MÉTODO E DISPOSITIVO PARA REPARAÇÃO POR PULVERIZAÇÃO A FRIO DE SUPERFÍCIES METÁLICAS REATIVAS

Description

1 / 25 METHOD AND DEVICE FOR COLD SPRAY REPAIR OF REACTIVE METALLIC SURFACES Divided from BR112025009393-2 Field

[0001] The present invention relates to thermal spraying technology and, more specifically, to the repair of reactive metal components and protective coatings. Background

[0002] Reactive metals have been used in many industrial applications, including in the energy, mining, oil and gas, and chemical sectors. The most common reactive metals include titanium, zirconium, niobium, and tantalum. For example, valves used to regulate the flow of materials such as liquids, gases, and slurries in industrial applications comprise components that include reactive metals. An example of such a valve is a metal-seated ball valve (MSBV).

[0003] MSBVs and other industrial equipment constructed with reactive metals coated with hard metal oxides may be used, for example, in hydrometallurgical plants where severe operating conditions exist. Severe operating conditions may include conditions involving high pressures, temperatures and / or aggressive chemicals. For example, hydrometallurgical plants may include high-pressure acid leaching circuits and / or pressure oxidation autoclave circuits with components comprising, for example, reactive metals and sometimes coated with hard reactive metal oxides or ceramics. Failure of these components, for example, failure of a valve to isolate a Petition 870260054675, dated 05 / 06 / 2026, page 14 / 60 2 / 25 process vessel, is particularly dangerous in these aggressive and toxic environments, as it can potentially harm workers on site or cause damage to surrounding structures or equipment.

[0004] In one example, severe operating MSBVs may be employed in operating conditions involving high pressure, high temperature, and / or highly corrosive environments. The ball and seats that make up the MSBVs may be manufactured, for example, from forged Inconel™ 718 PH alloy, super duplex stainless steel alloys, and various grades of titanium, including grades 2, 3, 4, or 12. To extend the service life of these components, the valve sealing surfaces may be coated with a thermally sprayed wear-resistant hard oxide or ceramic, including TiO2, Cr3C2, Cr2O3, or Al2O3. However, valve failure may still be caused by degradation of the sealing surface. For example, failures may include: (1) valve failure for open or closed cycle due to excessive friction between the sealing surfaces; and (2) valve failure during isolation due to failures in the sealing surfaces.Degradation of the sealing surface can, for example, be caused by wear mechanisms, including plastic deformation, abrasion, erosion, galling, and scaling. These wear mechanisms can also be combined with corrosion, for example, corrosion caused by H3O+, S2-, Cl-, or F- ions in solution or by trapped solid particles (FeS, Fe2S, FeAsS) present in the flow between the sealing surfaces. Although the example given above refers to valves, and specifically MSBVs, many other industrial applications and articles have a coating. Petition 870260054675, dated 05 / 06 / 2026, page 15 / 60 3 / 25 similar reactive metal protector and sometimes a hard metal oxide or ceramic coating on the reactive metal surface.

[0005] Ball valve components in high-wear environments have previously been repaired in two ways, depending on the extent of the damage. When the depth of the damage to the ball valve is only a few hundred micrometers and therefore only affects the lining, machining and redepositioning are used, conventional thermal spray coating is employed. For more severe damage extending to the forged metals, the ball or seat components need to be remelted and remanufactured. Prolonged damage to these components therefore represents significant repair costs and delays in manufacturing processes as the components are remanufactured. In most cases, the damaged component is simply replaced with a new component, as this can be more economical than remanufacturing, and the damaged components are returned to the foundry as scrap metal. Brief description of the figures

[0006] Figure 1 is a schematic of a device for performing a method to restore a protective coating, repair a damaged surface, or rebuild an eroded wear surface of industrial equipment, as described in this disclosure.

[0007] Figure 2 shows an example of a ball valve failure due to erosion. Petition 870260054675, dated 05 / 06 / 2026, page 16 / 60 4 / 25

[0008] Figure 3 shows an example of ceramic coating flaking failure on the ball of a ball valve.

[0009] Figure 4 shows an example of a ball valve failure due to flashing (i.e., drawing).

[0010] Figure 5 shows a block morphology of a reactive metal powder and its microstructure.

[0011] Figure 6 shows a coral-like morphology of a reactive metallic powder and its microstructure.

[0012] Figure 7 shows an example of a coating made by spraying particles of block morphology according to an embodiment of the invention.

[0013] Figure 8 shows an example of a coating made by spraying particles with a coral-like morphology, according to one embodiment of the invention.

