Multiple material systems for selective beam sintering

• US 5,076,869 A
• Filed: 07/30/1990
• Issued: 12/31/1991
• Est. Priority Date: 10/17/1986
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Marcus, Harris L., Beaman, Joseph J., Bourell, David L., Barlow, Joel W., Deckard, Carl R.
• Primary Examiner(s): Powell, William A.
• Application Number:
  US07/559,338
• Time in Patent Office: 519 Days
• Field of Search: 156/62.2, 156/89, 156/272.8, 156/278, 156/242, 156/245, 156/643, 156/345, 156/500, 156/501, 156/283, 219/121.6, 219/121.61, 219/121.63, 219/121.64, 219/121.65, 219/121.66, 219/121.73, 219/121.8, 219/121.85, 264/58, 264/113, 264/125, 264/126, 264/127, 264/22, 425/174, 419/5, 419/8
• US Class Current: 264/497
• CPC Class Codes: B05C 19/00 Apparatus specially adapted for applying particulate materials to surfaces
• CPC Class Codes: B05C 19/008 Accessories or implements for use in connection with applying particulate materials to surfaces; not provided elsewhere in B05C19/00
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/366 Scanning parameters, e.g. hatch distance or scanning strategy
• CPC Class Codes: B22F 10/60 Treatment of workpieces or articles after build-up
• CPC Class Codes: B22F 12/13 to preheat the material
• CPC Class Codes: B22F 12/41 characterised by the type, e.g. laser or electron beam
• CPC Class Codes: B22F 12/44 characterised by the configuration of the radiation means
• CPC Class Codes: B22F 12/49 Scanners
• CPC Class Codes: B22F 12/52 Hoppers
• CPC Class Codes: B22F 2003/1052 assisted by energy absorption enhanced by the coating or powder
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/004 Filling molds with powder feeding material to presses in general B30B15/302
• CPC Class Codes: B22F 3/105 by using electric current other than for infrared radiant energy, laser radiation or plasma B22F3/11 takes precedence; by ultrasonic bonding B22F3/115 takes precedence
• CPC Class Codes: B22F 3/26 Impregnating making ferrous alloys by impregnation C22C33/0242
• CPC Class Codes: B22F 7/02 of composite layers B22F7/002 takes precedence
• CPC Class Codes: B23K 26/08 Devices involving relative movement between laser beam and workpiece
• CPC Class Codes: B23K 26/082 Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
• CPC Class Codes: B23K 26/34 Laser welding for purposes other than joining
• CPC Class Codes: B23K 35/0244 : Powders, particles or spheres; Preforms made therefrom
• CPC Class Codes: B23K 35/3613 : Polymers, e.g. resins
• CPC Class Codes: B29C 35/045 : using gas or flames
• CPC Class Codes: B29C 41/12 : Spreading-out the material on a substrate , e.g. on the surface of a liquid
• CPC Class Codes: B29C 41/46 : Heating or cooling
• CPC Class Codes: B29C 64/153 : using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B33Y 10/00 : Processes of additive manufacturing
• CPC Class Codes: B33Y 70/10 : Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: C23C 24/08 : by application of heat or pressure and heat C23C24/04 takes precedence
• CPC Class Codes: C23C 24/10 : with intermediate formation of a liquid phase in the layer
• CPC Class Codes: C23C 26/02 : applying molten material to the substrate
• CPC Class Codes: G05B 19/41 : characterised by interpolation, e.g. the computation of intermediate points between programmed end points to define the path to be followed and the rate of travel along that path G05B19/25, G05B19/31, G05B19/37, G05B19/39, G05B19/40 take precedence
• CPC Class Codes: G05B 2219/49013 : Deposit layers, cured by scanning laser, stereo lithography SLA, prototyping
• CPC Class Codes: G05B 2219/49018 : Laser sintering of powder in layers, selective laser sintering SLS
• CPC Class Codes: Y02P 10/25 : Process efficiency
• CPC Class Codes: Y02P 90/02 : Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A method and apparatus for selectively sintering a layer of powder to produce a part comprising a plurality of sintered layers. The apparatus includes a computer controlling a laser to direct the laser energy onto the powder to produce a sintered mass. The computer either determines or is programmed with the boundaries of the desired cross-sectional regions of the part. For each cross-section, the aim of the laser beam is scanned over a layer of powder and the beam is switched onto sinter only the powder within the boundaries of the cross-section. Powder is applied and successive layers sintered until a completed part is formed. Preferably, the powder comprises a plurality of materials having different dissociation or bonding temperatures. The powder preferably comprises blended or coated materials.

