Laser-assisted reagent activation and modification of self-passivating metals

Abstract

Disclosed herein is a method of treating an article made of a self-passivating metal, the method comprising applying an agent to a surface portion of the article and applying a laser to the surface portion of the article to chemically activate the agent, wherein chemical activation of the agent treats the surface portion to modify one or more properties.

Description

[0001] Related Applications

[0002] This application claims priority to and all benefits of U.S. Provisional Patent Application Serial No. 63 / 348,065, filed on June 2, 2022, entitled LASER-ASSISTED REAGENT ACTIVATION AND PROPERTYMODIFICATION OF SELF-PASSIVATING METALS, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to materials and methods involved in surface treatment of metals using laser activation. Such activation may occur after metal processing or forging. It may also be applied to articles produced via additive manufacturing. Specifically, the present disclosure relates to processes and methods for treating the surface of a metal article by heating the metal surface using a laser and / or a chemically active agent to change one or more mechanical properties, chemical properties, and / or electrical properties of at least a portion of the surface of the metal article. Background Art

[0004] Low temperature carburizing

[0005] Case hardening is a widely used industrial process for increasing the surface hardness of formed metal products. For example, carburizing is a typical commercial process for hardening formed metal products. During the carburizing process, the formed metal product is contacted with gaseous carbon compounds at high temperatures, whereby carbon atoms released by the decomposition of the carbon compounds diffuse into the surface of the product. Hardening occurs by the following means: these diffused carbon atoms react with one or more metals in the workpiece (the terms "workpiece" and "product" are used interchangeably in this article) to form different chemical compounds (i.e., carbides), which are then precipitated in the metal as discrete, extremely hard crystalline particles to form the workpiece surface. See Stickels, "Gas Carburizing", pages 312 to 324, Volume 4, ASM Handbook, 1991, ASM International.

[0006] In the mid-1980s, a technique was developed for hardening the surface layer of stainless steel in which the shaped metal article is contacted with a carburizing gas at low temperatures, typically below 500°C (932°F). At these temperatures, if carburization does not continue for too long, the carbon atoms diffuse into the surface of the shaped metal article, typically to a depth of 20-50 μm, without forming carbide precipitates. Nevertheless, an exceptionally hard surface layer is obtained, which is believed to be due to the stress imposed on the metal's crystal lattice by the diffused carbon atoms. In addition, the corrosion resistance of the steel is not impaired and is even improved, as the presence of carbide precipitates is minimal.

[0007] This technique, known as "low temperature carburizing", is described in many publications, including US5,556,483, US5,593,510, US5,792,282, US6,165,597, US6,547,888, EPO 0787817, Japan 9-14019 (Kokai 9-268364) and Japan971853 (Kokai 9-71853). The disclosures of these documents are incorporated herein by reference.

[0008] Nitriding and carbonitriding

[0009] In addition to carburizing, nitriding and carbonitriding can also be used for surface hardening of various metals. Nitriding works in much the same way as carburizing, except that instead of using a carbon-containing gas that decomposes to produce carbon atoms for surface hardening, nitriding uses a nitrogen-containing gas that decomposes to produce nitrogen atoms for surface hardening.

[0010] However, as with carburizing, if nitriding is done at higher temperatures without rapid quenching, hardening occurs by the formation and precipitation of discrete compounds of the diffused atoms, i.e., nitrides. On the other hand, if nitriding is done at lower temperatures without a plasma, hardening occurs by the nitrogen atoms that have diffused into the metal lattice imposing stress on this lattice without the formation of these precipitates. As is the case with carburizing, stainless steels are not usually nitrided by conventional (high temperature) or plasma nitriding because the inherent corrosion resistance of the steel is lost when the chromium in the stainless steel reacts with the diffused nitrogen atoms to cause nitride formation.

[0011] Recent testing of low temperature nitrocarburizing has shown that effective surface hardening of austenitic alloys is achieved by low temperature nitrocarburizing using solid reagent precursors. See U.S. Patent No. 10,214,805 and U.S. Patent Application No. 17 / 242,555, the entire contents of each of which are incorporated herein by reference. The surface hardening process injects a large amount of carbon and nitrogen into the surface of the formed metal product. The interstitial carbon and nitrogen significantly improve the hardness, corrosion resistance and fatigue resistance of the treated product. In addition, if carried out at a slightly elevated temperature of about 500°C, a precipitate layer may be formed on the surface of the part, thereby further improving the hardness in that area. The sensitization effect (reduced corrosion resistance) common to these alloys in the precipitation area is offset by the surrounding treated material, which has excellent corrosion resistance relative to the base alloy. In addition, the surface treatment produces high compressive stress, which can close pores and alleviate similar defects.

[0012] In carbonitriding (also referred to and used interchangeably herein as "nitrocarburizing"), a workpiece is exposed to both a nitrogen-containing gas and a carbon-containing gas, whereby both nitrogen atoms and carbon atoms diffuse into the workpiece for case hardening. Like carburizing and nitriding, carbonitriding can be accomplished at higher temperatures, in which case case hardening occurs through the formation of nitride and carbide precipitates, or at lower temperatures, in which case case hardening occurs through a sharply localized stress field generated in the metal lattice by interstitially dissolved nitrogen and carbon atoms that have diffused into such lattice. For convenience, all three processes (i.e., carburizing, nitriding, and nitrocarburizing (carbonitriding)) are collectively referred to in this disclosure as "low temperature case formation," "low temperature case hardening," "low temperature case hardening process," or "hardening process."

[0013] The role of reagents in hardening

[0014] Because the temperatures involved in low temperature surface hardening are very low, carbon atoms and / or nitrogen atoms may not penetrate the outer passive layer of certain metals like stainless steel. Therefore, low temperature surface hardening of these metals is usually preceded by a step in which the formed metal article is contacted with a halogen-containing gas (such as HF, HCl, NF3, F2 or Cl2) at high temperature (e.g., 200°C to 400°C) to make the protective oxide coating of the steel transparent to carbon atoms and / or nitrogen atoms (making the protective oxide coating transparent to carbon atoms and / or nitrogen atoms is also known and referred to herein as "activation" and "depassivation"). The halide gas chemistry reduces the passive oxide film, which then makes the oxide film "transparent" to nitrogen atoms and carbon atoms. The passive film is already optically transparent because it is only a few angstroms thick.

[0015] Surface preparation and Bayer layer

[0016] Low temperature surface hardening is often used for workpieces with complex shapes. In order to form these shapes, some type of metal forming operation is usually required, such as a cutting step (e.g., sawing, scraping, machining) and / or a forging process step (e.g., forging, stretching, bending, etc.). Due to these steps, structural defects in the crystal structure and contaminants (such as lubricants, moisture, oxygen, etc.) are often introduced into the near-surface region of the metal. Therefore, in most complex-shaped workpieces, a highly defective surface layer is usually produced, which has an ultrafine grain structure caused by plastic deformation and a significant level of contamination. This layer, which can be up to 2.5 μm thick and is called a Bayer ratio layer, is formed immediately below the protective, coherent chromium oxide layer or other passivation layer of stainless steel and other self-passivating metals.

[0017] As noted above, the conventional method for activating stainless steel for low temperature case hardening is by contact with a halogen-containing gas. These activation techniques are not substantially affected by this Bayer ratio layer.

