作者: De Gong Chang, Xue Feng Wang, Fu Qin Yang, Jiang Zhong Wang
摘要: The effects of the lubricant properties on the lubricating performance of the tripod sliding universal joint were studied under thermal condition by numerical method. The obtained results show that increasing lubricant viscosity increases the film thickness whereas increasing viscosity-pressure coefficient or viscosity-temperature coefficient is just the reverse. The pressure hardly depends on the viscosity-pressure coefficient or viscosity-temperature coefficient, and a larger lubricant viscosity induces only a remarkable second pressure peak. Increasing lubricant viscosity or viscosity-pressure coefficient increases the temperature whereas the increasing viscosity-temperature coefficient reduces it.
302
作者: Jie Jiang, Dang Sheng Xiong, Jian Liang Li, Yan Shi
摘要: Components of space machines often works at high temperature and vacuum, or on other rigour conditions, the traditional liquid lubricant cannot satisfy the requirement. The common solid lubricant is hard to supply between two friction surfaces continuously and it is easily decomposed and failure at high temperature. It is an urgent need to study a new type of lubrication technology. In this paper, the surface of 1Cr18Ni9Ti with high hardness and micro dimples was prepared through laser texturing and plasma molybdenizing/plasma nitriding duplex treatment. The textured surface was coated with MoS2 lubricating film and the friction and wear properties from room temperature to high temperature were evaluated. The results show that the laser surface textured dimples trap hard abrasive particles and reduce the damage to the lubricating film, and thus decrease the wear rate. The optimum dimple density of 7.1% is obtained. At elevated temperature, the wear rate of molybdenized texture or nitrided texture is lower than that of the matrix and single textured surface.
706
作者: Hong Rui Ao, Deng Pan, Hong Yuan Jiang
摘要: The contact at head/disk interface in hard disk drives subject to an external shock has been studied using the finite element method. A rigid cylinder moving over a two-layered thin film was implemented to simulate the contact between the recording slider and the disk. The effects of different friction coefficients on the von Mises stress of two-layered thin film were investigated. The relation between pressed depth and width of deformation has been obtained. Results show that the amplitude decreases with increase of friction coefficient while the period of slider motion is diminution. In addition, the stress distribution fits Hertzian contact theory.
2339
作者: San Ming Du, Yong Ping Niu, Yong Zhen Zhang
摘要: In the present study, 20 Wt. % ZrO2-Al2O3-17 wt.% TiO2 powders were sprayed using a plasma-spray technique after a NiAl bond layer was deposited on plain carbon steel substrate. The produced coatings were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) including energy-dispersive spectroscopy (EDS). The tribological properties of coatings against hard alloy ball were investigated by using a pin-on-disc tribo-meter under dry environments. The predominant wear mechanism of coating is fatigue.
420
作者: S.R. Chauhan, Sunil Thakur
摘要: In this paper the friction and wear characteristics of vinylester and vinylester composites have been investigated under dry sliding conditions for different applied normal load, sliding speed and sliding distance. The experiments have been carried on a pin on disc arrangement at normal room temperature conditions. The influence of friction and wear parameters like normal load, speed, sliding distance and percentage of filler content on the friction and wear rate has been investigated. In this study, a plan of experiments based on the techniques of Taguchi was performed to acquire data in a controlled way. An orthogonal array L27 (313) and Analysis of variance (ANOVA) were applied to investigate the influence of process parameters on the coefficient of friction and sliding wear behaviour of these composites. The Taguchi design of experiment approach eliminates the need for repeated experiments and thus saves time, material and cost. The results showed that with increase in the applied normal load and sliding speed the coefficient of friction and specific wear rate decreases under dry sliding conditions. It is also found that a thin film formed on the counterface seems to be effective in improving the tribological characteristics. The results showed that the inclusion of cenosphere as filler materials in vinylester composites will increase the wear resistance of the composite significantly.
569
