APPLICATION OF THE MODIFIED GREENWOOD AND WILLIAMSON CONTACT MODEL FOR THE PREDICTION OF THERMAL CONTACT RESISTANCE

The modified Greenwood and Williamson (GW) contact model has been reported to yield good order-of magnitude estimates of the number of contacts and real contact area fraction resulting from the contact of two surfaces. A series of experiments has been performed to ascertain whether the modified GW model can be used to determine the contact parameters required for the prediction of the thermal contact resistance across pressed metal contacts in a vacuum environment. The predicted values of contact resistance agree quite favorably with the measured values. In general, the predicted values are within 25% of the measured values for isotropically rough surfaces, and within 50% for strongly anisotropic surfaces. The utilization of the modified GW model results in only slightly more accurate predictions of the thermal contact conductance across pressed metal contacts than does the utilization of the original GW model. Both the original and the modified GW contact models allow the relatively accurate determination of the contact parameters required for the prediction of the thermal contact resistance across pressed metal contacts in a vacuum environment.