Additive Friction Stir Deposition onto Cold-Sprayed Barrier Layers

Abstract

A method of manufacturing an article is described. In S102, the method comprises obtaining a first layer having a first surface and an opposing second surface, where the first layer comprises and / or is the first metal, the first metal being a heat-treatable first aluminum alloy. In S104, the method comprises providing a second layer on the first surface of the first layer by cold spraying particles thereon comprising a second metal, where the second metal is a second aluminum alloy. In S106, the method comprises depositing a third layer on the second layer by additive friction stir deposition using a third metal, where the third metal is a third aluminum alloy.

Description

[Technical Field]

[0001] The present invention relates to additive friction stir deposition. [Background technology]

[0002] Deposition of high-strength, non-heat-treatable alloys, such as Scalmalloy (RTM), onto Al-Zn alloy plates (i.e., substrates), e.g., 7xxx plates such as 7050 T7651, using additive friction stir deposition (also known as MELD) results in high levels of thermal softening of the plates, even though the as-deposited strength of the Scalmalloy deposit is good. Therefore, the challenge lies in avoiding thermal degradation at the interface and within the 7xxx substrate. Mitigation options include pre-cooling the substrate and / or depositing it in a freshly solution-treated state. Both of these options are seen as improving rather than solving the problem and are very difficult to achieve. Cooling the substrate involves significant expense and introduces thermal strain / stress issues during subsequent temperature normalization. Deposition in either the T351 or W51 state (2xxx or 7xxx alloys, respectively) provides only limited relaxation at the heat-affected zone boundary, otherwise overaging would occur. The primary softening immediately adjacent to the deposit would likely only be slightly reduced. For the 7xxx options, the W51 state is also unstable, so the plate will likely need to be refrigerated after solution treatment / drawing (at the plate mill) and then shipped at <-40°C, possibly between North America and Europe. Also, pre-processing under refrigeration before additive friction stir deposition would be extremely difficult and costly.

[0003] Nevertheless, there is still a need to improve additive friction stir deposition. Summary of the Invention

[0004] According to a first aspect of the present invention, there is provided a method of manufacturing an article, the method comprising: obtaining a first layer having a first surface and an opposite second surface, wherein the first layer comprises and / or is a first metal, the first metal being a heat-treatable first aluminum alloy; providing a second layer on the first surface of the first layer by cold spraying particles having a second metal thereon, wherein the second metal is a second aluminum alloy; depositing a third layer on the second layer by additive friction stir deposition using a third metal, wherein the third metal is a third aluminum alloy; Equipped with.

[0005] According to a second aspect of the present invention, a first layer, wherein the first layer comprises and / or is a first metal, the first metal being a heat-treatable first aluminum alloy; a second layer on the first layer, wherein the second layer comprises cold sprayed particles comprising a second metal thereon, the second metal being a second aluminum alloy; a third layer on the second layer, wherein the third layer comprises and / or is an additive friction stir deposited third metal, and the third metal is a third aluminum alloy; An article comprising:

[0006] According to a third aspect of the present invention, there is provided the use of a cold-sprayed layer of an Al-Mg-(Sc,Zr) based alloy on a heat-treatable aluminum alloy as a barrier layer.

[0007] According to a fourth aspect of the present invention there is provided a method of manufacturing an article, the method comprising: obtaining a first layer having a first surface and an opposite second surface, wherein the first layer comprises and / or is a first metal, the first metal being a heat-treatable first aluminum alloy; providing a second layer on the first surface of the first layer by cold spraying particles having a second metal thereon, wherein the second metal is a second aluminum alloy; depositing a third layer on the second barrier layer by additive friction stir deposition using a third metal, wherein the third metal is a third aluminum alloy, the second layer is a barrier layer, and the heat-treatable first aluminum alloy is heat treated to a T or W temper designation prior to applying the second layer thereon; Equipped with.