[0014] Figure 9 shows an example of metal-seated ball valve components that can be coated according to the methods described herein. Detailed description

[0015] In one aspect, the present disclosure provides a method for recoating a damaged reactive metallic surface using a cold spray coating of reactive metals. The recoating of damaged metals may include, for example, restoring a protective coating on a substrate, repairing or reconstructing an eroded or damaged wear surface comprising a reactive metal. The method can be used to repair damage that otherwise could not be corrected by conventional means such as welding or weld overlay. The methods and devices described herein are applicable to Petition 870260054675, dated 05 / 06 / 2026, page 17 / 60 5 / 25 any number of surfaces, substrates or components comprising or covered by a reactive metal (broadly referred to herein as reactive metallic surfaces), such as for high-wear environments.

[0016] Cold spraying is a solid-state deposition process in which a jet of high-speed particles (e.g., 300–1200 m / s) strikes a surface. The particles in the cold spraying process are accelerated in a spray gun nozzle along with a pressurized gas. Unlike thermal spraying processes (as discussed later), cold spraying utilizes lower temperature and higher speed spraying.

[0017] In one aspect, the method comprises providing an inert gas and reactive metallic particles in powder form and heating the particles to a limiting temperature that is lower than the melting point of the particles. The gas with entrained metallic particles is emitted from a nozzle at a selected velocity to accelerate the particles to a limiting velocity while maintaining the solid state of the particles. The particles can be directed to a reactive metallic surface, for example, a reactive base metal surface of a substrate and / or an existing wear-resistant protective coating comprising a reactive metal. On impact, the particles plastically deform to bond to the base metal and / or the existing protective coating, to form a repaired reactive metallic surface that is continuous with the existing reactive metallic surface (i.e., continuous with the base metal). Petition 870260054675, dated 05 / 06 / 2026, p. 18 / 60 6 / 25 reactive or with a wear-resistant protective coating, when present). The reactive metal particles may be in powder form and may be non-spherical.

[0018] Upon impact with the target surface, the particles undergo severe plastic deformation. Plastic deformation can lead to the particles bonding together and to the impact surface, and can also result in coating buildup. The gas temperature is maintained below the melting points of the particles, so they remain in a solid state. This method can have distinct advantages and unique applications compared to thermal spraying processes due to its operation at low temperatures (e.g., temperature below the melting point of the particles). Thermal spray coating deposition processes include plasma spraying, arc spraying, flame spraying, and high-velocity oxyfuel (HVOF) spraying. Thermal spraying processes use droplets of molten or semi-molten material, e.g., metals, ceramics, and polymeric materials, which are heated and deposited onto a surface.These processes have been used in the aerospace, shipping, oil and gas, and mining industries and can be used to form coatings on materials. Unlike a thermal spraying process, a cold spraying process reduces or eliminates harmful phase transformations, oxidation, or decarburization of powders, and therefore the method may be suitable for heat-sensitive raw materials. Reactive metals are highly reactive and, if they reach their melting temperature, need to be fully coated. Petition 870260054675, dated 05 / 06 / 2026, page 19 / 60 7 / 25 (shielded) by inert gases in an ultra-clean working environment. Furthermore, high impact-induced deformations and the heat generated in a conventional thermal spraying process can cause partial or complete recrystallization and the evolution of an ultrafine microstructure, which can be detrimental to the coating's hardness or toughness. The continuous impact of high-speed particles in the cold spraying process, as disclosed herein, can produce a blasting and compaction effect, which can result in densification and coating deposition with near-theoretical density (i.e., the apparent density of a material without porosity and stoichiometric composition). Additionally, spray coatings according to this disclosure may have residual compressive stresses and a hardening effect due to high-speed impact and plastic deformation of the surface layer.

[0019] Coating the surface in accordance with this disclosure may require a dense coating, for example, comprising a porosity of less than about 1%. The coating may also require high adhesion strength to accommodate larger repair surface areas or greater thicknesses, for example, greater than about 2-3 mm, and coating delamination caused by the buildup of residual stress. Coating a reactive metallic surface with a pre-existing protective coating over forged or cast metal of the same or different material may be carried out by methods in accordance with this disclosure. In one example, the method of coating the reactive metallic surface comprises bonding metal particles to the existing margins of the Petition 870260054675, dated 05 / 06 / 2026, page 20 / 60 8 / 25 protective coating, so that the repair results in a continuous protective coating. Any one or more of the following process parameters: (1) powder or particle morphology, (2) cold spray device, (3) nozzle or spray gun travel speed and powder feed rate, (4) gas temperature and pressure, (5) wear surface preparation, and (6) surface preheating, as described further herein, may be adjusted or modified to influence the coating.

