Coated articles and related methods

Abstract

Coated articles and related methods are described. In some cases, the coated articles may exhibit high strength, hardness, brightness, abrasion resistance, corrosion resistance, and other desirable structural and functional properties. In some embodiments, the coatings may include an alloy, such as a nickel-tungsten alloy and/or metal oxides.

1 . A method for electrodepositing a coating, comprising:
 providing an anode, a cathode, an electrodeposition bath associated with the anode and the cathode, and a power supply connected to the anode and the cathode; and   driving the power supply to generate a waveform to electrodeposit a coating, the waveform including a segment comprising at least one forward pulse and at least one reverse pulse,   wherein the at least one forward pulse has a duration and an average forward current density, and the at least one reverse pulse has a duration and an average reverse current density,   wherein the ratio of the average forward current density integrated over the duration of the forward pulse to the average reverse pulse integrated over the duration of the reverse pulse is between 0.5 and 5.   
   
   
       2 . The method of  claim 1 , wherein the at least one reverse pulse immediately follows the at least one forward pulse. 
   
   
       3 . The method of  claim 1 , wherein the segment includes multiple forward pulses and reverse pulses. 
   
   
       4 . The method of  claim 1 , wherein the ratio of the sum of the average forward current density of each forward current pulse integrated over the duration of each forward current pulse to the sum of the average reverse current density for each reverse current pulse integrated over the duration of each reverse current pulse is between 0.5 and 5. 
   
   
       5 . The method of  claim 1 , wherein the waveform includes a preceding segment prior to the segment. 
   
   
       6 . The method of  claim 5 , wherein the preceding segment comprises only a single forward pulse. 
   
   
       7 . The method of  claim 5 , wherein the segment forms a second portion of the coating and the preceding segment forms a first portion of the coating having a different composition than the second portion of the coating, wherein the second portion is formed on the first portion. 
   
   
       8 . The method of  claim 7 , wherein the second portion comprises nickel, tungsten and oxygen, wherein the weight percentage of tungsten in the upper portion is between 1 and 20 percent. 
   
   
       9 . The method of  claim 1 , wherein the coating comprises a metal alloy. 
   
   
       10 . The method of  claim 1 , wherein the coating comprises a nickel tungsten alloy. 
   
   
       11 . The method of  claim 1 , wherein the segment of the waveform has a duration of between 10 seconds and 180 seconds. 
   
   
       12 . The method of  claim 1 , wherein the electrodeposition bath comprises tungsten species and nickel species. 
   
   
       13 . A method for electrodepositing a coating, comprising:
 providing an anode, a cathode, an electrodeposition bath associated with the anode and the cathode, and a power supply connected to the anode and the cathode; and   driving the power supply to generate a waveform to electrodeposit a coating, the waveform including a segment comprising at least one forward pulse and at least one reverse pulse,   wherein the at least one forward pulse has a duration between about 1 and about 100 ms, with an average forward current density of between about 0.01 and 1 A/cm 2 , and   the at least one reverse pulse has a duration between about 1 and about 100 ms, with an average reverse current density of between about 0.01 and 1 A/cm 2 .   
   
   
       14 . The method of  claim 13 , wherein the at least one reverse pulse immediately follows the at least one forward pulse. 
   
   
       15 . The method of  claim 13 , wherein the segment includes multiple forward pulses and reverse pulses. 
   
   
       16 . The method of  claim 13 , wherein the coating comprises a nickel tungsten alloy. 
   
   
       17 . The method of  claim 13 , wherein the coating comprises a first portion and a second portion on the first portion, the second portion comprising nickel, tungsten and oxygen, wherein the weight percentage of tungsten in the upper portion is between 1 and 20 percent. 
   
   
       18 . The method of  claim 13 , wherein the electrodeposition bath comprises tungsten species and nickel species. 
   
   
       19 . A method of forming a coated article, the method comprising:
 providing an anode, a cathode, an electrodeposition bath associated with the anode and the cathode, and a power supply connected to the anode and the cathode, wherein the electrochemical bath comprises nickel species and tungsten species; and   driving the power supply to generate a waveform to electrodeposit a coating on a substrate to form a coated article, the coating comprising nickel and tungsten,   wherein the article has a CASS corrosion lifetime of at least 2 hours.   
   
   
       20 . A method of forming a coated article, the method comprising:
 providing an anode, a cathode, an electrodeposition bath associated with the anode and the cathode, and a power supply connected to the anode and the cathode, wherein the electrochemical bath comprises nickel species and tungsten species; and   driving the power supply to generate a waveform to electrodeposit a coating on a substrate to form a coated article, the coating having a first portion and a second portion, the second portion comprising nickel, tungsten and oxygen, wherein the weight percentage of tungsten in the second portion is between 1 and 20 percent.