[0008] According to a fifth aspect of the present invention, there is provided the use of a cold-sprayed layer of an Al-Mg-(Sc,Zr) based alloy on a heat treatable aluminium alloy as a barrier layer, wherein the barrier layer is between the heat treatable aluminium alloy and the additive friction stir deposited aluminium alloy. DETAILED DESCRIPTION OF THE INVENTION

[0009] According to a first aspect of the present invention, there is provided a method of manufacturing an article, the method comprising: obtaining a first layer having a first surface and an opposite second surface, wherein the first layer comprises and / or is a first metal, the first metal being a heat-treatable first aluminum alloy; providing a second layer on the first surface of the first layer by cold spraying particles having a second metal thereon, wherein the second metal is a second aluminum alloy; depositing a third layer on the second layer by additive friction stir deposition using a third metal, wherein the third metal is a third aluminum alloy; Equipped with.

[0010] In this manner, the second layer provides a thermal barrier between the relatively hot, but solid-state, additive friction stir deposition process and the heat-treated first aluminum alloy of the first layer, thereby mitigating or avoiding its thermal softening. In this manner, the relatively high deposition rates of additive friction stir deposition can be utilized without degrading the properties of the first layer. The second layer is incorporated (i.e., integrated) into the article and can be the same aluminum alloy as the third layer. The method is a method for manufacturing an article. In one example, the article comprises and / or is an aerospace part, such as an airframe part, a vehicle part, such as an engine part, or a medical part, such as an implantable medical device.

[0011] The method comprises obtaining a first layer having a first surface and an opposing second surface, wherein the first layer comprises and / or is a first metal. In one example, the first layer comprises and / or is, for example, a plate or extrusion that undergoes controlled stretching during its manufacture. It should be understood that the first layer provides or is a substrate for cold spraying, as described below.

[0012] The first metal is a heat-treatable first aluminum alloy. In one example, the heat-treatable first aluminum alloy is a 2XXX, 6XXX, 7XXX, or 8XXX series forged aluminum alloy. 2XXX, 6XXX, 7XXX, or 8XXX series forged aluminum alloys are known.

[0013] In one example, the heat-treatable first aluminum alloy is heat-treated in a T or W temper (i.e., to a T or W temper) before applying the second layer thereon. In one example, a method comprises heat-treating the heat-treatable first aluminum alloy in a T or W temper before applying the second layer thereon. In this manner, the heat-treatable first aluminum alloy is heat-treated in a T or W temper before applying the second layer thereon by cold spraying. That is, the T or W temper is not adversely affected or affected by the cold spraying. In one example, the first layer comprises and / or is and / or is formed from plate, and the T designation is T351 (e.g., 2024, 2014, 2014A, 2050, etc.), T651, T851, T7651, T7451, or T77351. In one example, the first layer comprises and / or is and / or is formed from plate, and the designation W is W51 (e.g., for 7XXX alloys). In one example, the first layer comprises and / or is and / or is formed from an extrusion, and the designation T is T3511, T6511, T8511, T76511, T74511, or T73511 (the final "1" here refers to straightening after drawing). In one example, the first layer comprises and / or is and / or is formed from an extrusion, and the designation W is W511 (e.g., for 7XXX alloys).

[0014] The method comprises providing a second layer on a first surface of the first layer by cold spraying particles comprising a second metal thereon. In one example, the particles are of the second metal (i.e., the particles consist essentially of or consist of the second metal).