[0018] However, this is not the case with the self-activation techniques described in the Somers et al. and Christiansen et al. disclosures noted above, in which the workpiece is activated by contact with acetylene or an "N / C compound." Rather, experience has shown that if the complex-shaped stainless steel workpiece is not surface treated to remove its Bayer ratio layer by electropolishing, mechanical polishing, chemical etching, or the like before surface hardening begins, these disclosed self-activating surface hardening techniques either do not work at all or, if they do work, produce results that are, at best, spotty and inconsistent from surface area to surface area.

[0019] See Ge et al., The Effect of Surface Finish on Low-Temperature Acetylene-Based Carburization of 316L Austenitic Stainless Steel, METALLURGICAL ANDMATERIALS TRANSACTIONS B, Vol. 458, December 2014, pp. 2338-2345, 2014 The Minerals, Metal & Materials Society and ASM International. As stated in the document, "[stainless] steel samples with improper surface finish due to, for example, machining cannot be successfully carburized by an acetylene-based process". See in particular FIG. 10(a) and the associated discussion on pages 2339 and 2343, which clearly show that the "machining-induced distribution layer" (i.e., the Bayer ratio layer) that has been intentionally introduced by etching and then scraping with a sharp scraper cannot be activated and carburized with acetylene, even though the surrounding parts of the workpiece that have been etched but not scratched are easily activated and carburized. Therefore, in practice, these self-activating surface hardening techniques cannot be used for stainless steel workpieces with complex shapes unless these workpieces are first pretreated to remove their Bayer ratio layers.

[0020] To address this problem, U.S. Pat. No. 10,214,805 discloses an improved process for low-temperature nitriding or carbonitriding of workpieces made of self-passivating metals, in which the workpieces are contacted with vapors generated by heating an oxygen-free halogenated nitrogen salt reagent. As described therein, in addition to providing the nitrogen and optionally carbon atoms required for nitriding and carbonitriding, these vapors are also able to activate the surfaces of the workpieces for these low-temperature surface hardening processes, even if these surfaces may carry a Bayer ratio layer as a result of previous metal forming operations. Thus, this self-activating surface hardening technology can be directly applied to these workpieces, even if they define complex shapes as a result of previous metal forming operations, and even if they have not first been pretreated to remove their Bayer ratio layer.

[0021] Additive Manufacturing

[0022] "Additive manufacturing" (AM, but also known as 3D printing) differs from more conventional manufacturing processes in that it forms 3D objects by adding material layer by layer, rather than machining or shaping a large block of material or forming it via a mold. A wide variety of materials can be used in AM, depending on the specific technology used. For example, plastics and ceramics can be 3D printed or "jetted." Certain polymers can be formed via extrusion or laser sintering. Metal layers or sheets can be laminated together to create 3D shapes. Powdered metals can be fused together via AM to create additive parts. The present disclosure is primarily concerned with the latter, i.e., metal materials formed by AM.

[0023] Metal AM typically begins with fusing particles of powdered metal to produce the layers of the target structure. Fusion techniques vary. They include laser or electron beam powder bed fusion (L-PBF or EB-PBF, respectively), and a laser deposition technique known as direct energy deposition (DED). Metal fusion deposition modeling (FDM) uses filaments infused with metal powder and a binder to print a 3D "green" body, which is then sintered to densify the powder. Other techniques that are often applied to AM products after 3D printing include hot isostatic pressing (HIP), which is primarily used for densification and porosity reduction.

[0024] exist Figure 1 An exemplary laser powder bed fusion process 100 is presented in FIG. Figure 1 As shown, metal powder 110a is provided via a powder delivery system 120. A piston 130 pushes the powder 110a upward. A roller 140 moves the powder 110a laterally toward the production piston 150. Once the powder enters the production powder bed, the powder 110b will stay on the production piston 150. Then light 160 from a laser 170 is applied to fuse the powder particles together. The scanner system 180 moves the light beam 160 so that the light beam traces the shape of the object 190 being made with the powder 110b. Typically, one layer of the object 190 is traced at a time. The production piston 150 continuously or gradually lowers the object 190 so that the completed layer can be removed from the path of the laser and a new layer can be made. In addition to the above, AM can also include "subtractive manufacturing" (SM). SM is a mechanical processing process that carves a solid raw material block into a desired 3D geometry and size by using a controlled material removal process. In addition to electric and manual tools, this process also relies heavily on the use of mechanical tools. The process can also include lasers or other cutting tools. In the sense that any of these processes will cause plastic deformation of the surface of the article, the process may introduce a deformed layer (e.g., a Bayer ratio layer). As described herein and in the references incorporated herein, the technology of the present disclosure can harden the material with or without such a deformed layer.

[0025] Additive manufacturing allows for the design of complex flow paths and unique geometries that are not possible using other manufacturing methods. However, this increased design freedom comes at a cost. For example, residual porosity in AM parts due to incomplete particle fusion can undermine mechanical strength and reduce corrosion resistance. Although these properties can be improved by post-processing heat treatments (e.g., HIP), heat treatments also come at a cost. They are typically performed at high temperatures and pressures, which typically results in annealed materials with lower yield strengths.

[0026] Although the laser powder bed fusion process described above can produce ferrules and components for other mechanical applications, hardening the outer surfaces of those components presents new challenges. Many of the processes used to harden materials in conventional manufacturing cannot be easily adapted to AM materials. Therefore, new methods of controlling the properties of materials used in AM are needed. DETAILED DESCRIPTION

[0027] As discussed above, most treatment methods apply the reagent to the surface of the workpiece to be treated by placing the reagent in contact with and / or in close proximity to the article or workpiece and heating the environment surrounding the entire article or workpiece. Such techniques may have the disadvantage of not being able to specifically target a particular surface of an article or workpiece or a particular portion of an article or workpiece surface for treatment. They also have the disadvantage of requiring hours or days to complete the heating and treatment. Many methods treat the same all There is a need for a method of selectively applying an agent to a specific surface or a specific portion of an article or workpiece surface to be selectively treated. There is also a need for local heating of the applied agent, such as via a laser, to locally precisely activate and harden the article or workpiece. There is also a need for applying the treatment in such a way that it does not take hours or days, but minutes or seconds.

[0028] The present disclosure relates to methods of treating articles, primarily using lasers and targeted focused reagents to activate various portions of the article. The laser and reagents can be applied to specific portions of the article in a relatively short period of time (e.g., seconds or minutes, rather than days or hours) to modify the article to promote property changes where the reagents are present. Examples of such properties modified in the surface of the article include enhanced corrosion resistance, mechanical properties, electrical resistance, and other properties.

[0029] Overview of Settings 200

[0030] Figure 2 One exemplary setup 200 to which lasers and reagents may be applied according to the present disclosure is shown. It should be understood that setup 200 is merely exemplary and illustrates general principles that may be used in conjunction with the present disclosure. Other setups and arrangements are possible, including those that vary the position of laser 222 relative to article 210, the method of delivery of reagents (e.g., via nozzle 226 and powder / gas 224), and the relative positioning of any of the components shown in setup 200.

[0031] Figure 2Surface 210a of substrate 210 is shown being processed. In some cases, substrate 210 may be an article and surface 210a may be an outer surface of article 210. Herein, the terms "part," "substrate," "article," and "workpiece" will be used interchangeably. However, it should be understood that substrate 210 is not limited to metal having any particular type of preparation. For example, article 210 may include machined or forged metal. Article 210 may include additively manufactured and / or formed metal without cold working or hot working.

