Electrolyte and process for the electrolytic polishing of a metallic substrate

Abstract

An electrolyte (EL) for the electrolytic polishing of a metallic substrate includes at least one acid compound (A), at least one fluoride compound (F), and at least one complexing agent (CA). Furthermore, a process for the electrolytic polishing of a metallic substrate wherein the electrolyte (EL) including at least one acid compound (A), at least one fluoride compound (F), and at least one complexing agent (CA) is applied.

1 . An electrolyte (EL) for the electrolytic polishing of a metallic substrate comprising:
 (i) at least one acid compound (A);   (ii) at least one fluoride compound (F); and   (iii) at least one complexing agent (CA).   
     
     
         2 . The electrolyte (EL) according to  claim 1 , further comprising:
 (iv) at least one medium (M); and   (v) at least one additive (AD).   
     
     
         3 . The electrolyte (EL) according to  claim 1 , wherein
 (i) the at least one acid compound (A) comprises an amount of not more than around 20 wt.-%, and/or   (ii) the at least one fluoride compound (F) comprises an amount of not more than around 40 wt.-%, and/or   (iii) the at least one complexing agent (CA) comprises an amount of not more than around 30 wt.-%,   based on the weight of the electrolyte (EL).   
     
     
         4 . The electrolyte (EL) according to  claim 2 , wherein
 (iv) the at least one medium (M) comprises an amount of at least around 10 wt.-%, and/or   (v) the at least one additive (AD) comprises an amount of not more than around 25 wt.-%,   based on the weight of the electrolyte (EL).   
     
     
         5 . The electrolyte (EL) according to  claim 1 , wherein the at least one acid compound (A) is selected from the group consisting of inorganic or organic acids such as sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, formic acid, acetic acid propionic acid, or mixtures thereof. 
     
     
         6 . The electrolyte according to  claim 1 , wherein the at least one fluoride compound (F) is selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, calcium fluoride, trifluoracetic acid, or mixtures thereof. 
     
     
         7 . The electrolyte according to  claim 1 , wherein the at least one complexing agent (CA) is selected from the group consisting of metylglycinediacetic acid (MGDA), ethylenediaminetetraacetate (EDTA), diethylenetriaminepentakismethylenephosphonic acid (DTPMP), aminopolycarboxylic acids (APC), diethylenetriaminepentaacetate (DTPA), nitrilotriacetate (NTA), triphosphate, 1,4,7,10 tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), phosphonate, gluconic acid, β-alaninediactetic acid (ADA), N-bis[2-(1,2 dicarboxy-ethoxy)ethyl]glycine (BCA5), N-bis[2-(1,2-dicarboxyethoxy)ethyl]aspartic acid (BCA6), tetracis(2-hydroxypropyl)ethylenediamine (THPED), N-(hydroxyethyl)-ethylenediaminetriacetic acid (HEDTA) or mixtures thereof. 
     
     
         8 . A process for the electrolytic polishing of a metallic substrate comprising: providing an electrolyte (EL) according to  claim 1  in an electrolytic cell comprising at least one electrode,
 (i) disposing a metallic substrate as an anode in the electrolytic cell, 
 (ii) applying a current from a power source between the at least one electrode and the metallic substrate, and 
 (iii) immersing the metallic substrate in the electrolyte (EL). 
 
     
     
         9 . The process according to  claim 8 , wherein the current is applied at a voltage of not more than around 100 V. 
     
     
         10 . The process according to  claim 8 , wherein the electrolyte has a temperature in the range of around 10 to around 95° C. 
     
     
         11 . The process according to  claim 8 , wherein the current is applied at a current density in the range of around 0.05 to around 10 A/cm 2    
     
     
         12 . The process according to  claim 8 , wherein the current is applied for a time in the range of around 1 to around 240 min.