关节轴承喷涂MoS_2/石墨复合涂层摩擦学性能的研究

以Mo S2/石墨为固体润滑剂,无机磷酸盐为胶粘剂,利用喷涂方式在GE20ES型关节轴承表面制备不同配比的Mo S2/石墨复合涂层,考察了这些复合涂层在旋转摆动条件下的摩擦磨损性能。结果表明,不同配方的Mo S2/石墨复合涂层均显示了较好的减摩耐磨性能,其中当Mo S2与石墨的配比为3∶1时,Mo S2与石墨有较好的协同效果,复合涂层的摩擦学性能最好。     

Film-forming mechanisms for self-lubricating radial spherical plain bearings with hybrid PTFE/aramid fabric liners modified by ultrasonic

PTFE/aramid woven fabric liners were modified by ultrasonic. With self-made wear tester, tribological properties of the self-lubricating radial spherical plain bearings with modified and unmodified liners over swivel times were investigated. With scanning electron microscope and energy disperse spectroscopy, the film-forming mechanisms were analyzed. Results show: ultrasonic modification can improve tribological performances of the liners. Through ultrasonic modification, continuous and stable PTFE transfer films which had better wear resistance formed in a shorter time. Bearings with modified liners occurred slight adhesive wear, while the bearings with unmodified liners occurred serious adhesive wear and abrasive wear during the test process.     

关节轴承磨损失效的研究现状及进展

从关节轴承磨损量的测量方法、试验研究以及关节轴承磨损寿命的计算模型三个方面,综述了国内外关节轴承磨损失效的研究现状及取得的成果。详细介绍了关节轴承磨损量的测量方法,以及摩擦副材料、工况、表面质量和制造工艺对关节轴承磨损失效的影响,总结了几种典型自润滑关节轴承磨损寿命计算模型,并探讨了关节轴承磨损失效存在的问题以及未来发展的趋势。     

Investigation of mechanical and tribological properties of amorphous diamond-like carbon coatings

We investigated the mechanical and tribological properties of amorphous diamond-like carbon (DLC) coatings deposited on Si(100) by a pulsed bias deposition technique. Tribological studies were performed using a pin-on-disc (POD) apparatus under a normal load of 6.25 N and at 10% relative humidity, with a ruby pin as a slider. Hardness measurements were performed using a nanoindenter and apparent fracture toughness using indentation techniques. We studied the influence of residual stresses on apparent fracture toughness. The data revealed that the thickness, hardness and compressive stress of the coating play different roles in the apparent fracture toughness. Crack initiation is influenced by the thickness and hardness of the coating, whereas crack propagation is influenced by the compressive stress in the film. The apparent fracture toughness of DLC coatings increased with coating hardness.     

高低温环境关节轴承脂润滑实验研究

在高低温实验器上进行了关节轴承在不同载荷和摆动速度下的脂润滑性能实验,结果表明载荷对于轴承扭矩的影响更大,利用温度和载荷的突变能够有效地判断关节轴承的工作失效。     

Effect of contact configuration on the durability and friction coefficient of pressure‐sprayed MoS2 coatings under fretting conditions

Fretting wear is often found at the contact surfaces of a tight assembly where small‐amplitude oscillatory movement occurs, which can be the concealed origin of some enormous accidents. Employment of solid lubrication coatings, as one of effective measurements to palliate the fretting damage, has been widely acknowledged. The present work studied the fretting behaviour of a molybdenum disulphide coating on SUS 316 stainless steel substrate by a relatively cheap and easy‐to‐use process: pressure spraying. Two contact configurations (cylinder‐on‐flat and ball‐on‐flat) were used in the tests with different displacement amplitudes (from 5 to 75 µm) and normal loads (from 100 to 400 N for ball‐on‐flat and from 400 to 1000 N for cylinder‐on‐flat). The results showed that large displacement amplitude is adverse to friction coefficient and coating lifetime and that under a critical contact pressure, coating endurance is improved contact pressure increases. Contact configuration influences friction coefficient by changing contact area and distribution of contact pressure. One master curve of average dissipated energy per cycle in initial stable stage was obtained for two contact configurations, which can be employed to approximately predict coating lifetime. Copyright © 2009 John Wiley & Sons, Ltd.     

