Method for hardening selected portion of metal article, additive manufacturing system associated therewith and metal article

Abstract

A method for hardening a selected portion of a metal article, an additive manufacturing system associated therewith, and a metal article, the method for hardening a selected portion of a metal article comprising: establishing a non-reactive atmosphere within a build chamber of the additive manufacturing system, an energy source is used to melt a metallic material to deposit the molten material in layers to build the metallic article, and a reaction atmosphere is established within the build chamber that causes a chemical reaction to harden a portion of a plurality of selected layers. An additive manufacturing system for hardening selected portions of a metal article includes a build chamber, a material handling assembly, a substrate, an energy source assembly, a translation assembly, and a system control assembly. A metal article includes a metal material layer deposited via an additive manufacturing process. A portion of the selected layer is hardened via a chemical reaction caused by a reaction atmosphere established during a period of the additive manufacturing process.

Description

Technical Field

[0001] The present disclosure as a whole relates to hardening selected portions of metal articles using an additive manufacturing process, including hardening precise internal locations of the metal articles. The present disclosure also relates to case-hardening precise surface locations of metal articles and providing a precise hardening depth limited only by the size of the metal article. Various techniques for switching between a reactive atmosphere for hardening portions of the metal article and a non-reactive atmosphere during which portions of the metal article are not hardened are also contemplated. In addition, various techniques for controlling material handling, energy sources, reactive gases, and non-reactive gases are also contemplated. Background Art

[0002] Current surface hardening methods that change the surface composition require heat treatment of the equipment and extensive pre- and post-conditioning of the parts. Titanium alloys have not yet developed an effective surface hardening process to replace steel in many product applications. Existing surface hardening technology for titanium has limitations related to the depth of the surface hardened layer and the location of the surface hardening on the part. Existing surface hardening technology is a furnace-based surface hardening process that requires a long duration in the furnace at high temperatures, which can produce undesirable grain growth in the alloy and the risk of part deformation due to long exposure to process temperatures.

[0003] Current additive manufacturing technology does not include a gas control system for precisely defining the hardening gas composition at the melt pool. Current equipment does not allow for the presence of multiple partial pressures of gases in the build chamber. Therefore, existing equipment does not allow for a reliable strengthening method.

[0004] Accordingly, those skilled in the art continue to engage in research and development efforts to improve techniques for precisely hardening metal articles during additive manufacturing processes. Summary of the invention

[0005] Methods for hardening selected portions of metal articles, additive manufacturing systems for hardening selected portions of metal articles, and examples of metal articles are disclosed. For example, a metal article with a selected portion hardened can be constructed in its entirety using additive manufacturing, or an existing metal article manufactured using other techniques can have hardening material selectively added using additive manufacturing. The following is a non-exhaustive list of examples of subject matter according to the present disclosure that may or may not be claimed.

[0006] In one example, a disclosed method for hardening a selected portion of a metal article includes: (1) establishing a non-reactive atmosphere within a build chamber of an additive manufacturing system; (2) using an energy source to melt a metal material to deposit the molten material in a plurality of layers, thereby building the metal article in combination with controlling translation of at least one of the metal article and the energy source based on a predetermined position of deposition of the molten material; and (3) selectively establishing a reactive atmosphere within the build chamber, the reactive atmosphere causing a chemical reaction to harden at least one selected portion of each of a plurality of selected layers of the plurality of layers in combination with the melting and subsequent solidification of the molten material.

[0007] In one example, the disclosed additive manufacturing system for hardening a selected portion of a metal article includes a build chamber, a material handling assembly, a substrate, an energy source assembly, a translation assembly, and a system control assembly. The build chamber is configured to provide a controlled environment for additive manufacturing of the metal article. The material handling assembly is configured to supply metal material into the build chamber in conjunction with an additive manufacturing process. The substrate is configured to at least temporarily hold the metal article during the additive manufacturing process. The energy source assembly is configured to use an energy source to melt the metal material to deposit the molten material in multiple layers, thereby building the metal article on the substrate. The translation assembly is configured to provide translational movement of at least one of the substrate and the energy source assembly based on a predetermined position of deposition of the molten material in conjunction with the additive manufacturing process. The system control assembly is in operative communication with the material handling assembly, the energy source assembly, and the translation assembly. The system control assembly is configured to control establishment of a non-reactive atmosphere within the build chamber, configured to control supply of the metallic material by the material handling assembly, configured to control melting of the metallic material by the energy source in conjunction with controlling the translation assembly, and configured to control selective establishment of a reactive atmosphere within the build chamber so as to induce a chemical reaction to harden at least a selected portion of each of a plurality of selected layers of the plurality of layers in conjunction with the melting and subsequent solidification of the molten material.

[0008] In one example, a disclosed metal article includes a plurality of layers of metallic material deposited in layers via an additive manufacturing process. At least a selected portion of each of a plurality of selected layers of the plurality of layers is hardened via a chemical reaction caused by a reactive atmosphere selectively established during a selected period of the additive manufacturing process. The remaining portions of the plurality of selected layers and the remaining layers of the plurality of layers are deposited during a remaining period of the additive manufacturing process in which a non-reactive atmosphere is established.

[0009] Clause 1. A method according to one example, wherein the translational movement of the metal article (200) and / or the energy source (1216) includes control of angular movement relative to at least one of the X-axis, the Y-axis, and the Z-axis.

[0010] Clause 2. The method according to an example, wherein the predetermined location for depositing the molten material is based on a three-dimensional digital model (1232) of the metal article (200).

[0011] Clause 3. The method according to one example, wherein the reaction atmosphere (1230) comprises a predetermined reaction gas mixture (1227) of at least one inert gas (1220) and at least one reaction gas (1224).

[0012] Clause 4. The method of clause 3, wherein the chemical reaction comprises nitridation.

[0013] Clause 5. The method of clause 4, wherein the at least one reactive gas (1224) comprises at least one of nitrogen, a nitrogen-based gas, and ammonia.

[0014] Clause 6. The method of Clause 3, wherein the chemical reaction comprises carburizing.

[0015] Clause 7. The method according to clause 6, wherein the at least one reaction gas (1224) comprises at least one of a carbon-based gas, acetylene gas, propane gas, butane gas, methane gas, and carbon monoxide gas.

[0016] Clause 8. The method according to one example, wherein each selected portion (204) of the metal article (200) that is hardened is based on a corresponding location in the three-dimensional digital model (1232) of the metal article (200) that is designated for hardening.

[0017] Clause 9. The method according to one example, wherein the at least one selected portion (204) of each of a plurality of selected layers (206) of the metal article (200) that is hardened includes one or more regions where portions of consecutive layers are hardened.

[0018] Item 10. A method according to Item 9, wherein the portion of the continuous layer that is hardened includes at least one portion whose hardening depth ranges from at least one of about 0.0001 inches, about 0.002 inches, about 0.004 inches, about 0.006 inches, about 0.008 inches, about 0.010 inches, about 0.020 inches, about 0.030 inches and about 0.040 inches to a depth through the metal article (200).

[0019] Clause 11. The method of Clause 9, wherein the one or more regions include at least one region located within the interior of the metal article (200), the region not extending to an exterior surface of the metal article (200).

[0020] Clause 12. The method of Clause 9, wherein the one or more regions include at least one region extending from a first layer to a continuous layer of the metal article (200).

[0021] Clause 13. The method of clause 9, wherein the one or more regions include at least one region extending from an inner layer of the metal article (200) to an outer surface of the metal article (200), such that a portion of the metal article (200) is surface hardened.

[0022] Clause 14. The method of clause 13, wherein the portion of the metal article (200) that is surface hardened includes at least one portion having a surface hardening depth greater than at least one of about 0.0001 inches, about 0.001 inches, about 0.010 inches, about 0.020 inches, about 0.030 inches, and about 0.040 inches.

[0023] Clause 15. The method according to an example, wherein the selective establishing (106) of the reactive atmosphere (1230) precedes the establishing (102) of the non-reactive atmosphere (1228).

[0024] Item 16. A method according to one example, wherein the establishing (102) of the non-reactive atmosphere (1228) and the selective establishing (106) of the reactive atmosphere (1230) are repeated during the melting (104) of the metal material (1208) to deposit molten material in the multiple layers (202) until the metal product (200) is completed.

[0025] Clause 17. A method according to an example, further comprising:

[0026] receiving (302) at least one inert gas (1220) from at least one first gas supply (1222); and

[0027] The at least one inert gas (1220) is delivered (304) to the build chamber (1202) to establish the non-reactive atmosphere (1228).

[0028] Clause 18. The method according to clause 17, further comprising:

[0029] An outlet path (1236) from the build chamber (1202) is opened (306) to purge gaseous contents (1238) of the build chamber (1202) in conjunction with delivering the at least one inert gas (1220) to the build chamber (1202).

[0030] Clause 19. The method of Clause 18, wherein the gaseous contents (1238) purged from the build chamber (1202) include at least one of air, one or more reactive gases, and one or more inert gases.

[0031] Clause 20. The method of clause 18, wherein the outlet path (1236) from the build chamber (1202) remains open during the additive manufacturing process to enable the at least one inert gas (1220) to flow continuously to the build chamber (1202).

[0032] Clause 21. The method according to clause 18, further comprising:

[0033] The exit path (1236) is directed (402) to be proximate to the molten material as the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer, thereby facilitating the removal of any reactive gas (1224) present near the molten material.

[0034] Clause 22. The method according to clause 18, further comprising:

[0035] A vacuum is applied (404) to the outlet path (1236) of the build chamber (1202) to assist in purging the gaseous contents (1238) of the build chamber (1202).

[0036] Clause 23. The method according to clause 22, further comprising:

[0037] The vacuum on the outlet path (1236) of the build chamber (1202) is stopped (406) after a predetermined time based on an expected completion of the purge.

[0038] Clause 24. The method according to clause 18, further comprising:

[0039] The exit path (1236) from the build chamber (1202) is closed (408) after a predetermined time to seal the build chamber (1202) during the additive manufacturing process.

[0040] Clause 25. According to an example method, the melting (104) of the metal material (1208) comprises:

[0041] A molten pool is formed (502) as the molten material is deposited on a substrate (1212) or on the metal article (200) to form a current layer.

[0042] Clause 26. The method of Clause 25, wherein at least one parameter of the molten pool is controlled to manage the chemical reaction that hardens the at least one selected portion (204) of the plurality of selected layers (206) of the metal article (200).

[0043] Clause 27. The method of Clause 26, wherein the at least one parameter of the molten pool includes at least one of metal pool size, metal pool temperature, and a transition time from molten material to solidification.

[0044] Clause 28. A method according to an example, further comprising:

[0045] receiving (602) at least one inert gas (1220) from at least one first gas supply (1222) and receiving at least one reactive gas (1224) from at least one second gas supply (1226); and

[0046] The at least one inert gas (1220) and the at least one reactive gas (1224) are delivered (604) to the build chamber (1202) to establish the reactive atmosphere (1230).

[0047] Clause 29. The method according to clause 28, further comprising:

[0048] When the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer, the at least one inert gas (1220) and the at least one reactive gas (1224) are directed (606) to a location within the build chamber (1202) proximate to the molten material.

[0049] Clause 30. The method according to clause 28, further comprising:

[0050] mixing (702) the at least one inert gas (1220) from the at least one first gas supply (1222) with the at least one reactive gas (1224) from the at least one second gas supply (1226) to form a predetermined reactive gas mixture (1227); and

[0051] The predetermined reaction gas mixture (1227) is delivered (704) to the build chamber (1202) to establish the reaction atmosphere (1230).

[0052] Clause 31. The method according to clause 30, further comprising:

[0053] The predetermined reaction gas mixture (1227) is directed (706) into the build chamber (1202) near the molten material as the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer.

[0054] Clause 32. The method according to clause 28, further comprising:

[0055] An outlet path (1236) from the build chamber (1202) is opened (802) to purge gaseous contents (1238) of the build chamber (1202) in conjunction with delivering the at least one inert gas (1220) and at least one reactive gas (1224) to the build chamber (1202).

[0056] Item 33. A method according to Item 32, wherein the outlet path (1236) from the build chamber (1202) remains open during the additive manufacturing process to enable the at least one inert gas (1220) and the at least one reactive gas (1224) to flow continuously to the build chamber (1202).

