Towards a 3-D Technique to Determine the Geometric Path of Electric Current Flow Through a Contact System

The effective conductivity of a contact system is an important characteristic used to link the microstructure of the contact system to its performance. A resistor network model has been developed from the cross-sectional slices of a given electrical contact system. This allows the total resistance across the model and hence the total conductance of the system to be calculated. This resistor network model development is based on the contact interface, of the contact system, which is presented as a 3-D contact map. The 3-D contact map consists of contact spots that have been extended across the two bodies of the contact system as asperities. In this modeling process, a technique is developed that pictures any cross-sectional slice of the contact system and shows in which voxels the electric current flows. An X-ray computed tomography method is used to collect the data for visualizing the contact system and preparing the 3-D contact map. A 250-V, 16-A rated ac single-pole rocker switch is used as the contact system for investigation.