Powder for layerwise manufacturing of objects
The invention describes powders for use in the production of spatial structures, i.e. molded bodies, using layer build-up methods, as well as methods for their efficient production. The powders have the special feature that they have good flow behavior, for one thing, and at the same time, have such a composition that the molded body that can be produced with the powder, using rapid prototyping, has significantly improved mechanical and/or thermal properties. According to a particularly advantageous embodiment, the powder has a first component that is present in the form of essentially spherical powder particles, which is formed by a matrix material, and at least one further component in the form of stiffening and/or reinforcing fibers, which are preferably embedded in the matrix material.
1. In solid freeform fabrication of objects using a powder-based generative rapid prototyping or manufacturing process, an improved powder wherein the improvement comprises, the powder having a first fraction that is present in the form of substantially spherical powder particles as a matrix material, and at least one other fraction in the form of strengthening and/or reinforcing fibers, wherein the medium length L 50 of the fibers is not greater than the medium grain size d 50 of the spherical powder particles and wherein the powder is supplied in an isolated powder form and not in a liquid medium during the freeform fabrication of objects.
2. The powder according to claim 1 , wherein the medium grain size d 50 of the spherical powder particles lies in the range from 40 to 70 μm.
3. In solid freeform fabrication of objects using a powder-based generative rapid prototyping or manufacturing process, an improved powder wherein the improvement comprises, the powder having a first fraction that is present in the form of substantially spherical powder particles as a matrix material, and at least one other fraction in the form of strengthening and/or reinforcing fibers, wherein the medium grain size d 50 of the spherical powder particles is in the range from 20 to 150 μm, and wherein the medium length L 50 of the fibers is not greater than the medium grain size d 50 of the spherical powder and wherein the powder is supplied in an isolated powder form and not in a liquid medium during the freeform fabrication of objects.
4. A powder according to claim 3 , wherein the medium grain size d 50 of the spherical powder particles lies in the range from 40 to 70 μm.
5. The powder according to claim 1 or 3 , wherein the fibers and the matrix material are mixed.
6. The powder according to claim 5 , wherein the volume fraction of the fibers is up to 25%.
7. The powder according to claim 5 , wherein the volume fraction of the fibers is up to 15%.
8. The powder according to claim 5 , wherein the volume fraction of the fibers is up to 10%.
9. The powder according to claim 1 or 3 , wherein the fibers are embedded into the matrix material.
10. The powder according to claim 9 , wherein the fibers are substantially fully enclosed by the matrix material.
11. The powder according to claim 10 , wherein the volume fraction of the fibers is greater than 15%.
12. The powder according to claim 10 , wherein the volume fraction of the fibers is greater than 25%.
13. The powder according to claim 10 , wherein the volume fraction of the fibers is greater than 30%.
14. A powder according to claim 1 or 3 comprising a first fraction that is present in the form of substantially spherical powder particles as a matrix material, and at least one other fraction in the form of strengthening and/or reinforcing fibers, wherein the fibers are embedded into the matrix material.
15. The powder according to claim 14 , wherein the fibers are substantially fully enclosed by the matrix material.
16. The powder according to claim 15 , wherein the volume fraction of the fibers is greater than 15%.
17. The powder according to claim 15 , wherein the volume fraction of the fibers is greater than 25%.
18. The powder according to claim 15 , wherein the volume fraction of the fibers is greater than 30%.
19. The powder according to claim 1 or 3 , wherein the matrix material is formed from a thermoplastic plastic material.
20. The powder according to claim 12 , wherein the thermoplastic plastic material is a polyamide.
21. The powder according to claim 20 , wherein the polyamide is PA11 or PA12.
22. The powder according to claim 1 or 3 , wherein the fibers are formed from carbon and/or glass fibers.
23. The powder according to claim 1 or 3 , wherein the matrix material is formed from an aromatic polyetherketone.
24. The powder according to claim 23 , wherein the aromatic polyketone is a polyaryletherketone (PEEK) plastic comprising polymerized units of oxy-1,4-phenylene-oxy-1,4-phenylene-carbony l-1,4-phenylene of the following formula:
25. The powder according to claim 1 or 3 , wherein the matrix material is formed from a metallic material.
26. The powder according to claim 1 or 3 , wherein the fibers are selected from the group consisting of ceramic and boron fibers.
27. The powder according to claim 25 , wherein the medium grain size d 50 of the spherical powder particles lies in the range from 10 to 100 μm.
28. The powder according to claim 26 , wherein the medium grain size d 50 of the spherical powder particles lies in the range from 10 to 100 μm.
29. The powder according to claim 25 , wherein the medium grain size d50 of the spherical powder particles lies in the range from 10 to 80 μm.
30. The powder according to claim 26 , wherein the medium grain size d50 of the spherical powder particles lies in the range from 10 to 80 μm.
31. The powder according to claim 14 , wherein the matrix material is formed from a thermoplastic plastic material.
32. The powder according to claim 31 , wherein the thermoplastic plastic material is a polyamide.
33. The powder according to claim 32 , wherein the polyamide is PA11 or PA12.
34. The powder according to claim 14 , wherein the fibers are formed from carbon and/or glass fibers.
35. The powder according to claim 14 , wherein the matrix material is formed from an aromatic polyetherketone.
36. The powder according to claim 35 , wherein the aromatic polyketone is a polyaryletherketone (PEEK) plastic comprising polymerized units of oxy-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene of the following formula:
37. The powder according to claim 14 , wherein the matrix material is formed from a metallic material.
38. The powder according to claim 14 , wherein the fibers are selected from the group consisting of ceramic and boron fibers.
39. The powder according to claim 37 , wherein the medium grain size d 50 of the spherical powder particles lies in the range from 10 to 100 μm.
40. The powder according to claim 38 , wherein the medium grain size d50 of the spherical powder particles lies in the range from 10 to 100 μm.
41. The powder according to claim 39 , wherein the medium grain size d50 of the spherical powder particles lies in the range from 10 to 80 μm.
42. The powder according to claim 38 , wherein the medium grain size d 50 of the spherical powder particles lies in the range from 10 to 80 μm.