[0020] In the methods described herein, the particles remain in a solid powder state throughout the cold spraying process and deform plastically upon impact with the target surface. The particles comprise a non-spherical morphology. The inventors have found that the use of spherical morphology particles does not achieve the desired coating characteristics, such as density and porosity. For example, the particles may have a morphology of one or more angular, blocky, and coral-like shapes. The particles may comprise an equiaxed microstructure such that the dimensions in all directions are approximately equal. In one example, the grain sizes of particles may range from hundreds of nanometers to a few micrometers. Compared to spherical particles, non-spherical morphology may exhibit coatings with lower porosity, higher hardness, and greater deposition efficiency.Without intending to limit oneself to a particular theory, the non-spherical morphology of particles can result in a higher aerodynamic drag coefficient and... Petition 870260054675, dated 05 / 06 / 2026, page 21 / 60 9 / 25 Therefore, such particles can reach a true particle velocity closer to the gas velocity. Higher particle velocity can result in greater kinetic energy, which is favorable, for example, for the deposition of a dense, uniform, and non-porous coating. Furthermore, these non-spherical particles may exhibit greater deformability due to higher particle velocity, specific surface area, and initial equiaxed microstructure.

[0021] The particles comprise reactive metals. For example, the particles may comprise titanium powder or alloys thereof. For example, the particles may comprise commercial purity titanium grades 1, 2 or 4, or palladium-stabilized titanium alloy (Ti-Pd) grades 7, 11, 16 or 17, or ruthenium-stabilized titanium (Ti-0.1Ru) grade 27. Alternatively or additionally, the particles may comprise one or more other reactive metals, such as zirconium, niobium, tantalum or any alloys thereof.

[0022] The methods disclosed herein may include a cold spraying device, such as a spray gun or other nozzle configuration adjusted to emit accelerated particles entrained in a gas toward a reactive pure-grade or alloy metal surface requiring repair. The cold spraying device, for example, the spray gun, may be mounted about 40 mm from the surface requiring repair. The distance of the cold spraying device from the surface, however, may be greater or less than 40 mm depending on the powder used (e.g., the material and size of the powder), as well as adjusted from Petition 870260054675, dated 05 / 06 / 2026, p. 22 / 60 10 / 25 depending on the type of cold spray device to increase effectiveness. For example, placing a cold spray device nozzle too close to a surface can cause bow shock (i.e., a region of recirculated gas, high density and low velocity) which can negatively influence particle deposition. Additionally, positioning the cold spray nozzle too far from the surface can cause particles to lose speed upon interacting with the air, affecting the effectiveness of the cold spray. The nozzle can be a convergent-divergent nozzle, for example, a convergent-divergent hourglass-shaped nozzle (also known as a Laval nozzle). As an example, a commercially available Giken PCS-1000 Plasma spray gun comprising a Laval nozzle made of WC-Co. can be used.In another example, a commercially available Kinetik 4000 spray gun from Cold Gas Technology (CGT) Germany, with a Laval nozzle made of SiC and a preheating chamber, can be used.

[0023] The gases used to carry the metallic particles may be compressed air or any one or more compressed gases, such as nitrogen or helium (referred to herein as a “carrier gas”). The carrier gas may be preheated. In one example, the carrier gas may be preheated to a temperature between about 710°C and about 950°C, for example, about 750°C to about 900°C, or for example, about 800°C to about 850°C. The gas may be pressurized between about 4 MPa(g) and about 3.5 MPa(g), for example, the gas supply pressure may be about 3.5 MPa(g), or about 3.75 MPa(g), or about 4 MPa(g). Petition 870260054675, dated 05 / 06 / 2026, p. 23 / 60 11 / 25

[0024] A desired combination of metal particle powder feed rate and spray gun travel speed can be selected to promote coating adhesion to the reactive metal surface. The spray gun travel speed is the speed at which the spray gun nozzle travels a path to complete 1 pass over the surface to be coated. For example, the spray gun travel speed can be about 10 mm / s to about 600 mm / s, for example, about 30 mm / s to about 400 mm / s, or about 100 mm / s to about 300 mm / s. The variation in the metal particle powder feed rate and / or the spray gun travel speed can be balanced to control and achieve a certain coating thickness per pass.For example, a coating comprising a thickness of at least about 2 mm, or at least about 3 mm, or at least about 5 mm can be obtained by adjusting the powder feed rate and / or the travel speed of the spray gun. A very high feed rate can increase the risk of nozzle clogging due to the accumulation of deposits in the throat and on the nozzle walls. A low feed rate can increase heat buildup and surface temperature and eventually lead to greater powder deformation. However, it can cause surface oxidation and deteriorate the particle / surface adhesion properties.