[0057] Clause 34. A method according to an example, further comprising:

[0058] receiving (902) at least one predetermined reactant gas mixture (1227) from at least one mixed gas supply (1229); and

[0059] The at least one predetermined reactive gas mixture (1227) is delivered (904) to the build chamber (1202) to establish the reactive atmosphere (1230).

[0060] Clause 35. The method according to clause 34, further comprising:

[0061] When the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer, the at least one predetermined reactive gas mixture (1227) is directed (906) to a location within the build chamber (1202) proximate to the molten material.

[0062] Clause 36. The method according to clause 34, further comprising:

[0063] An outlet path (1236) from the build chamber (1202) is opened (908) to purge gaseous contents (1238) of the build chamber (1202) in conjunction with delivering the at least one predetermined reactive gas mixture (1227) to the build chamber (1202).

[0064] Clause 37. A method according to clause 36, wherein the outlet path (1236) from the build chamber (1202) remains open during the additive manufacturing process to enable one or more of the at least one inert gas (1220) and the at least one predetermined reactive gas mixture (1227) to flow continuously to the build chamber (1202).

[0065] Clause 38. A method according to an example, further comprising:

[0066] Alternating (1002) between the establishment (102) of the non-reactive atmosphere (1228) and the selective establishment (106) of the reactive atmosphere (1230) during the melting (104) of the metal material (1208) so as to deposit unhardened molten material during the period of the non-reactive atmosphere (1228) and to deposit hardened molten material during the period of the reactive atmosphere (1230), so that the metal article (200) includes a first region in which at least some portions of the continuous layer are hardened and a second region in which at least other portions of the continuous layer are not hardened.

[0067] Item 39. A method according to Item 38, wherein the melting (104) of the metal material (1208) for depositing the molten material in the multiple layers (202) to construct the metal product (200), and the translational movement of the metal product (200) and / or the energy source (1216) are paused at a selected position, wherein there is a predetermined transition from the non-reactive atmosphere (1228) to the reactive atmosphere (1230), and vice versa.

[0068] Clause 40. The method of Clause 39, wherein the selected position and the predetermined transition are based on a three-dimensional digital model (1232) of the metal article (200) designated for hardening.

[0069] Clause 41. A method according to an example, further comprising:

[0070] heat treating (1102) the metal article (200) after completing the additive manufacturing process to optimize the hardening of the selected portion of the metal article that hardened during the additive manufacturing process; and

[0071] The metal article (200) is machined (1104) to produce a smooth finish on the metal article (200).

[0072] Clause 42. An additive manufacturing system (1200) for hardening a selected portion of a metal article (200), the additive manufacturing system comprising:

[0073] a build chamber (1202) configured to provide a controlled environment (1204) for additive manufacturing of the metal article (200);

[0074] a material handling assembly (1206) configured to supply a metal material (1208) into the build chamber (1202) in conjunction with an additive manufacturing process;

[0075] a substrate (1212) configured to at least temporarily hold the metal article (200) during the additive manufacturing process;

[0076] an energy source assembly (1214) configured to use an energy source (1216) to melt the metal material (1208) to deposit the molten material in a plurality of layers (202) to build the metal article (200) on the substrate (1212);

[0077] a translation assembly (1210) configured to provide translational movement of at least one of the substrate (1212) and the energy source assembly (1214) based on a predetermined location of deposition of the molten material in conjunction with the additive manufacturing process; and

[0078] A system control assembly (1218) operably communicating with the material handling assembly (1206), the energy source assembly (1214), and the translation assembly (1210), the system control assembly (1218) being configured to control the establishment of a non-reactive atmosphere (1228) within the build chamber (1202), to control the supply of the metal material (1208) through the material handling assembly (1206), to control the melting (104) of the metal material (1208) through the energy source (1216) in combination with controlling the translation assembly (1210), and to control the selective establishment of a reactive atmosphere (1230) within the build chamber (1202) so as to cause a chemical reaction to harden at least a selected portion (204) of each of a plurality of selected layers (206) of the plurality of layers (202) in combination with the melting (104) and subsequent solidification of the molten material.

[0079] Clause 43. The additive manufacturing system of clause 42, wherein the non-reactive atmosphere (1228) comprises at least one inert gas (1220).

[0080] Clause 44. The additive manufacturing system of clause 43, wherein the at least one inert gas (1220) comprises at least one of argon, helium, neon, and nitrogen.

[0081] Clause 45. The additive manufacturing system of clause 42, wherein with respect to the additive manufacturing process, the metal material (1208) comprises at least one of a metal powder and a metal wire.

[0082] Clause 46. The additive manufacturing system of clause 42, wherein the metallic material (1208) comprises at least one of titanium, a titanium alloy, steel, corrosion resistant steel, precipitation hardened corrosion resistant steel, maraging steel, and an iron-steel alloy.

[0083] Clause 47. The additive manufacturing system of clause 42, wherein the energy source (1216) comprises one or more of at least one laser beam, at least one electron beam, and at least one plasma arc.

[0084] Clause 48. An additive manufacturing system according to clause 42, wherein the system control component (1218) is configured to control at least one parameter of the energy source (1216) and the translation component (1210) to manage the chemical reaction that hardens at least one selected portion (204) of the multiple selected layers (206) of the metal article (200).

[0085] Clause 49. An additive manufacturing system according to clause 48, wherein the at least one parameter of the energy source (1216) and the translation assembly (1210) includes at least one of the following: an energy source residence time at a selected predetermined position associated with hardening of at least one selected portion (204) of each of the multiple selected layers (206) of the metal article (200), a laser deposition residence time associated with the energy source (1216), a plasma arc residence time associated with the energy source (1216), and an electron beam residence time associated with the energy source (1216).

[0086] Clause 50. An additive manufacturing system according to clause 42, wherein the system control component (1218) is configured to control the translation component (1210) with respect to linear movement of the metal article (200) along at least one of an X-axis, a Y-axis, and a Z-axis.

[0087] Clause 51. An additive manufacturing system according to clause 50, wherein the system control component (1218) is configured to control the translation component (1210) with respect to rotational movement of the metal article (200) relative to at least one of the X-axis, the Y-axis, and the Z-axis.

[0088] Clause 52. An additive manufacturing system according to clause 50, wherein the system control component (1218) is configured to control the translation component (1210) with respect to angular movement of the metal article (200) relative to at least one of the X-axis, the Y-axis, and the Z-axis.

[0089] Clause 53. An additive manufacturing system according to clause 42, wherein the system control component (1218) is configured to store or access a three-dimensional digital model (1232) of the metal product (200), and the predetermined position of deposition of the molten material is based on the three-dimensional digital model.

[0090] Clause 54. The additive manufacturing system of clause 42, wherein the reaction atmosphere (1230) comprises a predetermined reaction gas mixture (1227) of at least one inert gas (1220) and at least one reaction gas (1224).

[0091] Clause 55. An additive manufacturing system according to clause 54, wherein the chemical reaction includes nitridation.

[0092] Clause 56. The additive manufacturing system of clause 55, wherein the at least one reactive gas (1224) comprises at least one of nitrogen, a nitrogen-based gas, and ammonia.

[0093] Clause 57. The additive manufacturing system of clause 54, wherein the chemical reaction comprises carburizing.

[0094] Clause 58. An additive manufacturing system according to clause 57, wherein the at least one reaction gas (1224) includes at least one of a carbon-based gas, acetylene gas, propane gas, butane gas, methane gas, and carbon monoxide gas.

[0095] Clause 59. An additive manufacturing system according to clause 42, wherein the system control component (1218) is configured to store or access a three-dimensional digital model (1232) of the metal product (200), and each selected portion (204) of the metal product (200) to be hardened at a corresponding position designated for hardening is based on the three-dimensional digital model.

[0096] Clause 60. An additive manufacturing system according to clause 42, wherein the at least one selected portion (204) of each of a plurality of selected layers (206) of the metal article (200) that is hardened includes one or more regions where portions of consecutive layers are hardened.

[0097] Item 61. An additive manufacturing system according to Item 60, wherein the portion of the continuous layer that is hardened includes at least one portion having a hardening depth ranging from at least one of about 0.0001 inches, about 0.002 inches, about 0.004 inches, about 0.006 inches, about 0.008 inches, about 0.010 inches, about 0.020 inches, about 0.030 inches, and about 0.040 inches to a depth through the metal article (200).

[0098] Clause 62. An additive manufacturing system according to Clause 60, wherein the one or more regions include at least one region located within the interior of the metal article (200), the region not extending to the outer surface of the metal article (200).

[0099] Clause 63. The additive manufacturing system of clause 60, wherein the one or more regions include at least one region extending from a first layer to a successive layer of the metal article (200).

[0100] Clause 64. An additive manufacturing system according to Clause 60, wherein the one or more regions include at least one region extending from an inner layer of the metal article (200) to an outer surface of the metal article (200), so that a portion of the metal article (200) is surface hardened.

[0101] Clause 65. An additive manufacturing system according to clause 64, wherein the portion of the metal article (200) that is surface hardened includes at least one portion having a surface hardening depth greater than at least one of approximately 0.0001 inches, approximately 0.001 inches, approximately 0.010 inches, approximately 0.020 inches, approximately 0.030 inches, and approximately 0.040 inches.

[0102] Clause 66. An additive manufacturing system according to clause 42, wherein the system control component (1218) is configured to initiate the additive manufacturing process by selectively establishing (106) the reactive atmosphere (1230) before establishing (102) the non-reactive atmosphere (1228).

[0103] Clause 67. An additive manufacturing system according to clause 42, wherein the system control component (1218) is configured to repeat the establishment (102) of the non-reactive atmosphere (1228) and the selective establishment (106) of the reactive atmosphere (1230) during the melting (104) of the metal material (1208) to deposit molten material in the multiple layers (202) until the metal product (200) is completed.

[0104] Clause 68. The additive manufacturing system of clause 42, wherein the system control component (1218) comprises:

[0105] A gas manifold assembly (1302), the gas manifold assembly comprising at least one inert gas inlet (1304) and at least one inert gas outlet (1306), the at least one inert gas inlet (1304) being configured to receive at least one inert gas (1220) from at least one first gas supply (1222) at a first inert gas inlet (1308), the gas manifold assembly (1302) being configured to direct the first inert gas inlet (1308) to a first inert gas outlet (1310), the gas manifold assembly (1302) being configured to provide the at least one inert gas (1220) to the build chamber (1202) via the first inert gas outlet (1310) to establish the non-reactive atmosphere (1228).

[0106] Clause 69. The additive manufacturing system of clause 68, wherein the build chamber (1202) comprises:

[0107] An outlet port (1234) configured to open an outlet path (1236) from the build chamber (1202) to purge gaseous contents (1238) of the build chamber (1202) in conjunction with delivering the at least one inert gas (1220) to the build chamber (1202).

[0108] Clause 70. The additive manufacturing system of clause 69, wherein the build chamber (1202) further comprises:

[0109] An exhaust conduit (1240) coupled to the outlet port (1234) and configured to direct the outlet path (1236) close to the molten material when the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer, thereby facilitating the removal of any reactive gas (1224) present near the molten material.

[0110] Clause 71. An additive manufacturing system according to clause 69, wherein the gaseous contents (1238) purged from the build chamber (1202) include at least one of air, one or more reactive gases, and one or more inert gases.

[0111] Clause 72. An additive manufacturing system according to clause 69, wherein the outlet port (1234) is configured to remain open during the additive manufacturing process so that the outlet path (1236) remains open to enable the at least one inert gas (1220) to flow continuously to the build chamber (1202).

[0112] Clause 73. The additive manufacturing system of clause 69, further comprising:

[0113] A vacuum pump (1242) is coupled to the outlet port (1234) of the build chamber (1202) and is configured to apply a vacuum to the outlet path (1236) to assist in purging the gaseous contents (1238) of the build chamber (1202).

[0114] Clause 74. An additive manufacturing system according to clause 73, wherein the vacuum pump (1242) is configured to stop the vacuum on the outlet path (1236) of the build chamber (1202) after a predetermined time based on an expected completion of the purge.

