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Sliding contact frictional behavior in sodium environments
SYSTEMATIC
polymer is formed in any case. It is concluded that the nature of the adsorbed film which precedes the formation of polymer is the main determining factor in wear and friction reduction. The results are explained by assuming that free radicals, produced b7 shearing an adsorbed film in the presence of catalyst, initiate polymer formation. Friction and Surface Deformation During Sliding on a Single Crystal of Copper. J. M. Bailey and A. T. Gwathmey. ASLE Trans., 5 (1962) 45-56, Discussion: p. 55-56; 12 figs., 2 tables, 15 refs. The effects of crystal orientation and temperature on sliding friction and surface deformation were studied by examination of indentations and wear tracks formed by styli on a single crystal of copper. Copper, diamond and sapphire indenters and sliders were used. Experiments were conducted at room temperature in air and in hydrogen at temperatures up to 800 C. The distribution of dislocation etch pits in the damaged regions was studied microscopically. Friction changed by 50 to over 500%. and track width changed by 15 to 35% as the direction of sliding on a given face in air was varied. These anisotropies are interpreted in terms of topography, work-hardening, and air oxide films. At higher temperatures diamond and sapphire sliders gave lower friction and larger track width than at room temperature. Friction sliders increased obtained with copper markedly with temperature. Surface deformation at intermediate temperatures resulted in recrystallization, and at higher temperature polygonization resulted. Static Friction between Clean Metal Surfaces. (in Japanese) R. Takagi and Y. Tsuya. J. Appl. Phys. Japan, z8 (1959) 481-486; 4 figs., 5 photos, 13 refs. See paper in this volume of Wear. Bearing and Lubricant Requirements for Some Aerospace Projects : Discussion and Preliminary Investigation. R. H. Larson and A. G. Piken. ASLE Tvans., 5 (1962) 1-7; 4 figs., 2 tables, II refs. Specific requirements of bearings and lubricants for nuclear engine controls and a hot gas flight stabilization system are given. The results of a lubricant survey are discussed, and the preliminary test results obtained in a 600°F lubricant evaluation program are presented. A brief discussion of the merits and limitations of gas lubricated bearings in extreme environments in included. The concluding remarks emphasize the need for increased bearing and lubricant research.
ABSTRACTS
4%
Friction, Wear, and Evaporation Rates of Various Materials in Vacuum to 10-7mmHg. D. H. Buckley, M. Swikert and R. L. Johnson, ASLE Trans., 5 (1962) S-23, Discussion: p. 22-23; 14 figs., I table, 23 refs. Evaporation data on soft metals, lubricating inorganic compounds, and various reference materials are reported for temperatures from 75” to IOOO’F in vacuum as low as IO-’ mm Hg. Observations on modes of vacuum degration (e.g., evaporation or dissociation) and methods of experimentation are related. Friction and wear data are presented for several unlubricated metals (e.g., type 440-C steel) and metals coated with inorganic (e.g., MoS2, CaFz) as well as with soft metal films in vacuum at ambient pressures between 10-6 and 10-r mm Hg. Friction and Wear Characteristics of Cermets at High Temperature and High Vacuum. R. D. Brown, R. A. Burton and P. M. Ku. ASLE Trans., 5 (1962) 24-31, Discussion: p, 30-31; 15 figs., 3 tables, g refs. The friction and wear characteristics of several bearing substrate materials and lubricants were determined over a temperature range from ambient to 2000°F, and in normal atmosphere with pressure varied from 760 to 10-e mm Hg. The sliding speed was 14 to 20 ft./min. The load ranged from 1500 to 15,000 p.s.i. Two oxide-bonded cermets (Cr-AleOa-W and Cr-AlaOa-Mo-TiOr) were found to exhibit low wear and moderate friction when run against themselves throughout a wide range of test conditions. A third cermet (Cr-AlsOa) showed very poor frictional properties. Three high-temperature alloys were also investigated for purposes of comparison. Test results are also presented which indicate that two of the cermets were effectively lubricated by precious metal films. Sliding Contact Frictional Behavior in Sodium Environments. J. W. Kissel, W. A. Glaeser and C. M. ,411en. ASLE Tvans., 5 (1962) 39-44; 7 figs., 14 refs. A study has been made of wear and friction phenomena associated with rubbing surfaces (primarily molybdenum) in sodium environments. Operating conditions include vacuum or argon environments and specimen temperatures from 80 to 1300OF. Sliding speeds were about one half inch per minute and contact stresses were about IOO,OOO psi. Sliding specimens consisted of a ball sliding on a flat rectangle. Wear and friction behavior were found to be influenced by surface films which were modified by the presence of liquid sodium. Lubrication of Diffusion-Beryllided Titanium. R. V. Klint and R. S. Owens. ASLE Trans., Wear, 5 (1962) 408-415
