Electrolyte for removing titanium-containing coatings and removing method using same

Abstract

An electrolyte for removing titanium-containing coatings from substrates is provided. The electrolyte includes alkali, accelerant, and inhibiter. The alkali is hydroxide. The accelerant is a complexant capable of complexing with titanium. The inhibiter is polyphosphate. A method for removing titanium-containing coatings from substrates is also described there.

1 . An electrolyte for removing titanium-containing coatings from substrates, comprising:
 an alkali, the alkali being hydroxide;   an accelerant, the accelerant being a complexant capable of complexing with titanium; and   an inhibiter, the inhibiter being polyphosphate.   
     
     
         2 . The electrolyte as claimed in  claim 1 , wherein the hydroxide is sodium hydroxide, potassium hydroxide, or a combination thereof. 
     
     
         3 . The electrolyte as claimed in  claim 2 , wherein the hydroxide has a concentration of about 10-300 g/L. 
     
     
         4 . The electrolyte as claimed in  claim 2 , wherein the hydroxide has a concentration of about 20-200 g/L. 
     
     
         5 . The electrolyte as claimed in  claim 1 , wherein the complexant comprises one or more of the group consisting of sodium potassium tartrate, sodium gluconate, sodium citrate, and edetic acid. 
     
     
         6 . The electrolyte as claimed in  claim 5 , wherein the complexant has a concentration of about 5-150 g/L. 
     
     
         7 . The electrolyte as claimed in  claim 5 , wherein the complexant has a concentration of about 20-100 g/L. 
     
     
         8 . The electrolyte as claimed in  claim 1 , wherein the polyphosphate is sodium tripolyphosphate, sodium pentapolyphosphate, or a combination thereof. 
     
     
         9 . The electrolyte as claimed in  claim 8 , wherein the polyphosphate has a concentration of about 0.5-10 g/L. 
     
     
         10 . The electrolyte as claimed in  claim 8 , wherein the polyphosphate has a concentration of about 2-8 g/L. 
     
     
         11 . The electrolyte as claimed in  claim 1 , wherein the electrolyte further comprises alcohol amino assistant agents selected from one or more of a group consisting of ethanolamine, diethanolamine, and triethanolamine. 
     
     
         12 . The electrolyte as claimed in  claim 11 , wherein the alcohol amino has a concentration of about 5-80 ml/L. 
     
     
         13 . The electrolyte as claimed in  claim 11 , wherein the alcohol amino has a concentration of about 10-50 ml/L. 
     
     
         14 . A method for removing titanium-containing coatings from substrates, comprising:
 providing an electrolyte, the electrolyte containing alkali, accelerant, and inhibiter;   immersing the substrate with the titanium-containing coating in the electrolyte, the substrate being an anode; and   electrifying the substrate to remove the titanium-containing coatings;   wherein the alkali is hydroxide; the accelerant is a complexant capable of complexing with titanium; and the inhibiter is polyphosphate.   
     
     
         15 . The method as claimed in  claim 14 , wherein the hydroxide is sodium hydroxide, potassium hydroxide, or a combination thereof. 
     
     
         16 . The method as claimed in  claim 14 , wherein the complexant comprises one or more of the group consisting of sodium potassium tartrate, sodium gluconate, sodium citrate, and edetic acid. 
     
     
         17 . The method as claimed in  claim 14 , wherein the polyphosphate is sodium tripolyphosphate, sodium pentapolyphosphate, or a combination thereof. 
     
     
         18 . The method as claimed in  claim 14 , wherein the electrolyte further comprises alcohol amino assistant agents selected from one or more of a group consisting of ethanolamine, diethanolamine, and triethanolamine. 
     
     
         19 . The method as claimed in  claim 14 , wherein the electrolyte has a temperature of about 50-95° C. and has an electric current density of about 1-10 A/dm 2  during the removing of the coating. 
     
     
         20 . The method as claimed in  claim 14 , wherein the substrate is made of stainless steel or ferric-based alloy, and the titanium-containing coating is titanium aluminum nitride coating, titanium carbide coating, titanium nitride, or other titanium containing coating.