Metallic materials with embedded luminescent particles

Abstract

Formation of an authentication element by deposition of a metal layer with embedded particles on a metal substrate, wherein the embedded particles are configured to convert energy from one wavelength to another. The embedded particles may be upconverters, downconverters, or phosphorescent phosphors, which can be detected and measured with analytical equipment when deposited in the metal layer. A metal substrate may include coinage.

1 . A method for depositing a metal layer having embedded luminescent particles onto a metal substrate, comprising:
 mixing the luminescent particles with a metallic material to produce a plating solution;   inserting the metal substrate into the plating solution; and   performing a plating process to coat the metal substrate with the metal layer, wherein the metal layer contains embedded luminescent particles.   
     
     
         2 . The method as recited in  claim 1 , wherein the plating process is an electroless plating process. 
     
     
         3 . The method as recited in  claim 1 , wherein the plating process is a dip plating process. 
     
     
         4 . The method as recited in  claim 1 , wherein the plating process is an electroplating process. 
     
     
         5 . The method as recited in  claim 4 , wherein the electroplating process includes a rotating barrel in which the metal substrate is contained when inserted into the plating solution. 
     
     
         6 . The method as recited in  claim 5 , wherein the electroplating process comprises rotating the barrel on a constant basis while the metal layer is electroplated onto the metal substrate. 
     
     
         7 . The method as recited in  claim 5 , wherein the electroplating process comprises rotating the barrel on an intermittent basis while the metal layer is electroplated onto the metal substrate. 
     
     
         8 . The method as recited in  claim 7 , wherein the intermittent basis is a rotation of the barrel for one or more periods of time that are less than periods of time the barrel is not rotated. 
     
     
         9 . The method as recited in  claim 8 , wherein the one or more periods of time are each approximately 25% of each of the periods of time the barrel is not rotated. 
     
     
         10 . A method for authenticating a metal object comprising:
 exciting the metal object with energy comprising a first wavelength;   detecting whether energy comprising a second wavelength is emitted from the metal object in response to the excitation of the metal object with energy comprising the first wavelength; and   determining that the metal object is authentic if the energy comprising the second wavelength is detected.   
     
     
         11 . The method as recited in  claim 10 , wherein the metal object comprises an electroplated metal layer with embedded luminescent particles configured to emit the energy comprising the second wavelength when excited by the energy comprising the first wavelength. 
     
     
         12 . The method as recited in  claim 11 , further comprising determining that the metal object is not authentic if the energy comprising the second wavelength is not detected. 
     
     
         13 . The method as recited in  claim 12 , wherein the metal substrate is a negotiable coin. 
     
     
         14 . A metal substrate comprising an electroplated metal layer on the metal substrate, the electroplated metal layer containing embedded luminescent particles. 
     
     
         15 . The metal substrate of  claim 14 , wherein the embedded luminescent particles have a composition configured to emit energy comprising a second wavelength when excited by energy comprising a first wavelength. 
     
     
         16 . The metal substrate of  claim 15 , wherein the electroplated metal layer has a composition in which the embedded luminescent particles are substantially distributed throughout the electroplated metal layer. 
     
     
         17 . The metal substrate of  claim 14 , wherein the electroplated metal layer is selected from the group consisting of nickel, nickel-phosphorus, copper, brass, gold, silver, and platinum. 
     
     
         18 . The metal substrate of  claim 17 , wherein the metal substrate is selected from the group consisting of copper, brass, bronze, mild steel, stainless steel, and titanium. 
     
     
         19 . The metal substrate of  claim 14 , wherein the metal substrate is a negotiable coin. 
     
     
         20 . The metal substrate of  claim 14 , comprising another electroplated metal layer containing embedded luminescent particles of a different composition than the previous embedded luminescent particles.