[0115] Clause 75. An additive manufacturing system according to clause 69, wherein the outlet port (1234) is configured to close the outlet path (1236) from the build chamber (1202) after a predetermined time to seal the build chamber (1202) during the additive manufacturing process.

[0116] Item 76. An additive manufacturing system according to Item 68, wherein the gas manifold assembly (1302) also includes at least one reaction gas inlet (1312) and at least one reaction gas outlet (1314), the at least one reaction gas inlet (1312) is configured to receive the at least one reaction gas (1224) from the at least one second gas supply (1226) at a first reaction gas inlet (1316), the gas manifold assembly (1302) is configured to guide the first reaction gas inlet (1316) to a first reaction gas outlet (1318), and the gas manifold assembly (1302) is configured to deliver the at least one reaction gas (1224) to the build chamber (1202) via the first reaction gas outlet (1318) to establish the reaction atmosphere (1228).

[0117] Clause 77. The additive manufacturing system of clause 76, wherein the build chamber (1202) comprises:

[0118] At least one supply conduit (1244), the at least one supply conduit being coupled to the first reaction gas outlet (1318) of the manifold assembly (1302), the at least one supply conduit (1244) being configured to direct the at least one inert gas (1220) and the at least one reaction gas (1224) to a position within the build chamber (1202) proximate to the molten material when the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer.

[0119] Clause 78. The additive manufacturing system of clause 76, wherein the build chamber (1202) comprises:

[0120] An outlet port (1234) configured to open an outlet path (1236) from the build chamber (1202) to purge the gaseous contents (1238) of the build chamber (1202) in conjunction with delivering the at least one inert gas (1220) and the at least one reactive gas (1224) to the build chamber (1202).

[0121] Item 79. An additive manufacturing system according to Item 78, wherein the outlet port (1234) is configured to remain open during the additive manufacturing process so that the outlet path (1236) remains open to enable the at least one inert gas (1220) and the at least one reactive gas (1224) to flow continuously to the build chamber (1202).

[0122] Clause 80. An additive manufacturing system according to clause 76, wherein the gas manifold assembly (1302) further comprises at least one reactive gas inlet (1312) and at least one reactive gas mixture outlet (1320), the at least one inert gas inlet (1304) being configured to receive the at least one inert gas (1220) at a second inert gas inlet (1322), the at least one reactive gas inlet (1312) being configured to receive the at least one reactive gas (1224) at a second reactive gas inlet (1324), and the gas manifold assembly (1302) being configured to mix the at least one reactive gas (1220) at the second inert gas inlet (1324). The at least one inert gas (1220) received at the first reaction gas inlet (1322) and the at least one reaction gas (1224) received at the second reaction gas inlet (1324) are combined to form a predetermined reaction gas mixture (1227), the gas manifold assembly (1302) is configured to guide the predetermined reaction gas mixture (1227) to the first reaction gas mixture outlet (1326), and the gas manifold assembly (1302) is configured to convey the predetermined reaction gas mixture (1227) to the construction chamber (1202) via the first reaction gas mixture outlet (1326) to establish the reaction atmosphere (1230).

[0123] Clause 81. The additive manufacturing system of clause 80, wherein the build chamber (1202) comprises:

[0124] At least one supply conduit (1244), the at least one supply conduit coupled to the first reaction gas mixture outlet (1326) of the manifold assembly (1302), the at least one supply conduit (1244) being configured to direct the predetermined reaction gas mixture (1227) to a position within the build chamber (1202) near the molten material when the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer.

[0125] Clause 82. The additive manufacturing system of clause 80, wherein the build chamber (1202) comprises:

[0126] An outlet port (1234) configured to open an outlet path (1236) from the build chamber (1202) to purge the gaseous contents (1238) of the build chamber (1202) in conjunction with delivering the at least one inert gas (1220) and the at least one reactive gas (1224) to the build chamber (1202).

[0127] Item 83. An additive manufacturing system according to item 82, wherein the outlet port (1234) is configured to remain open during the additive manufacturing process so that the outlet path (1236) remains open to enable the at least one inert gas (1220) and the at least one reactive gas (1224) to flow continuously to the build chamber (1202).

[0128] Item 84. An additive manufacturing system according to Item 68, wherein the gas manifold assembly (1302) also includes at least one reaction gas mixture inlet (1328) and at least one reaction gas mixture outlet (1320), the at least one reaction gas mixture inlet (1328) being configured to receive a predetermined reaction gas mixture (1227) at a first reaction gas mixture inlet (1330), the gas manifold assembly (1302) being configured to guide the predetermined reaction gas mixture (1227) to a second reaction gas mixture outlet (1332), and the gas manifold assembly (1302) being configured to deliver the predetermined reaction gas mixture (1227) to the build chamber (1202) via the second reaction gas mixture outlet (1332) to establish the reaction atmosphere (1230).

[0129] Clause 85. The additive manufacturing system of clause 84, wherein the build chamber (1202) comprises:

[0130] At least one supply conduit (1244), coupled to the second reaction gas mixture outlet (1332) of the manifold assembly (1302), and the at least one supply conduit (1244) is configured to direct the at least one predetermined reaction gas mixture (1227) to a position within the build chamber (1202) near the molten material when the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer.

[0131] Clause 86. The additive manufacturing system of clause 84, wherein the build chamber (1202) comprises:

[0132] An outlet port (1234) configured to open an outlet path (1236) from the build chamber (1202) to purge gaseous contents (1238) of the build chamber (1202) in conjunction with delivering the at least one predetermined reactant gas mixture (1227) to the build chamber (1202).

[0133] Item 87. An additive manufacturing system according to item 86, wherein the outlet port (1234) is configured to remain open during the additive manufacturing process so that the outlet path (1236) remains open to enable one or more of the at least one inert gas (1220) and the at least one predetermined reactive gas mixture (1227) to flow continuously to the build chamber (1202).

[0134] Clause 88. An additive manufacturing system according to clause 42, wherein the energy source (1216) is configured to form a molten pool in combination with the melting (104) of the metal material (1208) when the molten material is deposited on the substrate (1212) or on the metal article (200) to form a current layer.

[0135] Clause 89. An additive manufacturing system according to clause 88, wherein the system control component (1218) is configured to control at least one parameter of the molten pool to manage the chemical reaction that hardens at least one selected portion (204) of the multiple selected layers (206) of the metal article (200).

[0136] Clause 90. The additive manufacturing system of clause 89, wherein the at least one parameter of the molten pool comprises at least one of metal pool size, metal pool temperature, and a transition time from molten material to solidification.

[0137] Clause 91. An additive manufacturing system according to clause 42, wherein the system control component (1218) is configured to alternate between the establishment (102) of the non-reactive atmosphere (1228) and the establishment (102) of the reactive atmosphere (1230) during the melting (104) of the metal material (1208) so as to deposit unhardened molten material during the period of the non-reactive atmosphere (1228) and to deposit hardened molten material during the period of the reactive atmosphere (1230), so that the metal article (200) includes a first region in which at least some portions of the continuous layer are hardened and a second region in which at least other portions of the continuous layer are not hardened.

[0138] Item 92. An additive manufacturing system according to Item 91, wherein the system control component (1218) is configured to pause the melting (104) of the metal material (1208) for depositing molten material in the multiple layers (202) to construct the metal article (200) and the translation movement provided by the translation component (1210) at a selected position, wherein there is a predetermined transition from the non-reactive atmosphere (1228) to the reactive atmosphere (1230) and vice versa.

[0139] Item 93. An additive manufacturing system according to Item 92, wherein the system control component (1218) is configured to store or access a three-dimensional digital model (1232) of the metal product (200), based on which the selected position and the predetermined transition are based on corresponding positions designated for hardening.

[0140] Clause 94. A metal product (200) comprising:

[0141] a plurality of layers (202) of metallic material (1208) deposited via an additive manufacturing process, at least one selected portion (204) of each of a plurality of selected layers (206) of the plurality of layers (202) being hardened via a chemical reaction caused by a reactive atmosphere (1230) selectively established during a selected period of the additive manufacturing process, and

[0142] The remaining portions (208) of the plurality of selected layers (206) and the remaining layers (210) of the plurality of layers (202) are deposited during a remaining period of the additive manufacturing process in which a non-reactive atmosphere (1228) is established.

[0143] Clause 95. The metal article of Clause 94, wherein the non-reactive atmosphere (1228) comprises at least one inert gas (1220).

[0144] Clause 96. The metal article of clause 94, wherein with respect to the additive manufacturing process, the metal material (1208) comprises at least one of a metal powder and a metal wire.

[0145] Clause 97. The metal article of clause 94, wherein the metal material (1208) comprises at least one of titanium, a titanium alloy, steel, a corrosion resistant steel, a precipitation hardened corrosion resistant steel, a maraging steel, and an iron steel alloy.

[0146] Clause 98. The metal article of clause 94, wherein the reaction atmosphere (1230) comprises a predetermined reaction gas mixture (1227) of at least one inert gas (1220) and at least one reaction gas (1224).

[0147] Clause 99. The metal article of Clause 98, wherein the at least one inert gas (1220) comprises at least one of argon, helium, neon, and nitrogen.

[0148] Clause 100. The metal article of Clause 98, wherein the chemical reaction comprises nitriding.

[0149] Clause 101. The metal article of clause 100, wherein the at least one reactive gas (1224) comprises at least one of nitrogen, a nitrogen-based gas, and ammonia.

[0150] Clause 102. The metal article of Clause 98, wherein the chemical reaction comprises carburizing.

[0151] Clause 103. The metal article of clause 102, wherein the at least one reactive gas (1224) comprises at least one of a carbon-based gas, acetylene gas, propane gas, butane gas, methane gas, and carbon monoxide gas.

[0152] Clause 104. The metal article of clause 94, wherein each selected portion (204) of the metal article (200) that is hardened is based on a corresponding location in the three-dimensional digital model (1232) of the metal article (200) that is designated for hardening.

[0153] Clause 105. The metal article of clause 94, wherein the plurality of layers (202) of the metal article (200) are arranged in alternating groups of the plurality of selected layers (206) having hardened and a plurality of remaining layers (210) having no hardening.

[0154] Clause 106. The metal article of clause 105, wherein the at least one selected portion (204) of each of the plurality of selected layers (206) having hardening is larger than other portions of the corresponding layer that are not hardened.

[0155] Clause 107. The metal article of clause 105, wherein the at least one selected portion (204) of each of the plurality of selected layers (206) having hardening comprises a corresponding layer and no portion of the corresponding layer is hardened.

[0156] Clause 108. The metal article of clause 94, wherein the at least one selected portion (204) of each of a plurality of selected layers (206) of the metal article (200) that is hardened comprises one or more regions where portions of a continuous layer are hardened.

[0157] Item 109. A metal article as described in Item 108, wherein the portion of the continuous layer that is hardened includes at least one portion whose hardening depth ranges from at least one of about 0.0001 inches, about 0.002 inches, about 0.004 inches, about 0.006 inches, about 0.008 inches, about 0.010 inches, about 0.020 inches, about 0.030 inches and about 0.040 inches to a depth through the metal article (200).

[0158] Clause 110. The metal article of clause 108, wherein the one or more regions include at least one region located within the interior of the metal article (200) that does not extend to an exterior surface of the metal article (200).

[0159] Clause 111. The metal article of Clause 108, wherein the one or more regions include at least one region extending from a first layer to a continuous layer of the metal article (200).

[0160] Clause 112. A metal product according to Clause 108, wherein the one or more regions include at least one region extending from an inner layer of the metal product (200) to an outer surface of the metal product (200), such that a portion of the metal product (200) is surface hardened.

[0161] Clause 113. A metal product according to Clause 112, wherein the portion of the metal product (200) that is surface hardened includes at least one portion having a surface hardening depth greater than at least one of about 0.0001 inches, about 0.001 inches, about 0.010 inches, about 0.020 inches, about 0.030 inches, and about 0.040 inches.

