se4Te1非晶态下插入损耗(IL)>-0.36 dB,串口对比度(CT)<-24 dB;Ge2Sb2Se4Te1晶态下IL>-0.44 dB,CT<-30.46 dB。利用仿真软件COMSOL模拟532 nm波长激光加热Ge2Sb2Se4Te1,结果显示:一个25 ns、峰值功率45 mW的高斯短脉冲可以使材料由晶态转化为非晶态;施加多个峰值功率20 mW、周期1 μs且占空比0.03%的高斯脉冲阵列可重回晶态。仿真结果表明,设计的光开关在通信波段通过激光加热可以快速实现切换光路的作用。 相似文献
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An Al86 Mn3 Be11 alloy cast into copper mould was subjected to metallographic investigation. The as-cast microstructure consisted of a quasicrystalline icosahedral phase (i-phase), Be4 AlMn phase and, occasionally, a hexagonal phase. Al-rich solid solution represented the dominant phase. The chemical compositions of phases were determined using AES. The composition of the Be4 AlMn slightly deviated from the stoichiometric composition, whereas the composition of the i-phase was approximately Al52 Mn18 Be30 , containing an appreciable amount of Be. The average composition of the hexagonal phase was Al66 Mn21 Be13 . Deep etching and particle extraction provided a deep insight into the three-dimensional morphology of the i-phase and the hexagonal phase, whereas Be4 AlMn was slightly attacked by the etchant. The i-phase was present predominantly in the form of dendrites and a rodlike eutectic phase. The hexagonal phase was primarily in the form of hexagonal platelets, whereas Be4 AlMn was rather irregular in shape. The morphology of the i-phase can be explained by predominant growth in 3-fold directions and the lowest energy of the 5-fold planes, leading to the faceting and adopting a pentagonal dodecahedron shape. The brightnesses of phases in the backscattered electron images were rationalized by determining their backscattering coefficients. TEM investigation showed considerable phason strain in the i-phase, and the polycrystalline nature of the Be4 AlMn phase. 相似文献
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C.J. Klenke 《Tribology International》1990,23(1)
A recent investigation suggests that selected oxides perform well as additives in molybdenum disulphide (MoS2) because of their ability to soften at asperity contacts with the result that the solid lubricant can attain and retain a preferred tribological orientation.This research determined the effectiveness of boric oxide (B2O3), when used as an additive in MoS2, for substrate temperatures ranging from 21°C to 316°C. This range was used to allow the asperity contact temperature to vary below and above the softening point of B2O3. It was found that a moderate friction coefficient and high wear, which is attributed to the additive acting abrasively, occurred when the asperity contact temperature was well below the softening point of the oxide. When the asperity contact temperature neared the softening point of the oxide, the friction coefficient increased dramatically and wear volume was reduced. It is postulated that B2O3 acted adhesively at the interface resulting in a higher coefficient of friction, and wear decreased due to an attainment of a preferred orientation by the MoS2. For asperity contact temperatures significantly above the softening point of B2O3, the friction coefficient returned to about the same value as for temperatures below the softening point. It is speculated that wear continued to increase moderately because of localized melting of the B2O3, permitting the MoS2 to be removed from the interface. These observations support a hypothesis that an additive, such as boric oxide, can soften as the asperity contact temperature approaches the softening point temperature of the additive so that the overall tribological conditions may be improved resulting in reduced interfacial wear. Significant changes in temperature, load or sliding velocity would, of course, dramatically alter the wear characteristics observed at the interface. 相似文献