摘要:

Comparison is made of the plastic deformation due to the friction of a sapphire ball, rubbing in air on the principal faces of four hexagonal metals of different lattice stacking ratio c/a: Be, Co, Zn and Cd, during the preliminary displacement.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983230

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The various equations representing special cases of boundary lubrication are examined and grouped as “models”, The study indicates that there are no serious inconsistencies, but that each model is so seriously limited in its coverage that large gaps exist in coverage. Methods for closure of these gaps are suggested and numerically explored to a limited extent. Hope is extended that in the near future it will be possible to compute wear rates from basic physical properties without actual experimentation on the specific lubricant and surfaces. This would constitute a useful new system for machine element design.Presented as an American Society pf Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983231

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The various theoretical hypotheses that have been put forward to explain the effect of the thickness of solid lubricant films on the friction between relatively sliding surfaces are described. The rise in friction that occurs with decreasing thickness when the films are very thin is discussed in detail and a new explanation of this phenomenon based upon an increasing degree of film penetration is put forward. A theoretical model to describe such a process is set up. The predicted variation of the friction made on this basis is in good agreement with existing experimental data. Experiments on a pin disc machine that were carried out to provide further evidence for checking the postulated mechanism are also described. Friction coefficient results obtained from these experiments with films of different thicknesses on surfaces of different roughnesses provide further evidence to support the given interpretation of the friction process. Explanations for certain discrepancies between the theoretical and experimental results are offered.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983232

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Addition of 0.02% phosphorus to a Cu-6Sn alloy reduces the desorption temperature for paraffin oil, containing 0.2% fatty acid, by more than 60 C. This means that, in the pin and ring geometry, the load carrying capacity in the boundary lubrication regime is lowered by a factor of 2 or more. Desorption is controlled by the over-all surface temperature of the bronze, rather than by the local hot-spot temperature. The desorption temperature is not influenced by viscosity and sliding speed. At conditions below critical, wear is probably of the abrasive type and the wear rate is independent of speed.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983233

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Sulfurized methyl 10-undecenoate was used as the substance typifying sulfurized fatty extreme-pressure lubricant additives. The characteristic chemical structures in sulfurized methyl un-decenoate are sulfur-bridged long-chain di-esters, of which 1,20-dicarbomelhoxy-9,12-dimethyl-10,11 -dithiaeicosane is an example. The antiwear performance of this dithio-ester with respect to hardened AISI1095 steel in a pin-and-disk apparatus was indistinguishable from that of sulfurized methyl undecenoate. Esters such as methyl laurate and 1,18-dicarbomethoxyocta-decane did not show the antiwear behavior typical of sulfurized methyl undecenoate. Organic sulfides—-di-n-octyl monosulfide, di-n-octyl disulfide, di-n-octyl tetrasulfide, di-sec-octyl disulfide, d-t-octyl disulfide—behaved much differently than sulfurized methyl undecenoate. A mixture of methyl laurate and di-sec-octyl disulfide showed the same kind of antiwear behavior as sulfurized methyl undecenoate.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983234

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Tests are described in which an SAE 1113 steel pin is rubbed on a similar disc at sliding speeds up to 100 m/s and loads up to 7 kgf. Measured pin sub-surface temperatures are used to predict total surface temperatures by considering the heat flow through an idealised single asperity tip, and from the existing theories of Jaeger, Archard and Barber. The frictional coefficient and transitions in the sliding process are shown to be related to the predicted total temperatures.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983235

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

An analytical program was conducted to establish recommended types of gas-lubricated journal bearings for use in miniature cryogenic turbomachinery. Very high rotative speeds, and the limiting damping properties of gas, indicated that fractional frequency whirl is prevalent, and the most difficult problem to overcome. Of the many journal bearing types investigated, the tilting pad hydro-dynamic and porous hydrostatic journal bearings were suited to the application.

ISSN:0569-8197    

DOI:10.1080/05698197108983236

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

An investigation has been made of the effects of sliding-load history on the friction of thin burnished films of MoS2. When friction test specimens were subjected to sliding in high vacuum (10−6to 10−9ton) and ultrahigh vacuum (below 10−10torr), the friction level was substantially reduced after sliding had been accomplished at high loads.

ISSN:0569-8197    

DOI:10.1080/05698197108983237

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor