Showing papers in "Tribology Transactions in 1964"
TL;DR: In this article, a method for calculating spring and damping coefficients for the tilting-pad journal bearing is presented, which includes the effect of pad inertia, and the parameter λ is used as an indicator of the compressibility effect of gas in bearing clearance.
Abstract: A method for calculating spring and damping coefficients for the tilting-pad journal bearing is presented. The analysis includes the effect of pad inertia. Numerical results are given in form of design curves for the centrally pivoted 4-shoe, 5-shoe, 6-shoe, and 12-shoe journal bearing. A comparison with test results is included. This paper deals with the effects of lubricant compressibility on the pressure profile and total load capacity in a partial journal bearing; pivot pressure as a measure of shoe load capacity; shoe friction characteristics; and optimum shoe clearance ratios for various speeds. The parameter λ is used as an indicator of the compressibility effect of gas in the bearing clearance. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois, May, 1964.
250 citations
TL;DR: In this paper, an experimental and mathematical study of elastohydrodynamic film formation is described for a rolling four-ball configuration utilizing steel bearing balls, where wear rates are determined in the microgram range, using a radiotracer tagged ball.
Abstract: An experimental and mathematical study of elastohydrodynamic film formation is described for a rolling four-ball configuration utilizing steel bearing balls. Wear rates are determined in the microgram range, using a radiotracer tagged ball. Existence and interruptions of elastohydrodynamic films are observed by measurement of electrical conductivity through the Hertzian contact. Surface microgeometry of the rolling tracks on the balls is statistically analyzed by processing electrical analogs of surface profiles through on-line computing equipment. Defining electrical contacts as asperity approaches through a separating film, the average duration and frequency of such approaches is computed from surface microgeometry statistics. A comparison of computed and observed values of contact conductivity parameters shows good order of magnitude agreement and yields estimates of average film thickness as a function of speed and load which agree, satisfactorily with the order of film thickness predicted by elastohy...
123 citations
TL;DR: A critical examination of Constantinescu's theory of turbulent fluid film lubrication has been undertaken as mentioned in this paper, and several of its anomalies were traced to violations of certain well-established basic phenomena in turbulent shear flows.
Abstract: A critical examination of Constantinescu's theory of turbulent fluid film lubrication has been undertaken. Several of its anomalies were traced to violations of certain well-established basic phenomena in turbulent shear flows. A new approach, which is free of some of these objections, has been made. It holds promise of yielding a more consistent turbulent lubrication theory. Comparison is given on infinitely long bearing with Constantinescu's results. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois, May, 1964.
71 citations
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TL;DR: In this article, a study was made of the surface temperatures generated by friction in a sliding system, where a fixed constantan ball riding on a rotating steel cylinder was used to determine the average surface temperature.
Abstract: A study was made of the surface temperatures generated by friction in a sliding system—a fixed constantan ball riding on a rotating steel cylinder. Using the principle of the Herbert-Gottwein dynamic thermocouple, time-average as well as instantaneous surface temperatures were determined. Some measurements were also made with imbedded thermocouples, and advantages and limitations of both methods are discussed. It was found that the average surface temperature was quite independent of running time and gross wear but increased markedly with increasing speed or load. Under the conditions used in this study (60–250-gm loads and 14–224 cm per second sliding velocities), average surface temperatures ranging from 87 to 239 F were obtained. It is shown that ΔTm = KQn, where ΔTm is the average rise in surface temperature, Q is the total rate of frictional heat supplied, n is approximately equal to 1/2, and K is a proportionality constant. The corresponding maximum surface temperatures reached in these experiments ...
66 citations
TL;DR: A series of studies were conducted in the jour-ball wear tester to better define the roles of volatility, environment, and polar impurities in boundary lubrication as discussed by the authors, and the effect of volatility as a factor in wear was conclusively shown.