[0032] The article 210 is typically a metal article that may or may not be mechanically processed or formed (e.g., AM forming) into a shape suitable for a particular application. As described in more detail below, in some cases, the metal of the article 210 may be self-passivating. The passivation layer of the article 210 may be present at the surface 210a. It may be formed of an oxide (such as chromium oxide or titanium oxide or a combination thereof). The article 210 and / or the surface 210a may include a Bayer ratio layer and / or other layers resulting from processing or the application of mechanical forces.

[0033] Article 210 may include materials

[0034] The article 210 may include exemplary metals including alloys including stainless steel (particularly stainless steel having 5 wt % to 50 wt % Ni and at least 10 wt % Cr), nickel-based alloys, and cobalt-based alloys. The article 210 may include high manganese stainless steel, such as high manganese steel or titanium-based alloys having at least 10 wt % Cr. The article 210 may preferably include one or more of the following alloys: 316L, 6Mo, 6HN, Incoloy 825, Inconel 625, Hastelloy C22, and Hastelloy C276.

[0035] Article 210 may include other steels, particularly stainless steel. Exemplary steels include 384SS, alloy 254, alloy 6HN, etc., and duplex alloys, such as 2205. The treatment disclosed herein may be applied to nickel alloys, nickel steel alloys, Hastelloy, nickel-based alloys. Exemplary nickel-based alloys include alloy 904L, alloy 20, alloy C276, etc. The treatment may also be applied to cobalt-based alloys, manganese-based alloys, and other alloys containing large amounts of chromium, such as titanium-based alloys. However, the treatment is not limited to such materials and may be applied to metals. In some variations, the treatment may also be applied to non-metals.

[0036] Stainless steels that can be incorporated into article 210 include stainless steels containing 5 wt % to 50 wt % (preferably 10 wt % to 40 wt %) Ni and chromium sufficient to form a protective layer of chromium oxide on the surface when the steel is exposed to air. This includes alloys with about 10% or more chromium. Some contain 10 wt % to 40 wt % Ni and 10 wt % to 35 wt % Cr. Examples include AISI 300 series steels, such as AISI 301, 303, 304, 309, 310, 316, 316L, 317, 317L, 321, 347, CF8M, CF3M, 254SMO, A286 stainless steel, and AL-6XN. AISI 400 series stainless steels as well as alloys 410, 416, and 440C are included. Cobalt-based alloys and high manganese stainless steels can be included, particularly stainless steels with at least 10 wt % Cr or titanium. The surface 210a of the metal may have a passivation coating formed of a chromium-rich oxide or a titanium-rich oxide, such as a continuous passivation coating. As a result of the metal forming operation, the metal may have one or more different defect-rich subsurface regions (e.g., which constitute a Bayer ratio layer). The metal may include, but is not limited to: 316L (UNS S31600), 6Mo (UNS S31254), 6HN (UNS N08367), Incoloy 825 (UNS N08825), Inconel 625 (UNS N06625), Hastelloy C22 (UNS N06022) or C276 (UNS N10276).

[0037] Other types of alloys that can be processed according to the present disclosure are nickel-based alloys, cobalt-based alloys, and manganese-based alloys, which include alloys containing enough chromium (e.g., about 10% or more chromium) to form a coherent protective chromium oxide protective coating when exposed to air. Examples of such nickel-based alloys include alloy 600, alloy 625, alloy 825, alloy C-22, alloy C-276, alloy 20Cb, and alloy 718, to name a few. Examples of such cobalt-based alloys include MP35N and Biodur CMM. Examples of manganese-containing alloys include AISI 201, AISI 203EZ, and Biodur 108. Still other alloys processed according to the present disclosure include titanium-based alloys. These alloys can form a titanium oxide coating when exposed to air, which inhibits the passage of nitrogen atoms and carbon atoms. Specific examples of such titanium-based alloys include Grade 2, Grade 4, and Ti 6-4 (Grade 5). Alloys based on other self-passivating metals (such as zinc, copper, and aluminum) can also benefit from the processing disclosed herein. Tool steels (eg, steels used in stamping dies) may also be included. Examples of suitable tool steels include hardened stellite-vanadium-based alloys and variations thereof.

[0038] The treatment may be applied to metals of any phase structure, including but not limited to austenite, ferrite, martensite, dual phase metals (eg, austenite / ferrite), and the like.

[0039] It should be understood that the treatment herein can be used with processed materials as described above. The product 210 can be at least one of casting, forging, work hardening, precipitation hardening, partial annealing, full annealing, forming, rolling, forging, machining, welding, additive manufacturing, powder metal sintering, hot isostatic pressing and stamping. The treatment can also be applied to unprocessed materials. The parts 210 in the present disclosure may or may not include a Bayer ratio layer. They can be work hardening and / or precipitation hardening. In addition, they can be formed, rolled, forged, machined or reduced. They can be substantially free of heavy scale and pollutants.

[0040] The present disclosure may be implemented for any metal or metal alloy that is self-passivating in the sense of forming a coherent protective chromium-rich oxide layer when exposed to air, which is capable of blocking the passage of nitrogen atoms and carbon atoms. Alternatively, the metal component 210 may not be self-passivating. These metals and alloys are described, for example, in patents related to low temperature surface hardening processes, examples of which include US5,792,282, US6,093,303, US6,547,888, EPO 0787817, and Japanese Patent Document 9-14019 (Kokai 9-268364). The process of the present disclosure may also be applied to materials that do not form a passivating layer.

[0041] The processes described herein can be applied not only to wrought metal alloys, but also to articles 210 or articles produced by other techniques including additive manufacturing (AM) and 3D printing. For example, such articles 210 or articles can be sintered via a laser (e.g., by selective laser sintering (SLS)). These articles 210 or articles can be additively manufactured in whole or in part. They can also be hot isostatically pressed, formed, rolled, forged, machined, or subtractively manufactured.

[0042] Application device 220 and laser 222

[0043] Figure 2 An application device 220 is shown which can apply laser light 222 and or reagent 224 or other chemicals. Figure 2 The device 220 is shown as applying a specific form, but it should be understood that the application device 220 takes any suitable form. For example, the application device 220 may include a laser beam 222 (also referred to herein as a "laser") and a nozzle 226 for applying a gas or powder 224 to the surface 210a, such as Figure 2As shown. It should be understood that other configurations are possible, including separating the laser 222 from the nozzle 226 and / or using any suitable number of lasers 222 or nozzles 226. Figure 2 A nozzle 226 is shown delivering a single gas or powder 224, but it is understood that the nozzle 226 can be configured to deliver different powders or gases 224. The apparatus 220 can apply the laser 222 and the powder / gas 224 simultaneously and / or in parallel. Applying the laser 222 can cause a chemical reaction in the article 210.

[0044] like Figure 2 As shown, applying a gas or powder 224 to a surface 210a simultaneously with a laser 222 can form a layer of deposited material 230. The deposited material 230 can act as a coating on the article 210. The coating 230 can change the properties of the surface 210a and / or the article 210. The interaction between the laser 222 and the gas or powder 224 can cause the gas or powder 224 to solidify to form the coating 230. As discussed in more detail below, the laser 222 can also or alternatively chemically activate the gas or powder 224 and / or the underlying article 210. For example, this can activate the gas or powder 224 so as to treat the surface 210a of the article 210 (e.g., carburizing, nitrocarburizing, or carbonitriding).

[0045] like Figure 2 As shown, the application device 220 may include a powder jet 224 formed in a nozzle 226. For example, the nozzle 226 may include a micro-stream jet. The jet may also include a jet of vapor or gas or liquid. When the element 224 is a powder, the flow through the nozzle 226 may include a gas, such as an inert gas, for pushing the powder 224 under pressure. The inert gas can prevent the surface 210a from oxidizing during processing. The pressure may be low pressure, medium pressure or high pressure.

