Methods for the electroerosion machining of high-performance metal alloys

Patent metadata

Field	Value
Publication number	US-2016101479-A1
Application number	US-201414510757-A
Country	US
Kind code	A1
Filing date	Oct 9, 2014
Priority date	Oct 9, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

A method of machining a work-piece formed of titanium-based material, using a machining apparatus, is described. The method includes the steps of providing an electrically-conductive electrode contained within a spindle assembly, in a pre-selected distance and position relative to the titanium-based work-piece; while electrically powering the electrode and the work-piece with a power supply. In the process, fluid electrolyte is circulated through at least two pathways in the machining apparatus—an internal conduit within the spindle assembly; and an external conduit. The charged electrode is moved relative to the work-piece in a plunging motion, to remove material from the work-piece at a relatively high rate, using a high-speed electro-erosion (HSEE) process.

First claim

What is claimed:

1 . A method of machining a work-piece formed of titanium-based material, using a machining apparatus, said method comprising the steps of:
(a) providing an electrically-conductive electrode contained within a spindle assembly, in a pre-selected distance and position relative to the titanium-based work-piece; while electrically powering the electrode and the work-piece with a power supply; (b) circulating fluid electrolyte through at least two pathways in the machining apparatus; wherein one pathway comprises an internal conduit within the spindle assembly; and a second pathway comprises an external conduit outside of the spindle assembly and at least partially within a gap between the electrode and the work-piece; and (c) moving the electrode relative to the work-piece in a plunging motion, to remove material from the work-piece at a relatively high rate, using a high-speed electro-erosion (HSEE) process.

2 . The method of claim 1 , wherein the electrode is rotated during the HSEE process at a linear speed of at least about 36,000 inches per minute.

3 . The method of claim 2 , wherein the linear speed is in the range of about 7,000 inches per minute to about 125,000 inches per minute.

4 . The method of claim 2 , wherein the electrode is operated under a current density of at least about 15 amps/mm 2 .

5 . The method of claim 1 , wherein the fluid electrolyte provides cooling to the work-piece and to the gap between the work-piece and the electrode, while also flushing away debris that results from machining.

6 . The method of claim 5 , wherein the fluid electrolyte includes one or more additives for increasing electrical discharge between the work-piece and the electrode.

7 . The method of claim 1 , wherein the spindle assembly is contained in or otherwise connected to a multi-axis machine configured to support and rotate the electrode.

8 . The method of claim 7 , wherein the multi-axis machine is in operative communication with a controller that is configured for distributing intermittent multiple electrical arcs between the electrode and the work-piece.

9 . The method of claim 1 , wherein the plunging motion is axial and generally perpendicular to the work-piece surface that requires removal of material.

10 . The method of claim 9 , wherein the plunging motion cuts pocket holes into the work-piece surface.

11 . The method of claim 1 , wherein the work-piece is a component of a turbine engine or a portion of an aircraft airframe.

12 . The method of claim 2 , wherein a total pressure value of circulating electrolyte fluid and the rotational speed of the electrode are simultaneously controlled by an automated mechanism, so as to maximize the efficiency of titanium removal from the work-piece.

13 . The method of claim 12 , wherein the electrode is energized by the power supply that applies a potential difference ΔV between the work-piece and the electrode, with a threshold current; said method further comprising:
(i) measuring the current at selected intervals during machining;
(ii) comparing the measured current with the threshold current to determine if the measured current indicates an out-of-control status;
(iii) generating a control signal upon the indication of an out-of-control status, said control signal resulting in the adjustment of at least one of (I) electrode rotation speed or (II) electrolyte flushing pressure, so as to return the machining step to an in-control status.

14 . A method of machining a titanium-based component, in which material is removed from selected regions of the component by using a high-speed electroerosion (HSEE) process in which an electrically-conductive electrode is controllably moved and rotated in a plunging, pocket-hole forming motion, relative to the component; and
wherein a fluid electrolyte is circulated through both an internal pathway within the electrode and an external pathway outside of the electrode and within a gap between the electrode and the component; and wherein a total pressure value of the circulating electrolyte fluid and the rotational speed of the electrode are simultaneously controlled by an automated mechanism, so as to maximize the efficiency of titanium removal from the component.

Assignees

• Gen Electric

Inventors

• Luo Yuanfeng
• Hayashi Steven Robert
• Trimmer Andrew Lee
• Cintula Mark James

Classifications

• B23H9/14

  Making holes · CPC title

• B23H5/02

  Electrical discharge machining combined with electrochemical machining · CPC title

• B23H1/10

  Supply or regeneration of working media · CPC title

• B23H5/14

  Supply or regeneration of working media · CPC title

• B23H2400/10

  for rotating the electrode · CPC title