Abstract: A series of studies was conducted in the jour-ball wear tester to better define the roles of volatility, environment, and polar impurities in boundary lubrication. A number of well-defined, super-refined mineral oils, free from polar impurities, were utilized as base stocks for these studies. The effect of volatility as a factor in wear is conclusively shown. Volatile base stocks were used to illustrate the effects of less volatile polar and nonpolar impurities. The relative importance of volatility of lubricity additives is also demonstrated. Methods for the quantitative measurement of dissolved gases including oxygen in the lubricant under practical test conditions are illustrated. The relationship between dissolved oxygen and wear is shown for several lubricants. The interrelationship between dissolved oxygen, lest temperature, load, and fluid is also discussed. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.
55 citations
TL;DR: In this article, the authors investigated the effect of polymers on bearing performance and found that polymers containing polymers have better bearing performance than straight mineral oils of the same low-shear viscosity.
Abstract: Oils containing polymers have been shown to give better bearing performance—lower friction and lower wear—than straight mineral oils of the same low-shear viscosity, in spite of their non-Newtonian character. This unexpected behavior has been investigated further in studies on solutions of different polymer types, using a range of molecular weights and concentrations for each type and blending all solutions to the same low shear viscosity. The viscosity and elasticity of these solutions were measured at different rates of shear in an ultrasonic crystal viscometer. The governing parameter controlling bearing performance appears to be the recoverable shear, which is related to the elastic modulus of the system. Polymer type, also appears to be important in determining the critical value of recoverable shear required for good bearing performance. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.
43 citations
TL;DR: The results of an experimental investigation of an externally pressurized, porous wall, nonrotating journal bearing that used air as a lubricant are compared with a previously published analysis and found to be in good general agreement, provided the eject of surface roughness is included in the determination of the clearance as mentioned in this paper.
Abstract: The results of an experimental investigation of an externally pressurized, porous wall, nonrotating journal bearing that used air as a lubricant are compared with a previously published analysis and found to be in good general agreement, provided the eject of surface roughness is included in the determination of the clearance. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, May, 1965.
41 citations
TL;DR: In this article, it was observed that the ease of decomposition and the order of stability of these metal dialkyldilhiophosphales were affected by: (a) the nature of the base oil used for the blends, (b) the presence of basic barium sulfonate in the blends.
Abstract: Thermal decomposition temperatures of oil blends of the sine, nickel, and cadmium salts of the same dialkyldithiophosphoric acid were determined by the use of the isoteniscope. It was observed that the ease of decomposition and the order of stability of these metal dialkyldilhiophosphales were affected by: (a) the nature of the base oil used for the blends, (b) the presence of basic barium sulfonate in the blends, (c) the presence of air in the isoteniscope, and (d) the pressure in the isoteniscope. The relationship of the experimental results to performance studies of the metal dialkyldilhiophosphates is discussed, and a critical evaluation of the decomposition mechanisms proposed to date is presented. It is concluded that the mechanism of the thermal decomposition of the metal organodilhiophosphates is not known, and that the relationship between thermal stability and anti-scuff performance is not completely understood. Presented as an American Society of Lubrication Engineers paper at the Lubrication C...
38 citations
TL;DR: In this article, the surface topography of bearing races was examined with an electron microscope and additive elements were measured on ball surfaces by X-ray fluorescence have indicated that surface films of appreciable thickness are formed by oil additives and that the additive composition controls both surface topographical and surface coating composition.
Abstract: Thrust ball bearing studies in which the surface topography of bearing races was examined with an electron microscope and in which additive elements were measured on ball surfaces by X-ray fluorescence have indicated that surface films of appreciable thickness are formed by oil additives and that the additive composition controls both surface topography and surface coating composition. Further, additive concentration, friction-time, and oil temperature studies have shown that the composition and/or thickness of the surface film is a function of the additive concentration, and suggest that most of the surface-active additives read in some manner rather than physically adsorb on surfaces. However, friction measurements correlate only to a limited degree with either the measured surface film composition or the observed topography. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.
34 citations
TL;DR: In this article, the coefficient of friction of a steel pin sliding on a steel ring lubricated with three commercial greases, various experimental greases or pastes, and other components of greases was measured.