[0015] Cold spray (also known as gas dynamic cold spray) is a known deposition process. Particles (typically having a diameter in the range of 1-50 μm, preferably 10-40 μm) are sprayed from a nozzle with a supersonic gas jet (typically He and / or N2) for 1200 ms. -1 The particles are accelerated to velocities up to 1000 rpm and impact a substrate, such as a second surface. Upon impact, the particles are plastically deformed and bond to it. A uniform layer is achieved by scanning or rastering the spray nozzle. Relatively thick layers can be achieved by repeated cold spraying, and deposition rates can be relatively high. High-pressure cold spray (HPCS) is used at pressures above 1.5 MPa, 2 m 3 HPCS uses nitrogen or helium at flow rates exceeding 1 / min and a thermal power of approximately 15-20 kW. HPCS is typically used to spray metal particles with diameters of 5-50 μm. Low-pressure cold spray (LPCS) uses pressures of 0.5-1.0 MPa and a flow rate of 0.5-2 m. 3 Compressed gas is used at a flow rate of 1000 kJ / min and a thermal power of 3-5 kW. LPCS can be used to spray a mixture of metal and ceramic particles. Including a ceramic component in the mixture results in a high-quality coating with relatively low energy consumption. Unlike thermal spraying (such as plasma spraying, arc spraying, flame spraying, or high-velocity oxy-fuel spraying), the particles do not melt during cold spraying. Rather, the heat input during cold spraying is relatively low, thereby reducing or eliminating residual stresses in the substrate and / or its deformation. Additionally, cold-sprayed layers have low porosity, which is typically closed (i.e., not interconnected).

[0016] In one example, the cold spray comprises cold spray using helium. In one example, the cold spray comprises cold spray using, for example, a pressure of greater than 1.5 MPa, 2 m 3 It is equipped with a high-pressure cold spray using He with a flow rate exceeding / min and a thermal power of approximately 15 to 20 kW.

[0017] In one example, providing a second layer on a first surface of a first layer by cold spraying particles having a second metal thereon comprises providing a second layer only on the first surface of the first layer by cold spraying particles having a second metal thereon on the first surface of the first layer, i.e., the method excludes cold spraying a second layer on an opposite second surface of the first layer, i.e., cold spraying on one surface.

[0018] In one example, the method comprises providing a second layer on a second surface opposite the first layer by cold spraying particles having a second metal thereon, i.e., the method includes cold spraying the second layer on a second surface opposite the first layer, i.e., cold spraying on both sides.

[0019] In one example, providing a second layer on the first surface of the first layer by cold spraying particles having a second metal thereon comprises selectively cold spraying the first surface, e.g., selectively cold spraying onto selected areas of the first surface. In this manner, the second surface can be selectively cold sprayed, e.g., to provide the second layer in desired areas, e.g., to provide the second layer only in desired areas.

[0020] In one example, cold spraying particles comprising a second metal onto the first surface comprises cold spraying particles comprising the second metal onto at least 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, or 99% of the area of ​​the first surface. In one example, cold spraying particles comprising a second metal onto the first surface comprises cold spraying particles comprising the second metal onto the entire first surface.

[0021] In one example, cold spraying particles comprising a second metal onto the first surface comprises cold spraying particles comprising the second metal directly onto the first surface, i.e., without an intermediate layer therebetween. In one example, cold spraying particles comprising a second metal onto the first surface comprises cold spraying particles comprising the second metal indirectly onto the first surface, i.e., with an intermediate layer therebetween.

