[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] The methods have been refined for manufacturing zirconium rods with mirror surface. The blank of the grade 110 zirconium alloy was coated prior to extrusion by a layer of copper 0.25 to 0.3 mm thick, then by 2 or 3 layers of colloidal graphite and dried in the air. Upon extrusion, copper was pickled off, and the blanks were zinc-coated in molten chlorides, phosphated and saponified. Rods rolled in the KhPT mill feature extra accuracy and a surface roughness of 0.63 mcm which requires o grinding. The use of metallic interfacial layers lowered labour expenses by 30 % and raised the yield of standard products

[en] Tribological studies were conducted on five different polyimide solid bodies formulated from the diamine 2,2-bis 4-(4-aminophenoxy)phenyl hexafluoropropane (4-BDAF) and the dianhydrides pyromellitic acid (PMDS) and benzophenonetetracarboxylic acid (BTDA). The following polyimides were evaluated 4-BDAF/PMDA, 4-BDAF/BTDA, 4-BDAF/80 mole percent PMDA, 20 mole percent BTDA, 4-BDAF/60 mole percent BTDA. Friction coefficients, polyimide wear rates, polyimide surface morphology and transfer films were evaluated at sliding speeds of 0.31 to 11.6 m/s and at temperatures of 25 C to 300 C. The results indicate that the tribological properties are highly dependent on the composition of the polyimide and on the experimental conditions. Two polyimides were found which produced very low wear rates but very high friction coefficients (greater than 0.85) under ambient conditions. They offer considerable potential for high traction types of application such as brakes

[en] Graphite is an excellent solid lubricant for surface coating, but its performance is significantly weakened by the vacancy or Stone-Wales (SW) defect. This study uses molecular dynamics simulations to explore the frictional behavior of a diamond tip sliding over a graphite which contains a single defect or stacked defects. Our results suggest that the friction on defective graphite shows a strong dependence on defect location and type. The 5-7-7-5 structure of SW defect results in an effectively negative slope of friction. For defective graphite containing a defect in the surface, adding a single vacancy in the interior layer will decrease the friction coefficients, while setting a SW defect in the interior layer may increase the friction coefficients. Our obtained results may provide useful information for understanding the atomic-scale friction properties of defective graphite

[en] The invention provides an elongated slender fuel element of cylindrical form having a locally flexible metallic sheath, a plurality of close-fitting nuclear fuel pellets in end-to-end stacked array therein, having longitudinal expansion relief provision in the ends of at least some pellets to substantially preclude differential axial expansion between pellet and sheath in operation, and a low-shear lining layer composed of siloxane lacquer or graphite interposed between the pellets and the sheath at the peripheral adjoining surfaces thereof to facilitate peripheral distribution of stresses in the sheath to reduce the likelihood of rupture failures extending longitudinally of the sheath due to a concentration of peripheral sheath expansion stresses

[en] Electrophoresis can be employed to deposit a wide variety of materials including MoS₂ coatings that exhibit properties comparable to the properties of sputtered MoS₂ coatings used as lubricants for vacuum applications. Coatings which display coefficients of friction as low as 0.03 can be deposited from an aqueous suspension containing approximately 2.5 wt %, micrometer-sized MoS₂ particles stablized with approximately 500 ppm of a nonionic surfactant. Uniform coatings with appropriate thicknesses can be deposited on nonplanar surfaces in minutes with minimal equipment. The morphology of the as-deposited coatings suggest that MoS₂ is electrophoretically active as a result of a net positive surface charge along the basal plane

[en] A selfsupporting fuel rod is described, containing cylindrical fuel pellets. To reduce the friction between the fuel pellets a thin layer of graphite is applied to one or both end surfaces of the pellets. (L.E.)

[en] Highlights: • Sliding speed has the significant effect on the tribological performance. • The good tribological behavior is attributed to formation of a tribo-film. • MLG with high strength can enhance the anti-rupture ability of tribo-film. • Ag can worked as the solid lubricant to provide good lubricating effect.

No abstract available

[en] A nickel matrix self-lubricating composite material developed by powder metallurgy process and its application is presented. The affect of the solid lubricant graphite content on the physical and mechanical properties of the material was studied. The friction and wear behavior of the material in high temperature and high pressure water is discussed. The life of rolling bearing cages made of this material was tested in high temperature and high pressure water, and the tests showed that the cages gave satisfactory performance and efficient lubrication for the bearings. (author)