Abstract: Measurements have been made of the coefficient of friction of a steel pin sliding on a steel ring lubricated with three commercial greases, various experimental greases or pastes, and other components of greases. After break-in at room temperature, heat was applied which reduced the friction of the greases to about half their room temperature value. The friction increased on cooling. The opposite effect was observed with base oil. The phenomenon was demonstrated in a ball thrust bearing operating under boundary conditions as a reduction in torque with heating and an increase in torque on cooling. The reduction in friction with heating was found to be due to the soap thickener. Pastes of CaCO3, fumed silica, and clay in oil, the base oil, and octadecane did not cause a reduction in friction. It was concluded that grease thickeners influence the friction of steel sliding on steel because of the formation of films on the surface of the metal. Presented as an American Society of Lubrication Engineers paper at...
24 citations
TL;DR: In this article, the fluid pressure between two parallel circular plates separated by a relatively thin film of oil was measured during sinusoidal axial vibration of the top plate, and the results of the experiment were compared with those predicted by inertialess considerations and an approximate solution which considers the fluid inertia.
Abstract: The fluid pressure between two parallel circular plates separated by a relatively thin film of oil was measured during sinusoidal axial vibration of the top plate. The results of the experiment were compared with those predicted by inertialess considerations and an approximate solution which considers the fluid inertia. On the basis of this investigation, in which Reynolds' number was varied up to a value of three, the inertialess solution gives good results for the film pressure for Reynolds' number up to about 0.4; at higher values, pressures greater than those predicted by inertialess considerations were obtained. An approximate solution considering the fluid inertia is shown to be in good agreement with the test data which can be represented by a third-degree polynomial equation. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois, May, 1964.
TL;DR: In this article, the authors summarized the research aimed at improving the oxidative stability of polyphenyl ethers by the use of additives and found that classic antioxidants such as amines and phenols are ineffective under extreme conditions.
Abstract: Recent changes in the design of aircraft engines have created a demand for lubricants that will perform satisfactorily under conditions far more rigorous than were ever experienced in the past. These increased demands cannot be met by conventional lubricants or by lubricants protected by conventional additives. Among synthetic lubricants being explored as functional fluids in this new area are the polyphenyl ethers. Polyphenyl ethers possess very good high-temperature properties. For example, bis(phenoxyphenoxy) benzenes are oxidatively stable to 500 F and thermally stable to 800 F. This paper summarizes the research aimed at improving the oxidative stability of polyphenyl ethers by the use of additives. It has been found that classic antioxidants such as amines and phenols are ineffective under extreme conditions. Chemical classes such as metal chelates, organometallics, and metal oxides inhibit oxidation of polyphenyl ethers at elevated temperatures. Presented as an American Society of Lubrication Engin...
TL;DR: In this paper, the results of tests on both heavily loaded gears of 12 DP and 35 mm bore ball bearings were reported, at pressures from 1 × 10−6 to 7 × 10 −9 torr and temperatures from −180 to 300°F.
Abstract: Results of tests on both heavily loaded gears of 12 DP and 35 mm bore ball bearings are reported. The gears and bearings were operated at unit compressive stresses upto 113,000 psi and 199,000 psi respectively, at pressures from 1 × 10−6 to 7 × 10−9 torr and temperatures from −180 to 300°F. The lubrication technique for the gears and bearings made use of composite materials containing a metal matrix, a film former, and a load carrying component. Contributed by the ASLE Aerospace Council and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois, May, 1964.
TL;DR: In this paper, a ball bearing with an epoxy-MoS2 composition retainer was used to simulate the loss of volatile matter from a bearing envelope through an opening to the space vacuum.
Abstract: Tests were made at low loads and moderate temperatures with sliders and ball bearings operating in test chambers each being continuously evacuated by an ion pump. The test chamber-ion pump system was used to simulate the loss of volatile matter from a bearing envelope through an opening to the space vacuum. Unlubricated specimens, MoS2-based films, soft metal films, self-lubricating materials, and oil lubrication were evaluated. In the slider tests, low friction was obtained with several MoS2-based lubricants, with no evidence of lubricant failure in up to 460 days vacuum exposure. Wear was kept minimal, so as not to obscure vacuum exposure effects. A ball bearing with an epoxy-MoS2 composition retainer gave the best performance—low friction without evidence of malfunction for 900 million revolutions (420 days of vacuum exposure). Pressure measurements during tests indicated that volatile matter was released by the rubbing process. Contributed to the American Society of Lubrication Engineers by the author.
