一种测定润滑脂抗微动磨损性能的方法

利用现有的费夫纳摩擦氧化试验机研究并考察了不同种类润滑脂的微动磨损性能。     

Tribological properties of nano‐calcium borate as lithium grease additive

Nano‐calcium borate (NCB) with an average particle size of about 70 nm was synthesised via ethanol supercritical fluid drying technique, and the morphology and microstructures of as‐prepared particles were characterised by means of scanning electron microscope (SEM, JEOL LTD., Tokyo, Japan) and X‐ray powder diffraction. The friction and wear behaviour of the NCB as additive in lithium grease were evaluated with an Optimol‐SRV IV (Optimol Instruments Prüftechnik GmbH, Munich, Germany) oscillating friction and wear tester (SRV tester). The morphology and surface composition of the worn surfaces of lower discs after SRV test were analysed by SEM and X‐ray photoelectron spectroscopy (XPS, Physical Electronics, Inc., USA). The result demonstrated that the anti‐wear and load‐carrying capacities of the lithium grease were significantly improved, and the friction coefficient of the lithium grease decreased with the addition of NCB additive. The analytical results of XPS indicate that the good tribological performance of NCB is attributable to the formation of a boundary lubrication film composed of deposited NCB and the tribochemical reaction products such as B₂O₃, CaO and iron oxides on the rubbing surface. Copyright © 2013 John Wiley & Sons, Ltd.     

C10—C20天然脂肪酸在润滑脂生产中的应用

Ｃ１０￣Ｃ２０天然脂肪酸是利用油脂化工厂的工艺下游酸作原料，经过深度精制处理而得到的一种新型混合脂肪酸。文章叙述了该脂肪的性能和在不同润滑脂产品中的应用效果。     

High-temperature solid lubricating substances

An evaluation of the results of studies of the friction of solids at elevated temperatures in a vacuum and in air has enabled the identification of promising materials for use as solid-lubricating substances within various temperature ranges. Solid-lubricating substances (solid greases) are commonly incorporated into composite materials and coatings. When several solid greases are introduced into a composition, their action results in synergism.     

低噪声润滑脂的摩擦磨损特性分析

用标准的立式万能摩擦磨损试验机的销盘实验,分析了低噪声润滑脂EMQ2与RS3润滑脂的摩擦磨损特性,针对磨合阶段、稳定磨损阶段、摩擦噪声与胶合失效进行分析.结果表明,在磨合阶段摩擦系数有较大变化,随后的稳定磨损阶段中摩擦系数变化减小;脂润滑的摩擦副的摩擦系数比油润滑显著增大、变化频率增加,在试验过程中出现嗡嗡声时,而在摩擦系数下降阶段不出现摩擦噪声;在摩擦副出现胶合失效前,摩擦副的摩擦系数急剧上升;在摩擦系数变化幅度达到10%左右时,摩擦副就出现胶合失效.并用扫描电镜（SEM）分析了试盘、试销摩擦副运转2 h后的磨斑表面形貌.     

Modified smectitic Tunisian clays used in the formulation of high performance lubricating greases

Two smectitic Tunisian clays were organically modified by exchange reaction with dioctadecyl dimethylammonium chloride (DODMA) and hexadecyl benzyl dimethylammonium chloride (HBDMA). The resulting organoclays were used in the formulation of lubricating greases. The results of the performance tests applied to the obtained greases showed that their physicochemical and mechanical characteristics are in conformity with the extreme-pressure (EP) greases specifications. The obtained greases present good EP properties with only 0.5% EP additives. The smectitic clays used could constitute a raw material in the formulation of high performance lubricating greases.     

O型丁腈橡胶密封圈耐润滑脂性能研究

研究了O型丁腈橡胶密封圈中腈基含量对其耐润滑脂性能的影响，讨论了不同性能润滑脂对丁腈橡胶的溶胀作用机理。在实际使用中，应科学地选用与橡胶密封圈相宜的润滑脂，从而保证产品使用的可靠性。     

Synergistic effects on the enhancement of thermal conductive properties of thermal greases

Efficient heat dissipation from electronic devices with high-degree integration and high-power density has become an urgent and complex problem. We report here novel thermal greases with an enhanced thermal conductivity using graphene flakes (GFs), hexagonal boron nitride (h-BN), and hydroxypropyl cellulose (HPC) as fillers. The obtained GF/h-BN/HPC thermal grease at 23 vol % h-BN loading exhibits a thermal conductivity enhancement 555%, compared with the pure PDMS matrix, and also about 50, 169, and 115% higher than that with GF/h-BN, h-BN/HPC and h-BN as the filler for the thermal grease, respectively. We attribute it to the synergistic effects among GF, h-BN, and HPC, due to the formation of thermally conductive networks. This study provides a strategy for preparing thermal greases for thermal management applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47726.     

Comparative study between prepared electrical grease and the imported one

Grease lubrication is a complex mixture of science and engineering, requiring an interdisciplinary approach, and is applied to the majority of bearings worldwide. Grease can be more than a lubricant; it is often expected to perform as a seal, corrosion inhibitor in electrical joints, electrical insulator and electrical connection improver. This work is concerned, therefore, with the comparative study between prepared electrical grease and the imported one. Physicochemical and electrical properties for the prepared grease and the imported one were evaluated. The results of dropping point, penetration, dynamic viscosity, corrosion inhibition, evaporation loss, total acid number and oil separation for the prepared grease under investigation are mostly the same compared with the imported grease. In addition, the results interpreted in terms of the physical and chemical properties of both greases revealed that no remarkable differences. In this respect, calorimetric study shows that the prepared grease, like the imported one, is thermally stable up to about 200 °C then decomposition and degradation started slightly faster and higher than that of the imported one. The electrical and dielectric parameters are very close at and around room temperature then the increase of charge carriers' mobility at higher temperatures explains the deviation from stability in case of the prepared grease. One can conclude that the prepared electrical grease could replace efficiently the imported electrical grease especially in isothermal application at and around room temperature.     

Correlation between friction and flow of lubricating greases in a new tribometer device

A tribometer requires speed and normal force control, as well as a torque measurement, to acquire tribological data. An air bearing‐supported rotational rheometer allows the measurement of the same variables, but in a broader range and with better accuracy. This and the intension to measure Stribeck curves, as well as the static friction with one single instrument, led to the idea to design an accessory turning a rheometer into a high‐resolution tribometer based on a ball on pyramid principle. Speed ramp and static friction measurements of oil‐lubricated systems illustrate the performance of the rheo‐tribometer. The flow behaviour of greases is more complex, and extensive rheological and tribological testing was performed on three greases of the American National Lubrication Grease Institute classes 0, 1 and 2 at the temperatures of 25 and −40°C. The influence of temperature could be monitored, and a correlation between rheology and tribology was found. To link the model system with real applications for greases, a ball bearing fixture for the tribological accessory has been designed for which first results are presented. Copyright © 2009 John Wiley & Sons, Ltd.