No abstract available

No abstract available

[en] The solid lubricant molybdenum disulfide is applied industrially in powder from as well as in many other forms and manifold ways. Due to raw material problems it seems to be necessary to develop alternative products

[en] In pursuit of energy efficiency and durability throughout human history, advances in lubricants have always played important roles. Ionic liquids (ILs) are room-temperature molten salts that possess unique physicochemical properties and have shown great potential in many applications with lubrication as one of the latest. While earlier work (2001–2011) primarily explored the feasibility of using ILs as neat or base lubricants, using ILs as lubricant additives has become the new focal research topic since the breakthrough in ILs’ miscibility in nonpolar hydrocarbon oils in early 2012. This work reviews the recent advances in developing ILs as additives for lubrication with an attempt to correlate among the cationic and anionic structures, oil-solubility, and other relevant physicochemical properties, and lubricating behavior. Effects of the concentration of ILs in lubricants and the compatibility between ILs and other additives in the lubricant formulation on the tribological performance are described followed by a discussion of wear protection mechanism based on tribofilm characterization. As a result, future research directions are suggested at the end.

No abstract available

[en] An investigation into suitable self lubricating dry bearing materials with relatively high radiation resistance and which will operate in a vacuum of 10^-6 torr. (author)

[en] Graphene oxide (GO) with abundant oxygen functional groups has been widely studied as friction-reduction additive in lubricating oil or directly as solid lubricant. However, the lubrication mechanisms of these groups in solid GO lubricants have not been well revealed yet. Herein, we report a new strategy to prepare hydroxyl-carboxyl-terminated GO, hydroxyl-terminated GO, less-hydroxyl-terminated GO, and reduced GO (rGO), and then employ them as a frictional research model to address this concern. The results reveal that a little amount of water confined in GO layers dominates the interlayer shearing resistance by confining hydrogen-bond interaction. The strongest confinement effect to hydrogen-bond is achieved in hydroxyl-terminated GO, leading to the lowest shearing resistance between GO layers and then the enhanced friction performances. This finding first reveals the synergistic lubrication mechanism of oxygen functional groups and confined interlayer water molecules, providing us a new design view to fabricate superior graphene-based solid lubrication materials.

[en] This documentation contains 5890 titles. It comprises the following topics: 1) Subdivision of subjects (German, English, French); 2) systematic bibliography of titles; 3) personal and corporate author indexes; 4) report and paper number index; 5) standard number index; 6) conference index by conference place; 7) subject index. (orig./HP)

[en] Friction torque in an angular contact ball bearing is dependent on the motion of the balls, lubricant viscosity and quantity, rotational speed and applied loads. To evaluate the friction torque in a ball bearing, the SKF methodology includes the geometrical parameters, lubricant viscosity and type of lubrication, operation speeds and applied loads (radial and axial). As is indicated in the SKF catalogue, the above-mentioned methodology can be used for applied loads equal to or larger than the recommended minimum load indicated. For very low applied loads and for dry or limit conditions, the SKF catalogue doesn’t indicate the adequate models to estimate the friction torque. Also, the presence of the cage is not directly included in the SKF methodology. Based on the spin down methodology, the authors performed experimental investigations on a 7205B modified angular contact ball bearing, by using only three balls with and without the cage. Experimental friction torques on the outer race has been obtained in dry conditions and the results were compared with the results obtained from the SKF catalogue. Important differences have been obtained. Also, it was evidenced that at very low loads the presence of the cage leads to an increase in the friction torque with more than one order of magnitude. (paper)

[en] Theoretical and applied aspects of friction and lubrication process control in leading engineering technologies of metal forming have been considered. Innovative modifiers of friction for process lubricants in forging and hot stamping have been suggested. The efficacy of pyro- and nanomodifiers has been confirmed experimentally. Compositions of lubricants as well as the ways of studying tribological phenomena in hot metal deformation have been suggested. (paper)