TL;DR: In this paper, the friction and wear characteristics of various carbon materials sliding on metals and aluminum oxide were determined in vacuum at ambient pressures from 760 to 10−9 mm Hg.
Abstract: The friction and wear characteristics of various carbon materials sliding on metals and aluminum oxide were determined in vacuum at ambient pressures from 760 to 10−9 mm Hg. The friction and wear experiments were conducted with a hemispherically tipped carbon rider, under a load of 1000 gm, sliding on various disks rotating at a speed of 390 ft per minute. The results of this investigation show that additional research on carbon in vacuum is warranted. Adsorbed surface films present on both carbons and metal, as well as the presence of oxide on metals, appreciably influenced the friction and wear obtained with carbons in vacuum. Some impregnants were beneficial in reducing friction and wear of carbon in vacuum while others were not. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.
TL;DR: In this paper, the rate of wear of a single crystal sapphire sphere depends on crystal orientation and slide direction, which is correlated with the shear mechanism of the crystal structure at elevated temperatures.
Abstract: The rate of wear of a single crystal sapphire sphere depends on crystal orientation and slide direction. This effect can be correlated with the shear mechanism of the crystal structure at elevated temperatures. On oxidized metal surfaces or on glass, sapphire appears to wear more rapidly than on freshly generated metal surfaces as a result of chemical degradation. The effect of crystal orientation, which is associated with the shear strength of the crystal, is therefore decreased. Lubrication appears to decrease wear, but the effect of crystal orientation on wear rate persists. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.
TL;DR: In this paper, an extensive study of this phenomenon is suggested as a means of achieving a sounder understanding of the mechanism of lubrication, and results obtained with a polyphenyl ether illustrate somewhat of an extreme of such an effect, while fluid decomposition products appear to influence lubrication with both mineral oils and silicones.
Abstract: High-temperature fluid lubrication is influenced by many factors. Among these factors are the products of degradation of the fluid. Operating at bulk temperatures well below the initial decomposition point, equipment hot spots produce temperatures that result in small but significant amounts of fluid degradation. The material thus formed affects the lubricating characteristics of the fluid. Results obtained with a polyphenyl ether illustrate somewhat of an extreme of such an effect. Likewise, fluid decomposition products appear to influence lubrication with both mineral oils and silicones. Intensive study of this phenomenon is suggested as a means of achieving a sounder understanding of the mechanism of lubrication. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.
TL;DR: In this paper, a Cocks wedge mechanism is used for wear analysis of mild steel, copper, aluminum, mild steel and zinc, and the mean values of the shape factors are independent of particle size.
Abstract: Unlubricated, highly loaded sliding experiments were conducted for systems of mild steel, copper, aluminum, and zinc. Load is critical in determining the wear mode. A Cocks wedge mechanism is the primary method of wear for copper, and for aluminum until a critical temperature is reached. The wear of steel is characterized by the formation of small un-joined fragments. The surfaces of wear particles were of two types; copper showed one type, and aluminum, mild steel, and zinc the other. Wear particle shape can be characterized by the ratios of dimensions (L/W) and (L/H). These factors are easily determined to good accuracy, and have distributions which are both far different in form and mean values for the various metals. The mean values of the shape factors are independent of particle size, and of each other. Surface roughness is not related to wear particle size for highly loaded sliding. Contributed by the ASLE Technical Committee on Lubrication Fundamentals and presented at the Annual Meeting of the Am...
TL;DR: In this article, the effects of lubricant compressibility on the pressure profile and total load capacity in a partial journal bearing, pivot pressure as a measure of shoe load capacity; shoe friction characteristics; and optimum shoe clearnace ratios for various speeds.
Abstract: This paper deals with the effects of lubricant compressibility on the pressure profile and total load capacity in a partial journal bearing; pivot pressure as a measure of shoe load capacity; shoe friction characteristics; and optimum shoe clearnace ratios for various speeds. The parameter A is used as an indicator of the compressibility effect of gas in the bearing clearance. Contributed by the ASLE. Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society fo Lubrication Engineers held in Chicago, Illinois, May, 1964.