Effect of current density,MoS2 content and bath agitation on tribological properties of electrodeposited nanostructured Ni-MoS2 composite coatings

ABSTRACT

Nanostructured nickel coatings with molybdenum disulphide particles were electrodeposited to form composite coatings. Three different current densities, i.e. 3, 5 and 7?A/dm² were investigated initially. The best results were obtained with 5 A/dm² for codeposition of nanostructured Ni-MoS₂ composite coatings. With the addition of 1–4?g/L molybdenum disulphide to the bath, the weight percentages of MoS₂ particles in the coatings were 23–38%. This increase of MoS₂ content was accompanied with decrease in friction coefficient of the coatings from 0.35 to 0.08. Wear resistance of the coatings was increased with increasing MoS₂ content and the weight loss was decreased from 1.4 to 0.7?mg. Hardness was decreased from 585 to 400 VHN with increasing the MoS₂ content. By increasing bath agitation speed up to 150?rpm, more MoS₂ particles were embedded in the matrix and the coatings showed better wear resistance. However, increase of agitation speed from 150 to 200?rpm caused a decrease of MoS₂ particles in the nickel matrix due to the turbulent motion of particles in the bath. Overall, it was shown that the lubricating effect of MoS₂ in the coating was more influential than the nanocrystallinity of the nickel matrix in improving tribological properties of these composite coatings.     

石墨烯/MoS2复合涂层多环境下的摩擦学性能

以MoS2作为润滑剂,以石墨烯(GE)作为润滑添加剂,采用喷涂法在GCr15钢样片表面制备不同含量的GE/MoS2复合涂层.利用HSR-2M型高速往复式摩擦磨损试验机测试涂层在干摩擦及海水环境中的摩擦磨损性能,并分析了磨痕形貌及磨损机制.结果表明:添加适量石墨烯可明显改善MoS2涂层的摩擦磨损性能,且海水环境中涂层的摩...     

Friction and wear behaviors of MoS2/Zr coated HSS in sliding wear and in drilling processes

MoS2 metal composite coatings have been successful used in dry turning, but its suitability for dry drilling has not been yet established. Therefore, it is necessary to study the friction and wear behaviors of MoS2/Zr coated HSS in sliding wear and in drilling processes. In the present study, MoS2/Zr composite coatings are deposited on the surface of W6Mo5Cr4V2 high speed steel(HSS). Microstructural and fundamental properties of these coatings are examined. Ball-on-disc sliding wear tests on the coated discs are carried out, and the drilling performance of the coated drills is tested. Test results show that the MoS2/Zr composite coatings exhibit decreases friction coefficient to that of the uncoated HSS in sliding wear tests. Energy dispersive X-ray(EDX) analysis on the wear surface indicates that there is a transfer layer formed on the counterpart ball during sliding wear processes, which contributes to the decreasing of the friction coefficient between the sliding couple. Drilling tests indicate that the MoS2/Zr coated drills show better cutting performance compared to the uncoated HSS drills, coating delamination and abrasive are found to be the main flank and rake wear mode of the coated drills. The proposed research founds the base of the application of MoS2 metal composite coatings on dry drilling.     