[0046] With respect to the treatments described below including the application of carbon and nitrogen, the application of powder / gas 224 (e.g., including a reagent) and / or laser 222 can minimize carbide and nitride precipitation in surface 210a and / or article 210. The application of powder / gas 224 (e.g., including a reagent) and / or laser 222 can further cause any carbide and nitride precipitates that are produced to be finely dispersed (rather than coarsely dispersed).

[0047] The laser 222 can take a variety of suitable forms and provide a variety of different types of lasers. For example, the laser 222 can provide colinear coherent lasers. The laser 222 can include one or more fiber lasers. The laser 222 can also include gas lasers, excimer lasers, excitation complex lasers, liquid-based lasers, dye-based lasers, chemical lasers, solid-state lasers, chemical lasers, semiconductor lasers, diode-based lasers, infrared lasers, and ultraviolet lasers. Regarding gas lasers, the gas may include at least one of CO2, He, and Ne. Regarding solid-state lasers, the laser may include at least one of yttrium aluminum garnet (YAG) lasers, ruby ​​lasers, high-pitched titanium lasers, high-pitched ice lasers, and titanium sapphire lasers.

[0048] The effect of the laser 222 on the surface 210a may vary. For example, the heating caused by the laser 222 may be sufficient to cause grain growth of metal grains in the article 210 and or its surface 210a. On the other hand, the power of the laser 222 may produce insufficient heating to cause grain growth. The power of the laser 222 may be sufficient to cause pyrolysis of the powder / gas 224 (e.g., reagent).

[0049] The application device 220 can be part of a larger system. For example, a control system (not shown) can guide the motion or movement of the device 220. The application device 220 can be part of a 3D printing system or other printing system, for example. The application device 220 can be freely movable in the x, y, and z directions, such as Figure 2 In particular, the application device 220 can be moved according to the treatment plan and / or can be rastered, lowered, lifted, or translated to treat certain portions of the article 210. The movement of the device 220 can be controlled via a computer, an algorithm, or via user input (e.g., via a joystick or other manual control).

[0050] The area of ​​surface 210a affected by laser 222 and powder / gas 224 may have a cm 2 、mm 2 or micrometer 2 The heating caused by laser 222 can be limited to this surface area. Alternatively, the heating caused by laser 222 can extend beyond the surface area. For example, the heating caused by laser 222 can include the area between laser 222 and surface area 210a.

[0051] As the application device 220 moves across the surface 210a, the powder / gas 224, and the laser 222, the device 220 may apply the powder / gas 224 and / or the laser 222 to different portions of the surface 210a. For example, the device 220 may apply the laser 222 and / or the powder / gas 224 to one end of the article 210 and not to the other end. In one example, the application device 220 may apply the laser 222 and / or the gas / power 224 to a portion of the article 210 that will be exposed to mechanical contact and / or wear in the final deployment of the article 210 to change the properties of the article 210 for the application. This may include portions of the article 210 that may mate or contact other metals, such as in valve applications. In addition, the application of the laser 222 and the powder / gas 224 may vary across the article 210. For example, it may be advantageous to change the power, intensity, or wavelength of the laser 222 on portions of the article 210 to cause a change in the properties of the article 210. In another example, it may be advantageous to vary the flux or intensity of the powder / gas 224 flowing to various portions of the surface 210a.

[0052] Surface treatment via application of powder / gas 224 (e.g., including an agent) and / or laser 222 may occur over any suitable timescale. For example, treatment with powder / gas 224 (e.g., including an agent) and / or laser 222 may occur over a minute or less. Treatment with powder / gas 224 (e.g., including an agent) and / or laser 222 may occur over a few minutes or hours. Treatment with powder / gas 224 (e.g., including an agent) and / or laser 222 may occur within the following exemplary time ranges: 0.2 minutes, 0.3 minutes, 0.4 minutes, 0.5 minutes, 0.6 minutes, 0.7 minutes, 0.8 minutes, 0.9 minutes, 1.0 minutes, 1.1 minutes, 1.2 minutes, 1.3 minutes, 1.4 minutes, 1.5 minutes, 1.6 minutes, 1.7 minutes, 1.8 minutes, 1.9 minutes, 2.0 minutes, 3.0 minutes, 4.0 minutes, 5.0 minutes, 10.0 minutes, 15.0 minutes, 30.0 minutes, 60.0 minutes. Treatment with powder / gas 224 (e.g., including an agent) and / or laser 222 may occur within a few hours or a few days. Treatment with powder / gas 224 (eg, including reagents) and / or laser 222 and / or a hardening step may occur while article 210 is in at least one of a manufacturing and fabrication process, such as any of the manufacturing and fabrication processes described herein.

[0053] Set the gas environment to 200

[0054] There may be many different variations of the environment of setup 200. For example, setup 200 may include an inert gas, nitrogen, argon, or other gas, such as a rare gas. The gas pressure in setup 200 may be 0.2 ATM to 1.6 ATM (including all sub-ranges) or above. Setup 200 may be substantially in a vacuum or in ambient air.

[0055] The arrangement 200 may further include a level of oxygen. When the arrangement 200 includes applying the laser 222 and the powder / gas 224 includes a reagent, the inclusion of oxygen may reduce the amount of spent reagent after any treatment applied to the article 210. This occurs because the inclusion of oxygen helps consume the reagent during the treatment. The arrangement 200 may further include a shielding gas, which includes a gas that can reduce or prevent oxygen exposure and / or help work with relatively small amounts of oxygen by amplifying the effects of oxygen, etc. Exemplary shielding gases that may be used are nitrogen, other nitrogen-containing gases (e.g., NH3), and carbon-containing gases (e.g., CO, C2H2, CH4, etc.).

[0056] The oxygen level in setting 200 can be any suitable level, for example, a volume ratio of oxygen to other gases of 0.005. Alternatively, setting 200 can be in a gas environment with 0.005 to 0.010 volume of oxygen to other gases, 0.010 to 0.020 volume of oxygen to other gases, 0.020 to 0.030 volume of oxygen to other gases, 0.030 to 0.040 volume of oxygen to other gases, 0.040 to 0.050 volume of oxygen to other gases, 0.050 to 0.055 volume of oxygen to other gases, 0.055 to 0.060 volume of oxygen to other gases, 0.060 to 0.070 volume of oxygen to other gases, 0.070 to 0.080 volume of oxygen to other gases. .080, 0.080 to 0.090 by volume for oxygen compared to other gases, 0.090 to 0.100 by volume for oxygen compared to other gases, 0.100 to 0.150 by volume for oxygen compared to other gases, 0.150 to 0.200 by volume for oxygen compared to other gases, 0.200 to 0.210 by volume for oxygen compared to other gases, 0.210 to 0.220 by volume for oxygen compared to other gases, 0.220 to 0.230 by volume for oxygen compared to other gases, 0.230 to 0.240 by volume for oxygen compared to other gases, 0.240 to 0.250 by volume for oxygen compared to other gases, 0 by volume for oxygen compared to other gases .250 to 0.260, 0.260 to 0.270 by volume for oxygen compared to other gases, 0.270 to 0.280 by volume for oxygen compared to other gases, 0.280 to 0.290 by volume for oxygen compared to other gases, 0.290 to 0.300 by volume for oxygen compared to other gases, 0.300 to 0.310 by volume for oxygen compared to other gases, 0.310 to 0.320 by volume for oxygen compared to other gases, 0.320 to 0.330 by volume for oxygen compared to other gases, 0.330 to 0.340 by volume for oxygen compared to other gases, 0.340 to 0.350 by volume for oxygen compared to other gases 0.350 to 0.360 by volume for oxygen than other gases, 0.360 to 0.370 by volume for oxygen than other gases, 0.370 to 0.380 by volume for oxygen than other gases, 0.380 to 0.390 by volume for oxygen than other gases, 0.390 to 0.400 by volume for oxygen than other gases, 0.400 to 0.410 by volume for oxygen than other gases, 0.410 to 0.420 by volume for oxygen than other gases, 0.420 to 0.430 by volume for oxygen than other gases, 0.430 to 0.440 by volume for oxygen than other gases and 0.440 to 0.450 by volume for oxygen than other gases.The arrangement 200 may include a gas environment having a ratio of 0.005 to 0.450 by volume of oxygen to other gases. As discussed above, the arrangement may also include a shielding gas.

