Graphite-graphite electrical contact under dynamic mechanical loading

A graphite-graphite contact was studied by measuring the contact electrical resistance during compressive cyclic loading. The contact resistance decreased quite reversibly upon loading, due to the dominance of elastic deformation. The contact resistance at the maximum stress remained the same upon cycling at any of the three stress amplitudes used. A decrease of the contact resistance at zero stress occurred upon cycling at stress amplitudes of 0.70 and 1.40 MPa. The decrease of the resistance at zero stress upon cycling is due to local plastic deformation at the asperities. The higher the stress amplitude, the fewer was the number of cycles for the resistance to level off.