工作温度对压力喷涂二硫化钼涂层摩擦学性能的影响

采用压力喷涂方法在 SUS316不锈钢基材上制备二硫化钼（MoS2）涂层,并在往复滑动球－平面配副下测试工作温度对其摩擦学性能的影响。实验结果表明：工作温度对 MoS2涂层的摩擦学性能有极大的影响,在100～300℃之间,涂层呈现出较好的减摩性,而在100～200℃之间耐磨性最好,300℃时涂层寿命急剧降低。综合考虑,压力喷涂 MoS2涂层最适合的工作温度范围为100～200℃。     

MoS2/Ti复合固体润滑膜的力学性能与摩擦特性

采用非平衡磁控溅射法在9Cr18轴承钢基底上制备了厚度约3μm的MoS2/Ti复合固体润滑膜,基于球形压头纳米压痕试验,采用连续刚度法对MoS2/Ti复合固体润滑膜的力学性能进行研究,探究MoS2/Ti复合固体润滑膜力学性能随压痕深度的变化规律;根据压痕试验载荷-位移曲线,采用Hertz接触理论计算MoS2/Ti复合固体润滑膜的弹性模量并与试验结果进行对比;利用CSM摩擦试验机对低速、低载下MoS2/Ti复合固体润滑膜的摩擦特性进行研究;基于压痕试验提出了一种能够更准确计算钢球加载时MoS2/Ti复合固体润滑膜接触应力的方法,并计算了摩擦试验不同载荷下的接触应力。结果表明:MoS2/Ti复合固体润滑膜的力学性能和摩擦特性都会受到表面形貌的影响;除表面初始压入阶段外,MoS2/Ti复合固体润滑膜的弹性模量和接触刚度都随着压痕深度的增大而增大;滑动速度和载荷共同影响MoS2/Ti复合固体润滑膜的摩擦特性。     

Role of MoS2 morphology on wear and friction under spectrum loading conditions

One of the ways by which grease is evaluated is by using a four‐ball wear test using ASTM D2266. However, actual applications may require bearings to be subjected to spectrum loading conditions. This study focuses on using ball milling to mitigate the wear from sharp edges in the MoS₂ particles. Two different blends of greases were formulated using MoS₂ in the as‐received state (unmilled) and milled MoS₂; they were tested under spectrum loading conditions where the load and frequency of the tests were treated as variables. It was found that ball milling of the MoS₂ significantly reduces the wear under spectrum loading condition both for ramp‐up and ramp‐down conditions. It was also shown that shortening the time step for both the ramp‐up and ramp‐down cycles resulted in larger wear for unmilled MoS₂ particles in comparison with milled MoS₂ particles in grease. The milling process did not play a significant role when frequency of the test was either ramped up or down. Copyright © 2015 John Wiley & Sons, Ltd.     

阀门零件表面二硫化钼涂覆工艺的研究

介绍了表面技术的分类及特点,阐述了阀门零部件二硫化钼涂覆技术的应用工艺。     

不同石墨烯添加量下MoS2基复合涂层的摩擦磨损及耐腐蚀性能

为改善MoS2基固体润滑涂层的摩擦磨损性能和耐蚀性能,制备了不同石墨烯（GE）添加量的MoS2复合涂层,利用HSR-2M摩擦磨损试验机测试了复合涂层的摩擦磨损性能,并分析了其磨损机理,通过极化曲线、交流阻抗谱（EIS）研究了涂层在3.5%NaCl溶液中的电化学腐蚀行为。试验结果表明,0.8-GE/MoS2复合涂层的摩擦磨损和耐腐蚀性能最优,其平均摩擦因数和磨损率分别为0.232和2.379×10-13 m3/(N·m),较未添加石墨烯的MoS2涂层分别降低了49.56%和43%,腐蚀速率（1.96×10-8 A/cm2）较纯MoS2涂层（5.54×10-6 A/cm2）降低了近2个数量级。石墨烯的二维片状结构具有良好的自润滑性能,在涂层中均匀分布时能有效阻隔腐蚀介质的渗透,因此,石墨烯的添加提高了MoS2基复合涂层的摩擦学性能和耐腐蚀性能,石墨烯的最优添加量为0.8%（质量分数）。     