[0057] Exemplary Reagents Used in the Processes of the Present Disclosure

[0058] As discussed above, powder / gas 224 may include "reagents", such as any of the reagents discussed herein. These reagents include chemicals used to increase the influx of nitrogen and / or carbon to article 210 during any of the processes described herein. Any suitable form of any reagent described herein may be used with the present disclosure. This includes powders, liquids, gases, and combinations thereof. As used herein, "reagents" include any substance, including non-polymeric N / C / H compounds or other compounds used to change the surface properties of the metal and / or the formation of the surface layer. The reagents may be applied as a powder, liquid, or vapor. The reagents may be applied as a coating.

[0059] Arrangement 200 can expose the article 210 to the pyrolysis products of a non-polymeric reagent comprising carbon and nitrogen. Pyrolysis can occur as a result of heating the reagent using a laser 222 and / or another heat source (e.g., resistive and / or inductive heating). Thus, the treatment of the present disclosure can include exposing the surface to a class of non-polymeric N / C / H compounds. Examples of suitable such reagents include guanidine [HNC(NH2)2] moieties or functionalities with or without HCl association (e.g., complexation) for surface layer formation. The guanidine moiety can have or not have a halide association. These reagents result in surface layer formation on the article 210 and improve hardening, corrosion resistance, and / or wear resistance.

[0060] In particular, the results show that at least three reagents belonging to this system, 1,1-dimethylbiguanidine hydrochloride (hereinafter referred to as "DmbgHCl"):

[0061]

[0062] and guanidine hydrochloride (hereinafter referred to as "GuHCl"):

[0063]

[0064] And biguanide hydrochloride (BgHCl) successfully causes extremely rapid surface hardening and other surface property enhancements under low temperature conditions, such as other mechanical property enhancements (e.g., enhanced Young's modulus), as well as chemical property enhancements (e.g., enhanced corrosion resistance) and electrical property enhancements. Guanidine [HNC(NH2)2] moieties or functionalities with HCl complexation are chemical structures common to DmbgHCl, GuHCl, and BgHCl. Reagents may include 1,1-dimethylbiguanide, 1,1-dimethylbiguanide hydrochloride (DmbgHCl), melamine, melamine hydrochloride, and mixtures thereof.

[0065] Other compounds including guanidine with HCl are also suitable, for example, melamine hydrochloride (MeHCl) and methylammonium chloride can provide similar results. Other guanidine-containing compounds that may achieve similar results in this context include triguanidines (the basic structure of triguanidines is: ), such as carboxamidinoiminodicarbonimide diamide hydrochloride.

[0066] Examples of guanidines, biguanides, biguanidines and triguanidines that produce similar results include chlorhexidine and chlorhexidine salts, analogs and derivatives such as chlorhexidine acetate, chlorhexidine gluconate and chlorhexidine hydrochloride, chlorpheniramine, alexidine and polyhexanide. Other examples of guanidines, biguanides, biguanidines and triguanidines that can be used according to the present invention are chlorproguanil hydrochloride, proguanil hydrochloride (currently used as an antimalarial agent), metformin hydrochloride, phenformin hydrochloride and buformin hydrochloride (currently used as an antidiabetic agent).

[0067] As discussed above, the guanidine part of the reagent may or may not be complexed with HCl. Similar results can be achieved with any hydrogen halide complexed reagent. The guanidine part of the reagent without HCl complex can also be mixed with other reagents (such as other reagents with HCl complex discussed in U.S. Patent Application No. 17 / 112,076, which is incorporated herein by reference in its entirety). They can include at least one functionality selected from guanidine, urea, imidazole and methylammonium. The reagent can be associated with HCl or Cl. The reagent can include at least one of guanidine hydrochloride, biguanidine hydrochloride, dimethylbiguanidine hydrochloride, methylammonium chloride. An important criterion can be whether the reagent or reagent mixture has a liquid phase when it decomposes in the temperature range of low-temperature nitrocarburizing (e.g., 450°C to 500°C). The degree to which the reagent evaporates without decomposition before reaching that temperature range is an important consideration.

[0068] The reagents used in the treatment disclosed herein include those containing non-polymeric N / C / H compounds. A mixture of different non-polymeric N / C / H compounds is included. Non-polymeric N / C / H compounds can supply nitrogen atoms and carbon atoms for surface formation, including simultaneous surface hardening, such as carburizing, nitriding and / or carbonitriding of product 210. A mixture of these compounds can be used to customize specific non-polymeric N / C / H compounds for specific operating conditions required for simultaneous surface hardening. Non-polymeric N / C / H compounds can be used for any surface changes, including hardening and changing any other surface property changes described herein. The reagent may have non-guanidine additives. The list of additives includes, but is not limited to: ammonium chloride, urea, melem, melam, imidazole, imidazole hydrochloride, methylamine, methylammonium chloride, dicyandiamide, acetamidine, acetamidine hydrochloride, ethylamine, ethylamine hydrochloride, formamidine, formamidine hydrochloride and mixtures thereof.

[0069] The non-polymeric N / C / H compound that can be used in the treatment disclosed herein can be a compound that (a) contains at least one carbon atom, (b) contains at least one nitrogen atom, (c) contains only carbon, nitrogen, hydrogen, and optionally halogen atoms, (d) is solid or liquid at room temperature (25° C.) and atmospheric pressure, and (e) has a molecular weight of ≤5,000 Daltons. Non-polymeric N / C / H compounds having a molecular weight of ≤2,000 Daltons, ≤1,000 Daltons, or even ≤500 Daltons are included. Non-polymeric N / C / H compounds containing a total of 4 to 50 C atoms + N atoms, 5 to 50 C atoms + N atoms, 6 to 30 C atoms + N atoms, 6 to 25 C atoms + N atoms, 6 to 20 C atoms + N atoms, 6 to 15 C atoms + N atoms, and even 6 to 12 C atoms + N atoms are included.