[0162] Item 114. A metal product according to Item 94, wherein in combination with the additive manufacturing process, the non-reactive atmosphere (1228) is established (102) and the reactive atmosphere (1230) is selectively established (106), which results in certain portions of the metal product (200) constructed during the period of the reactive atmosphere (1230) being hardened and other portions constructed during the period of the non-reactive atmosphere (1228) not being hardened, so that the metal product (200) includes a first region in which at least certain portions of a continuous layer are hardened and a second region in which at least other portions of the continuous layer are not hardened.

[0163] Other examples of the disclosed method for hardening a selected portion of a metal article, additive manufacturing system for hardening a selected portion of a metal article, and metal article will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0164] Figure 1 is a flow chart of an example of a method for hardening a selected portion of a metal article;

[0165] Figure 2 It is a functional layered diagram of an example of a metal product;

[0166] Figure 3 (and Figure 1 ) is a flow chart of another example of a method for hardening a selected portion of a metal article;

[0167] Figure 4 (and Figure 1 and Figure 3 ) is a flow chart of yet another example of a method for hardening a selected portion of a metal article;

[0168] Figure 5 (and Figure 1 ) is a flow chart of yet another example of a method for hardening a selected portion of a metal article;

[0169] Figure 6 (and Figure 1 ) is a flow chart of yet another example of a method for hardening a selected portion of a metal article;

[0170] Figure 7 (and Figure 1 and Figure 6 ) is a flow chart of another example of a method for hardening a selected portion of a metal article;

[0171] Figure 8 (and Figure 1 , Figure 4 and Figure 6) is a flow chart of yet another example of a method for hardening a selected portion of a metal article;

[0172] Fig. 9 (and Figure 1 and Figure 4 ) is a flow chart of yet another example of a method for hardening a selected portion of a metal article;

[0173] Fig.10 (and Figure 1 ) is a flow chart of yet another example of a method for hardening a selected portion of a metal article;

[0174] Fig.11 (and Figure 1 ) is a flow chart of another example of a method for hardening a selected portion of a metal article;

[0175] Fig.12 is a functional block diagram of an example of an additive manufacturing system for hardening a selected portion of a metal article;

[0176] Fig.13 is used for Fig.12 A functional block diagram of an example of a gas manifold assembly of an additive manufacturing system;

[0177] Fig.14 yes Fig.13 A functional block diagram of an example of a first configuration of a gas manifold assembly;

[0178] Fig.15 yes Fig.13 a functional block diagram of an example of a second configuration of a gas manifold assembly;

[0179] Fig.16 yes Fig.13 a functional block diagram of an example of a third configuration of a gas manifold assembly;

[0180] Fig.17 yes Fig.13 a functional block diagram of an example of a fourth configuration of a gas manifold assembly;

[0181] Fig.18 yes Fig.13 a functional block diagram of an example of a fifth configuration of a gas manifold assembly;

[0182] Fig.19 is used for Fig.12 A functional block diagram of an example of a build chamber of an additive manufacturing system;

[0183] Fig. 20 is a block diagram of the aircraft production and maintenance methodology; and

[0184] Fig.21 This is a schematic diagram of the aircraft. DETAILED DESCRIPTION

[0185] Overall reference Figures 1 to 12 By way of example, the present disclosure relates to methods 100 , 300 , 400 , 600 , 700 , 800 , 900 , 1000 , 1100 for hardening selected portions of a metal article 200 . Figure 1 An example of method 100 is disclosed. Figure 2 An example of a metal article 200 is disclosed. Figure 1 and Figure 3 An example of a method 300 is disclosed. Figure 1 , Figure 3 and Figure 4 An example of a method 400 is disclosed. Figure 5 An example of forming a molten pool is disclosed in connection with the method 100 . Figure 1 and Figure 6 An example of a method 600 is disclosed. Figure 1 , Figure 6 and Figure 7 An example of a method 700 is disclosed. Figure 1 , Figure 4 , Figure 6 and Figure 8 An example of a disclosure method 800 is disclosed. Figure 1 , Figure 4 and Fig. 9 An example of method 900 is disclosed. Figure 1 and Fig.10 An example of method 1000 is disclosed. Figure 1 and Fig.11 An example of method 1100 is disclosed. Fig.12 Various examples of additive manufacturing system 1200 are disclosed.

[0186] Reference again Figure 1 , Figure 2 and Fig.12In one or more examples, a method 100 for hardening a selected portion of a metal article 200 includes establishing 102 a non-reactive atmosphere 1228 within a build chamber 1202 of an additive manufacturing system 1200. At 104, a metal material 1208 is melted using an energy source 1216 to deposit the molten material in a plurality of layers 202, thereby building the metal article 200 in combination with controlling translational movement of at least one of the metal article 200 and the energy source 1216 based on a predetermined position of the molten material deposition. At 106, a reactive atmosphere 1230 is selectively established within the build chamber 1202, the reactive atmosphere causing a chemical reaction to harden at least one selected portion 204 of each of a plurality of selected layers 206 of the plurality of layers 202 in combination with melting 104 and subsequent solidification of the molten material. For example, a metal article with a selected portion hardened may be built in its entirety using additive manufacturing, or an existing metal article manufactured using other techniques may have hardened material selectively added using additive manufacturing. In other examples, a vacuum may be initially applied to establish a suitable environment.

[0187] In another example of the method 100, the non-reactive atmosphere 1228 includes at least one inert gas 1220. In another example, the at least one inert gas 1220 includes argon, helium, neon, nitrogen, or any other suitable inert gas in any suitable combination. For example, nitrogen can be used as a non-reactive gas or inert gas for certain metal materials. However, nitrogen can be a reactive gas for other metal materials (such as titanium). In another example of the method 100, with respect to the additive manufacturing process, the metal material 1208 includes metal powder, metal wire, or any other suitable metal material in any suitable combination. In another example of the method 100, the metal material 1208 includes titanium, titanium alloy, steel, corrosion-resistant steel, precipitation hardened corrosion-resistant steel, maraging steel, iron-steel alloy, or any other suitable metal material in any suitable combination. In another example of the method 100, the energy source 1216 includes at least one laser beam, at least one electron beam, at least one plasma arc, or any other suitable energy source in any suitable combination.

[0188] In various examples, the depth of a given layer in the plurality of layers 202 deposited during the additive manufacturing process ranges from about 0.0001 inches to about 0.001 inches, about 0.001 inches to about 0.002 inches, about 0.002 inches to about 0.004 inches, about 0.004 inches to about 0.010 inches, about 0.010 inches to about 0.020 inches, or any other suitable depth range for an additive manufacturing process. The minimum depth of a given layer is based on a minimum deposition thickness. The deposition thickness may be based on at least one of the metal material feedstock size and the energy provided to generate the molten pool. For example, an additive manufacturing energy source may be used for "smoothing" and, using a reactive atmosphere, a very thin hardened layer may be deposited on a metal article. In various other examples, the reactive atmosphere 1230 can include a mixture in which the reactive gas ranges from about 0.1% to about 50%, about 0.2% to about 40%, about 0.5% to about 30%, about 0.8% to about 20%, about 1.0% to about 10%, or any other suitable reactive gas percentage. For example, when a higher reactive gas percentage (e.g., greater than 50%) is appropriate for a given operation, a higher percentage is contemplated for the mixture.

[0189] In another example of the method 100, the translational movement of the metal article 200, the translational movement of the energy source 1216, the operation of the energy source 1216, or any other suitable parameter in any suitable combination is controlled to manage a chemical reaction that hardens at least one selected portion 204 of the plurality of selected layers 206 of the metal article 200. In another example, the energy source 1216 and at least one parameter of the translational movement of the metal article 200 and / or the energy source 1216 include an energy source dwell time at a selected predetermined location associated with hardening of at least one selected portion 204 of each of the plurality of selected layers 206 of the metal article 200, a laser deposition dwell time associated with the energy source 1216, a plasma arc dwell time associated with the energy source (1216), an electron beam dwell time associated with the energy source 1216, or any other suitable parameter in any suitable combination. The control of the translational movement, the operation of the energy source, and the corresponding parameters may be based on the three-dimensional digital model 1232 of the metal article 200.

[0190] In yet another example of the method 100, the translational movement of the metal article 200 and / or the energy source 1216 includes control of linear movement along at least one of the X-axis, the Y-axis, and the Z-axis. In yet another example, the translational movement of the metal article 200 and / or the energy source 1216 includes control of rotational movement relative to at least one of the X-axis, the Y-axis, and the Z-axis. In yet another example, the translational movement of the metal article 200 and / or the energy source 1216 includes control of angular movement relative to at least one of the X-axis, the Y-axis, and the Z-axis. In yet another example of the method 100, the predetermined position for depositing the molten material is based on the three-dimensional digital model 1232 of the metal article 200.

[0191] In another example of method 100, the reaction atmosphere 1230 includes a predetermined reaction gas mixture 1227 of at least one inert gas 1220 and at least one reaction gas 1224. In another example, the chemical reaction includes nitriding. In another example, at least one reaction gas 1224 includes nitrogen, nitrogen-based gas, ammonia or any other suitable reaction gas in any suitable combination. In another example, the chemical reaction includes carburizing. In another example, at least one reaction gas 1224 includes carbon-based gas, acetylene gas, propane gas, butane gas, methane gas, carbon monoxide gas or any other suitable reaction gas in any suitable combination. When the reaction gas or the byproduct of the chemical reaction produces a hazardous gas mixture, the process will be managed by using at least one of vacuum, partial pressure, inert gas purge and gas safety control system. In another example of method 100, each selected portion 204 of the hardened metal product 200 is based on the corresponding position designated for hardening in the three-dimensional digital model 1232 of the metal product 200.

[0192] In yet another example of method 100, at least one selected portion 204 of each of the plurality of selected layers 206 of the hardened metal article 200 includes one or more regions where a portion of a continuous layer is hardened. In another example, the portion of the continuous layer that is hardened includes at least one portion having a hardened depth ranging from about 0.0001 inches to a depth through the metal article 200, about 0.002 inches to a depth through the metal article 200, about 0.004 inches to a depth through the metal article 200, about 0.006 inches to a depth through the metal article 200, about 0.008 inches to a depth through the metal article 200, about 0.010 inches to a depth through the metal article 200, about 0.020 inches to a depth through the metal article 200, about 0.030 inches to a depth through the metal article 200, about 0.040 inches to a depth through the metal article 200, or any other suitable hardened depth range. In yet another example, the one or more regions include at least one region located inside the metal article 200 that does not extend to the outer surface of the metal article 200. In yet another example, the one or more regions include at least one region extending from the first layer of the metal article 200 to the continuous layer. As described above, the metal article 200 can be constructed with an intermittently hardened internal structure to accommodate any design requirements at the level of the deposited layer. For example, the metal article 200 may include an internal region that forms a metal matrix composite. In yet another example, the one or more regions include at least one region extending from the inner layer of the metal article 200 to the outer surface of the metal article 200, so that a portion of the metal article 200 is surface hardened. In yet another example, the surface hardened portion of the metal article 200 includes at least one portion whose surface hardening depth exceeds at least one of about 0.0001 inches, about 0.001 inches, about 0.010 inches, about 0.020 inches, about 0.030 inches, and about 0.040 inches, or any other suitable surface hardening depth.

[0193] In yet another example of the method 100, the selective establishment 106 of the reactive atmosphere 1230 precedes the establishment 102 of the non-reactive atmosphere 1228. In yet another example of the method 100, the establishment 102 of the non-reactive atmosphere 1228 and the selective establishment 106 of the reactive atmosphere 1230 are repeated during the melting 104 of the metal material 1208 to deposit the molten material in the plurality of layers 202 until the metal article 200 is completed.

[0194] Reference again Figures 1 to 3 and Fig.12 In one or more examples, the method 300 for hardening a selected portion of the metal article 200 further includes Figure 1Method 300 begins at 302, where at least one inert gas 1220 is received from at least one first gas supply 1222. At 304, at least one inert gas 1220 is delivered to build chamber 1202 to establish non-reactive atmosphere 1228. Method 300 continues from 304 to 102 of method 100.

[0195] In another example, method 300 continues from 302 to opening 306 an outlet path 1236 from build chamber 1202 to purge gaseous contents 1238 of build chamber 1202 in conjunction with delivering at least one inert gas 1220 to build chamber 1202. Method 300 continues from 306 to 102 of method 100.

