Studies on friction and transfer layer: role of surface texture

Abstract

Friction influences the nature of transfer layer formed at the interface between tool and metal during sliding. In the present investigation, experiments were conducted using ''Inclined Scratch Tester'' to understand the effect of surface texture of hard surfaces on coefficient of friction and transfer layer formation. EN8 steel flats were ground to attain surfaces of different textures with different roughness. Then super purity aluminium pins were scratched against the prepared steel flats. Scanning electron micrographs of the contact surfaces of pins and flats were used to reveal the morphology of transfer layer. It was observed that the coefficient of friction and the formation of transfer layer depend primarily on the texture of hard surfaces, but independent of surface roughness of hard surfaces. It was observed that on surfaces that promote plane strain conditions near the surface, the transfer of material takes place due to the plowing action of the asperities. But, on a surface that promotes plane stress conditions the transfer layer was more due to the adhesion component of friction. It was observed that the adhesion component increases for surfaces that have random texture but was constant for the other surfaces.

The Role of Adhesive Forces and Mechanical Interaction on Material Transfer in Hot Forming of Aluminium

“…The effect of surface finish has also been identified as relevant. For instance, Menezes et al [9] studied the effect of roughness on the friction coefficient generated in unidirectional sliding; results showed that surface deformation and ploughing significantly contributed to the frictional force.…”

Snapping Surfaces

“…Based on materials choice, a wide variety of external stimuli can trigger this stress development, such as temperature, pH, solvent swelling, magnetism, electric current, and light. This strategy has great potential for the design of responsive surfaces, which will impact a variety of applications including: release-on-command coatings [3] and adhesives, [4][5][6][7] on-command frictional changes, [8,9] instant modification of optical properties at an interface, [10,11] rapid response drug delivery, [12][13][14] chemical sensing, [15][16][17] and antimicrobial devices. [18] To fabricate the active surface structures, we use the Euler buckling of plates to generate a controlled array of microlens shells under equibiaxial compressive stress (Fig.…”

Study on the Correlation between Microstructure Corrosion and Wear Resistance of Ag-Cu-Ge Alloys

“…In this way, the hardness and modulus vs. depth profiles were obtained for both the main phases of each sample. Nanoscratching [18] was performed with the same instrument, loading the sample up to a maximum of 0.5 mN (other test parameters: scratch length 200 µm, scratch velocity 1 µm/s). The friction coefficient was continuously monitored during the nanoscratch test.…”

“…A reduction of the friction coefficient directly involves a reduction of the surface contact stress during sliding contact, thus enhancing the scratch and wear resistance of the component. Also, the higher values of surface roughness evidenced by AFM for sample 1470 could give rise to significantly higher values of surface contact stresses during nanoscratch tests [18]. We can conclude that the addition of germanium to Sterling silver, and an opportune passivation treatment, not only improves its tarnishing and fire stain resistance, reducing the frequency of the re-polishing and increasing the time between one re-polishing treatment and the subsequent one, but it also increases the wear resistance of the alloy.…”