[0070] Specific classes of non-polymeric N / C / H compounds that can be used with the disclosed treatments include primary amines, secondary amines, tertiary amines, azo compounds, heterocyclic compounds, ammonium compounds, azides, and nitriles. Of these compounds, compounds containing 4 to 50 C atoms + N atoms are desirable. Compounds containing 4 to 50 C atoms + N atoms, alternating C=N bonds, and one or more primary amine groups are included. Examples include melamine, aminobenzimidazole, adenine, benzimidazole, guanidine, biguanidine, triguanidine, pyrazole, cyanamide, dicyandiamide, imidazole, 2,4-diamino-6-phenyl-1,3,5-triazine (benzoguanamine), 6-methyl-1,3,5-triazine-2,4-diamine (acetoguanamine), 3-amino-5,6-dimethyl-1,2,4-triazine, 3-amino-1,2,4-triazine, 2-(aminomethyl)pyridine, 4-(aminomethyl)pyridine, 2-amino-6-methylpyridine and 1H-1,2,3-triazolo(4,5-b)pyridine, 1,10-phenanthroline, 2,2'-bipyridine and (2-(2-pyridyl)benzimidazole). Specific triguanidines include 1,3-bis(diaminomethylene)guanidine and N-carbamimidyl imine dicarboxamide.

[0071] Also included are three triazine isomers, and various aromatic primary amines containing 4 to 50 C atoms + N atoms, such as 4-methylaniline (p-toluidine), 2-toluidine (o-toluidine), 3-methylaniline (m-toluidine), 2-aminobiphenyl, 3-aminobiphenyl, 4-aminobiphenyl, 1-naphthylamine, 2-naphthylamine, 2-aminoimidazole and 5-aminoimidazole-4-carbonitrile. Also included are aromatic diamines containing 4 to 50 C atoms + N atoms, such as 4,4'-methylene-bis (2-toluidine), benzidine, 4,4'-diaminodiphenylmethane, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene and 2,3-diaminonaphthalene. Also included are hexamethylenetetramine, benzotriazole and ethylenediamine.

[0072] Any reagent described herein can be associated with HCl. In some cases, HCl can help depassivation or other chemical processes. In some cases, HCl association can increase the phase transition temperature of the reagent.

[0073] Another class of compounds including some of the above compounds is a compound that forms a nitrogen-based chelating ligand (e.g., a guanidine moiety) and a polydentate ligand containing two or more nitrogen atoms arranged to form separate coordination bonds with a single central metal atom. Compounds that form bidentate chelating ligands of this type are included. Examples include o-phenanthroline, 2,2'-bipyridine, aminobenzimidazole, and proguanil. In addition to [HNC(NH2)2], the guanidine moiety can also be more generally represented by [R-(H2NC=NH)]. Urea moieties having [R-NH(H2NC=O)] are included.

[0074] Yet another class of non-polymeric N / C / H compounds included are compounds described in WO 2016 / 027042 (the disclosure of which is incorporated herein in its entirety) for producing carbon nitride and / or one (or more) carbon nitride intermediates. The intermediate species may participate in or contribute to the low temperature activation and hardening of the article 210. Precursors that may include melamine and GuHCl may form various carbon nitride species. These species, having the empirical formula C3N4, include stacked layers or sheets one atom thick, the layers being formed of carbon nitride, in which there are three carbon atoms for every four nitrogen atoms. Solids containing as few as 3 such layers and as many as 1000 or more layers are possible. Although carbon nitride is made in the absence of other elements, doping with other elements is contemplated.

[0075] Yet another included subgroup of included non-polymeric N / C / H compounds are compounds containing 20 or fewer C atoms + N atoms and at least 2 N atoms.

[0076] In some cases, at least two of the N atoms in these compounds are not primary amines attached to a 6-carbon aromatic ring, either directly or through an intermediate aliphatic moiety. In other words, while one or more of the N atoms in these particular non-polymeric N / C / H compounds may be primary amines attached to a 6-carbon aromatic ring, at least two of the N atoms in these compounds should be in a different form, e.g., a secondary or tertiary amine or a primary amine attached to something other than a 6-carbon aromatic ring.

[0077] The N atoms in this subgroup of non-polymeric N / C / H compounds (i.e., non-polymeric N / C / H compounds containing 20 or fewer C atoms + N atoms and at least 2 N atoms) may be linked to each other, such as occurs in an azole moiety, but more typically are linked to each other via one or more intermediate carbon atoms. Urea may also be included.

[0078] In this subgroup of non-polymeric N / C / H compounds, compounds containing 15 or less C atoms + N atoms and compounds containing at least 3 N atoms are included. Compounds containing 15 or less C atoms + N atoms and at least 3 N atoms are included.

[0079] This subgroup of non-polymeric N / C / H compounds can be considered to have a relatively high degree of nitrogen substitution. In this context, a relatively high degree of nitrogen substitution will be considered to mean that the N / C atomic ratio of the compound is at least 0.2. Included are compounds with an N / C atomic ratio of 0.33 or greater, 0.5 or greater, 0.66 or greater, 1 or greater, 1.33 or greater, or even 2 or greater. Included are non-polymeric N / C / H compounds with an N / C atomic ratio of 0.25 to 4, 0.3 to 3, 0.33 to 2, and even 0.5 to 1.33.

[0080] Included in this subgroup are non-polymeric N / C / H compounds containing 10 or fewer C+N atoms, especially compounds having an N / C atomic ratio of 0.33 to 2 and even 0.5 to 1.33.

[0081] Included in this subgroup are non-polymeric N / C / H compounds containing 8 or fewer C+N atoms, especially compounds having an N / C atomic ratio of 0.5 to 2 or even 0.66 to 1.5, especially triguanidine-based agents.

[0082] In order to achieve this relatively high degree of nitrogen substitution, the non-polymeric N / C / H compounds of this subgroup may contain one or more nitrogen-rich moieties, examples of which include imine moieties [C=NR], cyano moieties [-CN], and azo moieties [RN=NR]. These moieties may be part of a 5- or 6-membered heterocyclic ring containing one or more additional N atoms, such as occurs when the imine moiety forms part of an imidazole or triazine group or when the oxazole moiety forms part of a triazine or triazole group.

[0083] These moieties may also be independent in the sense that they are not part of a larger heterocyclic group. If this is the case, two or more of these moieties may be linked to each other via an intermediate C atom and / or N atom, such as occurs, for example, when multiple imine moieties are linked to each other via an intermediate N atom, such as occurs in 1,1-dimethylbiguanidine hydrochloride, or when a cyano group is linked to an imine moiety via an intermediate N atom, such as occurs in 2-cyanoguanidine. Alternatively, the moiety may simply be pendant from the rest of the molecule, such as occurs in 5-aminoimidazole-4-carbonitrile, or the moiety may be directly attached to a primary amine, such as occurs in 1,1-dimethylbiguanidine hydrochloride, formamidine hydrochloride, acetamidine hydrochloride, 2-cyanoguanidine, cyanamide, and cyanoguanidine monohydrochloride.

[0084] In non-polymeric N / C / H compounds containing one or more secondary amines, the secondary amine may be part of a heterocycle containing 0, 1 or 2 additional N atoms. An example of such a compound, in which the secondary amine is part of a heterocycle containing no additional N atoms, is 1-(4-piperidinyl)-1H-1,2,3-benzotriazole hydrochloride. Examples of such a compound, in which the heterocycle contains one additional N atom, are 2-aminobenzimidazole, 2-aminomethylbenzimidazole dihydrochloride, imidazole hydrochloride, and 5-aminoimidazole-4-carbonitrile. An example of such a compound, in which the secondary amine is part of a heterocycle containing two additional N atoms, is benzotriazole. Alternatively, the secondary amine may be attached to a cyano moiety, such as occurs in 2-cyanoguanidine and cyanoguanidine monohydrochloride.

