CONTACT COAT FOR FERRIED SWITCHES AND METHOD OF ITS APPLICATION Russian patent published in 1994 - IPC

FIELD: electrical engineering. SUBSTANCE: alloy composition and structure are formed in the course of application by using proposed method and ensure desired properties of contact coat. The later is composed of gold and two alloying components: nickel and rhodium; nickel content is 6.0-26% , that of rhodium is 0.01-1.0% . Deposition is performed at 35-60 C, current density of 1.5-14 A/sq. dm using electrolyte of the following composition, g/l: gold (metal) 2.5-16.0; nickel (metal) 0.7-8.6; rhodium (metal) in the form of 0.5- 1.5 complex compound containing ethylenediamine 0.5-1.5, potassium pyrophosphate 50-160, Seignette salt 50-100, all used as chelation ligands; pH value 6.5-8.5. EFFECT: improved quality of contact coat. 2 cl, 2 dwg, 2 tbl