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设计了适合研究树脂基汽车复合摩擦材料摩擦性能的小样试验,进行不同环境温度、不同滑动速度和定载荷下的摩擦试验。并通过扫描电子显微镜的分析手段,结合摩擦学原理分析了摩擦材料的热衰退机理,得出树脂基汽车复合摩擦材料热衰退的实质是树脂的高温热分解所生成的润滑层或气垫层的动力润滑而导致摩擦因数的明显下降,其机理是从典型的磨粒磨损和粘着磨损的干摩擦过渡到具有流体润滑磨粒磨损的润滑摩擦等结论。 相似文献
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采用环块式摩擦磨损实验研究了一种新型摩擦材料在水润滑状态下不同载荷与转速对试样摩擦学性能的影响,并对比干摩擦条件下的摩擦学性能变化,借助磨损表面形貌观察分析其磨损机理。实验结果表明:水润滑条件下,摩擦系数随着载荷的增大而减小,随着转速的提高先增加后减小;磨损率随着载荷与转速的提高都减小。相同载荷与转速下,干摩擦时磨损机理以磨粒磨损和黏着磨损为主,而水润滑条件下水形成边界润滑,磨损机理以磨粒磨损和轻微的黏着磨损为主;水润滑条件下摩擦系数和磨损率均低于干摩擦,主要是由于水起到了润滑和冷却的作用,阻止了转移膜的形成,并在材料表面形成水膜起到了边界润滑的作用。 相似文献
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为提高水润滑轴承的承载能力,利用水凝胶在水润滑条件下的水合作用来改善热塑性聚氨酯(TPU)轴承材料的摩擦学性能。利用聚乙烯醇、海藻酸钠、壳聚糖等材料制备水凝胶颗粒,并通过熔融共混法制备水凝胶/TPU复合材料;在0.3和0.5 MPa的载荷下测试复合材料的摩擦磨损性能,利用激光干涉表面轮廓仪和扫描电子显微镜观察其磨损表面形貌,分析其磨损机制。结果表明:水凝胶微粒可以通过水合润滑改善摩擦副的润滑条件,从而降低摩擦因数和磨损量,提高复合材料的摩擦性能;水凝胶质量分数4%时复合材料具有最佳的摩擦磨损性能,其在0.3和0.5 MPa工况下相对于TPU试样的平均摩擦因数减少率分别为52.31%和43.94%。研究结果为开发高性能水润滑轴承材料提供了一种方法。 相似文献
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利用数显式高速环块摩擦试验机,对赛龙轴承试块/镀镍钢环配副,分别在干摩擦、湿润滑、海水润滑条件下,进行摩擦磨损试验研究,分析赛龙轴承的摩擦磨损性能.结果表明:赛龙干摩擦时的平均摩擦因数为0.4左右,相对其他非金属材料,赛龙的干摩擦性能较好,但赛龙不耐高温,高温时材料表面会被破坏生成丝状磨屑;湿润滑时赛龙的摩擦因数比干摩擦时的低,说明湿润滑时已处于边界润滑状态;海水润滑时摩擦因数较低,此时润滑状态逐渐变为完全流体动压润滑状态.正交试验结果表明,干摩擦和湿润滑时,转速变化对摩擦因数的影响较大;海水润滑时,载荷变化对摩擦因数影响较大. 相似文献
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针对舰艇推进系统用水润滑轴承低噪声设计需求,研制改性尼龙(PA)的轴承材料及轴承样机,利用多功能摩擦磨损试验机对改性PA材料样品进行摩擦学性能试验,并与丁腈橡胶和赛龙SXL材料的摩擦学性能进行对比;在水润滑轴承试验台上开展PA轴承样机转速特性试验和载荷特性试验,获取不同比压和转速下摩擦因数和振动特性数据。研究结果表明:与丁腈橡胶和赛龙SXL材料相比,改性PA材料具有摩擦因数小、磨损率低的优点;低转速下,水润滑轴承摩擦因数随转速增大而减小,随比压增大而增大,转速增加至100 r/min后,摩擦因数变化趋势逐渐减缓;在工作转速范围内改性PA材料水润滑轴承无异常摩擦振动和噪声。研究结果为舰艇低噪声水润滑艉轴承设计提供参考。 相似文献
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为了研究密封端面材料配对对干摩擦机械密封性能的影响,使用自主设计研发的干摩擦机械密封试验系统,选择浸锑石墨、浸树脂石墨,分别与38CrMoAlA(不喷涂)、38CrMoAlA(表面喷涂Cr 2O 3)、40CrNiMoA(表面喷涂Cr 2O 3)3种典型的材料配对进行干摩擦和磨损试验,并对端面温升、磨损率、摩擦功耗和泄漏率等试验结果进行对比分析。结果表明:在干摩擦状态下,对于不同材料配对,摩擦磨损规律显示出了多元性;在6组端面配对中,浸锑石墨与38CrMoAlA(表面喷涂Cr 2O 3)配对性能最佳,浸金属石墨更适用于极端工况,摩擦磨损性能更佳,但浸树脂石墨材料密封性能更好,泄漏率更小;动环表面喷涂材料可有效提高动环表明硬度,优化表面结构,改善动环摩擦磨损性能和密封性能;动环基体材料对配对性能影响不可忽视,导热效果好、线膨胀系数低的材料可降低端面温度。 相似文献
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Effects of Resin Type and Fiber Length on the Mechanical and Tribological Properties of Brake Friction Materials 总被引:2,自引:0,他引:2
In this study, the effects of resin type and fiber length on mechanical properties and friction characteristics of automotive