polymer is formed in any case. It is concluded that the nature of the adsorbed film which precedes the formation of polymer is the main determining factor in wear and friction reduction. The results are explained by assuming that free radicals, produced b7 shearing an adsorbed film in the presence of catalyst, initiate polymer formation. Friction and Surface Deformation During Sliding on a Single Crystal of Copper. J. M. Bailey and A. T. Gwathmey. ASLE Trans., 5 (1962) 45-56, Discussion: p. 55-56; 12 figs., 2 tables, 15 refs. The effects of crystal orientation and temperature on sliding friction and surface deformation were studied by examination of indentations and wear tracks formed by styli on a single crystal of copper. Copper, diamond and sapphire indenters and sliders were used. Experiments were conducted at room temperature in air and in hydrogen at temperatures up to 800 C. The distribution of dislocation etch pits in the damaged regions was studied microscopically. Friction changed by 50 to over 500%. and track width changed by 15 to 35% as the direction of sliding on a given face in air was varied. These anisotropies are interpreted in terms of topography, work-hardening, and air oxide films. At higher temperatures diamond and sapphire sliders gave lower friction and larger track width than at room temperature. Friction sliders increased obtained with copper markedly with temperature. Surface deformation at intermediate temperatures resulted in recrystallization, and at higher temperature polygonization resulted. Static Friction between Clean Metal Surfaces. (in Japanese) R. Takagi and Y. Tsuya. J. Appl. Phys. Japan, z8 (1959) 481-486; 4 figs., 5 photos, 13 refs. See paper in this volume of Wear. Bearing and Lubricant Requirements for Some Aerospace Projects : Discussion and Preliminary Investigation. R. H. Larson and A. G. Piken. ASLE Tvans., 5 (1962) 1-7; 4 figs., 2 tables, II refs. Specific requirements of bearings and lubricants for nuclear engine controls and a hot gas flight stabilization system are given. The results of a lubricant survey are discussed, and the preliminary test results obtained in a 600°F lubricant evaluation program are presented. A brief discussion of the merits and limitations of gas lubricated bearings in extreme environments in included. The concluding remarks emphasize the need for increased bearing and lubricant research.
ABSTRACTS
4%
Friction, Wear, and Evaporation Rates of Various Materials in Vacuum to 10-7mmHg. D. H. Buckley, M. Swikert and R. L. Johnson, ASLE Trans., 5 (1962) S-23, Discussion: p. 22-23; 14 figs., I table, 23 refs. Evaporation data on soft metals, lubricating inorganic compounds, and various reference materials are reported for temperatures from 75” to IOOO’F in vacuum as low as IO-’ mm Hg. Observations on modes of vacuum degration (e.g., evaporation or dissociation) and methods of experimentation are related. Friction and wear data are presented for several unlubricated metals (e.g., type 440-C steel) and metals coated with inorganic (e.g., MoS2, CaFz) as well as with soft metal films in vacuum at ambient pressures between 10-6 and 10-r mm Hg. Friction and Wear Characteristics of Cermets at High Temperature and High Vacuum. R. D. Brown, R. A. Burton and P. M. Ku. ASLE Trans., 5 (1962) 24-31, Discussion: p, 30-31; 15 figs., 3 tables, g refs. The friction and wear characteristics of several bearing substrate materials and lubricants were determined over a temperature range from ambient to 2000°F, and in normal atmosphere with pressure varied from 760 to 10-e mm Hg. The sliding speed was 14 to 20 ft./min. The load ranged from 1500 to 15,000 p.s.i. Two oxide-bonded cermets (Cr-AleOa-W and Cr-AlaOa-Mo-TiOr) were found to exhibit low wear and moderate friction when run against themselves throughout a wide range of test conditions. A third cermet (Cr-AlsOa) showed very poor frictional properties. Three high-temperature alloys were also investigated for purposes of comparison. Test results are also presented which indicate that two of the cermets were effectively lubricated by precious metal films. Sliding Contact Frictional Behavior in Sodium Environments. J. W. Kissel, W. A. Glaeser and C. M. ,411en. ASLE Tvans., 5 (1962) 39-44; 7 figs., 14 refs. A study has been made of wear and friction phenomena associated with rubbing surfaces (primarily molybdenum) in sodium environments. Operating conditions include vacuum or argon environments and specimen temperatures from 80 to 1300OF. Sliding speeds were about one half inch per minute and contact stresses were about IOO,OOO psi. Sliding specimens consisted of a ball sliding on a flat rectangle. Wear and friction behavior were found to be influenced by surface films which were modified by the presence of liquid sodium. Lubrication of Diffusion-Beryllided Titanium. R. V. Klint and R. S. Owens. ASLE Trans., Wear, 5 (1962) 408-415