Contact resistance of mesh gaskets on coated aluminum joints

The contact resistance of knitted mesh/elastomer EMI gaskets mated to coated aluminum contact materials has been measured as a function of cyclic make-and-break compression of the gasketed joint. Using a computer controlled pneumatic test fixture which implements four-wire resistance readings on multiple gasketed samples, data has been collected for the gasket mated to chromate conversion coated, titanium nitride (TiN) coated, and bare aluminum contacts. The measurements were taken for over 6000 contact cycles with various aging periods between cycle segments. Results indicate that the TiN coated contacts have significantly lower and more stable contact resistance than either the conversion coated or bare aluminum contacts