[0196] In yet another example of method 300 , gaseous contents 1238 purged from build chamber 1202 include air, one or more reactive gases, one or more inert gases, or any other gas that may be present within build chamber 1202 , in any suitable combination.

[0197] In yet another example of method 300 , outlet path 1236 from build chamber 1202 remains open during the additive manufacturing process to enable at least one inert gas 1220 to flow continuously to build chamber 1202 .

[0198] Reference again Figures 1 to 4 and Fig.12 In one or more examples, the method 400 for hardening a selected portion of the metal article 200 further includes Figure 1 and Figure 3 Method 100, 300. Method 400 from Figure 3 306 continues to guide 402, where the exit path 1236 is directed to be close to the molten material when the molten material is deposited on the substrate 1212 or the metal article 200 to form the current layer, thereby facilitating the removal of any reactive gas 1224 present near the molten material. For example, the substrate 1212 can be a build plate. The method 400 continues from 402 to Figure 1 of 102.

[0199] In another example, method 400 again includes Figure 1 and Figure 3 In this example, the method 400 starts from Figure 3306 of the method 400 continues to applying 404 a vacuum to the outlet path 1236 of the build chamber 1202 to assist in the purging of the gaseous contents 1238 of the build chamber 1202. At 406, the vacuum on the outlet path 1236 of the build chamber 1202 is stopped after a predetermined time based on the expected completion of the purge. For example, the vacuum may be stopped by closing a valve at the outlet port 1234, the vacuum pump 1242, or anywhere in between. From 406, the method 400 continues to Figure 1 102. For example, a vacuum may be applied at different times to establish a suitable environment.

[0200] In another example, the method 400 further includes Figure 1 and Figure 3 In this example, the method 400 starts from Figure 3 306 continues to closing 408 the exit path 1236 from the build chamber 1202 after a predetermined time to seal the build chamber 1202 during the additive manufacturing process. Method 400 continues from 408 to Figure 1 of 102.

[0201] Reference again Figure 1 , Figure 2 , Figure 5 and Fig.12 In another example of method 100 , in one or more examples, melting 104 of metal material 1208 includes forming 502 a molten pool as the molten material is deposited on substrate 1212 or metal article 200 to form a current layer.

[0202] In yet another example of the method 100, at least one parameter of the molten pool is controlled to manage a chemical reaction that hardens at least one selected portion 204 of the plurality of selected layers 206 of the metal article 200. In another example, the at least one parameter of the molten pool includes a metal pool size, a metal pool temperature, a transition time from molten material to solidification, or any other suitable parameter. The operation of the energy source and the control of the corresponding parameters can be based on the three-dimensional digital model 1232 of the metal article 200.

[0203] Reference again Figure 1 , Figure 2 , Figure 6 and Fig.12 In one or more examples, the method 600 for hardening a selected portion of the metal article 200 further includes Figure 1 Method 100. Method 600 from Figure 1104 continues to 602, where at least one inert gas 1220 is received from at least one first gas supply 1222 and at least one reactive gas 1224 is received from at least one second gas supply 1226. At 604, at least one inert gas 1220 and at least one reactive gas 1224 are delivered to build chamber 1202 to establish reactive atmosphere 1230. Method 600 continues from 604 to Figure 1 of 106.

[0204] In another example, method 600 also includes directing 606 at least one inert gas 1220 and at least one reactive gas 1224 to a location within build chamber 1202 proximate to the molten material as the molten material is deposited on substrate 1212 or metal article 200 to form a current layer. For example, a dedicated nozzle or gas injector 1246 may be used to direct at least one inert gas 1220 and at least one reactive gas 1224 to a location proximate to the molten material. In this example, method 600 continues from 606 to Figure 1 of 106.

[0205] Reference again Figure 1 , Figure 2 , Figure 6 , Figure 7 and Fig.12 In one or more examples, a method 700 for hardening a selected portion of a metal article 200 includes: Figure 1 and Figure 6 Method 100, 600. Method 700 from Figure 6 602 continues to 702, where at least one inert gas 1220 from at least one first gas supply 1222 is mixed with at least one reactive gas 1224 from at least one second gas supply 1226 to form a predetermined reactive gas mixture 1227. At 704, the predetermined reactive gas mixture 1227 is delivered to the build chamber 1202 to establish a reactive atmosphere 1230. Method 700 continues from 704 to Figure 1 of 106.

[0206] In another example, method 700 also includes directing 706 a predetermined reaction gas mixture 1227 to a location within build chamber 1202 near the molten material as the molten material is deposited on substrate 1212 or metal article 200 to form the current layer. For example, a dedicated nozzle or gas injector 1246 may be used to direct the predetermined reaction gas mixture 1227 to a location near the molten material. In this example, the method continues from 706 to Figure 1 of 106.

[0207] Reference again Figure 1 , Figure 2 , Figure 4 , Figure 6 , Figure 8 and Fig.12 In one or more examples, a method 800 for hardening a selected portion of a metal article 200 includes: Figure 1 , Figure 4 and Figure 6 Methods 100, 400, 600. Method 800 from Figure 6 602 continues to 802, where an outlet path 1236 from the build chamber 1202 is opened to purge the gaseous contents 1238 of the build chamber 1202 in conjunction with delivering at least one inert gas 1220 and at least one reactive gas 1224 to the build chamber 1202. Method 800 continues from 802 to Figure 1 In yet another example of method 800, outlet path 1236 from build chamber 1202 remains open during the additive manufacturing process to enable at least one inert gas 1220 and at least one reactive gas 1224 to flow continuously to build chamber 1202. In yet another example, method 800 continues from 802 to Figure 4 404, where a vacuum is applied to the outlet path 1236. Then, at 406, the vacuum is stopped. For example, the vacuum may be stopped by closing a valve at the outlet port 1234, the vacuum pump 1242, or anywhere in between. In this example, the method 800 continues from 406 to Figure 1 In yet another example, method 800 continues from 802 to Figure 4 408, wherein the exit path 1236 is closed. In this example, the method 800 continues from 408 to Figure 1 of 106.

[0208] Reference again Figure 1 , Figure 2 , Figure 4 , Fig. 9 and Fig.12 In one or more examples, a method 900 for hardening a selected portion of a metal article 200 includes: Figure 1 and Figure 4 Method 100, 400. Method 800 from Figure 1 104 continues to 902, where at least one predetermined reaction gas mixture 1227 is received from at least one mixed gas supply source 1229. At 904, at least one predetermined reaction gas mixture 1227 is delivered to the build chamber 1202 to establish a reaction atmosphere 1230. Method 900 continues from 904 to Figure 1 of 106.

[0209] In another example, method 900 also includes directing 906 at least one predetermined reactive gas mixture 1227 to a location within build chamber 1202 proximate to the molten material as the molten material is deposited on substrate 1212 or metal article 200 to form the current layer. For example, a dedicated nozzle or gas injector 1246 may be used to direct at least one predetermined reactive gas mixture 1227 to a location proximate to the molten material. In this example, method 900 proceeds from 906 to Figure 1 of 106.

[0210] In another example, method 900 also includes opening 908 an outlet path 1236 from build chamber 1202 to purge gaseous contents 1238 of build chamber 1202 in conjunction with delivering at least one predetermined reactive gas mixture 1227 to build chamber 1202. In another example, outlet path 1236 from build chamber 1202 remains open during the additive manufacturing process to enable one or more of at least one inert gas 1220 and at least one predetermined reactive gas mixture 1227 to flow continuously to build chamber 1202. In yet another example, method 900 continues from 908 to Figure 4 404, where a vacuum is applied to the outlet path 1236. Then, at 406, the vacuum is stopped. For example, the vacuum may be stopped by closing a valve at the outlet port 1234, the vacuum pump 1242, or anywhere in between. In this example, the method 900 continues from 406 to Figure 1 In yet another example, method 900 continues from 908 to Figure 4 408, wherein the exit path 1236 is closed. In this example, the method 900 continues from 408 to Figure 1 of 106.

[0211] Reference again Figure 1 , Figure 2 , Fig.10 and Fig.12 In one or more examples, a method 1000 for hardening a selected portion of a metal article 200 includes: Figure 1 Method 100. Method 1000 from Figure 1106 continues to 1002 for alternating 1002 between establishing 102 a non-reactive atmosphere 1228 and selectively establishing 106 a reactive atmosphere 1230 during melting 104 of the metal material 1208 so as to deposit unhardened molten material during periods of the non-reactive atmosphere 1228 and to deposit hardened molten material during periods of the reactive atmosphere 1230 such that the metal article 200 includes a first region in which at least some portions of the continuous layer are hardened and a second region in which at least other portions of the continuous layer are not hardened. In other examples of the method 100, the alternating 1002 may be achieved by moving the metal article 200 from a first system dedicated to additive manufacturing using the non-reactive atmosphere 1228 to a second system dedicated to additive manufacturing using the reactive atmosphere 1230. The transition between the first system and the second system may be based on hardened and unhardened regions defined in the design of the metal article 200.

[0212] In another example of method 1000, melting 104 of metal material 1208 for depositing molten material in plurality of layers 202 to build metal article 200, and translational movement of metal article 200 and / or energy source 1216 are paused at a selected location where there is a predetermined transition from non-reactive atmosphere 1228 to reactive atmosphere 1230, or vice versa. In another example, the selected location and the predetermined transition are based on a three-dimensional digital model 1232 of metal article 200 designated for hardening.

[0213] Reference again Figure 1 , Figure 2 , Fig.11 and Fig.12 In one or more examples, a method 1100 for hardening a selected portion of a metal article 200 includes: Figure 1 Method 100. Method 1100 from Figure 1 106 continues to 1102 for heat treating the metal article 200 after the additive manufacturing process is completed to optimize the hardening of selected portions of the metal article that hardened during the additive manufacturing process. At 1104 , the metal article 200 is machined to produce a finish on the metal article 200 .

[0214] Overall reference by example Figure 1 , Figure 2 and Figures 12 to 19 , the present disclosure is directed to an additive manufacturing system 1200 for hardening selected portions of a metal article 200 . Figure 1 An example of a method 100 for hardening a selected portion of a metal article 200 is disclosed. Figure 2 An example of a metal article 200 is disclosed. Fig.12 Various examples of additive manufacturing system 1200 are disclosed. Fig.13Various examples of a gas manifold assembly 1302 for use with an additive manufacturing system 1200 are disclosed. Figures 14 to 18 Various examples of configurations of the gas manifold assembly 1302 are disclosed. Fig.19 Various examples of build chamber 1202 of additive manufacturing system 1200 are disclosed.

[0215] Reference again Figure 1 , Figure 2 and Fig.12 In one or more examples, an additive manufacturing system 1200 for hardening a selected portion of a metal article 200 includes a build chamber 1202, a material handling assembly 1206, a substrate 1212, an energy source assembly 1214, a translation assembly 1210, and a system control assembly 1218. The build chamber 1202 is configured to provide a controlled environment 1204 for additive manufacturing of the metal article 200. The material handling assembly 1206 is configured to supply a metal material 1208 to the interior of the build chamber 1202 in conjunction with an additive manufacturing process. The substrate 1212 is configured to at least temporarily hold the metal article 200 during the additive manufacturing process. For example, the substrate 1212 can be a build plate. The energy source assembly 1214 is configured to use an energy source 1216 to melt the metal material 1208 to deposit the molten material in a plurality of layers 202, thereby building the metal article 200 on the substrate 1212. Translation assembly 1210 is configured to provide translational movement of at least one of substrate 1212 and energy source assembly 1214 based on a predetermined position of deposition of molten material in conjunction with an additive manufacturing process. System control assembly 1218 is in operative communication with material handling assembly 1206, energy source assembly 1214, and translation assembly 1210. System control assembly 1218 is configured to control establishment of non-reactive atmosphere 1228 within build chamber 1202, to control supply of metallic material 1208 by material handling assembly 1206, to control melting 104 of metallic material 1208 by energy source 1216 in conjunction with controlling translation assembly 1210, and to control selective establishment of reactive atmosphere 1230 within build chamber 1202 to cause a chemical reaction to harden at least a selected portion 204 of each of a plurality of selected layers 206 of plurality of layers 202 in conjunction with melting 104 and subsequent solidification of the molten material. For example, a metal article with selected portions hardened may be constructed in its entirety using additive manufacturing, or an existing metal article manufactured using other techniques may have hardened material selectively added using additive manufacturing. In other examples, a vacuum may be initially applied to establish a suitable environment.