[0085] In this subgroup of non-polymeric N / C / H compounds containing one or more tertiary amines, the tertiary amine may be part of a heterocycle containing an additional 1 or 2 N atoms, an example of which is 1-(4-piperidinyl)-1H-1,2,3-benzotriazole hydrochloride.

[0086] In some variations, the non-polymeric N / C / H compound used will contain only N atoms, C atoms, and H atoms. The specific non-polymeric N / C / H compound used will be halogen-free. In other aspects of the disclosure, the non-polymeric N / C / H compound may contain one or more optional halogen atoms or may be associated or complexed with one or more optional halogen atoms.

[0087] One way this can be achieved is by including a hydrohalic acid, such as HCl, in the compound in an associated or complexed form. If this is the case, such a non-polymeric N / C / H compound is referred to in the present disclosure as being "complexed". On the other hand, if the non-polymeric N / C / H compound has not been complexed with such an acid, the compound is referred to in the present disclosure as being "uncomplexed". In those cases where neither "complexed" nor "uncomplexed" is used, it will be understood that the term in question refers to both complexed and uncomplexed non-polymeric N / C / H compounds.

[0088] If desired, the non-polymeric N / C / H compounds of the present disclosure may be complexed with suitable halogen acids, such as HCl and the like (e.g., HF, HBr, and HI). In this context, "complexed" will be understood to mean the type of association that occurs when a simple halogen acid, such as HCl, is combined with a nitrogen-rich organic compound, such as 2-aminobenzimidazole. Although HCl may dissociate when both are dissolved in water, 2-aminobenzimidazole does not. In addition, when the water evaporates, the solid obtained is composed of a mixture of these individual compounds on an atomic basis, such as a complex. The solid is not entirely composed of salts, in which the Cl- anions from the HCl are ionically bound to the N atoms in the 2-aminobenzimidazole, which have become positively charged by absorbing H+ cations from the HCl.

[0089] What you can do with setting 200

[0090] General property change treatment

[0091] The treatments mentioned below can be performed before, after, or during application of the laser 222 and / or the powder / gas 224 via the arrangement 200. In one example, the treatments described below (e.g., hardening) can be performed after the reagent in the powder / gas 224 has been applied to the surface 210a and chemically activated via the laser 222. In another example, the treatments described below can be performed while the reagent in the powder / gas 224 is being applied to the surface 210a and / or the reagent is activated via the laser 222. It should be understood that other variations are within the scope of the present disclosure.

[0092] The treatments disclosed herein can change the mechanical, chemical, and electrical properties of the surface 210a of the article 210. Such treatments can also change the thermodynamic, bioactive, and / or magnetic properties of the surface 210a of the article 210. For any hardening process disclosed herein, treatments including, for example, applying the reagents disclosed herein can activate the surface. The treatment can protect portions of the surface from the application of other treatments and / or exposure to liquid or gaseous substances. An example is a metal (e.g., copper) treatment that prevents portions from being exposed to, for example, vapors, such as those produced by the pyrolysis of a chemical reagent (e.g., any chemical reagent disclosed, described, cited, or implied herein). The surface 210a of the article 210 can have one or more treatment types / compositions to apply different properties to different portions of the same article 210.

[0093] Exemplary treatments may be applied to impart or improve mechanical or physical properties, including but not limited to hardness, wear resistance, and Young's modulus of the surface. Exemplary treatments may be applied to impart improved chemical properties on the surface, such as corrosion resistance. The treatments may increase the electrical resistance of the surface 210a. The treatments may reduce the hydrogen permeability of the surface portion 210a.

[0094] Suitable treatments produce a heterogeneous top amalgam of iron or nickel-based alloy metal atoms. Some such treatments include one or more metal phases, including at least one or more of austenite, martensite, and ferrite. Some such treatments contain one or more of the following: interstitial carbon atoms, interstitial nitrogen atoms, a dispersion of fine metal carbide precipitates, a dispersion of fine metal carbide precipitates, a dispersion of fine metal nitride precipitates, coarse metal carbide precipitates, and coarse metal nitride precipitates.

[0095] After the treatment is applied, a second treatment may use the portion of the article 210 affected by the first treatment to change the properties of the underlying article 210. For example, the heat treatment may cause the agent to passivate the article 210 for a hardening process, such as nitriding, carburizing, and nitrocarburizing in the hardening processes discussed and / or cited herein by reference. Heating the area affected by the first treatment may also cause a hardening process, for example, in which nitrogen and / or carbon released during the treatment diffuses into the surface of the article 210, thereby hardening the surface of the article 210. Exposing the treated surface to a certain gas or agent may cause a skin layer to form at the surface of the article.

[0096] Another treatment that can be performed using the arrangement 200 is cleaning the surface 210a. This cleaning can be achieved, in particular, by applying a laser 222 to the surface 210a. Cleaning the surface 210a can also occur by other means (e.g., other types of ablation and / or mechanical cleaning) before applying the reagent and applying the laser. More generally, cleaning the surface 210a can include cleaning by laser 222, cleaning by heating (via laser 222 or other means), cleaning by resistive heating, cleaning by induction, cleaning by convection, electron beam cleaning, and cleaning by reaction.

[0097] Hardening

[0098] One of the processes disclosed herein for changing the properties includes a method for hardening the article 210. The present disclosure may facilitate and / or perform any hardening process explicitly described and / or implied or incorporated by reference herein. Such hardening processes may include interstitial injection and / or diffusion of atomic substances. Such hardening processes include any process for hardening steel or alloys using nitrogen and / or carbon diffusion. Hydrogen diffusion may also be part of these processes. These processes include conventional carburizing, nitriding, carbonitriding and nitrocarburizing, and low-temperature carburizing, nitriding, carbonitriding and nitrocarburizing. As described herein, the process includes a hardening process involving the use of reagents or other chemicals. The reagent can activate the metal for hardening, such as by providing a passivation layer so that it allows the diffusion of nitrogen and / or carbon. The process disclosed herein may also be used in a hardening process (e.g., a machining technique) that does not involve the diffusion of carbon or nitrogen. The process described herein may be compatible with one or more of these hardening processes, wherein the process is performed simultaneously and / or synergistically. In some cases, the processes described herein may also be used to prevent or inhibit hardening and / or other physical, chemical, and electrical processes on certain portions of article 210 .

[0099] More than one hardening treatment described herein may be performed. For example, with respect to nitrogen and carbon introduction, the hardening treatment may be applied simultaneously, sequentially, or alternatingly in stages or pulses. The hardening treatment may be applied in combination with any other treatment described herein, including the property-changing treatments described above.

[0100] The hardening and / or property-changing treatment may form a surface layer or an outer layer of surface hardening. That layer may increase and / or improve at least one of hardness, corrosion resistance, and wear resistance. The layer may change other properties of the surface with or without the formation of a surface layer, including but not limited to mechanical properties, elasticity, magnetic properties, thermodynamic properties, bioactive properties, electrical properties, and mass density.