[0025] The particle feed rate, or the rate at which particles are drawn into the gas, may be between about 1.5 g / min and about 60 g / min, for example, between Petition 870260054675, dated 05 / 06 / 2026, p. 24 / 60 12 / 25 approximately 10 g / min and approximately 56 g / min, or for example, between approximately 15 g / min and approximately 35 g / min, or for example, between approximately 20 g / min and approximately 30 g / min. Particles entrained in the gas can be accelerated in the gas stream.

[0026] A base metal or reactive metal surface onto which the particles are sprayed may comprise a pure or alloy grade of reactive metal similar to or equal to the reactive metal grade of the particles. In one example, the wear-resistant protective coating may similarly comprise a pure or alloy grade of reactive metal that is equal to or similar to the reactive metal grade of the particles. The protective coating material may be different from the underlying base metal material. The base metal, for example, may comprise rolled metal, cast metal, forged metal, or molten metal. In one example, an additional ceramic or oxide coating may be applied to the reactive metal surface after repair, or to the wear-resistant protective coating. The ceramic or oxide coating may comprise Cr2O3, TiO2, or other hard metal oxides.Ceramic oxide coatings can be applied using thermal spraying processes, such as air plasma spraying (APS) or high-velocity oxyfuel (HVOF).

[0027] The reactive metallic surface requiring coating can first be prepared by roughening the surface. Mechanical particle / surface anchoring and coating adhesion can be improved by roughening the surface before spray coating application. In cases where grains may become embedded in the surface, the surface can be prepared by Petition 870260054675, dated 05 / 06 / 2026, page 25 / 60 13 / 25 Abrasive blasting. Abrasive blasting, for example using high or low pressure abrasive blasting, can be carried out, for example, at an angle of 45° to the surface normal. After abrasive blasting, the surface can be cleaned by brushing and / or air blasting to remove abrasive blasting material residue from the surface. In other examples, the wear surface can be further prepared using laser surface structuring and ablation and / or grinding and machining. Laser ablation and laser surface structuring are particularly useful for preparing damaged surfaces with cracks, craters, small indentations or other surface features that cannot be practically removed by grinding or machining due to the geometry of the defect.

[0028] Wear surfaces of equipment comprising a reactive metallic surface requiring repair may be a component of a larger assembly or piece of equipment. In one example, the equipment may be constructed of a composite of two different metals, comprising a reactive base metal substrate and a wear-resistant protective coating. In another example, the reactive metallic surface may be constructed of a composite of two or more different metals, for example, three metals, and may comprise a reactive base metal substrate, a ductile intermediate layer, and a wear-resistant protective coating. The equipment requiring repair may be, for example, the inner surface of a metal-lined autoclave, a metallurgical or chemical process vessel, a Petition 870260054675, dated 05 / 06 / 2026, page 26 / 60 14 / 25 metal-coated nozzle cap, a metal-coated reducing flange, or a metal-seated ball valve. Damage to the reactive metal surface may be limited to erosion of the protective layer, or the damage may extend deeper into the reactive metal surface, for example, including erosion of the ductile intermediate layer when present and / or the reactive base metal layer. Figure 2 shows an example of ball valve failure due to erosion. Other examples of surface wear include coating flaking, as shown in Figure 3, drawing, as shown in Figure 4, cavitation wear, and impact wear. Damaged areas in the protective layer may be defined by a void in the protective layer that exposes the underlying metal. In the recoating process as described herein, the sprayed particles may adhere to the edges of the protective coating, creating the void to form a continuous repaired protective coating.In other examples, the particles may additionally bond to an underlying reactive metallic layer beneath the protective coating. For example, the particles may bond to both the base metal of the substrate and the protective coating, or to the base metal, the ductile layer, and the protective coating, provided each is compatible with the metal powder. Because metal powders do not bond to oxide coatings, such oxide coatings, if present, may be removed (e.g., if damaged) or masked during repair processes to allow the metal powders to bond to the reactive metallic surface or wear-resistant coating to restore the wear surface or coating. Petition 870260054675, dated 05 / 06 / 2026, p. 27 / 60 15 / 25 a condition similar to that of a new one. An oxide or ceramic coating can be reinserted as a top layer in a later step using thermal spraying processes, if desired.

