Claims
- 1. A method of laser casting a copper-based alloy or composite comprising:milling elemental copper powder with at least one other material which absorbs laser energy more readily than elemental copper powder to form a copper-based mixture; and laser casting said copper-based alloy or composite by application of a laser to said copper-based mixture; wherein said milling is conducted for a period sufficient to form at least a partial coating of said at least one material on particles of said elemental copper powder.
- 2. The method according to claim 1, wherein said milling step comprises ball milling said powder mixture for a period of from about 1 to 4 hours.
- 3. The method according to claim 1, wherein said milling step comprises mechanically mixing said powder mixture for a period of at least about 1 hour and subsequently ball milling said powder mixture for a period of about 2 hours.
- 4. The method according to claim 2, wherein said ball mill is run at a speed of from about 150 to about 300 rpm using a ball size of from about 15 mm to about 30 mm diameter.
- 5. The method according to claim 2, wherein the weight ratio of ball to powder is from 5-20:1.
- 6. The method according to claim 1, wherein said at least one other material comprises elemental Ni.
- 7. The method according to claim 6, wherein said Ni is present in an amount of at least about 5% by weight.
- 8. The method according to claim 1, wherein said at least one other material comprises elemental Ti and C.
- 9. The method according to claim 8, wherein said at least one other material further comprises elemental Ni.
- 10. The method according to claim 8, wherein the amount of Ti and C in said mixture are such that during said laser casting step, said Ti and C react with each other to form in situ TiC in an amount of 50% by weight or less, and wherein said Ni is present in an amount of about 10% by weight.
- 11. The method according to claim 1, wherein said at least one other material comprises TiC and elemental Ni.
- 12. The method according to claim 1, wherein said at least one other material comprises WC.
- 13. The method according to claim 12, wherein said WC is present in an amount of from about 10% to 60% by weight.
- 14. The method according to claim 12, wherein said at least one other material further comprises elemental Ni.
- 15. The method according to claim 12, wherein said at least one other material further comprises elemental W.
- 16. The method according to claim 1, wherein said at least one other material comprises elemental Fe.
- 17. The method according to claim 16, wherein said Fe is present in an amount of at least about 10% by weight.
- 18. The method according to claim 17, wherein said Fe is present in an amount of from about 10% to 50% by weight.
- 19. The method according to claim 16, wherein said at least one other material further comprises Ni.
- 20. The method according to claim 1, wherein said at least one other material comprises elemental W or Ni.
- 21. The method according to claim 20, wherein said W is present in an amount of about 10% by weight.
- 22. The method according to claim 1, wherein process controlling agent is added in said milling step in an amount to substantially prevent cold welding of particles of said mixture.
- 23. The method according to claim 22, wherein said process controlling agent is added in an amount of up to about 3% by weight.
- 24. The method according to claim 1, wherein the laser applied to said mixture during said laser casting is a CO2 laser with a wavelength of 10.6 μm.
- 25. The method according to claim 24, wherein said laser is selectively applied to said mixture at a laser scanning speed of from 100 to 1500 mm/min.
- 26. The method according to claim 24, wherein said laser is applied at a laser power of from about 100 to about 1500 W using a beam spot diameter of from about 0.2 to about 5.0 mm.
- 27. The method according to claim 1, wherein said laser casting step is carried out under an inert atmosphere of argon gas.
- 28. The method according to claim 1, wherein said laser casting is carried out under a 10 reduction atmosphere of CO.
- 29. An article cast using a method according to claim 1.
- 30. The article according to claim 29, comprising a single-layer or multi-layer structure.
- 31. The article according to claim 29, wherein said article is an EDM electrode, rapid die and moulding tooling or system composites.
- 32. A method of laser casting a metal-based alloy or composite comprising:milling elemental metal powder having a relatively high reflectivity at a wavelength of the laser with at least one other material which absorbs laser energy more readily than said elemental metal powder to form a metal-based mixture; and laser casting said metal-based allay or composite by application of a laser to said copper-based mixture; wherein said milling is conducted for a period sufficient to form at least a partial coating of said at least one material on particles of said elemental metal powder.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9804031 |
Nov 1998 |
SG |
|
Parent Case Info
This application is the national phase under 35 U.S.C. §371 of PCT International Application No. PCT/SG99/00116 which has an International filing date of Nov. 10, 1999, which designated the United States of America.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/SG99/00116 |
|
WO |
00 |
US Referenced Citations (13)
Foreign Referenced Citations (1)
Number |
Date |
Country |
WO 9208567 |
May 1995 |
WO |
Non-Patent Literature Citations (1)
Entry |
Van der Schueren, B. et al., “Powder deposition in selective metal powder sintering”, Rapid Prototyping Journal, vol. 1. No. 3, 1995, pp. 23-31. |