[0101] Although each creative aspect, concept and feature of the present invention can be described and shown herein as embodied in combination in exemplary embodiments, these various aspects, concepts and features can be used individually or in various combinations and sub-combinations thereof in many alternative embodiments. Unless explicitly excluded herein, all such combinations and sub-combinations are intended to fall within the scope of the present invention. Further, although each alternative embodiment (such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives to form, assembly and function, etc.) about each aspect, concept and feature of the present invention may be described herein, this description is not intended to be a complete or exhaustive enumeration of available alternative embodiments (whether currently known or developed later). Those skilled in the art can easily incorporate one or more of the creative aspects, concepts or features into additional embodiments and uses within the scope of the present invention, even if such embodiments are not explicitly disclosed herein. Additionally, even if some features, concepts or aspects of the present invention can be described herein as preferred arrangements or methods, this description is not intended to imply that such features are necessary or necessary, unless it is explicitly stated that the situation is so. Further, exemplary or representative values ​​and ranges may be included to help understand the present disclosure, however, such values ​​and ranges should not be interpreted in a limiting sense, but are intended to be critical values ​​or ranges only when explicitly stated as such. Further, exemplary or representative values ​​and ranges may be included to help understand the present disclosure, however, such values ​​and ranges should not be interpreted in a limiting sense, but are intended to be critical values ​​or ranges only when explicitly stated as such. Parameters identified as "approximately" or "about" a specified value are intended to include both the specified value and the value within 10% of the specified value, unless otherwise explicitly stated. In addition, it should be understood that the drawings attached to the present application may but need not be drawn to scale, and therefore can be understood to teach various ratios and proportions apparent in the drawings. In addition, although various aspects, features and concepts may be explicitly identified herein as being creative or forming part of the present invention, such identification is not intended to be exclusive, but there may be creative aspects, concepts and features that are fully described herein without being explicitly identified as such or identified as part of a specific invention, and the present invention is instead set forth in the appended claims. Descriptions of exemplary methods or processes are not limited to including all steps as required in all cases, nor should the order in which the steps are presented be construed as required or necessary unless expressly so stated.

Claims

1. A method of treating an article made of a self-passivating metal to improve the surface properties of the metal, comprising: applying an agent to a surface portion of the article; as well as Laser light is applied to the surface portion of the article to chemically activate the agent, wherein the chemical activation of the agent treats the surface portion, thereby modifying one or more properties of the surface portion.

2. The method of claim 1, wherein applying the reagents comprises applying at least one of the reagents via: at least one of a powder jet, a liquid jet, or a vapor jet; High-pressure nozzles using inert gas; the voltage potential difference between the reagent and the surface moiety; Micro-head flow jet; as well as 3D electronic printer system.

3. The method of any one of claims 1 and 2, further comprising performing said applying said agent and said applying said laser to another surface portion of said article.

4. The method of any one of claims 1 to 3, wherein the reagent comprises at least one of a guanidine functionality and a halide association.

5. The method of any one of claims 1 to 4, wherein the guanidine functionality comprises guanidine chloride, biguanide, biguanide hydrochloride, 1,1-dimethylbiguanide, and 1,1-dimethylbiguanide hydrochloride.

6. The method of any one of claims 1 to 5, wherein the reagent comprises ammonium chloride, urea, melem, melam, imidazole, imidazole hydrochloride, methylamine, methylammonium chloride, dicyandiamide, acetamidine, acetamidine hydrochloride, ethylamine, ethylamine hydrochloride, formamidine and formamidine hydrochloride.

7. The method according to any one of claims 1 to 6, wherein the laser light is a co-linear coherent laser light.

8. The method of any one of claims 1 to 7, wherein the laser generating the laser light comprises at least one of the following: Fiber lasers; Gas lasers; Excimer laser; Excitation complex laser; Liquid-based lasers; Dye-based lasers; Chemical lasers; Solid-state lasers; Chemical lasers; Semiconductor lasers; diode-based lasers; Infrared lasers; as well as Ultraviolet laser.

9. The method of claim 8, wherein the gas laser comprises at least one of a CO2 laser and a HeNe laser.

10. The method of claim 8, wherein the solid-state laser comprises at least one of an yttrium aluminum garnet (YAG) laser, a ruby ​​laser, a high-pitched titanium laser, a high-pitched ice laser, and a titanium sapphire laser.

11. The method of any one of claims 1 to 10, wherein the surface portion has mm 2 or micrometer 2 Surface area of ​​magnitude.

12. The method of claim 11, wherein the heating produced by the laser in the surface portion is confined to the surface region.

13. The method of claim 11, wherein the heating produced by the laser in the surface portion includes a region between a laser source and the surface region.

14. The method of claim 12, wherein the laser-induced heating is insufficient to cause grain growth.

15. The method of claim 12, wherein the laser-induced heating is sufficient to cause pyrolysis of the reagent.

16. The method of claim 12, further comprising introducing an inert gas into the environment of the article prior to or concurrently with said heating.

17. The method of claim 16, wherein the inert gas prevents oxidation of the surface moiety.

18. The method of any one of claims 1 to 17, wherein said applying the reagent and said applying the laser are performed simultaneously.

19. The method of any one of claims 1 to 18, wherein said applying said laser causes a chemical reaction in said article.

20. The method of any one of claims 1 to 19, wherein at least one of the following: said applying said agent does not coat said article; and The reagents are recycled to improve utilization efficiency.

21. The method of any one of claims 1 to 20, wherein the pressure in the environment of the article is 1 ATM or higher.

22. A method as claimed in any one of claims 1 to 21, wherein the treating comprises hardening the article.

23. The method of claim 22, further comprising at least one of the following: interstitial implantation and diffusion of atomic hydrogen, carbon and nitrogen into said surface portions; Improving the wear resistance of the surface portion; Improving the corrosion resistance of the surface portion; increasing the Young's modulus of the surface portion; increasing the electrical resistance of the surface portion; and The hydrogen permeability of the surface portion is reduced.

24. The method of any one of claims 1 to 23, wherein said applying said agent and said applying laser minimizes carbide and nitride precipitation in said surface portion.

25. The method of claim 24, wherein any carbide and nitride precipitates produced during said applying said reagent and said applying said laser are finely dispersed.

26. The method of any one of claims 1 to 25, wherein said treating of said metal occurs in one minute or less.

27. The method of claim 26, wherein said treating of said metal occurs while said article is in at least one of a machining and fabrication process.

28. The method of claim 26, wherein said processing of said metal limits the amount of spent reagents.

29. The method of any one of claims 1 to 28, further comprising cleaning the surface portion prior to said applying the agent and said applying the laser.

30. The method of claim 29, wherein said cleaning said surface portion comprises at least one of cleaning by laser, cleaning by heating, cleaning by resistive heating, cleaning by induction, cleaning by convection, electron beam cleaning, and cleaning by reactive means.

31. The method of any one of claims 1 to 30, wherein the article comprises a self-passivating metal.

32. The method of claim 31, wherein the article further comprises stainless steel, nickel-based alloys, and cobalt-based alloys having 5 wt% to 50 wt% Ni and at least 10 wt% Cr.

33. The method of claim 31, wherein the article further comprises a high manganese stainless steel or titanium-based alloy having at least 10 wt. % Cr.

34. The method of claim 31, wherein the article further comprises at least one of the following steel alloys: 316L, 6Mo, 6HN, Incoloy 825, Inconel 625, Hastelloy C22, and Hastelloy C276.

35. The method of claim 31, wherein the surface portion has a continuous protective coating.

36. The method of claim 35, wherein the continuous protective coating is a passivation layer formed of chromium oxide or titanium oxide.

37. The method of any one of claims 1 to 36, wherein the article has a Bayer ratio layer.

38. The method of any one of claims 1 to 37, wherein the article is at least one of forged, formed, and stamped.

39. The method of any one of claims 1 to 38, wherein the article is additively manufactured.

40. An article prepared according to any one of claims 1 to 39.

41. An apparatus for performing the method of any one of claims 1 to 39.

42. A system for performing the method of any one of claims 1 to 39.

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