[0029] Preheating the reactive metal surface before particle deposition can promote strong coating-to-surface bonding. This is due to the surface softening effect, which leads to intense plastic deformation, resulting in mechanical interlocking when the first layer of particle coating is deposited. Furthermore, the severe plastic deformation of the softened surface can help create a more oxide-free interface, which can then provide intimate contact between the sprayed particles and the surfaces, potentially increasing the likelihood of metallurgical bonding. In one example, a gas jet at a relatively low transverse velocity can be used to preheat the surface. In another example, a heating stage can be used to preheat the surface.For example, the surface can be preheated immediately before coating deposition using an 800°C gas jet with a spray gun travel speed of 200 mm / s (1 or 2 passes) and 50 mm / s (1 or 2 passes).

[0030] Figure 1 provides a schematic diagram 100 comprising a device for performing the method described herein for restoring a protective coating, repairing or rebuilding an eroded or damaged wear surface of industrial equipment. A pressurized gas reservoir 110 provides a pressurized carrier gas, such as Petition 870260054675, dated 05 / 06 / 2026, page 28 / 60 16 / 25 air, nitrogen or helium, to an electric heater 114 to increase and control the gas temperature between about 710°C and about 950°C. The pressurized carrier gas, supplied at a pressure between about 3.5 MPa(g) and about 4 MPa(g), is also directed to a powder feeder 112. The powder feeder 112 comprises non-spherical reactive metal powder particles. The particles are preferably of the same or similar reactive metal to that of the equipment 116 to be repaired, restored or rebuilt. The powder and gas converge in the cold spraying device 118, for example, in the spray gun, so that the particles are carried along in the gas. The temperature of the particles increases below the melting point of the particles due to the heated gas. The particles are then accelerated to supersonic speeds in the nozzle 120 of the spray gun together with the pressurized and preheated gas.Shortly before spraying the surface of equipment 116, the surface is blasted and may be preheated (not shown). The particles are then directed to the surface and deform plastically on impact, leading to bonding and coating buildup. Examples

[0031] In an example test, two non-spherical powder morphologies were tested. The first was obtained from Oerlikon Metco, Switzerland, with a blocky morphology, as shown in Figure 5, and the second was obtained from Cristal Metals, USA, with a coral-like morphology, as shown in Figure 6. The commercially available Giken Plasma and Kinetik 4000 spray guns were used for testing. In the Giken Plasma equipment, the gas pressure was 4 Petition 870260054675, dated 05 / 06 / 2026, page 29 / 60 17 / 25 For the Kinetik 4000, the following sets of gas supply pressure and gas preheating temperature conditions were used: 720°C - 760°C at 4 MPa and 800°C - 3.5 MPa. The gas preheating temperature was 800°C and 950°C before entering the nozzle.

[0032] Using the Giken Plasma spraying device, each of the two grade 4 titanium powder morphologies was sprayed using 3 passes (with a thickness of ~1 mm). After comparing the two morphologies using the same process conditions, observations showed that the blocky powder morphology led to lower porosity, while the coral-like morphology still provided acceptable porosity. For both coatings, grain inclusions were observed at the coating / surface interface, which could reduce adhesion strength. For blocky powder, smaller grains were also tested, which led to lower grain particle inclusions.

[0033] The block powder was also sprayed using the Kinetik 4000 spraying device from CGT Germany using two gas parameters, namely 720°C at 4 MPa and 800°C at 3.5 MPa, using 3 passes. Significantly lower porosity was measured for both, with an even lower value for the latter condition. Using the same spraying condition, the coatings were sprayed using 12 passes with a thickness of 5.6 mm. The coating porosity and grain inclusion remained significantly low. However, due to the accumulation of residual stresses, in some cases, the coatings were delaminated upon removal of the sample from the support. Petition 870260054675, dated 05 / 06 / 2026, page 30 / 60 18 / 25

[0034] Two other parameters were tested, including preheating the surface using a gas jet before feeding the powder into the nozzle, as well as a much smaller thickness per pass using a higher gun travel speed.

[0035] Surface preheating was performed using a gas jet with gun travel speeds of 200 mm / s and 50 mm / s. This was tested with and without thickness reduction per pass, increasing the gun speed to 500 mm / s. Surface preheating and coating thickness reduction per pass were effective in reducing residual stresses to a point where the coatings did not delaminate after removal.

[0036] To help improve adhesion, a lower feed rate was tested with a lower gun travel speed, maintaining surface preheating and reducing the thickness per pass. This resulted in an adherent coating that resists the mechanical stresses caused by backing removal and cutting, remaining adherent to the surface.

