Characteristics of Surface Topography and Static Friction on Scraped Surface Slideway—Part 1

1980 ◽  
Vol 102 (2) ◽  
pp. 97-103 ◽  
Author(s):  
S. Kato ◽  
E. Marui ◽  
A. Kobayashi ◽  
T. Matsubayashi
Keyword(s):  
Surface Topography ◽  
Boundary Lubrication ◽  
Complex Surface ◽  
Static Friction ◽  
Friction Characteristics ◽  
Depth Direction ◽  
Ellipsoidal Shape

The complex surface topography of a scraped surface is studied quantitatively. The scraped surfaces are composed of the surface elements which are formed by each scraping operation, distribute in the depth direction, and have many asperities. Based on this model, the microscopic contacting problem between two scraped surfaces and static frictional characteristics are investigated under boundary lubrication. As a result, it is clarified that the ellipsoidal shape of the asperity tip of scraping surface may be regarded as optimal from the point of static friction, and the static friction characteristics are considerably influenced by the scraping directions.

The Influence of Lubricants on Static Friction Characteristics Under Boundary Lubrication

1985 ◽  
Vol 107 (2) ◽  
pp. 188-194 ◽  
Author(s):  
S. Kato ◽  
E. Marui ◽  
A. Kobayashi ◽  
S. Senda
Keyword(s):  
Machine Tool ◽  
Surface Topography ◽  
Contact Pressure ◽  
Boundary Lubrication ◽  
Carrying Capacity ◽  
Static Friction ◽  
Load Carrying Capacity ◽  
Sliding Speed ◽  
Friction Characteristics ◽  
Load Carrying

Based on a new boundary lubrication model, the characteristics of lubricants under boundary lubrication at low sliding speed and low contact pressure such as in machine tool slideways are investigated in relation to surface topography. It is clarified theoretically and ascertained experimentally that the property of lubricants under boundary lubrication can be estimated by the newly defined appraisal coefficient of boundary lubrication property determined by the thickness and load carrying capacity of adsorbed lubricant film and the surface topography.

Characteristics of Surface Topography and Static Friction on Scraped Surface Slideway—Part 2

1980 ◽  
Vol 102 (2) ◽  
pp. 104-108
Author(s):  
S. Kato ◽  
E. Marui ◽  
A. Kobayashi ◽  
T. Matsubayashi
Keyword(s):  
Surface Topography ◽  
Boundary Lubrication ◽  
Static Friction ◽  
Topographic Effects ◽  
Friction Characteristics ◽  
Nondimensional Parameter ◽  
Large Coefficient ◽  
Parameter Coefficient

The relation between static friction characteristics and surface topography of contacting scraped surfaces are theoretically examined under boundary lubrication. As a result, it is clarified that the topographic effects on static friction of a scraped surface can be evaluated quantitatively by a nondimensional parameter (coefficient of surface topography). The sliding characteristics of scraped surface slideway can be improved by using surfaces having a large coefficient of surface topography.

scholarly journals Boundary lubrication.—The temperature coefficient

1922 ◽  
Vol 101 (713) ◽  
pp. 487-492 ◽  
Keyword(s):  
Experimental Method ◽  
Temperature Coefficient ◽  
Boundary Lubrication ◽  
Static Friction ◽  
Effect Of Temperature ◽  
Dry Air ◽  
Electric Grids ◽  
Continuous Sheet ◽  
A Current

The experimental method employed was that described in earlier papers. A slider having a spherical face is made to slide over a plate in an atmosphere of rigorously clean and dry air. The friction measured is static friction and the object of the experiments the determination of the effect of temperature. This has now been studied over a range of 15°C. to 110°C., and it may be said at once that the relations discovered are of a totally unexpected character. More than one attempt to study the effect of temperature was defeated by the fact that lubricating vapours were given off from the walls of the chamber in which the plate and slider were enclosed. This difficulty was completely removed by using a chamber with double walls, the inner wall being a continuous sheet of nickel. Between the walls were placed the electric grids for heating the chamber. The stream of dry air with which the chamber was flooded was also heated by being passed through a tube of silica, which was maintained at the required temperature by a coil of wire through which a current was passing. The temperature of the stream of air and the temperature of the chamber were recorded electrically.

