Additively manufactured non-uniform porous materials and components in-situ with fully material, and related methods, systems and computer program product
An additively manufactured non-uniform porous material in-situ with dense material for the in situ additive manufacturing of both porous and dense material in the same part so that no secondary process is required. The additively manufactured non-uniform porous material in-situ with dense material generally includes additively manufactured porous material which can be tuned for porosity and density, has the ability to be built in situ with dense material, and can also be tuned for response to pressure waves. Also included are computer program products, methods and components and systems manufactured using the methods.
1. An additive manufacturing method, the method steps comprising:
determining a desired non-uniform porosity profile across an injector to be manufactured for a rocket engine, said injector comprising a porous disk and a fully dense exterior, said porous disk further comprising a porous region and a denser region;
calculating and programming for the desired porosity profile, based at least on particle size and materials characteristics of powder in a powder source, energy source settings, laser settings, and a build profile for the injector to be manufactured;
covering a surface with the powder from the powder source;
scanning selectively the energy with the laser settings and the build profile at least once across the powder to at least partially melt the powder exposed to the energy to form fully dense wire-like lines and at least partially sinter the powder between the wire-like lines to form the porous region and at least partially bind the powder with prior layers and adjacent areas; and
repeating the covering and scanning steps to build the injector layer by layer until a lattice-like structure of pore channels forms from the wire-like lines creating channel walls with the at least partially sintered powder inside the pore channels,
wherein the step of scanning creates the porous region in the injector at first energy source settings and a first build profile, a denser region in the injector at second energy source settings and a second build profile, and the fully dense exterior,
a full penetration mechanically bonded interface between each of the porous region, the denser region, and the fully dense region, and
wherein the build profile informs the step of scanning to make non-overlapping passes to create the wire-like lines in a layer in a first direction and in one or more successive iterations of the scanning step to make wire-like lines in at least a second direction at an angle to the lines in the first direction creating a tortuosity of the pore channels capable of controlling or dampening fluid flow in the pore channels.
2. The method of claim 1 , wherein the step of scanning creates the full penetration mechanically bonded interface using a scan strategy that overlaps the first build profile and the second build profile so that the scanning of the energy creates the porous region and then creates the wire-like lines directly over portions of the porous region.
3. The method of claim 1 , wherein the build profile informs the step of scanning to make one pass that substantially overlaps a second pass to cause the powder to bind to a previously scanned layer without overheating the top of the powder to cause the porosity to decrease to less than the build profile.
4. The method of claim 1 , wherein the step of scanning plugs pore channels at random to control flow through the lattice-like structure.
5. The method of claim 1 , wherein the step of scanning skips the wire-like lines in at least an area of at least one layer to enable flow through the skipped area in that layer in a direction parallel to the at least one layer, and the skipped area in the at least one layer is sandwiched in between lattice-like structures in other layers.
6. The method of claim 1 , wherein the step of scanning makes at least some of a first pass that substantially overlaps at least some of a second pass at a first energy level to create a porous region and another section of the first pass at a second energy level to create a fully dense region, wherein the first energy level is lower than the second energy level.
7. The method of claim 1 , wherein the step of scanning makes at least some of a first pass that substantially overlaps at least some of a second pass at a first scan speed to create a porous region and another section of the first pass at a second scan speed to create a fully dense region, wherein the first scan speed is faster than the second scan speed.
8. The method of claim 7 , wherein the porous region is structurally supported by the denser region.
9. The method of claim 1 , wherein the step of scanning creates a porous disk having a different porosity on a combustion chamber facing side of the disk than the porosity on a side of the disk opposite to the combustion chamber facing side.
10. The method of claim 1 , wherein an atmosphere for additively manufacturing the injector is a reactive gas.
11. The method of claim 1 , wherein the first build profile and the second build profile has relatively no scan separation distance between them at the full penetration mechanically bonded interface.
12. The method of claim 1 , further comprising a second step of scanning selectively the energy with the laser settings and the build profile at least once across the powder to least partially-sinter the powder to form a porous region and at least partially bind the powder with prior layers and adjacent areas, wherein the second step of scanning is applied intermittently, forming the channel walls discontinuously across layers.
13. The method of claim 12 , wherein the second scanning step scans at least two layers without creating wire-like lines between scanning steps.
14. The method of claim 12 , wherein the second scanning step scans a random number of consecutive layers without creating wire-like lines between scanning steps.
15. The method of claim 12 , wherein the forming the channel walls discontinuously across layers have skipped layers that allows enhanced air flow within the lattice-like structure in a direction substantially perpendicular to a radius of the porous disk.
16. The method of claim 1 , wherein the step of scanning is repeated so that each layer is formed with wire-like lines.
17. The method of claim 1 , wherein the angle is an acute angle.
18. The method of claim 1 , a transpiration cooling flow of around 0.1% to 5% fluid flow through the pore channels.
19. The method of claim 1 , wherein the pattern of wire-like lines forms a helical channel wall structure.
20. The method of claim 1 , wherein the pattern of wire-like lines forms a grid channel wall structure.
21. The method of claim 1 , wherein the pattern of wire-like lines forms a pseudo-random channel wall structure.
22. The method of claim 1 , wherein the wire-like lines strengthen the porous material.
23. The method of claim 1 , wherein the wire-like lines control the fluid flow directions and pathways through the injector.
24. The method of claim 1 , wherein the wire-like lines control the fluid flow direction to be perpendicular to layers being formed by the scanning step.
25. The method of claim 1 , wherein the porosity profile further comprises a face plate having a porosity configured to cause a pressure drop.
26. The method of claim 25 , wherein the pressure drop is 5%.
27. The method of claim 26 , wherein the pressure drop is large enough to prevent combustion effects from propagating upstream from the porous disk into fluid systems.
28. The method of claim 26 , wherein the pressure drop is large enough enable higher throttling capabilities of the rocket engine.
29. The method of claim 1 , wherein the porosity is controlled to regulate a fluid pressure drop and face cooling of the porous disk based on the rocket engine.