[0022] The second metal is a second aluminum alloy. In one example, the second aluminum alloy is a heat-treatable second aluminum alloy. In one example, the heat-treatable second aluminum alloy is a 2XXX, 6XXX, 7XXX, or 8XXX series wrought aluminum alloy. In one example, the second aluminum alloy is a non-heat-treatable second aluminum alloy. In one example, the non-heat-treatable first aluminum alloy is a 5XXX series aluminum alloy. In one example, the non-heat-treatable second aluminum alloy is an Al-Mg-Sc alloy such as 5028, an Al-Mg-Zr alloy, an Al-Mg-Sc-Zr alloy, or an Al-Mg-Zr-Sc alloy, typically an Al-Mg-(Zr,Sc) alloy containing one or both of Zr and Sc, and optionally containing Er. Generally, the addition of scandium to aluminum alloys (typically 0.1% to 0.5% by weight) results in the precipitation of nanoscale Al3Sc precipitates. The nanoscale Al3Sc precipitates increase the alloy's yield strength by 50 to 70 MPa. The nanoscale Al3Sc precipitates limit excessive grain growth in the heat-affected zone of welded aluminum alloy components. This has two beneficial effects: the nanoscale Al3Sc precipitates are smaller than other precipitates that form in other aluminum alloys, reducing the width of the precipitate-free zones typically present at grain boundaries in age-hardenable aluminum alloys. Scandium is also a powerful grain refiner in cast aluminum alloys and, atomically, is the most powerful strengthener in aluminum, resulting from both grain refinement and precipitation strengthening. Nanoscale Al3Sc precipitates are resistant to coarsening at relatively high temperatures (approximately 350°C), in contrast to typical commercial 2xxx and 6xxx alloys, which rapidly lose strength due to the rapid coarsening of these strengthening precipitates at temperatures above 250°C. The addition of erbium and zirconium has been shown to increase the coarsening resistance of Al-Sc alloys up to approximately 400°C. This is achieved by forming a slowly diffusing zirconium-rich shell around a scandium- and erbium-rich precipitate core, forming a strengthening precipitate with the composition Al3(Sc, Zr, Er).Further improvements in coarsening resistance will allow these aluminum alloys to be used at increasingly higher temperatures. In one preferred example, the non-heat-treatable second aluminum alloy is Skalmalloy (RTM) (available from APWORKS GmbH, Germany), e.g., CT PR SCALMALLOY F. Skalmalloy is typically supplied as a powder made by nitrogen gas atomization and having a typical composition as summarized in Table 1 and a typical particle size distribution as summarized in Table 2.

[0023] [Table 1]

[0024] [Table 2]

[0025] In one example, the particles comprising the second metal have a particle size range (i.e., distribution) of 1 to 500 μm, preferably at least 46, 51, 61, 64, 101, or 151 μm, for example, preferably 64 to 250 μm or 101 to 250 μm. Typical particle size ranges for sintering additive manufacturing processes are: selective laser melting (SLM), also known as laser PBF, LPBF, or L-PBF: 20 to 60 μm; selective laser sintering (SLS): 15 to 45 μm; directed energy deposition (DED): 50 to 150 μm; electron beam melting (EBM): 50 to 150 μm; laser beam melting (LBM): 10 to 60 μm; and spray deposition: 5 to 50 μm. Skalmalloy is typically available in particle size ranges of 20 to 63 μm and 20 to 100 μm. That is, preferably, the particles comprising the second metal are too large compared to the typical particle size range for such melting or sintering additive manufacturing processes, e.g., LPBF, so the particles comprising the second metal can be sourced as a by-product of typical fabrication.Generally, particle size ranges can be determined in accordance with ASTM F3049 - 14 Standard Guide for Characterizing Properties of Metal Powders Used for Additive Manufacturing Processes and standards referenced therein; ASTM E2651 - 19 Standard Guide for Powder Particle Size Analysis; ASTM B214 - 16 Standard Test Method for Sieve Analysis for Metal Powders; ASTM B822 - 20 Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by Light Scattering; and ISO / ASTM52907 - 19 Additive manufacturing - Feedstock materials - Methods to characterize metallic powders. It should be understood that most particle size analysis techniques report particle size in terms of the "equivalent spherical diameter."

[0026] In one example, the thickness of the second layer is determined, at least in part, by the heat input during deposition of the third layer.

[0027] In one example, the ratio of the thickness of the second layer to the thickness of the third layer is in the range of 1:2 to 2:1.

[0028] In one example, the thickness of the second layer is in the range of 1 mm to 20 mm, preferably in the range of 3 mm to 15 mm, and more preferably in the range of 7 mm to 10 mm.

[0029] Generally, cold spray deposits are at least 3 mm thick, and likely 10-12 mm or more. The optimum thickness is expected to be about 7-10 mm, based on the HAZ depth seen on 7050 plates. MELD deposit thicknesses can be thicker than cold spray and, depending on many factors, can actually be very thick, with little limit (e.g., several hundred mm). Thus, in a typical application, we see cold spray deposits of 10 mm and MELD deposits that can range from as little as 10 mm to perhaps >200 mm and even >>200 mm.

[0030] The method comprises depositing a third layer on the second layer by additive friction stir deposition using a third metal, wherein the third metal is a third aluminum alloy.

