Effect of Atmospheric Exposure on the Contact Resistance of Selected Tin Alloys

Abstract

Atmospheric exposure of plated specimens in a rural outdoor location showed that both tin‐zinc and tin‐cadmium alloy coatings on steel maintained a lower contact resistance than did equal thicknesses of tin, tin‐lead, or tin‐antimony alloys. After exposure for over 2 months, the contact resistances under a 50g load for 5–38 µm thicknesses of tin‐zinc and tin‐cadmium ranged between 10–100 mohms, although both coatings rapidly lost their luster. The tin‐lead alloy maintained the lowest contact resistance of all the coatings tested, although it failed to provide corrosion protection as good as equal thicknesses of tin‐zinc or tin‐cadmium.