Fresnel calculation of holograms for micrometer-scale material structuring on substrates with complex surface topography

2017 ◽  
Author(s):  
Alexander Kabardiadi-Virkovski ◽  
Tobias Baselt ◽  
Andrés Fabián Lasagni ◽  
Peter Hartmann
Keyword(s):  
Surface Topography ◽  
Complex Surface ◽  
Micrometer Scale

Regional-scale groundwater flow in a Canadian Shield setting

2009 ◽  
Vol 46 (7) ◽  
pp. 813-827 ◽  
Author(s):  
Jonathan F. Sykes ◽  
Stefano D. Normani ◽  
Mark R. Jensen ◽  
Edward A. Sudicky
Keyword(s):  
Groundwater Flow ◽  
Surface Topography ◽  
Regional Scale ◽  
Three Dimensional ◽  
Complex Surface ◽  
Crystalline Rock ◽  
Canadian Shield ◽  
Water Drainage ◽  
Distribution Models ◽  
Matrix Permeability

A three-dimensional numerical analysis of a 5734 km2 watershed situated in the Canadian Shield has been conducted to illustrate aspects of regional-scale groundwater flow in a crystalline rock setting. An essential requirement of the analysis is the preservation and accurate description of the complex topography, surface water drainage network, groundwater salinity distribution, and permeability distributions. The postglacial evolution of the groundwater flow system was investigated using the finite difference model SWIFT-III. Robustness was assessed by exploring the sensitivity of groundwater flow to topography, variable matrix permeability distribution models, pore-water salinity, and the dissipation of elevated initial pore pressures that result from ice that overlaid the watershed in the last glacial period. Groundwater flow analyses indicate that freshwater heads in all model layers are highly correlated with the complex surface topography such that the transition from zones of groundwater recharge to zones of discharge occurs over distances that can be relatively short. Shallow flow to a depth of tens of metres dominates the overall water balance, and the length of flow paths is relatively short. The analyses of this study indicate that the flow in deeper rock is not regional but rather is a subdued reflection of the local-scale surface topography.

scholarly journals Development of the high precision measurement device of static friction characteristics between surfaces at the fixed coupling section

2019 ◽  
Vol 85 (878) ◽  
pp. 19-00275-19-00275
Author(s):  
Fumihiko INAGAKI ◽  
Noboru MORITA ◽  
Hirofumi HIDAI ◽  
Souta MATSUSAKA ◽  
Tatsuo OHMORI ◽  
...  
Keyword(s):  
High Precision ◽  
Precision Measurement ◽  
Static Friction ◽  
High Precision Measurement ◽  
Measurement Device ◽  
Friction Characteristics ◽  
Fixed Coupling

Performance Improvement Under Boundary Lubrication Conditions Using Slider Bearings With Silicon Nitride/Steel in High Torque Hydraulic Motors

1999 ◽  
Vol 122 (1) ◽  
pp. 348-353 ◽  
Author(s):  
O. Isaksson ◽  
R. Larker
Keyword(s):  
Silicon Nitride ◽  
Boundary Lubrication ◽  
Static Friction ◽  
Chromium Steel ◽  
Gray Iron ◽  
Dynamic Coefficients ◽  
Hydraulic Motors ◽  
Surface Topographies ◽  
Intermediate Surface ◽  
Lubrication Conditions

The influence of materials and surface topography on static and dynamic coefficients of friction was experimentally investigated in a test apparatus under boundary and mixed lubrication conditions. Specimen materials were gray iron and silicon nitride Si3N4 of different surface topographies, sliding against chromium steel at a maximum Hertzian line contact pressure of 50 MPa. The lubricant was a standard mineral-based hydraulic fluid (ISO VG 68) held at +40°C or −28°C. The static and dynamic coefficients of friction under boundary lubrication conditions were both significantly reduced by the change from grey iron to silicon nitride as sliding material against Cr-steel, while the lowest static friction with Si3N4 was found for an intermediate surface roughness. [S0742-4787(00)04601-4]

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