High-Field Anodizing Apparatus

Abstract

Disclosed herein is a high-field anodizing apparatus, in which nanostructures are formed on a surface of a metal by immersing a metal anode and a counter electrode into an electrolyte charged in an anodizing cell to oxidize the metal, comprising: a power supply unit for applying a predetermined pattern of voltage between the metal anode and counter electrode in the electrolyte; a temperature control unit for maintaining the temperature of the metal anode, counter electrode and electrolyte constant; and a reaction rate control unit for measuring the value of current generated by the voltage supplied by the power supply unit and controlling the concentration of the electrolyte using the current value to maintain the current constant. The high-field anodizing apparatus is advantageous in that it is possible to prevent the damage of nanostructures caused by the rapid melting of a metal or the dielectric breakdown of an oxide film attributable to high-field anodization and to control the growth rate of nanostructures, thus greatly improving the productivity of nanostructures.

1 . A high-field anodizing apparatus, in which nanostructures are formed on a surface of a metal by immersing a metal anode and a counter electrode into an electrolyte charged in an anodizing cell to oxidize the metal, comprising:
 a power supply unit for applying a predetermined pattern of voltage between the metal anode and counter electrode in the electrolyte;   a temperature control unit for maintaining the temperature of the metal anode, counter electrode and electrolyte constant; and   a reaction rate control unit for measuring the value of current generated by the voltage supplied by the power supply unit and controlling the concentration of the electrolyte using the current value to maintain the current constant.   
     
     
         2 . The high-field anodizing apparatus according to  claim 1 , wherein the metal anode is made of any one of Al, Ti, Zr, Hf, Ta, Nb, W, and alloys thereof, and is pretreated by heat treatment, electrolytic grinding or chemical grinding. 
     
     
         3 . The high-field anodizing apparatus according to  claim 1 , wherein the counter electrode has a tubular shape. 
     
     
         4 . The high-field anodizing apparatus according to  claim 3 , wherein the electrolyte is cooled by allowing cooling water to flow into the tubular counter electrode. 
     
     
         5 . The high-field anodizing apparatus according to  claim 1 , wherein the power supply unit applies any one of direct voltage, alternating voltage, pulse voltage, bias voltage and combinations thereof between the metal anode and the counter electrode, and controls the voltage depending on the distances among pores of nanostructures. 
     
     
         6 . The high-field anodizing apparatus according to  claim 1 , wherein the temperature control unit is provided at the rear side of the metal anode, and comprises a temperature sensor and a cooling unit, and, if necessary, further comprises a heating unit. 
     
     
         7 . The high-field anodizing apparatus according to  claim 6 , wherein the temperature control unit further comprises an electrolyte cooling unit for lowering the temperature of the electrolyte. 
     
     
         8 . The high-field anodizing apparatus according to  claim 1 , wherein the reaction rate control unit comprises: a measuring unit for measuring the current generated between the metal anode and the counter electrode by the voltage supplied by the power supply unit; and a high-concentration electrolyte supply unit which is opened when the value of current measured by the measuring unit is lower than the predetermined value thereof, and which is closed when the value of current measured by the measuring unit is higher than the predetermined value thereof.