brake materials were studied. Three types of resin, viz. straight phenolic resin (SR), cashew nut shell liquid modified resin
(CR), and melamine resin (MR) were used as matrix material. Lapinus with different lengths was used as inorganic fiber. Three
series of friction composites composed of nine composites in the form of brake materials were manufactured. Physical, mechanical,
and tribological properties of all composites were investigated. The friction tests were performed using a Chase type friction
tester. The results showed that both resin type and fiber length played an important role on the mechanical and tribological
properties of the friction materials. The highest and the lowest friction coefficient for resin types were recorded for SR
and MR composites, respectively, while MR and CR composites showed the highest and the lowest wear resistance, respectively.
For the fiber length considered, increasing the fiber length increased the wear resistance of the composites. The coefficient
of friction, in general, showed a good correlation with the wear resistance of the composites. But, there was no clear correlation
with the mechanical and tribological properties of the composites. The morphological features of worn surfaces and wear debris
of the composites were analyzed in order to understand the friction and wear mechanisms of this tribosystem. 相似文献
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ABSTRACTIn this article, brake discs are exposed to high thermal stress, causing thermal fatigue damage. The aim of this work is to study the evolution of the wear behavior of brake disc materials, such as cast iron, chromium steel, and metal matrix composites, under the influence of thermal fatigue. The brake disc specimens are heated and then cooled rapidly. Then, wear tests are carried out using a pin-on-disc-type tribometer. Organic and semimetallic friction materials are used for all wear tests. The results show that thermal fatigue affects the structure of the contact surfaces of all of the disc specimens by increasing their roughness. Furthermore, the wear rate of the friction materials increased, except a reduction of the wear rate is noted for the semimetallic friction material rubbing against cast iron. Moreover, thermal fatigue has no significant influence on the coefficient of friction. The worn surface of the metal matrix composite sliding against semimetallic friction material is characterized by abrasive and adhesive wear mechanisms. 相似文献