[0031] It is understood that the second metal and the third metal are mutually compatible such that the third metal can be deposited onto the second metal by additive friction stir deposition. It is understood that mutual compatibility does not require compositional and / or chemical compatibility because additive friction stir deposition is a solid state process, as described below.

[0032] It should be understood that depositing a third layer on a second layer excludes fusion deposition.

[0033] Additive friction stir deposition (AFSD) (also known as friction stir deposition or MELD (RTM)) is a known deposition process based on friction stir welding. Additive friction stir deposition is a low-temperature, solid-state process. This solid-state deposition process shares some similarities with other high-shear and high-temperature solid-state processes, such as shear extrusion or friction stir welding and processing (FSW / P), but differs significantly in that the feedstock material (i.e., the third metal) is fed through a rotating hollow tool and deposited onto a substrate (i.e., the second layer) while the feedstock remains entirely in a solid state. The feedstock, which can be in rod (typically round or square) or powder form, is extruded through a non-consumable rotating cylindrical tool. The rotation and feeding generate heat and plastically deform the feedstock under controlled pressure from the tool, while successive layers are deposited onto the substrate. Once a layer is added, the tool is lifted to begin deposition of successive layers on top of it, creating a strong metallurgical bond between the layers. The benefits of additive friction stir deposition include grain refinement, homogenization, and reduced porosity. Additive friction stir deposition typically results in a wrought microstructure. Because the deposited material is sufficiently dense, debinding, sintering, or HIPing is not required. Because additive friction stir deposition is a solid-state process, problems such as porosity, hot cracking, elemental segregation, and dilution (typically associated with fusion-based processes) are reduced or eliminated because the material(s) do not solidify from a liquid phase. During additive friction stir deposition processing, temperatures are similar to those in the stir zone (SZ) of FSW and are estimated to be 0.6–0.9 Tm, where Tm is the melting point of the material(s). Additive friction stir deposition is a highly scalable process, with melting temperatures reaching 1000 cm for aluminum alloys. 3It has a relatively high deposition rate of over 1 / h, allowing for the repair, coating, and / or construction of fully dense materials, including relatively large three-dimensional articles. Because additive friction stir deposition is a solid-state process, it avoids the controlled atmosphere chamber and powder bed of fused deposition processes such as laser powder bed fusion bonding. Because additive friction stir deposition is a solid-state process, residual stresses are reduced.

[0034] In one example, the third aluminum alloy is a heat-treatable third aluminum alloy. In one example, the heat-treatable third aluminum alloy is a 2XXX, 6XXX, 7XXX, or 8XXX series wrought aluminum alloy. In one example, the third aluminum alloy is a non-heat-treatable third aluminum alloy. In one example, the non-heat-treatable first aluminum alloy is a 5XXX series aluminum alloy. In one example, the non-heat-treatable third aluminum alloy is an Al-Mg-Sc alloy such as 5028, an Al-Mg-Zr alloy, an Al-Mg-Sc-Zr alloy, or an Al-Mg-Zr-Sc alloy, generally an Al-Mg-(Zr,Sc) alloy containing one or both of Zr and Sc, and optionally containing Er. In a preferred example, the non-heat-treatable second aluminum alloy is Skalmalloy. The third aluminum alloy may be as described with respect to the second aluminum alloy.

[0035] In one example, depositing a third layer onto the second layer by additive friction stir deposition using a third metal includes depositing the third layer onto the second layer by additive friction stir deposition of successive (i.e., multiple) layers using the third metal.

