Tool-electrode capable of producing sealing slots in a cmc material by means of edm

Patent metadata

Field	Value
Publication number	US-2025041957-A1
Application number	US-202218717347-A
Country	US
Kind code	A1
Filing date	Nov 28, 2022
Priority date	Dec 8, 2021
Publication date	Feb 6, 2025
Grant date	—

Abstract

A tool-electrode for machining an imprint in a conductive part by sinking-die type electrical-discharge machining. It includes a conductive body having lower and upper opposite surfaces, two opposite main lateral surfaces, lower and upper areas superposed according to a die-sinking direction of the tool-electrode, the lower area comprising the lower surface and a portion of the main lateral surfaces, the upper area including the upper surface and the other portion of the main lateral surfaces. The body is provided, at least in the lower area, with a plurality of openings selected from among channels or slots; a channel is an opening which opens onto at least one of the upper and lower surfaces; a slot is an opening which opens onto the lower surface and onto the two main lateral surfaces.

First claim

1 . A tool-electrode for machining, in a part made of an electrically-conductive material, an imprint by sinking-die type electrical-discharge machining, the tool-electrode including a body made of an electrically-conductive material having a lower face and an upper face, opposite to each other, and two main lateral faces, opposite to each other, the body having a lower area and an upper area, which are superimposed according to a die-sinking direction (Z) of the tool-electrode, the lower area comprising the lower face and a portion of the main lateral faces and the upper area comprising the upper face and the other portion of the main lateral faces,
wherein the body is provided, at least in the lower area, with a plurality of openings selected from among channels or slots, a channel being an opening that opens onto at least one amongst the upper and lower faces, a slot being an opening that opens onto the lower face and onto the two main lateral faces, each channel having a diameter smaller than or equal to twice the die-sinking machining gap (G), and each slot having a width, defined by a distance between two lateral walls of the slot, smaller than or equal to twice the die-sinking machining gap (G), and a height, in the die-sinking direction, larger than or equal to three times the depth of the imprint to be made, wherein the die-sinking machining gap is comprised between 0.02 mm and 0.3 mm.

2 . The tool-electrode according to claim 1 , including channels in the lower area and which extend in the upper area, each channel opening onto both the lower face and the upper face of the body.

3 . The tool-electrode according to claim 2 , wherein the distance between two adjacent channels is larger than or equal to twice the die-sinking machining gap.

4 . The tool-electrode according to claim 1 , including openings only in the lower area, these openings consisting of slots.

5 . The tool-electrode according to claim 4 , wherein the distance between two adjacent slots is larger than or equal to twice the die-sinking machining gap.

6 . The tool-electrode according to claim 1 , including slots in the lower area and channels in the upper area, each channel of the upper area opening onto a slot of the lower area.

7 . The tool-electrode according to claim 1 , wherein the body is made of a CuCrZr copper alloy.

8 . The tool-electrode according to claim 1 , wherein the imprint to be machined having to have given depth, length, and width, the body of the electrode has a thickness that is smaller than a value corresponding to the width of the imprint, from which the die-sinking machining gap is subtracted twice.

9 . A machining device for machining an imprint by die-sinking type electrical-discharge machining, comprising a tool-electrode according to claim 1 , and means cooperating with the openings of the tool-electrode to create a machining liquid circulation in the bottom of the imprint being formed, said means being selected from among means for injecting pressurized machining liquid into the plurality of openings of the tool-electrode, when the openings are channels, and means for injecting machining liquid around the electrode, when the openings are slots.

10 . A method for forming an imprint in a part made of an electrically-conductive material by electrical-discharge machining, implementing a machining device according to claim 9 , and comprising the steps of:
immersing the part in a machining liquid; forming a blank of the imprint, by die-sinking the tool-electrode according to the die-sinking direction and concomitant injection of machining liquid into the plurality of openings of the tool-electrode to create a machining liquid circulation in the bottom of the blank; finishing the imprint by placing the tool-electrode at the center of the blank and off-centering the tool-electrode in a plane perpendicular to the die-sinking direction, wherein the eccentricity radius is larger than or equal to the die-sinking machining gap.

11 . The method according to claim 10 , wherein the imprint to be machined is a sealing slot and the part is made of SiC/SiC composite material.

Assignees

• Safran Aircraft Engines

Inventors

• Lecomte Janvier François
• Boesch Aurélie
• Guilbaud Freddy Guy

Classifications

• B23H9/006

  Cavity sinking (B23H9/14 takes precedence) · CPC title

• B23H1/06 Primary

  Electrode material · CPC title

• B23H1/04 Primary

  Electrodes specially adapted therefor or their manufacture (B23H9/00 takes precedence) · CPC title