Frictional adhesion

Tribological Behavior. Tribological performance of ceramics, which includes friction, adhesion, wear, and lubricated behavior of two soHd materials in contact, has been reviewed (52). 

Whilman, L.J. and Colton, R.J., Design and calibration of a scanning force microscope for friction, adhesion, and contact potential studies. Rev. Sci. fnsirum., 66, I (1995). Ba.selt, D.R. and Baldeschwieler, J.D., Imaging spectro.scopy with the atomic-force microscope. J. AppL Pliys., 76(1), 33-38 (1994). 

As for other materials, the soil stiffnesses, Kv, Kh, and K0 are limited by ultimate soil capacities. Furthermore, reversals of movement and uplift can generate zero resistance and must be appropriately included in the analysis. The lateral stiffness, Kh, is determined from friction, adhesion, and passive pressure as applicable with an appropriate moment arm, h. 

In any particular wear situation several mechanisms are usually involved but one may predominate. Abrasive wear requires hard, sharp cutting edges and high friction. Fatigue abrasion occurs with rough but blunt surfaces and does not need high friction. Adhesion wear is less common but can occur on smooth surfaces. 

H Z ID fc o -Coefficient of Friction— -Adhesive Character— —Thermal Stability- —Mechanical Strength at High Temp.— —Softening Temperature- ui H PTFE or TFE FEP Poly tetrafiuoroelhylene Copolymer of hexafiuoropropylene and telrafluoroethyiene or fluorinated ethylene... 

Correlation Among Friction, Adhesion Force, Removal Rate, and Surface Quality in Cu CMP... 

Gansheimer showed that chemical reactions take place between the sulphur of molybdenum disulphide and metallic surfaces during sliding contact, but established no direct correlation with friction, adhesion or wear life. 

The presence of a closely packed layer of adsorbed molecules at a polymer surface will have a marked effect on many of its surface properties, such as friction, adhesiveness, and wettability. These properties of an adsorbed film have already foimd some application in industry. Allan [1] has demonstrated that small amounts of oleylamide incorporated in polyethylene foil will diffuse to the surface of the foil and greatly reduce the friction and adhesion between sheets of the plastic. A committee from the Piedmont Section of the American... 

For polymer-polymer sliding pairs,(ll) adhesion appears to be the dominant mechanism of polymer friction. Adhesion can also take place at the polymer-metal interface provided that surface roughness is below a certain value.(12) For a smooth surface, it is difficult to differentiate fatigue from adhesive wear.(5)... 

Equation 1 assumes that the shear stress at the interface is constant as a result of complete interfacial debonding. With good adhesion, only partial debonding or other micro-mechanical events such as transverse matrix cracking are observed, which invalidate the assumption of a constant interfacial shear stress. As a result, alternative data reduction techniques have been developed. For example, Tripathi and Jones developed the cumulative stress-transfer function, which deals with the limitations given above. This has been further refined by Lopattananon et al into the stress-transfer efficiency from which an ineffective length of that fibre in that resin can be determined. In this model, the matrix properties and frictional adhesion at debonds can be included in the analysis. It is also possible to use the three-phase stress-transfer model of Wu et al to include the properties of an interphase. 

Friction - adhesion aspects A D ROBERTS Influence of adhesion on friction Schallamach waves... 

Fibers rub against each other in assemblies when stretched, bent or sheared. Textile materials also rub against tissues and bones when used as implants. The friction and adhesion involved in such contacts cause surface damage, which adversely affects the long-term performance of an implant. Also, the particles generated by the friction/adhesion processes can cause a reaction and lead to inflammation of the surrounding tissues. Consequently, the ability of polymers and fibers to resist abrasion damage is an important... 

---