[0036] In one example, depositing a third layer on a second layer by additive friction stir deposition using a third metal includes depositing a third layer on the second layer by additive friction stir deposition using particles of the third metal. In one example, the particles are of the third metal (i.e., the particles consist essentially of or consist of the third metal). In one example, the particles of the third metal have a particle size range (i.e., distribution) of 1 to 500 μm, preferably at least 46, 51, 61, 64, 101, or 151 μm, for example, preferably 64 to 250 μm or 101 to 250 μm. Typical particle size ranges for fusion or sintering additive manufacturing processes are: selective laser melting (SLM), also known as laser PBF, LPBF, or L-PBF: 20-60 μm; selective laser sintering (SLS): 15-45 μm; directed energy deposition (DED): 50-150 μm; electron beam melting (EBM): 50-150 μm; laser beam melting (LBM): 10-60 μm; and spray deposition: 5-50 μm. Skalmalloy is typically available in particle size ranges of 20-63 μm and 20-100 μm. Preferably, the third metal particles are too large compared to the typical particle size ranges for such fusion or sintering additive manufacturing processes, such as LPBF, so the third metal particles can be supplied as a by-product of typical fabrication. The third metal particles can be as described for the second metal particles.

[0037] In one example, the method comprises aging the second and / or third layers before and / or after providing them, thereby improving the mechanical properties of the layers.

[0038] In one example, the ratio of the hardness of the first layer before and after the deposition of the third layer, e.g., before and after the deposition of the second layer followed by the third layer, is in the range of 1:0.50 to 1:1.50, preferably 1:0.75 to 1:1.25, and more preferably 1:0.90 to 1:1.10. That is, the hardness of the first layer is substantially unaffected by the deposition of the third layer due to the presence of the second layer in between. It should be understood that the change in hardness is related to the deposition of the third layer, rather than, for example, aging and / or heat treatment. For example, if the first layer is, e.g., 7050 W51 prior to deposition, and cold spray deposition completely protects the first layer from the heat of the third layer, the hardness should not change, and therefore the ratio should be approximately 1:1. However, W51 is, by definition, unstable, and therefore hardness increases over time after solution processing and controlled stretching. Conversely, hardness may actually increase after deposition, but simply due to the passage of time, as short time intervals result in a relatively low hardness and increase with time, rather than as a result of deposition. Alternatively, the treatment could be applied to, for example, a 2014A plate in the T351 condition, then age hardened to the T851 condition after cold spray and MELD deposition, and an increase in hardness could be seen, but again, the hardness of the substrate plate should not be affected by the deposition treatment.

[0039] In one example, the method comprises: providing a fourth layer on a second surface opposite the first layer by cold spraying particles comprising a second metal thereon, wherein the second metal is a second aluminum alloy; depositing a fifth layer on the fourth layer by additive friction stir deposition using a third metal, wherein the third metal is a third aluminum alloy; Equipped with.

[0040] That is, the cold spray layer and the additive friction stir deposited layer are applied on both sides (i.e., both surfaces). Applying the fourth layer and depositing the fifth layer may be as described for applying the second layer and depositing the third layer, respectively, mutatis mutandis.

[0041] According to a second aspect of the present invention, a first layer, wherein the first layer comprises and / or is a first metal, the first metal being a heat-treatable first aluminum alloy; a second layer on the first layer, wherein the second layer comprises cold sprayed particles comprising a second metal thereon, the second metal being a second aluminum alloy; a third layer on the second layer, wherein the third layer comprises and / or is an additive friction stir deposited third metal, and the third metal is a third aluminum alloy; An article comprising:

[0042] According to a third aspect of the present invention, there is provided the use of a cold-sprayed layer of an Al-Mg-(Sc,Zr) based alloy on a heat-treatable aluminum alloy as a barrier layer.

[0043] Throughout this specification, the terms "comprising" or "comprises" mean including the specified component(s) but not excluding the presence of other components. The terms "consisting essentially of" or "consists essentially of" mean including the specified components but excluding other components, except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for purposes other than achieving the technical effects of the invention, such as colorants.

[0044] The terms "consisting of" or "consists of" mean including the specified components, but excluding other components.

[0045] Wherever appropriate and depending on the context, use of the terms "comprises" or "comprising" may be interpreted to include the meanings "consisting essentially of" or "consisting essentially of," as well as "consists of" or "consisting of."

