Computer controlled electropolishing system

• US 4,935,865 A
• Filed: 06/02/1988
• Issued: 06/19/1990
• Est. Priority Date: 06/02/1988
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Rowe, Mark S., Underwood, Charles R., Harper, Charles E. Jr.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/202,631
• Time in Patent Office: 747 Days
• Field of Search: 364/474.26, 364/474.02, 364/474.04, 364/188, 364/189, 364/496, 204/129.1, 204/129.2, 204/224 M
• US Class Current: 700/83
• CPC Class Codes: C25F 7/00 Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects for both electrolytic coating and removal C25D; Servicing or operating

Abstract

The system described is a computer controlled electropolisher designed to generate the characteristic electropolishing curve and display the data in real time for a given set of conditions. The operator-to-system interface is achieved through menu-driven software which is designed to be user-friendly at all levels of operation. Computer programming skills are not required to operate the system. There are four main program available to the operator from the system main menu. These programs allow the operator to become familiar with the system and its capabilities, access the material and electrolyte libraries, perform an electropolishing experiment under computer control, and recall data from the system data base for analysis, comparison, and graphic presentation.

Claims

1. An electropolishing system using a computer with display means, for control of a cell in which a specimen is electropolished using a selected electrolyte, a programmable power supply having an interface with the computer, the power supply being coupled to said cell to supply selected values of voltage to cause current flow through the cell which is sensed via the interface means, and program means which includes an electropolishing experiment program means for generating a characteristic curve for a given set of conditions;

wherein said electropolishing experiment program means includes means for entering the following parameters;

starting voltage, ending voltage, voltage increment, current limit, current sampling interval, stirring setpoint, temperature setpoint, and temperature tolerance;

command means for commanding the programmable power supply via said interface to output a voltage corresponding to said starting voltage;

characteristic curve generating means for plotting a current versus voltage graph, including means for reading a first value of current via said interface, followed by current readings at time intervals equal to said current sampling interval, means for plotting each current reading as a point on said display means in real time, means executed after each current reading to determine if equilibrium conditions have been reached as indicated by successive current readings being equal within a given accuracy, the value then being designated as a settled current value, means effective once equilibrium has been achieved for a particular voltage for plotting a line on said display means representing the settled current value and for commanding the power supply to increase the voltage by said voltage increment;

means for causing repeated operation of said characteristic curve generating means for each voltage increment until the voltage reaches said ending voltage;

and means for aborting the experiment before said ending voltage is reached.

2. An electropolishing system according to claim 1, wherein the program means further includes system description program means, electrolyte and material library program means, and data base/analysis program means, along with main menu means providing selection from among the following options:

(a) description of the system, (b) access electrolyte/material library, (c) run experiment program, (d) run data base/analysis program, and (e) edit electrolyte/material library;

wherein said electropolishing experiment program means includes means effective while an experiment is being conducted for controlling and monitoring all critical parameters, to thereby allow the operator (metallographer) to analyze the data while it is being displayed in real time on the display means;

wherein the data base/analysis program means provides access to data stored in s system data base, with means for preferentially searching existing data files with respect to work order number, initiating engineer, electrolyte composition, and material composition, which allows the operator to analyze a particular file or group of files, wherein said data base/analysis program means includes means to output experimental results is graphic form to said display means, with data from a plurality of files plotted on the same graph for comparison, wherein the display means comprises a CRT and a plotter, and the output in graphic form may be to either the CRT or the plotter.

3. An electropolishing system according to claim 2, wherein the electrolyte and material library program means comprises memory means and processing means for providing a list of suggested electrolytes for polishing various metal alloys, and also affords access to an extensive list of electrolytes, the chemical compositions of the electrolytes, and the safety precautions which pertain to the use of the electrolytes, with menu selection means, so that by choosing the appropriate menu option the operator can view the information on the CRT or obtain a hard copy from a printer, and edit means for allowing the operator to add, delete, or change entries in the electrolyte and material library files.

4. A system for providing data for erosion of a workpiece for shape or surface change, using a computer with display means, a programmable power supply coupled to said cell and having an interface with the computer, program means which includes an experiment program means for generating a characteristic curve for a given set of conditions;

wherein said experiment program means includes means for entering the following parameters;

starting voltage, ending voltage, voltage increment, current limit, and current sampling interval;

command means for commanding the programmable power supply to output a voltage corresponding to said starting voltage;

characteristic curve generating means for plotting a current versus voltage graph, including means for reading a first value of current via said interface, followed by current readings at time intervals equal to said current sampling interval, means for plotting each current reading as a point on said display means in real time, means executed after each current reading to determine if equilibrium conditions have been reaches as indicated by successive current readings being equal within a given accuracy, the value then being designated as a settled current value, means effective once equilibrium has been achieved for a particular voltage for plotting a line on said display means representing the settled current value and for commanding the power supply to increase the voltage by said voltage increment;

means for causing repeated operation of said characteristic curve generating means for each voltage increment until the voltage reaches said ending voltage.