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A block-on-ring test setup is employed to investigate tribological performance of Sn-based overlay plated bearing materials under mixed and boundary lubrication condition. Pb-containing bearing material is also studied as a reference. Sn-based and Pb-based overlays have shown similar transition in friction when rotational speed is varied. Under relatively longer test duration, Sn-based overlays exhibit comparable friction and wear properties with that of Pb-based overlay. It takes longer time to obtain steady-state friction for Sn-based overlay than Pb-based overlay. Wear behavior of tested samples are also similar except for tests in the mixed lubrication regime where Sn-based overlays show better wear resistance. In the Sn-based overlays main wear mechanisms are adhesive and abrasive wear leading to exposure of the Ni interlayer. 相似文献
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分别以45#钢、铍青铜、碳化硅颗粒基体改性铍青铜、氧化铝涂层为对偶材料与同一种树脂基摩擦材料在MM1000-II型摩擦磨损试验机上进行干式摩擦磨损试验,研究对偶材料对树脂基摩擦材料摩擦磨损性能的影响;利用偏光显微镜观察材料磨损后的表面微观形貌。结果表明:氧化铝涂层对偶材料的磨损率最低,摩擦因数适中,但摩擦因数稳定性较差;对偶材料为45#钢时摩擦因数较低,但摩擦因数的稳定系最好;对偶材料为铍青铜时摩擦磨损性能最佳,摩擦因数较高且稳定性较好,铍青铜本身和与之匹配的摩擦材料的磨损率都很低,且摩擦表面均没有形成孔洞和犁沟;改性铍青铜在各方面都表现出较差的性能。 相似文献
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钢纤维和莫来石纤维增强陶瓷基摩擦材料的性能研究 总被引:1,自引:1,他引:0
采用热压烧结法制备出钢纤维和莫来石纤维增强陶瓷基摩擦材料,对比分析钢纤维、钢纤维和莫来石纤维的混杂纤维以及莫来石纤维增强陶瓷基摩擦材料的机械性能和摩擦磨损特性。利用扫描电子显微镜(SEM)观察不同温度下的磨损表面和磨屑形貌,并研究其磨损机制。研究结果表明,钢纤维和莫来石陶瓷混杂纤维增强的陶瓷基摩擦材料具有较高的机械强度以及良好的摩擦稳定性和耐磨性能,以莫来石纤维增强的陶瓷基摩擦材料,摩擦因数表现出严重的热衰退,且具有低的耐磨损性能。SEM分析表明,在从低温到高温的摩擦过程中,钢纤维和莫来石陶瓷混杂纤维增强的陶瓷基摩擦材料的磨损形式主要由黏着磨损转化为黏着磨损与磨粒磨损的复合磨损形式,而以莫来石纤维增强的陶瓷基摩擦材料,其磨损形式以磨粒磨损为主。 相似文献
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针对高频摆动关节轴承摩擦热对自润滑纤维复合材料摩擦磨损性能的影响,研制了高频使用条件下的玻璃纤维增强聚四氟乙烯(GF/PTFE)自润滑纤维复合材料,利用MYB~500高频高载摆动摩擦磨损试验机,对其进行不同摩擦温度下的摩擦磨损性能测试,研究摩擦热作用下材料自润滑性能和磨损性能衰退特征,分析磨损产物和摩擦表面以及不同摩擦温度下材料的磨损机理。结果表明,摩擦热对材料自润滑性能影响显著,适当的摩擦温度范围能够保证材料的自润滑性能,摩擦温度和摩擦因数之间互为耦合作用,对材料的磨损性能具有一定的影响;高摩擦热作用于自润滑过程及机理的改变,造成材料的磨损性能衰退现象。因此,不同温度下材料的磨损特征具有明显的差异化,其中低摩擦温度下(60~120℃)材料自润滑性能优异,磨损率很低;140℃摩擦温度条件下材料摩擦磨损性能开始衰退;材料在高摩擦温度下(140~180℃)的磨损初期自润滑性能良好、磨损轻微,而中后期磨损严重。微观分析表明,低摩擦温度下材料的磨损机理以轻微粘着和疲劳磨损为主;高摩擦温度下材料的磨损以片状剥落、纤维剪切破坏为主,且磨损面局部损伤特征明显,磨损严重。 相似文献