[0046] The optional features described herein may be used, where appropriate, individually or in combination with one another, particularly in the combinations set forth in the appended claims. Optional features of each aspect or exemplary embodiment of the invention described herein are also applicable, where appropriate, to all other aspects or exemplary embodiments of the invention. In other words, those skilled in the art who read this specification should consider the optional features of each aspect or exemplary embodiment of the invention to be interchangeable and combinable between different aspects and exemplary embodiments. [Brief explanation of the drawings]

[0047] Embodiments of the present invention will now be described, by way of example only, with reference to the drawings, in which: [Figure 1] FIG. 1 illustrates a method according to an exemplary embodiment. [Figure 2] FIG. 2 illustrates a method according to an exemplary embodiment in more detail. [Figure 3] FIG. 3 illustrates the method of FIG. 2 in more detail. [Figure 4] FIG. 4 illustrates the method of FIG. 2 in more detail. [Figure 5] FIG. 5 illustrates an article according to an exemplary embodiment. Detailed Description of the Drawings

[0048] 1 illustrates a method 100 according to an exemplary embodiment. The method is a method for manufacturing an article.

[0049] At S102, the method comprises obtaining a first layer having a first side and an opposing second side, wherein the first layer comprises and / or is a first metal, and the first metal is a heat-treatable first aluminum alloy.

[0050] At S104, the method comprises providing a second layer on the first surface of the first layer by cold spraying particles comprising a second metal thereon, wherein the second metal is a second aluminum alloy.

[0051] At S106, the method comprises depositing a third layer on the second layer by additive friction stir deposition using a third metal, wherein the third metal is a third aluminum alloy.

[0052] The method may include any of the steps described in relation to the first aspect.

[0053] 2 illustrates in more detail a method according to an exemplary embodiment. The method is a method for manufacturing an article. The method comprises obtaining a first layer 10 having a first side 11 and an opposing second side 12, wherein the first layer 10 comprises and / or is a first metal, the first metal being a heat-treatable first aluminum alloy.

[0054] Figure 3 shows in more detail the method of Figure 2. The method comprises providing a second layer 20 on the first surface 11 of the first layer 10 by cold spraying particles 23 having a second metal thereon, where the second metal is a second aluminum alloy.

[0055] Figure 4 illustrates in more detail the method of Figure 2. The method comprises depositing a third layer 30 on the second layer 20 by additive friction stir deposition 34 using a third metal, where the third metal is a third aluminum alloy.

[0056] FIG. 5 shows an article 5 according to a comparative example.

[0057] More specifically, Figure 5 shows a photograph of a Rockwell "B" hardness survey of an Al-Mg-Sc alloy (i.e., the third layer) deposited (i.e., directly) on a 7050 substrate (i.e., the first layer) by additive friction stir deposition. Although the scale is not shown and the interface location must be inferred, the HAZ appears to be approximately 10 mm deep.

[0058] The identified solution is to deposit an intermediate layer of scale malloy (i.e., the second layer between the first and third layers) by cold spraying directly from the powder state. This intermediate layer forms a thermal barrier between the (high-temperature) MELD process and the (room-temperature) 7xxx substrate. The thickness of the intermediate layer is 5-10 mm. The inventions described in the original claims of this application are set forth below. [1] A method of manufacturing an article, comprising: obtaining a first layer having a first surface and an opposite second surface, wherein the first layer comprises and / or is a first metal, the first metal being a heat-treatable first aluminum alloy (102); providing a second layer on the first surface of the first layer by cold spraying particles comprising a second metal thereon, wherein the second metal is a second aluminum alloy (104); depositing a third layer on the second layer by additive friction stir deposition using a third metal, wherein the third metal is a third aluminum alloy (106); the second layer is a barrier layer; the heat-treatable first aluminum alloy is heat-treated to a T or W temper designation prior to application of the second layer thereon; A method comprising: [2] The method of [1], wherein the heat-treatable first aluminum alloy is a wrought aluminum alloy of the 2XXX, 6XXX, 7XXX, or 8XXX series. [3] The method according to [1] or [2], wherein the second aluminum alloy is a non-heat-treatable second aluminum alloy. [4] The method according to [3], wherein the non-heat-treatable second aluminum alloy is an Al-Mg-Sc alloy, an Al-Mg-Zr alloy, an Al-Mg-Sc-Zr alloy, or an Al-Mg-Zr-Sc alloy. [5] The method of any one of [1] to [4], wherein the thickness of the second layer is determined, at least in part, by heat input during deposition of the third layer. [6] The method according to [5], wherein the ratio of the thickness of the second layer to the thickness of the third layer is within a range of 1:2 to 2:1. [7] The method according to [5] or [6], wherein the thickness of the second layer is in the range of 1 mm to 20 mm. [8] The method of any one of [1] to [7], wherein the cold spraying comprises cold spraying using helium. [9] The method according to any one of [1] to [8], wherein the third aluminum alloy is a non-heat-treatable third aluminum alloy.

