Field and laboratory studies of corrosion inhibiting lubricants for gold-plated connectors

Field and laboratory studies were conducted to evaluate the performance of several families of lubricant coatings which are relatively unknown in the contact field and for which few technical data are available. These coatings conform to two existing military standards-MIL-C-81309 and MIL-C-87177A. The net electrical performance of these materials on electrical connectors having porous gold coatings was evaluated in field exposures conducted over a 1-year period at nine relatively severe sites, both indoors and sheltered outdoors, within the United States. The studies were designed to evaluate net benefits, if any, arising from the potentially offsetting effects of corrosion inhibition and dust. Supporting laboratory studies were conducted to further evaluate coating characteristics and performance. The results of this work showed large differences in performance among materials conforming to existing specifications. This ranged from extremely good net performance, to virtually no net effect, to even apparent increases in corrosion. It was concluded, however, that among the best lubricants, there is a very large net benefit. This new class of materials appears to provide extreme corrosion protection to a degree which cannot be matched by "conventional" lubricants. Field and laboratory studies have indicated no known engineering risk associated with the use of these materials over a broad range of environmental conditions.