Time scales for cold welding and the origins of stick-slip friction

Data from an instrument that measures conductance, stiffness, and rupture strength of junctions indicates that when two macroscopic metal surfaces are brought into contact a nanometer size junction spontaneously forms over a long time scale (∼60 s). Furthermore, the parameters of junction rupture match the observed dynamics of stick-slip friction. This suggests that stick-slip friction has its origins in the formation and rupture of junctions that form between surfaces in contact.