[0216] In another example of the additive manufacturing system 1200, the non-reactive atmosphere 1228 includes at least one inert gas 1220. In a further example, the at least one inert gas 1220 includes argon, helium, neon, nitrogen, or any other suitable inert gas in any suitable combination. For example, nitrogen can be used as a non-reactive gas or inert gas for certain metal materials. However, nitrogen can be a reactive gas for other metal materials (such as titanium). In another example of the additive manufacturing system 1200, with respect to the additive manufacturing process, the metal material 1208 includes metal powder, metal wire, or any other suitable metal material in any suitable combination. In another example of the additive manufacturing system 1200, the metal material 1208 includes titanium, titanium alloy, steel, corrosion-resistant steel, precipitation hardened corrosion-resistant steel, maraging steel, iron-steel alloy, or any other suitable metal material in any suitable combination. In another example of the additive manufacturing system 1200, the energy source 1216 includes at least one laser beam, at least one electron beam, at least one plasma arc, or any other suitable energy source in any suitable combination. In yet another example of the method 100 , the energy source 1216 includes at least one laser beam, at least one electron beam, at least one plasma arc, or any other suitable energy source in any suitable combination.

[0217] In various examples, the depth of a given layer in the plurality of layers 202 deposited during the additive manufacturing process ranges from about 0.0001 inches to about 0.001 inches, about 0.001 inches to about 0.002 inches, about 0.002 inches to about 0.004 inches, about 0.004 inches to about 0.010 inches, about 0.010 inches to about 0.020 inches, or any other suitable depth range for an additive manufacturing process. The minimum depth of a given layer is based on a minimum deposition thickness. The deposition thickness may be based on at least one of the metal material feedstock size and the energy provided to generate the molten pool. For example, an additive manufacturing energy source may be used for "smoothing" and, using a reactive atmosphere, a very thin hardened layer may be deposited on a metal article. In various other examples, the reactive atmosphere 1230 can include a mixture in which the reactive gas ranges from about 0.1% to about 50%, about 0.2% to about 40%, about 0.5% to about 30%, about 0.8% to about 20%, about 1.0% to about 10%, or any other suitable reactive gas percentage. For example, when a higher reactive gas percentage (e.g., greater than 50%) is appropriate for a given operation, a higher percentage is contemplated for the mixture.

[0218] In another example of the additive manufacturing system 1200, the system control component 1218 is configured to control at least one parameter of the energy source 1216 and the translation component 1210 to manage a chemical reaction that hardens at least one selected portion 204 of the plurality of selected layers 206 of the metal article 200. In another example, the at least one parameter of the energy source 1216 and the translation component 1210 includes an energy source dwell time at a selected predetermined location associated with hardening of at least one selected portion 204 of each of the plurality of selected layers 206 of the metal article 200, a laser deposition dwell time associated with the energy source 1216, a plasma arc dwell time associated with the energy source 1216, an electron beam dwell time associated with the energy source 1216, or any other suitable parameter in any suitable combination. The translation movement, operation of the energy source, and control of the corresponding parameters can be based on the three-dimensional digital model 1232 of the metal article 200.

[0219] In yet another example of the additive manufacturing system 1200, the system control component 1218 is configured to control the translation component 1210 with respect to linear movement of the metal article 200 in at least one of the X-axis, the Y-axis, and the Z-axis. In yet another example, the system control component 1218 is configured to control the translation component 1210 with respect to rotational movement of the metal article 200 relative to at least one of the X-axis, the Y-axis, and the Z-axis. In yet another example, the system control component 1218 is configured to control the translation component 1210 with respect to angular movement of the metal article 200 relative to at least one of the X-axis, the Y-axis, and the Z-axis. In yet another example of the additive manufacturing system 1200, the system control component 1218 is configured to store or access a three-dimensional digital model 1232 of the metal article 200, on which the predetermined location of the deposition of the molten material is based.

[0220] In yet another example of the additive manufacturing system 1200, the reaction atmosphere 1230 includes a predetermined reaction gas mixture 1227 of at least one inert gas 1220 and at least one reaction gas 1224. In another example, the chemical reaction includes nitridation. In yet another example, the at least one reaction gas 1224 includes nitrogen, nitrogen-based gas, ammonia, or any other suitable reaction gas in any suitable combination. In yet another example, the chemical reaction includes carburization. In yet another example, the at least one reaction gas 1224 includes carbon-based gas, acetylene gas, propane gas, butane gas, methane gas, carbon monoxide gas, or any other suitable reaction gas in any suitable combination. When the reaction gas or byproducts of the chemical reaction produce a hazardous gas mixture, the process will be managed by using at least one of vacuum, partial pressure, inert gas purge, and gas safety control system.

[0221] In another example of the additive manufacturing system 1200, the system control component 1218 is configured to store or access a three-dimensional digital model 1232 of the metal article 200, each selected portion 204 of the metal article 200 being hardened at a corresponding location designated for hardening being based on the three-dimensional digital model. In yet another example of the additive manufacturing system 1200, at least one selected portion 204 of each of the plurality of selected layers 206 of the hardened metal article 200 includes one or more regions where portions of a continuous layer are hardened. In another example, the portion of the continuous layer that is hardened includes at least one portion having a hardening depth ranging from at least one of about 0.0001 inches to a depth through the metal article 200, about 0.002 inches to a depth through the metal article 200, about 0.004 inches to a depth through the metal article 200, about 0.006 inches to a depth through the metal article 200, about 0.008 inches to a depth through the metal article 200, about 0.010 inches to a depth through the metal article 200, about 0.020 inches to a depth through the metal article 200, about 0.030 inches to a depth through the metal article 200, about 0.040 inches to a depth through the metal article 200, or any other suitable hardening depth. In yet another example, the one or more regions include at least one region located within the interior of the metal article 200 that does not extend to an exterior surface of the metal article 200. As described above, the metal article 200 can be constructed with an intermittently hardened interior structure to accommodate any design requirements at the level of the deposited layers. For example, the metal article 200 may include an inner region that forms a metal matrix composite. In yet another example, the one or more regions include at least one region extending from a first layer of the metal article 200 to a continuous layer. In yet another example, the one or more regions include at least one region extending from an inner layer of the metal article 200 to an outer surface of the metal article 200, such that a portion of the metal article 200 is case hardened. In yet another example, the case hardened portion of the metal article 200 includes at least one portion having a case hardening depth exceeding about 0.0001 inches, about 0.001 inches, about 0.010 inches, about 0.020 inches, about 0.030 inches, about 0.040 inches, or any other suitable case hardening depth.

[0222] In yet another example of the additive manufacturing system 1200, the system control component 1218 is configured to start the additive manufacturing process by selectively establishing 106 the reactive atmosphere 1230 before establishing 102 the non-reactive atmosphere 1228. In yet another example of the additive manufacturing system 1200, the system control component 1218 is configured to repeat the establishing 102 of the non-reactive atmosphere 1228 and the selective establishing 106 of the reactive atmosphere 1230 during the melting 104 of the metal material 1208 to deposit the molten material in the plurality of layers 202 until the metal article 200 is completed.

[0223] Reference again Figure 1 , Figure 2 and Figures 12 to 19 In one or more examples of additive manufacturing system 1200, system control assembly 1218 includes gas manifold assembly 1302. Gas manifold assembly 1302 includes at least one inert gas inlet 1304 and at least one inert gas outlet 1306. At least one inert gas inlet 1304 is configured to receive at least one inert gas 1220 from at least one first gas supply 1222 at a first inert gas inlet 1308. Gas manifold assembly 1302 is configured to direct first inert gas inlet 1308 to first inert gas outlet 1310. Gas manifold assembly 1302 is configured to provide at least one inert gas 1220 to build chamber 1202 via first inert gas outlet 1310 to establish non-reactive atmosphere 1228.

[0224] In another example of the additive manufacturing system 1200, the build chamber 1202 includes an outlet port 1234 configured to open an outlet path 1236 from the build chamber 1202 to purge the gaseous contents 1238 of the build chamber 1202 in conjunction with delivering at least one inert gas 1220 to the build chamber 1202. In another example, the build chamber 1202 also includes an exhaust conduit 1240 coupled to the outlet port 1234 and configured to direct the outlet path 1236 to the vicinity of the molten material when the molten material is deposited on the substrate 1212 or on the metal article 200 to form the current layer, thereby facilitating the removal of any reactive gas 1224 present near the molten material. For example, the substrate 1212 can be a build plate. In yet another example, the gaseous contents 1238 purged from the build chamber 1202 include air, one or more reactive gases, one or more inert gases, or any other gas that may be present within the build chamber 1202 in any suitable combination. In yet another example, the outlet port 1234 is configured to remain open during the additive manufacturing process so that the outlet path 1236 remains open to enable the at least one inert gas 1220 to flow continuously to the build chamber 1202. In yet another example, the additive manufacturing system 1200 also includes a vacuum pump 1242 coupled to the outlet port 1234 of the build chamber 1202 and configured to apply a vacuum to the outlet path 1236 to assist in the purging of the gaseous contents 1238 of the build chamber 1202. In yet another example, the vacuum pump 1242 is configured to stop the vacuum on the outlet path 1236 of the build chamber 1202 after a predetermined time based on the expected completion of the purge. For example, the vacuum can be stopped by closing the valve at the outlet port 1234, the vacuum pump 1242, or anywhere in between. In yet another example, the outlet port 1234 is configured to close the outlet path 1236 from the build chamber 1202 after a predetermined time to seal the build chamber 1202 during the additive manufacturing process.

[0225] In yet another example of additive manufacturing system 1200, gas manifold assembly 1302 further includes at least one reactive gas inlet 1312 and at least one reactive gas outlet 1314. At least one reactive gas inlet 1312 is configured to receive at least one reactive gas 1224 from at least one second gas supply 1226 at a first reactive gas inlet 1316. Gas manifold assembly 1302 is configured to direct first reactive gas inlet 1316 to first reactive gas outlet 1318. Gas manifold assembly 1302 is configured to deliver at least one reactive gas 1224 to build chamber 1202 via first reactive gas outlet 1318 to establish reactive atmosphere 1228. In another example, build chamber 1202 includes at least one supply conduit 1244 coupled to first reactive gas outlet 1318 of manifold assembly 1302. At least one supply conduit 1244 is configured to direct at least one inert gas 1220 and at least one reactive gas 1224 to a location within the build chamber 1202 proximate to the molten material as the molten material is deposited on the substrate 1212 or on the metal article 200 to form a current layer. For example, a dedicated nozzle or gas injector 1246 may be used to direct at least one inert gas 1220 and at least one reactive gas 1224 to a location proximate to the molten material. In yet another example, the build chamber 1202 includes an outlet port 1234 configured to open an outlet path 1236 from the build chamber 1202 to purge the gaseous contents 1238 of the build chamber 1202 in conjunction with delivering at least one inert gas 1220 and at least one reactive gas 1224 to the build chamber 1202. In yet another example, outlet port 1234 is configured to remain open during the additive manufacturing process such that outlet path 1236 remains open to enable continuous flow of at least one inert gas 1220 and at least one reactive gas 1224 to build chamber 1202 .