[0037] Tables 1 and 2 below show the powders, process parameters and coating characteristics of various tests according to the methods described above. Petition 870260054675, dated 05 / 06 / 2026, page 31 / 60 Table 1: Post and Process Parameters Powder Spraying Surface Preparation (grain size) Spraying System Substrate / Surface Dimension (mm) Preheating (gun travel speed mm / s) Gas Preheating Temperature (°C) Gas Pressure (MPa) Feed Rate (g / min) Gun Travel Speed ​​(mm / s) Number of Passes #1c Ti (coral) Grit-24 PG-LW 76.2x25.4 (3x1 inches) - 800 4 56 200 3 #2c Ti (coral) Grit-24 PG 76.2x25.4 (3x1 inches) - 950 4 56 200 3 #3c Ti (coral) Grit-24 PG-LW 76.2x25.4 (3x1 inches) - 800 4 56 200 8 #4c Ti (coral) Grit-24 PG-LW Specimen 25.4 (1 inch) diameter - 800 4 56 200 8 #5c Ti (coral) Grit-24 PG 76.2x25.4 (3x1 inches) - 800 4 20 200 3 #6c Ti (coral) Grit-24 PG 76.2x25.4 (3x1 inches) - 800 4 20 200 6 #7c Ti (coral) Grit-24 PG 76.2x25.4 (3x1 inches) - 800 4 20 600 12 #1b Ti (in blocks) Grit-24 PG 76.2x25.4 (3x1 inches) - 800 4 35 200 4 #2b Ti (in blocks) Grit-60 PG 76.2x25.4 (3x1 inches) - 800 4 20 200 5 19 / 25 Petition 870260054675, dated 05 / 06 / 2026, p. 32 / 60 Powder Spraying Surface Preparation (grain size) Spraying System Substrate / Surface Dimension (mm) Preheating (gun travel speed mm / s) Gas Preheating Temperature (°C) Gas Pressure (MPa) Feed Rate (g / min) Gun Travel Speed ​​(mm / s) Number of Passes #3b Ti (in blocks) Grit-60 CGT 76.2x25.4 (3x1 inch) - 720 4 25 200 3 #4b Ti (in blocks) Grit-60 CGT 76.2x25.4 (3x1 inch) - 800 3.5 25 200 3 #5b Ti (in blocks) Grit-60 CGT Specimen 25.4 (1 inch) diameter - 800 3.5 25 200 3 #6b Ti (in blocks) Grit-60 CGT 76.2x76.2 (3x3 inches) - 800 3.5 25 200 12 #7b Ti (in blocks) Grit-60 CGT 76.2x76.2 (3x3 inches) 200-1 passage 800 3.5 25 200 12 #8b Ti (in blocks) Grit-60 CGT 76.2x25.4 (3x1 inches) - 800 3.5 10 500 20 #9b Ti (in blocks) Grit-60 CGT 76.2x25.4 (3x1 inches) - 800 3.5 29 500 30 #10b Ti (in blocks) Grit-60 CGT 76.2x76.2 (3x3 inches) 50-2 passages 800 3,5 29 500 20 #11b Ti (in blocks) Grit-60 CGT 76.2x76.2 (3x3 inches) 50-2 passages 800 3.5 10 250 36 20 / 25 Petition 870260054675, dated 05 / 06 / 2026, p. 33 / 60 Table 2: Coating characteristics Sprayer Deposition Efficiency (%) Thickness (mm) Porosity Within passes (%) Porosity Between passes (%) Adhesion Strength (ksi) Qualitative Adhesion #1c 82 0.9 9 1.7 adherent #2c 70 1.1 10 1.2 adherent #3c 82 4.5 9 1.7 adherent #4c - 4.5 9 1.7 2.7±0.5 adherent #5c 88 4.5 10 5 flaking #6c 85 5 10 5 flaking #7c 90 5 1.7 1.1 adherent #1b 55 0.9 2.2 ± 0.7 2.2 ± 0.7 Interface Grains adherent #2b 60 1 2.6 ± 0.5 2.6 ± 0.5 - Adherent - Grain-free #3b 75 1.1 0.07±0.03 0.07±0.03 - Adherent - Grain-free #4b 99 1.3 0.02±0.01 0.02±0.01 - Adherent - Grain-free #5b 99 1.3 0.02±0.01 0.02±0.01 5±2 Adherent - Grain-free #6b 99 5.6 0.02±0.01 0.02±0.01 - Coating flaking #7b 99 5.8 0.02±0.01 0.02±0.01 - Coating flaking after cutting 21 / 25 Petition 870260054675, dated 05 / 06 / 2026, page 34 / 60 Sprayer Deposition Efficiency (%) Thickness (mm) Porosity Within passes (%) Porosity Between passes (%) Adhesion Strength (ksi) Qualitative Adhesion #8b 99 1.9 0.01 0.01 - Adherent - Grain-free #9b 99 3.1 0.01 0.01 - Adherent - Grain-free #10b 99 5.3 0.01 0.01 - Coating flaking #11b 99 4.9 0.01 0.01 > 9 ± 1 Adherent - Grain-free 22 / 25 Petition 870260054675, dated 05 / 06 / 2026, page 35 / 60 23 / 25