PTFE/芳纶织物衬垫自润滑关节轴承性能试验

对比分析研究了同型号国产与进口PTFE/芳纶织物衬垫自润滑关节轴承的粘结质量、摩擦学性能以及承载性能,研究结果表明:进口轴承的剥离强度、摩擦磨损性能以及承载性能均略优于国产同型号的关节轴承;国内自润滑关节轴承的衬垫粘结质量、摩擦学性能以及承载性能需要进一步提高。     

Y2O3改性石墨/CaF2/TiC/镍基合金复合涂层微观组织与摩擦学性能研究

为提高石墨/CaF₂/TiC/镍基合金（GCTN）复合涂层的力学性能和摩擦学性能,运用等离子喷涂技术在45钢表面制备了Y₂O₃改性GCTN复合涂层,研究了Y₂O₃对复合涂层的微观组织、显微硬度、断裂韧性和摩擦磨损性能的影响。结果表明：Y₂O₃改性GCTN复合涂层主要由γ-Ni、CrB、Cr7C₃、TiC、CaF₂和石墨等物相组成。Y₂O₃在等离子火焰加热作用下与C元素反应生成活性元素Y,Y净化了复合涂层的微观组织,并细化了CrB、Cr₃C7等硬质相晶粒,提高了其致密性。当Y₂O₃质量分数为0.5%时,复合涂层的显微硬度和断裂韧性分别为593.3MPa和6.82MPa·m^1/2,比不含Y₂O₃的复合涂层分别增大了8%和22%,其机理主要是Y₂O₃细化了CrB、Cr₃C₇等硬质相晶粒,起到了细化强化作用。由于GCTN-0.5Y₂O₃复合涂层的显微硬度和断裂韧性显著提高,减少了其黏着磨损和微观断裂磨损,因而GCTN-0.5Y₂O₃复合涂层的摩擦因数和磨损率最小,分别为0.085和0.39×10-3mm3/m。     

石墨含量对石墨固体润滑涂层摩擦学性能的影响

利用简便的刷涂法在钢基体表面制备了石墨固体润滑涂层。利用MM-200型摩擦磨损试验机对不同石墨含量的固体润滑涂层进行了详细的摩擦学性能对比试验。结果发现．石墨固体润滑涂层的摩擦学性能与石墨含量之间呈“马鞍形”变化规律，当石墨的质量分数为28％时，固体润滑涂层的减摩、耐磨性能最佳。     

Investigation of the tribological properties of silicon containing zinc–aluminum based journal bearings

In this study, frictional behavior of thin-walled journal bearings produced from Zn–Al–Cu–Si alloys was investigated using a purpose-built journal bearing test rig. The alloys were produced by permanent mould casting. Mechanical properties such as ultimate tensile strength, elongation, hardness and microstructure of these alloys were determined. The friction properties of the bearings produced from these alloys were also investigated. In this investigation, the effects of surface roughness and bearing pressure on the frictional properties of the journal bearings were taken into account. The results showed that friction factor decreased with increasing bearing pressure especially in the mixed and full-film lubrication zones. It was found that high surface roughness led to high friction factor. The ZnAl27Cu2Si1 and ZnAl40Cu2Si1 bearings showed full Stribeck curve tendency while ZnAl27Cu2Si2 bearing did not exhibit the typical diagram having no full-film lubrication zone at the pressure of 0.7 and 1.1 MPa.     

热喷涂MoS2/PA(聚酰胺)复合涂层的摩擦学性能及磨损机理研究

利用热喷涂技术在45钢上制备了MoS2／PA(聚酰胺)复合涂层，考察了不同填料含量复合涂层的摩擦磨损性能，采用SEM分析涂层及对偶磨损表面形貌，并探讨了填料对复合涂层摩擦磨损性能的影响机制。结果表明：填料含量大于39／6时，虽然摩擦因数较小，但磨损率很大，且大于纯PA涂层的磨损率；当填料含量小于3％时，涂层摩擦学性能有所提高。