Stick Slip Contact Mechanics Between Dissimilar Materials
P M. McGuiggan
Measurements of the contact diameter as a function of loading between a mica surface and a silica surface (mica/silica) in air are reported. The contact mechanics results show that the interaction generally follows JKR theory. However, an additional and unexpected step function is superimposed on the JKR curve. Thus, the contact diameter increases in a step-like fashion with increasing load. The steps were seen only for increasing load, and are not observed when measuring symmetric mica/mica or silica/silica contact mechanical properties. The steps disappear with humidity. Friction forces between the surfaces were also measured and the shear stress of a silica/mica interface was 100 times greater than the shear stress of a mica/mica interface. This large shear stress retards the increase in contact area as the load is increased and leads to the observed step-like behavior.
adhesion, dissimilar materials, JKR, mica, silica
Stick Slip Contact Mechanics Between Dissimilar Materials, Nature Materials
(Accessed December 8, 2023)