[0038] The process parameters can be adjusted based on the specific surface area of ​​the equipment or the surface area of ​​the substrate to be repaired, restored, or rebuilt. In Table 2 above, tests where the coating showed adhesion were considered successful. Tests that resulted in coating flaking were considered unsuccessful depositions, and the process parameters were adjusted. In test 1b, although the coating was adherent, it resulted in some grains at the coating interface. Therefore, the remaining tests were conducted with smaller grain sizes to help avoid grains at the interface. Figure 7 shows an example of a coating at 1000 µm magnification and at 100 µm magnification, made by spraying block-morphology particles according to one embodiment of this development.Figure 8 shows an example of a coating at 500 pm and 50 pm magnification, made by spray coating of particles with a coral-like morphology, according to one embodiment of this discovery.

[0039] In one example, the recoating method as disclosed herein can be used to restore a pre-existing protective coating on a surface. The protective coating may be formed of the same metal, a similar metal, or a different metal from that of the underlying base layer that forms the substrate. In another example, the recoating method can be used to repair a damaged substrate base layer, followed by the restoration of an external protective coating. In yet another example, the recoating method can be used to reconstruct a surface of Petition 870260054675, dated 05 / 06 / 2026, page 36 / 60 24 / 25 wear and tear of an industrial piece of equipment, including an eroded coating layer and a base layer.

[0040] Representative examples of components or equipment with reactive metal wear surfaces that can be repaired, restored, or rebuilt using the coating method described herein include: forged balls, seats, and stems of metal-seated ball valves, for example, such as the components shown in Figure 9; internal or external surfaces of forged or cast valve bodies; composite sprinklers as described in U.S. Patents Nos. 7,968,048 and 7,976,774, which are incorporated herein by reference; vortex locators, apex cones, and wear inserts for gas cyclones; dip tubes for introducing and / or removing process slurry from metallurgical equipment; agitator impellers or turbine discs and blades; internal surfaces of a metal-lined autoclave, metallurgical or chemical process vessel, a metal-lined nozzle cap, or a metal-lined reducing flange;Compartment walls, anti-vortex deflectors, immersion tube supports, sprinklers, and other internal devices for autoclaves and metallurgical or chemical reactors; devices for decelerating supersonic flow, as described in U.S. Patent No. 8,176,941, which is incorporated herein by reference; and devices for reducing pressure, as described in U.S. Patent No. 8,670,958 and related U.S. Patent Applications 09 / 895,039 and 11 / 127,918, which are incorporated herein by reference. Petition 870260054675, dated 05 / 06 / 2026, page 37 / 60 25 / 25

[0041] It should be understood that the embodiments of the invention described above and the representative examples are merely illustrative of numerous and varied other embodiments, which may constitute applications of the principles of the invention. Such other embodiments and applications can be easily conceived by those skilled in the art without departing from the spirit or scope of this invention, and it is the inventor's intention that such derivatives be considered within the scope of this invention.

[0042] Although the invention has been described in connection with certain embodiments, it is not limited to them. Instead, the invention includes all embodiments that may fall within the scope of this disclosure. Petition 870260054675, dated 05 / 06 / 2026, pages 38 / 60

Claims

1 / 6 CLAIMS 1. A method for coating a reactive metallic surface, the method being characterized in that it comprises: providing a carrier gas; providing reactive metallic particles in powder form, the particles having a non-spherical morphology with a drag coefficient that is greater than that of spherical particles; heating the reactive metallic particles to a limiting temperature that is lower than the melting point of the particles; emitting the gas from a nozzle at a selected gun travel speed and dragging the reactive metallic particles in the gas to accelerate the particles to a limiting speed that keeps the particles in a solid state within the gas; directing the accelerated particles to the reactive metallic surface, wherein the reactive metallic surface comprises a pure grade or alloy grade of reactive metal similar to or equal to the grade of the reactive metal of the particles;Contacting the reactive metal surface with accelerated particles causes the particles to undergo plastic deformation, resulting in the particles bonding to the reactive metal surface to form a repaired reactive metal surface that is continuous with an existing reactive metal surface.

2. Method according to claim 1, characterized in that the carrier gas is compressed air or one or more of nitrogen or helium gas. Petition 870260054675, dated 05 / 06 / 2026, page 39 / 60 2 / 6 3. Method according to claim 1, characterized in that the carrier gas is preheated to a temperature between 720 and 950 degrees Celsius at a supply pressure between 3.5 MPa(g) and 4 MPa(g).

