Silver electroplating compositions and methods for electroplating silver with low coefficients of friction

Abstract

Silver electroplating compositions deposit silver with low coefficients of friction on substrates, such as nickel, copper and copper alloys. The silver deposits have coefficients of friction of less than or equal to 1 in contrast to many conventional silver deposits which typically have coefficients of friction greater than 1, such as 1.5. The silver deposits also have improved wear resistance in contrast to silver deposited from many conventional silver electroplating baths. The low coefficients of friction and improved wear resistance of silver deposited from the silver electroplating compositions is especially suitable for connectors and electronics finishes. Preferably, the silver electroplating compositions are cyanide-free silver electroplating compositions.

1 - 11 . (canceled) 
     
     
         12 . An article comprising a silver layer on a substrate, wherein the silver layer has a coefficient of friction of 1 or less without the use of lubricants. 
     
     
         13 . The article of claim  11 , wherein the silver layer is 99% by metals basis or greater silver metal. 
     
     
         14 . The article of  claim 12 , wherein the silver layer further has a coefficient of friction of 0.6 or less without the use of lubricants. 
     
     
         15 . The article of  claim 12 , wherein the silver layer has a carbon content of 0.1 to 5% by mass basis, excluding particles with domain sizes above 100 nm in diameter. 
     
     
         16 . The article of  claim 15 , wherein the silver layer has a carbon content of 0.5 to 3.5% by mass basis, excluding particles with domain sizes above 100 nm in diameter. 
     
     
         17 . The article of  claim 16 , wherein the silver layer has a carbon content of 1 to 3% by mass basis, excluding particles with domain sizes above 100 nm in diameter.