[10] The method according to [7], wherein the third aluminum alloy is an Al-Mg-Sc alloy, an Al-Mg-Zr alloy, an Al-Mg-Sc-Zr alloy, or an Al-Mg-Zr-Sc alloy.

[11] The method according to any one of [1] to

[10] , comprising aging before and / or after providing the second layer and / or the third layer.

[12] The method according to any one of [1] to

[11] , wherein the ratio of the hardness of the first layer before and after depositing the third layer is in the range of 1:0.75 to 1:1.25.

[13] Use of a cold-sprayed layer of an Al-Mg-(Sc,Zr) based alloy on a heat-treatable aluminum alloy as a barrier layer, the barrier layer being between the heat-treatable aluminum alloy and an additive-friction-stir-deposited aluminum alloy.

Claims

1. 1. A method of manufacturing an article, comprising: obtaining a first layer having a first surface and an opposite second surface, wherein the first layer comprises or consists of a first metal, the first metal being a heat-treatable first aluminum alloy (102); providing a second layer on the first surface of the first layer by cold spraying particles comprising a second metal thereon, wherein the second metal is a second aluminum alloy (104); depositing a third layer on the second layer by additive friction stir deposition using a third metal, wherein the third metal is a third aluminum alloy (106); the second layer is a barrier layer; the heat-treatable first aluminum alloy is heat-treated to a T or W temper designation prior to providing the second layer thereon; A method comprising:

2. 10. The method of claim 1, wherein the heat-treatable first aluminum alloy is a 2xxx, 6xxx, 7xxx, or 8xxx series wrought aluminum alloy.

3. The method of claim 1 or 2, wherein the second aluminum alloy is a non-heat-treatable second aluminum alloy.

4. 4. The method according to claim 3, wherein the non-heat-treatable second aluminum alloy is an Al-Mg-Sc alloy, an Al-Mg-Zr alloy, an Al-Mg-Sc-Zr alloy, or an Al-Mg-Zr-Sc alloy.

5. The method of claim 1 or 2, wherein the thickness of the second layer is determined at least in part by the heat input during deposition of the third layer.

6. 6. The method of claim 5, wherein the ratio of the respective thicknesses of the second layer and the third layer is in the range of 1:2 to 2:

1.

7. The method of claim 5, wherein the thickness of the second layer is in the range of 1 mm to 20 mm.

8. The method of claim 1 or 2, wherein the cold spraying comprises cold spraying using helium.

9. 3. The method of claim 1, wherein the third aluminum alloy is a non-heat-treatable third aluminum alloy.

10. 8. The method according to claim 7, wherein the third aluminum alloy is an Al-Mg-Sc based alloy, an Al-Mg-Zr based alloy, an Al-Mg-Sc-Zr based alloy, or an Al-Mg-Zr-Sc based alloy.

11. 3. The method of claim 1, further comprising ageing before and / or after applying the second and / or third layers.

12. 1. Use of a cold-sprayed layer of an Al—Mg—(Sc,Zr) based alloy on a heat-treatable aluminum alloy as a barrier layer, the barrier layer being between the heat-treatable aluminum alloy and an additive-friction-stir-deposited aluminum alloy.

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