摘要:

For solid lubricant films such as oxides, soft metals and molybdenum disulfide in a resin low friction and low wear have been found when the film thickness lies between 10−6and 10−2cm, and high friction and high wear outside these limits. At the 10−3−cm limit, the rise in friction occurs because the load is carried by the film rather than by the substrate, while the rise in wear is caused by the formation of large wear particles. The experimental data appear to agree reasonably well with theoretical predictions based on the concepts of characteristic junction size and wear particle size.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis, Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972159

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

A recently developed model of adhesive wear for liquid lubricants has been modified to include the effect of vapor pressure on the wear rate for vapor lubricants at low pressures or high vacuum. Two distinctly different tests of the model were made with published data on the wear of graphite in varying atmospheres. In addition to correlating the experimental wear data as a function of pressure and heat of adsorption, the calculated value of the wear coefficient kmfor graphite-graphite contact from both correlations is internally consistent.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis, Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972160

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

A technique has been developed, whereby mechanical strength and excellent oxidation resistance is imparted to self-lubricating bodies of high lubricant content. By an “amalgamation” of powdered solid lubricants, such as tungsten diselenide, with a gallium alloy, followed by a subsequent compression-curing cycle, self-lubricating surfaces have been formed that resist oxidation at a temperature of 1500 F. This paper presents friction-wear characteristics of these materials at temperatures to 950 F. They offer potential as load-bearing surfaces and seals in high temperature applications for both oxidizing and inert or vacuum environment.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis, Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972161

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Compact of molybdenum disulfide powder were made, without the use of a binder, over a wide range of compacting pressures and length-to-diameter ratios. Their specific gravity, hardness, and compressive and tensile properties were determined at approximately sea-level pressure and 75 F. The ultimate compressive strength and ultimate tensile strength were found to be essentially functions of specific gravity only, and the relationships are presented. The modulus of elasticity was found to be essentially the same in compression and in tension, and is also presented as a function of specific gravity.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis, Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972162

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The thermal stability properties of n-hexadecane, super-refined mineral oils, and oligomers have been measured as a function of time and temperature. The versatility of the PRL pressure cylinder thermal stability test is demonstrated. Chromatographic techniques to provide quantitative data on the products of decomposition are described. The similarity in mechanism is shown for the thermal degradation of pure hydrocarbons and mineral oils, while distinctly different mechanisms are shown for mineral oils and oligomers. Differences in the thermal degradation reactions in the gas and liquid phases emphasize the need for close control of any standard long time thermal stability test because of secondary reactions involved. The large effects of small amounts of gas and volatile products formed on the measurements conventionally used to estimate thermal degradation are discussed.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis, Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972163

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

An hypothesis of the mechanism of the formation and growth of deposits from jet-engine lubricants in today's jet engines is discussed. Deposit formations are most often found in areas of the engines which are not flood-lubricated. Lubricant is transported as a spray or mist to hot static areas of the engine where deposits can form. The “Oil Mist Deposits Test,” a laboratory technique which can be used to differentiate between the deposit-forming tendencies of lubricants, is presented. The results obtained by the laboratory technique are equated to levels of deposits found in field engines.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis, Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972164

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Friction measurements on steel, glass, and copper with a stainless steel rider on solutions of poly(n-alkyl methacrylate)s show that as the length of alkyl group is increased the coefficient of friction is reduced. The friction values are almost the same as those obtained with n-alkyl acetates having the same alkyl length. Changes in concentration from 0.01 to 10 mg/ml yield at most an insignificant increase in friction. The progressive friction reduction with increasing alkyl length is explained in terms of increasing lateral interactions of the adsorbed polymer film with increasing fraction of alkyl lengths having one free end. These lateral interactions lead to progressively increasing rigidity which contributes to friction reduction. Measurements with copolymers of n-hexadecyl methacrylate and methacrylic acid show minimum friction with approximately 50% of methacrylic acid indicating that strongly polar groups which can interact with the surface and long alkyl groups both contribute to friction reduction. When either is decreased in concentration in the film near the surface, friction increases.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis, Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972165

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The EP films generated by borate-containing lubricants were studied to determine their structure and mode of action. Films were generated on SAE Machine test specimens with a blend of tribenzyl borate in solvent neutral oil. Study of the generated films in situ and after chemical stripping show them to be amorphous structures a few thousand angstroms thick containing boron, ferrous iron and organic components. Attempts to reproduce film material synthetically are described. Surfaces with borate EP films are shown to be harder than the steel substrate. Thus, they do not conform to the usual concept of more conventional EP agents which are generally believed to provide an easily-sheared film.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972166

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Friction and wear experiments with 1-cetene and cetane on stainless steel demonstrated the effect of a carbon-carbon double bond in the boundary lubrication of stainless steel. Experiments with cold-rolled steel, nickel, and chromium indicated the chromium to be the constituent in the steel that is markedly affected. The use of the unsaturated 1-cetene resulted in a lowering of the friction coefficient and the wear over its saturated analog, cetane. It is postulated that the improvement in friction and wear observed using the olefin 1-cetene is due to chemical attachment to the chromium or chromium oxide present in the wearing surface of the stainless steel reducing the amount of intermetallic contact. Experiments using the pure polar olefin vinyl stearate as the lubricant resulted in even further improvement of the frictional properties of stainless steel rubbing surfaces than the olefin alone, and a mechanism is proposed. It is also shown that these same improvements in frictional properties can be obtained when polar olefins such as vinyl stearate are used as additives to ordinary hydrocarbon oils.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Minneapolis, Minnesota, October 18–20, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972167

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The antiwear characteristics of pure metal O,O-dialkylphosphorodithioates in n-hexadecane are determined for steel-on-steel and copper-on-steel systems under mild conditions of sliding. Their effectiveness is found to be directly related to their rate of thermal decomposition; and more thermally stable structures exhibited better antiwear characteristics. This demonstrates that differences in wear are due to differences in chemical, not adhesive, wear. Because thermal stability is systematically dependent upon alkyl group structure and metal cation size, it is concluded that neither the alkyl group nor the metal play a direct role in the effectiveness of the additive in reducing wear. The nature of the surface reaction leading to chemical wear is not known.Contributed to the American Society of Lubrication Engineers by the author. Manuscript received August 12, 1966.

ISSN:0569-8197    

DOI:10.1080/05698196708972168

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor