Selective sintering additive manufacturing method

1. A method for producing a component layer-by-layer, comprising the steps of:

depositing particulate material to form a layer of particulate material having a first area over a build platform;

applying at least one exothermic material over the build platform so that a second area of the first area is uniformly coated with the exothermic material, wherein the second area is smaller than the first area;

selectively applying radiant energy to a third area of the layer in a specific pattern that defines the geometry of a cross-sectional layer of the component to trigger an exothermic reaction in the at least one exothermic material and sinter the third area of the layer, wherein the third area is a portion of and smaller than the second area; and

repeating the steps of depositing, applying, and sintering for a plurality of layers until the component is complete.

2. The method of claim 1 wherein the at least one exothermic material includes a radiant-energy-curable binder, the method further comprising using the application of radiant energy to selectively cure the binder in the specific pattern, concurrent with the step of sintering.

3. The method of claim 1 wherein the at least one exothermic material includes a non-binding reactant.

4. The method of claim 1 wherein the second area comprises a majority of the first area.

5. The method of claim 1 wherein the second area comprises a shape which roughly approximates a perimeter of the cross-sectional layer of the component.

6. The method of claim 1 wherein the particulate material is applied such that the particulate material in at least one of the layers has a different composition than the particulate material in another one of the layers.

7. The method of claim 1 wherein at least one of the layers is divided into two or more portions, and the particulate material is applied such that the particulate material in at least one of the portions has a different composition than the particulate material in another one of the portions.

8. The method of claim 1 wherein the application of radiant energy is applied by one of the following: projecting a patterned image comprising a plurality of pixels, scanning at least one build beam over the surface of the particulate material, and a combination thereof.

9. The method of claim 8 wherein additional radiant energy is applied by scanning at least one build beam over the surface of the particulate material.

10. The method of claim 1 wherein the at least one exothermic material is applied using one or more spray nozzles.

11. The method of claim 1 wherein the particulate material contains a mixture of more than one material.

12. The method of claim 1 further comprising sintering the completed component.

13. The method of claim 12 further comprising infiltrating a lower-melting-temperature material into the component during or after sintering.

14. The method of claim 1 wherein the particulate material is premixed with at least one exothermic material.

15. A method for producing a component layer-by-layer, comprising:

depositing a layer including a particulate material, a first binder curable using a first curing process, and a second binder curable using a second curing process over a build platform, the layer covering a first area, wherein at least one of the binders comprises an exothermic material;

wherein at least one of the binders of the layer is deposited so that a second area of the first area is uniformly coated with the at least one binder, wherein the second area is smaller than the first area;

curing the first and second binders by using the first and second curing processes, wherein radiant energy is applied to at least one of the binders in a third area of the layer in a specific pattern that defines the geometry of a cross-sectional layer of the component to selectively cure the at least one of the binders, and concurrently selectively sintering the particulate material using the application of radiant energy to trigger an exothermic reaction in the exothermic material, wherein the third area is a portion of and smaller than the second area; and

repeating the steps of depositing, applying, and concurrently curing and sintering for a plurality of layers until the component is complete.

16. The method of claim 15 wherein at least one of the first and second binders is premixed with the particulate material.

17. The method of claim 15 wherein at least one of the first and second binders is applied over the build platform subsequent to depositing the particulate material, such that a selected portion of the first area is uniformly coated with binder.

18. The method of claim 15 wherein the second area comprises a majority of the first area.

19. The method of claim 15 wherein the second area comprises a shape which roughly approximates a perimeter of the cross-sectional layer of the component.

20. The method of claim 15 wherein at least one of the first and second binders is cured prior to the deposition of the other binder.

21. The method of claim 15 wherein the first and second binders are cured sequentially.

22. The method of claim 15 wherein the particulate material is applied such that the particulate material in at least one of the layers has a different composition than the particulate material in another one of the layers.

23. The method of claim 15 wherein at least one of the layers is divided into two or more portions, and the particulate material is applied such that the particulate material in at least one of the portions has a different composition than the particulate material in another one of the portions.

24. The method of claim 15 wherein the application of radiant energy is applied by projecting a patterned image comprising a plurality of pixels.

25. The method of claim 24 wherein additional radiant energy is applied by scanning at least one build beam over the surface of the particulate material.

26. The method of claim 15 wherein the radiant energy is applied by scanning at least one build beam over the surface of the particulate material.

27. The method of claim 15 where the particulate material contains a mixture of more than one material.

28. The method of claim 15 further comprising sintering the completed component.

29. The method of claim 28 further comprising infiltrating a lower-melting-temperature material into the component during or after sintering.