[0226] In yet another example, the gas manifold assembly 1302 further includes at least one reactive gas inlet 1312 and at least one reactive gas mixture outlet 1320. The at least one inert gas inlet 1304 is configured to receive at least one inert gas 1220 at the second inert gas inlet 1322. The at least one reactive gas inlet 1312 is configured to receive at least one reactive gas 1224 at the second reactive gas inlet 1324. The gas manifold assembly 1302 is configured to mix the at least one inert gas 1220 received at the second inert gas inlet 1322 and the at least one reactive gas 1224 received at the second reactive gas inlet 1324 to form a predetermined reactive gas mixture 1227. The gas manifold assembly 1302 is configured to direct the predetermined reactive gas mixture 1227 to the first reactive gas mixture outlet 1326. The gas manifold assembly 1302 is configured to deliver the predetermined reactive gas mixture 1227 to the build chamber 1202 via the first reactive gas mixture outlet 1326 to establish the reactive atmosphere 1230. In yet another example, the build chamber 1202 includes at least one supply conduit 1244 coupled to the first reactive gas mixture outlet 1326 of the manifold assembly 1302. The at least one supply conduit 1244 is configured to direct a predetermined reactive gas mixture 1227 to a location within the build chamber 1202 near the molten material as the molten material is deposited on the substrate 1212 or on the metal article 200 to form a current layer. For example, a dedicated nozzle or gas injector 1246 may be used to direct the predetermined reactive gas mixture 1227 to a location near the molten material. In yet another example, the build chamber 1202 includes an outlet port 1234 configured to open an outlet path 1236 from the build chamber 1202 to purge the gaseous contents 1238 of the build chamber 1202 in combination with delivering at least one inert gas 1220 and at least one reactive gas 1224 to the build chamber 1202. In yet another example, outlet port 1234 is configured to remain open during the additive manufacturing process such that outlet path 1236 remains open to enable continuous flow of at least one inert gas 1220 and at least one reactive gas 1224 to build chamber 1202 .

[0227] In yet another example of additive manufacturing system 1200, gas manifold assembly 1302 further includes at least one reactive gas mixture inlet 1328 and at least one reactive gas mixture outlet 1320. At least one reactive gas mixture inlet 1328 is configured to receive a predetermined reactive gas mixture 1227 at a first reactive gas mixture inlet 1330. Gas manifold assembly 1302 is configured to direct the predetermined reactive gas mixture 1227 to a second reactive gas mixture outlet 1332. Gas manifold assembly 1302 is configured to deliver the predetermined reactive gas mixture 1227 to build chamber 1202 via second reactive gas mixture outlet 1332 to establish reactive atmosphere 1230. In another example, build chamber 1202 includes at least one supply conduit 1244 coupled to second reactive gas mixture outlet 1332 of manifold assembly 1302. At least one supply conduit 1244 is configured to direct at least one predetermined reactive gas mixture 1227 to a location within the build chamber 1202 proximate to the molten material as the molten material is deposited on the substrate 1212 or on the metal article 200 to form a current layer. For example, a dedicated nozzle or gas injector 1246 may be used to direct at least one predetermined reactive gas mixture 1227 to a location proximate to the molten material. In yet another example, the build chamber 1202 includes an outlet port 1234 configured to open an outlet path 1236 from the build chamber 1202 to purge the gaseous contents 1238 of the build chamber 1202 in conjunction with delivering the at least one predetermined reactive gas mixture 1227 to the build chamber 1202. In yet another example, the outlet port 1234 is configured to remain open during the additive manufacturing process so that the outlet path 1236 remains open to enable one or more of the at least one inert gas 1220 and the at least one predetermined reactive gas mixture 1227 to flow continuously to the build chamber 1202.

[0228] Reference again Figure 1 , Figure 2 and Fig.12 In one or more examples, in another example of the additive manufacturing system 1200, the energy source 1216 is configured to form a molten pool in conjunction with the melting 104 of the metal material 1208 when the molten material is deposited on the substrate 1212 or on the metal article 200 to form a current layer. In another example, the system control component 1218 is configured to control at least one parameter of the molten pool to manage a chemical reaction that hardens at least one selected portion 204 of the plurality of selected layers 206 of the metal article 200. In yet another example, the at least one parameter of the molten pool includes a metal pool size, a metal pool temperature, a transition time from molten material to solidification, or any other suitable parameter. The translation movement, the operation of the energy source, and the control of the corresponding parameters can be based on the three-dimensional digital model 1232 of the metal article 200.

[0229] In yet another example of the additive manufacturing system 1200, the system control component 1218 is configured to alternate between establishing 102 of the non-reactive atmosphere 1228 and establishing 102 of the reactive atmosphere 1230 during the melting 104 of the metal material 1208 so as to deposit unhardened molten material during the period of the non-reactive atmosphere 1228 and to deposit hardened molten material during the period of the reactive atmosphere 1230 so that the metal article 200 includes a first region in which at least some portions of the continuous layer are hardened and a second region in which at least other portions of the continuous layer are not hardened. In another example, the system control component 1218 is configured to pause the melting 104 of the metal material 1208 and the translation movement provided by the translation component 1210 for depositing the molten material in the plurality of layers 202 to build the metal article 200 at a selected position, wherein there is a predetermined transition from the non-reactive atmosphere 1228 to the reactive atmosphere 1230 and vice versa. In yet another example, the system control component 1218 is configured to store or access a three-dimensional digital model 1232 of the metal article 200, and the selected positions and predetermined transitions on the three-dimensional digital model are based on the corresponding positions designated for hardening. In other examples, the additive manufacturing system 1200 may include a first system dedicated to additive manufacturing using a non-reactive atmosphere 1228 and a second system dedicated to additive manufacturing using a reactive atmosphere 1230. In these examples, alternation of hardened and non-hardened areas in the metal article 200 may be achieved by moving the metal article back and forth between the first system and the second system based on the hardened and non-hardened areas defined in the design of the metal article 200.

[0230] Overall reference by example Figure 2 and Fig.12 , the present disclosure relates to a metal product 200 . Figure 2 An example of a metal article 200 is disclosed. Fig.12 Various examples of additive manufacturing systems 1200 for hardening selected portions of metal articles 200 are disclosed.

[0231] Reference again Figure 2 and Fig.12 In one or more examples, the metal article 200 includes a plurality of layers 202 of a metal material 1208 deposited via an additive manufacturing process. At least a selected portion 204 of each of a plurality of selected layers 206 of the plurality of layers 202 is hardened via a chemical reaction caused by a reactive atmosphere 1230 selectively established during a selected period of the additive manufacturing process. The remaining portions 208 of the plurality of selected layers 206 and the remaining layers 210 of the plurality of layers 202 are deposited during the remaining period of the additive manufacturing process in which a non-reactive atmosphere 1228 is established.

[0232] In another example of the metal article 200, the non-reactive atmosphere 1228 includes at least one inert gas 1220. In yet another example of the metal article 200, with respect to the additive manufacturing process, the metal material 1208 includes metal powder, metal wire, or any other suitable metal material in any suitable combination. In yet another example of the metal article 200, the metal material 1208 includes titanium, titanium alloy, steel, corrosion resistant steel, precipitation hardened corrosion resistant steel, maraging steel, iron steel alloy, or any other suitable metal material in any suitable combination. In yet another example of the method 100, the energy source 1216 includes at least one laser beam, at least one electron beam, at least one plasma arc, or any other suitable energy source in any suitable combination.

[0233] In various examples, the depth of a given layer in the plurality of layers 202 deposited during the additive manufacturing process ranges from about 0.0001 inches to about 0.001 inches, about 0.001 inches to about 0.002 inches, about 0.002 inches to about 0.004 inches, about 0.004 inches to about 0.010 inches, about 0.010 inches to about 0.020 inches, or any other suitable depth range for an additive manufacturing process. The minimum depth of a given layer is based on a minimum deposition thickness. The deposition thickness may be based on at least one of the metal material feedstock size and the energy provided to generate the molten pool. For example, an additive manufacturing energy source may be used for "smoothing" and, using a reactive atmosphere, a very thin hardened layer may be deposited on a metal article. In various other examples, the reactive atmosphere 1230 can include a mixture in which the reactive gas ranges from about 0.1% to about 50%, about 0.2% to about 40%, about 0.5% to about 30%, about 0.8% to about 20%, about 1.0% to about 10%, or any other suitable reactive gas percentage. For example, when a higher reactive gas percentage (e.g., greater than 50%) is appropriate for a given operation, a higher percentage is contemplated for the mixture.

[0234] In another example of the metal article 200, the reaction atmosphere 1230 includes a predetermined reaction gas mixture 1227 of at least one inert gas 1220 and at least one reaction gas 1224. In a further example, the at least one inert gas 1220 includes argon, helium, neon, nitrogen, or any other suitable inert gas in any suitable combination. For example, nitrogen can be used as a non-reactive gas or an inert gas for certain metal materials. However, nitrogen can be a reaction gas for other metal materials (such as titanium). In another example, the chemical reaction includes nitriding. In another example, the at least one reaction gas 1224 includes nitrogen, a nitrogen-based gas, ammonia, or any other suitable reaction gas in any suitable combination. In another example, the chemical reaction includes carburizing. In another example, the at least one reaction gas 1224 includes a carbon-based gas, acetylene gas, propane gas, butane gas, methane gas, carbon monoxide gas, or any other suitable reaction gas in any suitable combination. When the reactive gases or byproducts of the chemical reaction generate hazardous gas mixtures, the process is managed by using at least one of vacuum, partial pressure, inert gas purge, and gas safety control systems. In another example of the metal article 200, each selected portion 204 of the metal article 200 that is hardened is based on a corresponding location in the three-dimensional digital model 1232 of the metal article 200 that is designated for hardening. In yet another example of the method 100, the energy source 1216 includes at least one laser beam, at least one electron beam, at least one plasma arc, or any other suitable energy source in any suitable combination.

[0235] In yet another example of the metal article 200, the plurality of layers 202 of the metal article 200 are arranged in alternating groups of a plurality of selected layers 206 having hardening and a plurality of remaining layers 210 having no hardening. In another example, at least one selected portion 204 of each of the plurality of selected layers 206 having hardening is larger than other portions of the corresponding layer having no hardening. In yet another example, at least one selected portion 204 of each of the plurality of selected layers 206 having hardening includes the corresponding layer, and no portion of the corresponding layer has hardening.

[0236] In yet another example of the metal article 200, the at least one selected portion 204 of each of the plurality of selected layers 206 of the hardened metal article 200 includes one or more regions where a portion of a continuous layer is hardened. In another example, the portion of the continuous layer that is hardened includes at least one portion having a hardened depth ranging from about 0.0001 inches to a depth through the metal article 200, about 0.002 inches to a depth through the metal article 200, about 0.004 inches to a depth through the metal article 200, about 0.006 inches to a depth through the metal article 200, about 0.008 inches to a depth through the metal article 200, about 0.010 inches to a depth through the metal article 200, about 0.020 inches to a depth through the metal article 200, about 0.030 inches to a depth through the metal article 200, about 0.040 inches to a depth through the metal article 200, or any other suitable hardened depth range. In yet another example, the one or more regions include at least one region located in the interior of the metal article 200 that does not extend to the outer surface of the metal article 200. As described above, the metal article 200 can be constructed with an intermittently hardened internal structure to accommodate any design requirements at the level of the deposited layer. For example, the metal article 200 may include an internal region that forms a metal matrix composite. In yet another example, the one or more regions include at least one region extending from the first layer of the metal article 200 to the continuous layer. In yet another example, the one or more regions include at least one region extending from the inner layer of the metal article 200 to the outer surface of the metal article 200, so that a portion of the metal article 200 is surface hardened. In yet another example, the surface hardened portion of the metal article 200 includes at least one portion whose surface hardening depth exceeds about 0.0001 inches, about 0.001 inches, about 0.010 inches, about 0.020 inches, about 0.030 inches, about 0.040 inches, or any other suitable surface hardening depth.

[0237] In yet another example of the metal article 200, in conjunction with the additive manufacturing process, the non-reactive atmosphere 1228 is repeatedly established 102 and the reactive atmosphere 1230 is selectively established 106, which results in certain portions of the metal article 200 built during the period of the reactive atmosphere 1230 being hardened and other portions built during the period of the non-reactive atmosphere 1228 being not hardened, such that the metal article 200 includes a first region in which at least certain portions of the continuous layer are hardened and a second region in which at least other portions of the continuous layer are not hardened.

[0238] Examples of metal articles 200 and additive manufacturing systems 1200 for hardening selected portions of metal articles 200 may be related to or used in the context of aircraft manufacturing. Although an aircraft example is described, the examples and principles disclosed herein may be applied to other products in the aerospace industry and other industries, such as the automotive industry, the aerospace industry, the construction industry, and other design and manufacturing industries. Thus, in addition to aircraft, the examples and principles disclosed herein may also be applied to the use of metal articles in the manufacture of various types of vehicles and in the construction of various types of buildings.

