当前申请(专利权)人地址：
Kings Place, 90 York Way, London, N1 9FX, United Kingdom
摘要：
In a first method of stress relieving a component 4, a pulsed square wave electrical current with a pulse width in the range 1-50 ms and a current density in the material in the range 10-10000 A/mm2 is applied via electrodes 2 either on a first side or on opposing sides of the component 4. In a second method, a pulsed electrical current is applied via electrodes 2 to a first side of the component 4, where the electrodes 2 are movable relative to each other so that the current density is adjustable. A pulsed magnetic flux can be applied in combination with the pulsed current. The methods can be used after forming the component by forging or drawing or during or after forming the component by welding or additive manufacture. The method can be used when repairing or modifying a gas turbine engine rotary blade.
权利要求：
CLAIMS
1. A method for relieving residual stress in a material by applying pulsed electrical current to the material, the current being applied as a square wave having a pulse width between 1ms and 50ms and providing a current density of between 10A/mm? and 10kA/mm?2 within the material.
2. A method according to claim 1 wherein the pulse width is between 3ms and 10ms.
3. A method according to claim 1 or claim 2, wherein the peak current density is of the order 50 to 500A/mm?2
4. A method according to any preceding claim, wherein the electrical pulse frequency is between 0.1 Hz and 1 kHz.
5. A method according to any preceding claim, wherein the material has a first surface and the current is applied to the material from electrodes located on the same surface and spaced apart.
6. A method according to claim 5, wherein the spacing of the electrodes is reduced to increase the current density within the material and increased to reduce the current density within the material.
7. A method according to any of claims 1 to 4, wherein the material has a first surface and a second surface and the current is applied between an electrode located on the first surface and an electrode located on the second surface.
8. A method according to any of claim 1 to claim 7 comprising relieving residual stress in a material by applying pulsed electrical current to the material after forging the material.
9. A method according to any of claim 1 to claim 7 comprising relieving residual stress in a material by applying pulsed electrical current to the material after drawing the material.
10. A method according to any of claim 1 to claim 7 comprising relieving residual stress in a material by applying pulsed electrical current to the material after forming the material.
11. A method according to any of claim 1 to claim 7 comprising relieving residual stress in a material by applying pulsed electrical current to the material after or during welding or additive manufacture of the material.
12. A method for relieving residual stress in a component by applying pulsed electrical current to the component, the current being applied via separate electrodes located on a first surface of the component, the electrode spacing being adjustable to provide a stress treatment current density between the electrodes.
13. A method according to claim 12, wherein the stress treatment current density is between 10A/mm? and 10kA/mm?2
14. A method according to claim 13, wherein the stress treatment current density is between 50 to 500A/mm?2.
15. A method according to any of claim 12 to claim 14, wherein the electrical pulse has a width of between 5us and 50ms
16. A method according to claim 15, wherein the electrical pulse has a width of between 1ms and 50ms.
17. A method according to any of claim 12 to claim 16, wherein the electrical pulse has a frequency between 0.1 Hz and 1 kHz.
18. A method according to any of claim 12 to claim 17, wherein the spacing of the electrodes is reduced to increase the current density within the material and increased to reduce the current density within the material.
19. A method according to any of claim 12 to claim 17, comprising relieving residual stress in a material by applying pulsed electrical current to the material after forging the material.
20. A method according to any of claim 12 to claim 17, comprising relieving residual stress in a material by applying pulsed electrical current to the material after drawing the material.
21. A method according to any of claim 12 to claim 17, comprising relieving residual stress in a material by applying pulsed electrical current to the material after forming the material.
22. A method according to any of claim 12 to claim 17, comprising relieving residual stress in a material by applying pulsed electrical current to the material during or after welding or additive manufacture of the material.
23. A method according to any one of the preceding claims comprising applying a combination of pulsed electrical current and magnetic flux to said material.
24. A method according to any one of the preceding claims wherein the magnetic pulse width is between 5 us and 1s.
25. A method according to any one of the preceding claims wherein the magnetic pulse frequency is between 0.1 Hz and 100Hz.
26. A method according to any one of the preceding claims wherein the magnetic pulse density is between 0.5 to 2.5 Tesla.
27. A circuit for applying pulsed electrical current to a material for the relief of residual stress, the circuit comprising a programmable power supply, a charging and discharging system, a power electronics module, a controller and connectors for outputting a square wave electric pulse to a component.
28. A circuit according to claim 27, wherein the programmable power supply is a DC power supply.
29. A circuit according to claim 27 or claim 28, wherein the charging and discharging system comprises one or more supercapacitors.
30. A circuit according to any of claim 27 to claim 29, wherein the power electronics module comprises one or more of a half bridge module of IGBT or MOSFET.
31. A circuit according to any of claim 27 to claim 30, wherein the square wave electric pulse has a pulse width between 1ms and 50 ms.
32. A circuit according to any of claim 27 to claim 31, wherein the connectors provide a current density of between 10Amm?2 and 10kA/mm?2 within the component.