Process for Electrochemical Stripping of Components

Abstract

A process for electrochemical stripping of components is disclosed. An operating point of the electrochemical stripping is determined under actual process conditions prior to the actual electrochemical stripping and is determined anew continuously, i.e., monitored and optionally adjusted during the electrochemical stripping.

1 - 8 . (canceled) 
     
     
         9 . A method for electrochemical stripping of components, in particular for stripping aluminum-coated components of a gas turbine, wherein an operating point of the electrochemical stripping is determined under actual process conditions prior to actual stripping, wherein the operating point of maximum stripping is determined as a function of a measured polarization current or a measured polarization conductance and is determined anew continuously during the electrochemical stripping, and wherein an applied direct voltage potential is adjusted accordingly. 
     
     
         10 . The method according to  claim 9 , wherein the stripping is performed using a two-electrode system. 
     
     
         11 . The method according to  claim 9 , wherein the direct voltage potential is increased to a value where the polarization conductance or a first derivation of the polarization current as a function of the direct voltage potential is approximately zero, and wherein the value of the direct voltage potential determines the operating point of stripping. 
     
     
         12 . The method according to  claim 9 , wherein the direct voltage potential is increased until the polarization current reaches a maximum as a function of the direct voltage potential, and wherein the maximum determines the operating point of the stripping. 
     
     
         13 . The method according to  claim 9 , wherein an alternating voltage is superimposed on the direct voltage potential during the stripping, wherein a change in the polarization current or the polarization conductance due to the superimposed alternating voltage is measured, and wherein the direct voltage potential is adjusted as a function thereof, so that the polarization current remains at a maximum. 
     
     
         14 . The method according to  claim 13 , wherein the alternating voltage has a low amplitude. 
     
     
         15 . The method according to  claim 14 , wherein the alternating voltage is ±5 mV. 
     
     
         16 . The method according to  claim 9 , wherein a value of the measured polarization current or the polarization conductance during the stripping is used to determine a termination criterion for the electrochemical stripping. 
     
     
         17 . The method according to  claim 9 , wherein a blade of a gas turbine having channels, in particular cooling channels, integrated into the blade is stripped, wherein the operating point is determined as a function of the measured polarization current or polarization conductance for stripping a surface of the blade, and wherein, after stripping the blade surface, a control potential is increased, so that the stripping of the blade surface comes to a standstill and stripping of the channels is performed. 
     
     
         18 . A method for electrochemical stripping of a component of a gas turbine engine, comprising the steps of:
 determining a value of an applied direct voltage potential for a maximum stripping rate of the electrochemical stripping process prior to commencing the stripping process;   commencing the electrochemical stripping process at the value of the direct voltage potential; and   continuously monitoring the value during the electrochemical stripping process.   
     
     
         19 . The method according to  claim 18 , wherein the step of determining the value includes the steps of determining when a measured value of a polarization current is at a maximum or a measured value of a polarization conductance is zero. 
     
     
         20 . The method according to  claim 19 , further comprising the step of adjusting the value during the electrochemical stripping process such that the measured value of the polarization current remains at the maximum or the measured value of the polarization conductance remains at zero. 
     
     
         21 . The method according to  claim 20 , wherein the step of adjusting the value includes the step of superimposing an alternating voltage on the direct voltage potential. 
     
     
         22 . The method according to  claim 20 , wherein the step of adjusting the value includes the step of reducing the direct voltage potential. 
     
     
         23 . The method according to  claim 20 , wherein the step of adjusting the value includes the step of increasing the direct voltage potential. 
     
     
         24 . The method according to  claim 18 , further comprising the step of terminating the electrochemical stripping process. 
     
     
         25 . The method according to  claim 24 , wherein the step of terminating the electrochemical stripping process includes the step of defining a termination criterion for the electrochemical stripping process. 
     
     
         26 . The method according to  claim 25 , wherein the step of defining the termination criterion includes the steps of measuring a value of a polarization current applied to the component at a commencement of the electrochemical stripping process and measuring a value of the polarization current applied to the component after commencement of the electrochemical stripping process. 
     
     
         27 . The method according to  claim 18 , further comprising the steps of:
 terminating the electrochemical stripping process on a surface of the component; and   commencing the electrochemical stripping process within a channel of the component.   
     
     
         28 . The method according to  claim 27 , wherein the steps of terminating the electrochemical stripping process on the surface of the component and commencing the electrochemical stripping process within the channel of the component includes the step of adjusting the value of the applied direct voltage potential.