Claims

1. A method of producing a part comprising the steps of:

depositing a powder onto a target surface, said powder comprising first and second materials; and

directing an energy beam at the target surface in such a manner that a selected portion of said powder corresponding to a cross-sectional region of the part is heated by the energy of said beam to a sufficient temperature that said first material in said selected portion adheres particles of said second material into a mass.

2. The method of claim 1, wherein said target surface is disposed within an environment comprising a gas which promotes sintering;

and wherein said directing step sinters said first material in said selected portion of said powder.

3. The method of claim 1, wherein said energy beam is at a selected wavelength;

and wherein said first material absorbs energy at the selected wavelength to a greater degree than said second material.

4. The method of claim 1, further comprising heating the powder prior to said directing step.

5. The method of claim 1, wherein said depositing step deposits a first layer of said powder;

and further comprising;

after said directing step, depositing a second layer of powder onto said target surface, said second layer of powder also comprising said first and second materials;

directing an energy beam at the target surface in such a manner that a selected portion of said second layer of powder corresponding to a second cross-sectional region of the part is heated by the energy of said beam to a sufficient temperature that said first material in said selected portion of said second layer adheres particles of said second material in said second layer into a mass, and together with the mass of said first layer of powder.

6. The method of claim 1, wherein said directing step sinters said first material in the selected portion of said powder.

7. The method of claim 1, further comprising, after said directing step, annealing said powder.

8. The method of claim 7, wherein said annealing dissociates said first material and sinters the second material.

9. The method of claim 7, wherein said annealing forms an alloy of said first and second materials.

10. The method of claim 1, wherein said first material is conductive.

11. The method of claim 10, wherein said second material is an insulating polymer.

12. The method of claim 1, wherein said second material is crystalline;

wherein said depositing step deposits a first layer of said powder;

and further comprising;

after said directing step, depositing a second layer of powder onto said target surface, said second layer of powder also comprising said first and second materials;

directing an energy beam at the target surface in such a manner that a selected portion of said second layer of powder corresponding to a second cross-sectional region of the part is heated by the energy of said beam to a sufficient temperature that said first material in said selected portion of said second layer adheres particle s of said second material in said second layer into a mass epitaxially with particles of said second material in said first layer of powder.

13. The method of claim 1, wherein said first material has a first bonding temperature, and said second material has a second bonding temperature greater than said first bonding temperature;

and wherein said directing step heats said selected portion of said powder to a temperature greater than said first bonding temperature.

14. The method of claim 13, wherein said depositing step comprises:

depositing a first layer comprising said first material; and

depositing, upon said first layer, a second layer comprising said second material.

15. The method of claim 13, wherein said depositing step comprises:

depositing a first layer comprising said second material; and

depositing, upon said first layer, a second layer comprising said first material.

16. The method of claim 13, wherein said directing step heats said selected portion of said powder to a temperature below said second bonding temperature.

17. The method of claim 1, wherein said first material has a first dissociation temperature, and said second material has a second dissociation temperature greater than said first dissociation temperature;

and wherein said directing step heats said selected portion of said powder to a temperature greater than said first dissociation temperature.

18. The method of claim 17, wherein said depositing step comprises:

depositing a first layer comprising said first material; and

depositing, upon said first layer, a second layer comprising said second material.

19. The method of claim 17, wherein said depositing step comprises:

depositing a first layer comprising said second material; and

depositing, upon said first layer, a second layer comprising said first material.

20. The method of claim 17, wherein said directing step heats said selected portion of said powder to a temperature below said second dissociation temperature.