4. Method according to claim 1, characterized in that the displacement speed of the gun is between 200 and 600 millimeters per second.

5. Method according to claim 1, characterized in that the particles are carried in the carrier gas at a rate between 10 grams per minute and 56 grams per minute.

6. Method according to claim 1, characterized in that the particles are titanium powder.

7. Method according to claim 1, characterized in that the particles are of commercial purity titanium grades 1, 2 or 4, or palladium-stabilized titanium alloy (Ti-Pd) grades 7, 11, 16 or 17, or ruthenium-stabilized alloy (Ti-0.1Ru) grade 27.

8. Method according to claim 1, characterized in that the particles are composed of one or more other reactive metals, such as zirconium, niobium, tantalum or alloys thereof.

9. Method according to claim 1, characterized in that the particles have a morphology of one or more angular, blocky, and coral-like shapes.

10. Method according to claim 1, characterized in that the particles comprise an equiaxed microstructure. Petition 870260054675, dated 05 / 06 / 2026, page 40 / 60 3 / 6 11. Method according to claim 1, characterized in that the particle size is between hundreds of nanometers and a few micrometers.

12. Method according to claim 1, characterized in that it further comprises heating the reactive metal surface before contact with the accelerated particles.

13. Method according to claim 1, characterized in that the reactive metallic surface is part of a component or equipment, such as a metal-seated ball valve.

14. Method according to claim 1, characterized in that the reactive metallic surface is a corrosion-resistant reactive metallic layer.

15. Method according to claim 1, characterized in that the reactive metallic surface is composed of a ductile intermediate layer between a protective coating and a reactive base metal.

16. Method according to claim 1, characterized in that the reactive metallic surface forms the inner surface of a metal-lined autoclave, a metallurgical or chemical process vessel, a metal-lined nozzle cap or a metal-lined reducing flange.

17. Method according to claim 1, characterized in that it further comprises coating the reactive metal surface until a repaired reactive metal surface with a thickness of at least 2 millimeters is formed. Petition 870260054675, dated 05 / 06 / 2026, page 41 / 60 4 / 6 18. Method according to claim 1, characterized in that the reactive metallic surface is a base metal that is a forged metallic product.

19. Method according to claim 1, characterized in that the reactive metallic surface is a base metal that is a molten metal product.

20. Method according to claim 1, characterized in that the reactive metallic surface is a base metal that is a rolled or molded metallic product.

21. Method according to claim 1, characterized in that it further comprises coating an area of ​​5806.44 square millimeters (9 square inches) or more of the reactive metal surface.

22. Method according to claim 1, characterized in that the particles are sprayed onto the reactive metal surface as a cold spray.

23. Method according to claim 1, characterized in that it further comprises passing the particles through a convergent-divergent nozzle while they are being accelerated.

24. Method according to claim 1, characterized in that the reactive metallic surface is heated to a temperature of at least 220 degrees Celsius before coming into contact with the particles.

25. Method according to claim 1, characterized in that the particles are emitted from the nozzle at a distance of about 40 mm from the reactive metal surface. Petition 870260054675, dated 05 / 06 / 2026, page 42 / 60 5 / 6 26. Method according to claim 1, characterized in that the repaired reactive metal surface is formed to have a porosity of less than 1%.

27. A method according to claim 1, characterized in that the existing reactive metallic surface creates a void exposing a different underlying metal, and further comprises contacting the different underlying metal with accelerated particles to cause the particles to undergo plastic deformation to bind the particles to the different underlying metal to form the repaired reactive metallic surface that is continuous with the existing reactive metallic surface.

28. Method according to claim 1, characterized in that the particles provided a blocky morphology, the method comprising feeding the particles at a feed rate between about 10 g / min and about 25 g / min, using a gun travel speed between about 200 mm / s and about 300 mm / s, preheating the carrier gas to a temperature between 720 and 950 degrees Celsius, supplying the carrier gas at a pressure between 3.5 MPa(g) and 4 MPa(g) and forming the repaired reactive metal surface with a porosity of less than 1%.

29. Method according to claim 1, characterized in that it further comprises applying a wear-resistant ceramic and / or oxide coating to the repaired reactive metal surface.

30. Method according to claim 29, characterized in that the wear-resistant ceramic oxide coating comprises Cr2O3, TiO2 or other hard metal oxides. Petition 870260054675, dated 05 / 06 / 2026, page 43 / 60 6 / 6 31. Invention of a product, method, system, kit or use, characterized by the fact that it comprises one or more elements disclosed in this patent application. Petition 870260054675, dated 05 / 06 / 2026, pp. 44 / 60

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