[0239] The foregoing detailed description refers to the accompanying drawings, which illustrate specific examples described in the present disclosure. Other examples with different structures and operations do not depart from the scope of the present disclosure. In different drawings, the same reference numerals may refer to the same features, elements or parts. Throughout the present disclosure, any one of a plurality of projects may be referred to as a project individually, and a plurality of projects may be collectively referred to as a project and may be referred to by similar reference numerals. In addition, as used herein, the features, elements, parts or steps preceded by the word "one" or "an" should be understood as not excluding a plurality of features, elements, parts or steps, unless such exclusion is explicitly stated.

[0240] Illustrative, non-exhaustive examples of the subject matter of the present disclosure are provided above, which may be, but not necessarily, claimed. Reference to "example" herein means that one or more features, structures, elements, components, characteristics and / or operating steps described in conjunction with the example are included in at least one aspect, embodiment and / or specific implementation of the subject matter of the present disclosure. Therefore, the phrases "an example", "another example", "one or more examples" and similar language throughout the present disclosure may but may not refer to the same example. In addition, the subject matter representing any example may but may not include the subject matter representing any other example. In addition, the subject matter representing any example may but may not be combined with the subject matter representing any other example.

[0241] As used herein, a system, device, equipment, structure, article, element, component, or hardware that is "configured to" perform a specified function is indeed capable of performing the specified function without any changes, rather than having the potential to perform the specified function only after further modification. In other words, a system, device, equipment, structure, article, element, component, or hardware that is "configured to" perform a specified function is specifically selected, created, implemented, utilized, programmed, and / or designed to perform the specified function. As used herein, "configured to" represents an existing characteristic of a system, device, structure, article, element, component, or hardware that enables the system, device, structure, article, element, component, or hardware to perform the specified function without further modification. For the purposes of this disclosure, a system, device, equipment, structure, article, element, component, or hardware that is described as "configured to" perform a particular function may additionally or alternatively be described as "suitable for" and / or "operable to" perform that function.

[0242] Unless otherwise indicated, the terms "first," "second," "third," etc. are used herein merely as labels and are not intended to impose order, position, or hierarchy requirements on the items to which these terms refer. Furthermore, reference to an item, such as a "second," does not require or preclude the presence of an item, such as a "first," or lower-numbered item, and / or an item, such as a "third," or higher-numbered item.

[0243] As used herein, when used with a list of items, the phrase "at least one of" means that different combinations of one or more of the listed items may be used, and only one of each item in the list may be required. For example, "at least one of item A, item B, and item C" may include, but is not limited to, item A or item A and item B. This example may also include item A, item B, and item C or item B and item C. In other examples, "at least one of" may be, for example, but not limited to, two items A, one item B, and ten items C; four items B and seven items C; and other suitable combinations. As used herein, the terms "and / or" and the " / " symbol include any and all combinations of one or more associated listed items.

[0244] As used herein, the terms "coupled", "coupled" and similar terms refer to two or more elements that are joined, linked, fastened, attached, connected, communicated or otherwise associated (e.g., mechanically, electrically, fluidically, optically, electromagnetically) with each other. In various examples, the elements may be associated directly or indirectly. For example, element A may be directly associated with element B. As another example, element A may be indirectly associated with element B, for example, via another element C. It will be understood that all associations between various disclosed elements are not necessarily represented. Therefore, couplings other than those depicted in the figures may also be present.

[0245] As used herein, the term "approximately" refers to or indicates a condition that is close to, but not exactly, the condition that still performs the desired function or achieves the desired result. As an example, the term "approximately" refers to a condition that is within an acceptable predetermined tolerance or precision, such as a condition within 10% of the condition. However, the term "approximately" does not exclude a condition that is exactly the condition. As used herein, the term "substantially" refers to a condition that is substantially the condition that performs the desired function or achieves the desired result.

[0246] exist Figure 1 and Figures 3 to 11 In the above, the blocks may represent operations, steps and / or parts thereof, and the lines connecting the various blocks do not imply any particular order or dependency of the operations or parts thereof. It will be understood that all dependencies between the various disclosed operations are not necessarily represented. Figure 1 and Figures 3 to 11 And the attached disclosure describing the operation of the disclosed method set forth herein should not be construed as necessarily determining the order in which the operations are to be performed. On the contrary, although an exemplary order is indicated, it should be understood that the order of the operations can be modified when appropriate. Therefore, the operations shown can be modified, added and / or omitted, and certain operations can be performed in different orders or simultaneously. In addition, those skilled in the art will appreciate that not all operations described need to be performed.

[0247] In the above mentioned Figure 2 and Figures 12 to 19 , may represent functional elements, features, or components thereof, and does not necessarily imply any particular structure. Therefore, modifications, additions, and / or omissions may be made to the structures shown. In addition, those skilled in the art will appreciate that not all of the above mentioned Figure 2 and Figures 12 to 19 All elements, features, and / or components described and shown in the description are required to be included in each example, and not all elements, features, and / or components described herein are necessarily described in each illustrative example. Figure 2 and Figures 12 to 19 Some elements, features and / or components described and shown in the drawings may be combined in various ways without necessarily including Figure 2 and Figures 12 to 19 , other drawings and / or the accompanying disclosure, even if one or more such combinations are not explicitly stated herein. Similarly, additional features not limited to the examples presented may be combined with some or all of the features shown and described herein. Unless explicitly stated otherwise, the above-mentioned Figure 2 and Figures 12 to 19The schematic diagrams of the examples depicted in the are not meant to imply architectural limitations with respect to the illustrative examples. Rather, while an illustrative structure is indicated, it should be understood that the structure may be modified where appropriate. Thus, modifications, additions, and / or omissions may be made to the structures shown. Additionally, in Figure 2 and Figures 12 to 19 In each of the embodiments, elements, features and / or components serving similar or at least substantially similar purposes are labeled with like numerals, and such elements, features and / or components may not be referenced to Figure 2 and Figures 12 to 19 Each of the components, features and / or parts may not be discussed in detail herein. Figure 2 and Figures 12 to 19 Each of the is labeled in , but for consistency, the reference numerals associated therewith may be utilized herein.

[0248] In addition, references throughout this specification to features, advantages, or similar language used herein do not mean that all features and advantages that can be achieved using the examples disclosed herein should be or are in any single example. Instead, language referring to features and advantages is understood to mean that a particular feature, advantage, or characteristic described in conjunction with an example is included in at least one example. Therefore, discussions of features, advantages, and similar language used throughout this disclosure may, but do not necessarily, refer to the same example.

[0249] Examples of the subject matter disclosed herein can be found in Fig. 20 Aircraft manufacturing and service method 2000 and the like are shown Fig.21 2100 is described in the context of the aircraft 2100 shown. In one or more examples, the disclosed methods and systems for associating test data of a part under test with a final product coordinate system can be used in aircraft manufacturing. During pre-production, maintenance method 2000 may include specification and design of aircraft 2100 (box 2002) and material procurement (box 2004). During production, component and subassembly manufacturing (box 2006) and system integration (box 2008) of aircraft 2100 may be performed. Thereafter, aircraft 2100 may be certified and delivered (box 2010) to be put into service (box 2012). While in service, aircraft 2100 may be scheduled for routine maintenance and maintenance (box 2014). Routine maintenance and maintenance may include modification, reconfiguration, refurbishment, etc. of one or more systems of aircraft 2100.

[0250] Each process of maintenance method 2000 may be performed or carried out by a system integrator, a third party, and / or an operator (e.g., a customer). For the purposes of this description, a system integrator may include, but is not limited to, any number of aircraft manufacturers and major system subcontractors; a third party may include, but is not limited to, any number of suppliers, subcontractors, and vendors; an operator may be an airline, a leasing company, a military unit, a service organization, etc.

[0251] like Fig.21 As shown, aircraft 2100 resulting from maintenance method 2000 may include fuselage 2102 having multiple high-level systems 2104 and interior 2106. Examples of high-level systems 2104 include one or more of propulsion system 2108, electrical system 2110, hydraulic system 2112, and environmental system 2114. Any number of other systems may be included. Although an aerospace example is shown, the principles disclosed herein may be applied to other industries, such as the automotive industry. Therefore, in addition to aircraft 2100, the principles disclosed herein may also be applied to other vehicles, such as land vehicles, sea vehicles, space vehicles, etc.

[0252] The disclosed systems and methods for associating test data of a tested part with a final product coordinate system may be employed during any one or more stages of the manufacturing and maintenance method 2000. For example, a component or subassembly corresponding to component and subassembly manufacturing (block 2006) may be processed or manufactured in a manner similar to a component or subassembly produced when the aircraft 2100 is in service (block 2012). In addition, one or more examples of systems, methods, or combinations thereof may be used during the production stage (blocks 2006 and 2008), such as by significantly speeding up the assembly of the aircraft 2100 or reducing the cost of the aircraft. Similarly, for example, but not limited to, one or more examples of systems or methods implemented, or combinations thereof, may be utilized while the aircraft 2100 is in service (block 2012) and / or during repair and maintenance (block 2014).

[0253] The described features, advantages, and characteristics of one example may be combined in one or more other examples in any suitable manner. Those skilled in the relevant art will recognize that the examples described herein may be practiced without one or more specific features or advantages of a particular example. In other cases, additional features and advantages that may not be present in all examples may be recognized in certain examples. In addition, although various examples of methods for hardening selected portions of metal products 100, 300, 400, 600, 700, 800, 900, 1000, 1100, and additive manufacturing systems for hardening selected portions of metal products 1200 and metal products 200 have been shown and described, modifications may be conceived by those skilled in the art after reading the specification. The present application includes such modifications and is limited only by the scope of the claims.

Claims

1. A method (100) for hardening a selected portion of a metal article (200), the method (100) comprising: establishing (102) a non-reactive atmosphere (1228) within a build chamber (1202) of an additive manufacturing system (1200); using an energy source (1216) to melt (104) a metal material (1208) to deposit the molten material in a plurality of layers (202) to construct the metal article (200) in combination with controlling translational movement of at least one of the metal article (200) and the energy source (1216) based on predetermined locations of deposition of the molten material; as well as A reactive atmosphere (1230) is selectively established (106) within the build chamber (1202) that causes a chemical reaction to combine the melting (104) and subsequent solidification of the molten material to harden at least a selected portion (204) of each of a plurality of selected layers (206) of the plurality of layers (202).

2. The method of claim 1, wherein the non-reactive atmosphere (1228) comprises at least one inert gas (1220).

3. The method of claim 2, wherein the at least one inert gas (1220) comprises at least one of argon, helium, neon, and nitrogen.

4. The method of claim 1, wherein with respect to the additive manufacturing process, the metal material (1208) comprises at least one of a metal powder and a metal wire.

5. The method of claim 1, wherein the metallic material (1208) comprises at least one of titanium, titanium alloys, steel, corrosion resistant steel, precipitation hardened corrosion resistant steel, maraging steel, and iron-steel alloys.

6. The method of claim 1, wherein the energy source (1216) comprises one or more of at least one laser beam, at least one electron beam, and at least one plasma arc.

7. A method according to claim 1, wherein at least one parameter of the translational movement of the metal article (200), the translational movement of the energy source (1216) and the operation of the quantity source (1216) is controlled to manage the chemical reaction of hardening at least one selected portion (204) of the multiple selected layers (206) of the metal article (200).

8. The method of claim 7, wherein the energy source (1216) and the at least one parameter of the translational movement of the metal article (200) and / or the energy source (1216) include at least one of: an energy source dwell time at a selected predetermined location associated with hardening of the at least one selected portion (204) of each of the plurality of selected layers (206) of the metal article (200), a laser deposition dwell time associated with the energy source (1216), a plasma arc dwell time associated with the energy source (1216), and an electron beam dwell time associated with the energy source (1216).

9. The method of claim 1, wherein the translational movement of the metal article (200) and / or the energy source (1216) comprises control of linear movement along at least one of an X-axis, a Y-axis, and a Z-axis.

10. The method of claim 9, wherein the translational movement of the metal article (200) and / or the energy source (1216) comprises control of rotational movement relative to at least one of the X-axis, the Y-axis, and the Z-axis.

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