TL;DR: The trifluoropropylmethylpolysiloxanes exhibited the best combination of physical and lubricity properties as discussed by the authors, and laboratory data were presented which described the physical properties and improved boundary lubrication of the fluids.
Abstract: As technological advances are being made, the need for lubricants with higher load carrying capacities and stability to various environmental conditions are required. Nonadditive silicone fluids have approached the stability and temperature range required but have fallen short in their antiwear and load carrying ability for ferrous metals. The advent of fluoroalkylsiloxanes has brought about the much sought for boundary lubrication for steel sliding against steel as well as for other metal combinations. The trifluoropropylmethylpolysiloxanes exhibited the best combination of physical and lubricity properties. Laboratory data are presented which describe the physical properties and improved boundary lubrication of the fluids. To complement the bench testing, results of application tests with a vane pump, piston pump, mechanical vacuum pump (vane type), and a reciprocating compressor are described. Solvent resistance, liquid oxygen compatibility, and resistance to chemical attack are also discussed. Present...
TL;DR: The experimental and analytical literature is reviewed briefly and is drawn upon to provide solutions for the interactions of weak pressure flows with a strong Couette flow, as would be experienced in turbulent film bearings as mentioned in this paper.
Abstract: The experimental and analytical literature is reviewed briefly and is drawn upon to provide solutions for the interactions of weak pressure flows with a strong Couette flow, as would be experienced in turbulent film bearings. In the pertinent derivations, care has been taken to avoid known pitfalls in the application of mixing-length theory. Insofar as is possible, the results are shown to be in accord with reported experimental measurements. The areas of uncertainty in these analyses are areas where further experimental measurements are called for. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois, May, 1964.
TL;DR: In this paper, the inherently compensated gas journal bearing was developed for small eccentricity ratios, and curves for static and dynamic gas film forces and for bearing gas flow requirements were presented.
Abstract: Lumped and distributed parameter analyses of the inherently compensated gas journal bearing are developed for small eccentricity ratios. Curves are presented for static and dynamic gas film forces and for bearing gas flow requirements. Experimental results are compared with the theories for the case of plane vibration. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois, May 1964.
TL;DR: In this article, a laboratory unit is described with a method for determining the deposit-forming tendencies and oxidation stabilities of lubricants in thin films, which can be used for comparative evaluation of base fluids and inhibited fluids.
Abstract: A laboratory unit is described with a method for determining the deposit-forming tendencies and oxidation stabilities of lubricants in thin films. The test oil is passed over a spinning aluminum disk heated to temperatures of 500–650 F, which provides a dynamic oil film of about 0.0003 inch thickness. Oxidation stability is determined by measurement of the oxygen consumed. The deposits on the disk are estimated visually. The test can be used for comparative evaluation of base fluids and inhibited fluids. Test results on a series of high-temperature lubricants approximate deposition data obtained in jet engine tests and in CRC high-temperature bearing tests. 1 This research was sponsored by the United States Air Forceunder contract AF33(616)-8021. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.
TL;DR: In this paper, the secondary effects which can influence the operation of self-acting gas-lubricated bearings are analyzed, i.e., effect of the inertia forces, thermal effects, turbulence, and effect of molecular character of the flow.
Abstract: Some secondary effects which can influence the operation of self-acting gas-lubricated bearings are analyzed, i.e., effect of the inertia forces, thermal effects, turbulence, and effect of the molecular character of the flow. In order to point out their qualitative influence as well as the conditions in which such influences can be important, the case of infinitely long bearings is considered, but for the computation of quantitative effects, the real case of finite bearings is used. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois, May, 1964.
TL;DR: In this paper, a disk machine was used to measure the thickness of the film separating the surfaces of heavily loaded rollers and the variation of film thickness with applied load and rolling speed has been studied.
