摘要:

Heats of immersion were determined for three base oils, their fractions as separated by polarity, and model compounds on a 52 100 steel surface. The method consists of calculating the heat of immersion based on surface tension and contact angle measurements made at temperatures from 25°C to 175°C. Friction and wear tests were performed on the same oils using micro-sample four-ball wear tests. The heat of immersion data were found to be inversely proportional to friction and wear. Model compounds with different functional groups similarly tested, however, suggest molecular structures have a significant role in influencing friction and wear when chemical reactions become the dominant lubrication mechanism rather than adsorption.

ISSN:1040-2004    

DOI:10.1080/10402008908981919

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Following development of machine design, mathematical models of the machine have to be improved. The most convenient methods are those which create models of separated sub-systems or sub-structures and then assemble them into a whole system. In this way the analysis is clearer, gives opportunities to check and correct dynamical properties of each sub-system before synthesizing and enables the design of better matched systems. It facilitates also on-site correction as the problem subsystem can be easier identified.

ISSN:1040-2004    

DOI:10.1080/10402008908981920

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Experiments are described in which elastohydrodynamic and boundary lubrication properties of O/W emulsions of mineral oil are studied with a variety of nonionic surfactants as the emulsifying agents. The changes in the minimum elastohydrodynamic film thickness are determined with different surfactants, with changes in oil concentration, with changes in emulsifying agent concentration, and with blending of different surfactants. These results can be quantitatively explained by a theory which assumes trapping of oil particles between steel surfaces with a certain probability. It is then shown that this trapping probability is correlated to the 'displacement energy' at the oil-water-steel boundaries. On the other hand, boundary lubrication properties of the emulsions are exclusively governed by those of the surfactants themselves suggesting that, under these lubricating conditions, their adsorbed films play a dominant role.Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in Baltimore, Maryland, October 16–19, 1988

ISSN:1040-2004    

DOI:10.1080/10402008908981921

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor