Tarnish films that form on copper surfaces at high humidity can creep over adjoining gold surfaces, causing increases in the contact resistance of the gold. In many cases, however, when gold‐plated contacts having exposed areas of copper are removed from equipment used for extended periods of time in environments known to contain sulfiding compounds, there has been little or no evidence of creepage. This protection against tarnish is caused by a naturally formed oxide and has been duplicated in the laboratory. When copper sulfide tarnish films do creep over gold surfaces, distinctive periodic bands are formed. The humidity dependence of the rate and maximum distance of the creepage have been studied.

No abstract

No abstract

not Available.

V3WO7‐5 (I) und V3‐4W0‐"O‐, (II) wurden durch Elektrolyse geschmolzener Mischungen von WO3 und V2O5 bei 750‐800°C in Form kristalliner Abscheidungen auf leitenden Substraten ( ;z.B. Kohlenstoff) synthetisiert.