Abstract: Systematic measurements with a disk machine of the thickness of the lubricating film separating the surfaces of heavily loaded rollers have been made, and the variation of film thickness with applied load and rolling speed has been studied. It was found that the results can be expressed by: H = hp + 0.2 = 0.7 W−0.2 (ηU)0.83 where H is the minimum film thickness in the contact in microns, W is the applied load per unit width in dynes per centimeter, and ηU is expressed in dynes per centimeter. Contributed to the American Society of Lubrication Engineers by the author.
TL;DR: High vacuum effects on dry friction coefficient, lubricated friction coefficient and load carrying capacity of lubricants were studied in this article, showing that high vacuum effects have a significant impact on the dry friction coefficients.
Abstract: High vacuum effects on dry friction coefficient, lubricated friction coefficient and load carrying capacity of lubricants
TL;DR: Alkylaryl and alkylpolyethylenoxy phosphate ester acids and their salts were found to be effective load-carrying and rust-inhibiting additives for metalworking fluids.
Abstract: Alkylaryl- and alkylpolyethylenoxy phosphate ester acids and their salts were found to be effective load-carrying and rust-inhibiting additives for metalworking fluids. Falex and four-ball data showed that performance in oil, emulsion, and water systems were dependent upon the hydrophobe type and ethylene oxide content. Chip tests demonstrated that chemical composition also influenced rust inhibition. Contributed by the ASLE Fluids for Metalworking Committee and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois, May, 1964.
TL;DR: In this paper, the authors examined bearing life under each condition while fully accounting for the effect of outer ring deflection on fatigue life, and showed that an optimum design with regard to outer ring section thickness in relation to diametral size and number of rollers per row does exist with respect to bearing fatigue life.
Abstract: The design of back-up roll bearings in cluster-type rolling mills has, historically, been dictated by past engineering trial and error experience. Thus, to cause the bearings to act, as nearly as practicable, similarly to conventionally supported bearings, the outer ring section is usually made very heavy precluding large ring deflections. There exists controversy among bearing manufacturers as to whether a bearing having many rollers of small diameter or one having a smaller number of larger rollers is best in this application. The study herein presented examines bearing life under each condition while fully accounting for the effect of outer ring deflection on fatigue life. The investigation further demonstrates that an optimum design with regard to outer ring section thickness in relation to diametral size and number of rollers per row does exist with respect to bearing fatigue life. Whether such design is compatible with possible outer ring destruction due to heavy roll loads can only be proved by on-...
TL;DR: In this paper, the authors used a modified four-ball tester with radiotraced phosphorus and sulfur to study the comparative reactivities of these elements in extreme pressure (EP) lubrication and as functions of temperature and load.
Abstract: The mechanism of extreme-pressure (EP) lubrication has been studied with various approaches in a number of laboratories over the past years. An investigation in this area was initiated recently in this laboratory with a modified four-ball tester [Manteuffel and Wolfram, ASLE Trans. 3, 157] wherein the lubricant temperature leaving the ball interfaces is recorded as the load is continuously increased. The patterns of the temperature-load curves generated under these conditions are dependent on the lubricant compositions. This investigation has now been extended with radiotraced phosphorus and sulfur to study the comparative reactivities of these elements in EP lubrication and as functions of temperature and load. A procedure was devised to measure the contents of the radiotraced elements in the ball scar area surfaces. The results indicated that phosphorus is much more reactive than sulfur in the EP lubrication. The data also confirmed that the lubrication reaction is very temperature-dependent. The phosph...
TL;DR: In this paper, a modification of the twist-compression bonding method was used to obtain the coefficients of adhesion for yttrium (Y), as well as four rare earth metals, samarium (Sm), gadolinium (Gd), dysprosium (Dy), and holmium (Ho), were reported.
Abstract: Results of adhesion tests performed on yttrium (Y), as well as four rare earth metals, samarium (Sm), gadolinium (Gd), dysprosium (Dy), and holmium (Ho), are reported. A modification of the twist-compression bonding method was used to obtain the coefficients of adhesion. Low adhesion values for the above metals were obtained as expected on the basis of the crystal structure considerations. A proposal is made to apply the atomic “size-factor” criterion to the prediction of adhesion properties of dissimilar metals. An illustration of the method is given in terms of adhesion of iron to the above mentioned metals. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.