Aluminum alloy powders for additive manufacturing, methods of producing the same and uses thereof

Abstract

The present application relates to aluminum alloy powders. More specifically, the present application relates to aluminum alloy powders comprising Al, Zr, Mg, Sc, Ce and Zn in various amounts. The present application includes methods for preparing these powders and methods using the same in additive manufacturing.

Description

ALUMINUM ALLOY POWDERS FOR ADDITIVE MANUFACTURING, METHODS OF PRODUCING THE SAME AND USES THEREOFCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of priority of co-pending U.S. Provisional Patent Application Nos. 63 / 695,840, which was filed September 17, 2024, and 63 / 696,798, which was filed September 19, 2024, the contents of which are incorporated herein by reference in their entirety.FIELD

[0002] The present application is in the field of aluminum alloys. More specifically, the present application relates to aluminum alloy powder material for use in additive manufacturing.BACKGROUND

[0003] Additive manufacturing is generally described as the construction of a three-dimensional object in which material is deposited, joined, or solidified layer by layer. 3D printing or additive manufacturing has gained popularity in the past years, and its applications have spread to various fields such as metal engineering, medical industries, aerospace, and automotive industries, etc.

[0004] The consistent production of defect-free aluminum-based components through additive manufacturing remains a challenge. Defect-free often refers to the absence of cracking and porosities / voids, but it can also encompass the ability to reproduce a component at the exterior / feature level faithfully.

[0005] As such, improved aluminum alloy material and methods for using it are needed, enabling the production of crack-free components that exhibit superior mechanical properties.SUMMARY

[0006] It has been shown herein that materials of the present application provide for additive manufacturing components with improved mechanical properties. The methods of the present application further provide for additive manufacturing components with improved mechanical properties.

[0007] Accordingly, the present application includes an aluminum alloy powder comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1 .0 wt%;Mg in an amount of about 1 .0wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 0 wt% to about 3 wt%; andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0008] The present application further includes an aluminum alloy powder for use as an additive manufacturing substrate, comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%,Mg in an amount of about 1 .0wt% to about 5 wt%,Sc in an amount of about 0.25 wt% to about 0.75 wt%,Ce in an amount of about 0 wt% to about 3 wt%, andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0009] Also included is an aluminum alloy powder for use in additive manufacturing of aerospace components, comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%,Mg in an amount of about 1 .0wt% to about 5 wt%,Sc in an amount of about 0.25 wt% to about 0.75 wt%,Ce in an amount of about 0 wt% to about 3 wt%, andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0010] The present application further includes a method of manufacturing an aluminum alloy powder for use as an additive manufacturing substrate, the method comprising, blending an AA535 aluminum alloy powder with at least one of zirconium dihydride or scandium oxide to generate the aluminum alloy powder, wherein the aluminum alloy powder comprises:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1 .0 wt%;Mg in an amount of about 1 .0 wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 0 wt% to about 3 wt%; andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0011] The present application also includes a method of manufacturing an aluminum alloy powder for use in additive manufacturing of aerospace components, the method comprising, blending an AA535 aluminum alloy powder with at least one of zirconium dihydride or scandium oxide to generate the aluminum alloy powder, wherein the aluminum alloy powder comprises:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1 .0 wt%;Mg in an amount of about 1 .0wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 0 wt% to about 3 wt%; andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0012] Accordingly, included is a method of additive manufacturing aerospace components comprising: providing an aluminum alloy powder of the present application as a substrate; melting and fusing the substrate to additively manufacture the aerospace components.

[0013] Also included is a method for reducing microcracking and / or porosity of additive manufacturing components, the method comprising: providing an aluminum alloy powder of the present application as a substrate; melting and fusing the substrate to additively manufacture the components.

[0014] Also included is use of AA535 aluminum alloy powder for preparing an aluminum alloy powder suitable for additive manufacturing of aerospace components.

[0015] The present application further includes use of AA535 aluminum alloy powder for preparing an aluminum alloy powder suitable for use as a substrate for additive manufacturing.

[0016] Further provided is use of an aluminum alloy powder of the present application for additive manufacturing aerospace components.

[0017] Also included is use of an aluminum alloy powder of the present application as a substrate for additive manufacturing.

[0018] Further included is use of an aluminum alloy powder of the present application for reducing microcracking in additive manufacturing components, for reducing porosity in additive manufacturing components, for increasing strength in additive manufacturing components, for increasing corrosion resistance in additive manufacturing components, and / or for increasing thermal conductivity in additive manufacturing components.

[0019] Other features and advantages of the present application will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments of the application, are given by way of illustration only and the scope of the claims should not be limited by these embodiments, but should be given the broadest interpretation consistent with the description as a whole.BRIEF DESCRIPTION OF DRAWINGS

[0020] The embodiments of the application will now be described in greater detail with reference to the attached drawings in which:

[0021] FIG.1 shows pictures of printed elements using AA535-1 (AA535+Ce+Sc) and AA535-2 (AA535+Ce+Sc+Zr), according to exemplary embodiments of the present application.

[0022] FIG.2 shows optical microscopy images of a printed element using AA535+Ce+Sc unblended (80 pm) printed at speed 1800mm / s, 1100mm / s and 400mm / s and power of 230W, 300W and 370W, where * indicates optimal printing parameters, according to exemplary embodiments of the present application.

[0023] FIG.3 shows optical microscopy images of a printed element using AA535+Ce+Sc unblended (110 pm) printed at speed 1800mm / s, 1100mm / s and400mm / s and power of 230W, 300W and 370W, according to exemplary embodiments of the present application.

[0024] FIG.4 is a graph of relative density vs volumetric energy density for AA535-1 , according to exemplary embodiments of the present application.

[0025] FIG.5 shows optical microscopy images of a printed element using AA535+Ce+Sc+Zr blended (80 pm) printed at speed 1800mm / s, 1100mm / s and 400mm / s and power of 230W, 300W and 370W, where * indicates optimal printing parameters, according to exemplary embodiments of the present application.

[0026] FIG.6 shows optical microscopy images of a printed element using AA535+Ce+Sc+Zr blended (110 pm) printed at speed 1800mm / s, 1100mm / s and 400mm / s and power of 230W, 300W and 370W, where * indicates optimal printing parameters, according to exemplary embodiments of the present application.

[0027] FIG.7 is a graph of relative density vs volumetric energy density for AA535-2, according to exemplary embodiments of the present application.

[0028] FIG.8 shows pictures of printed elements using AA7075-1 (AA7075+Sc), AA7075-2 (AA7075+Zn+Sc+Zr) and AA7075-3 (AA7075+Sc+Zr), according to exemplary embodiments of the present application.

[0029] FIG.9 shows optical microscopy images of a printed element using AA7075+Sc unblended (80 pm) printed at speed 1800mm / s, 1100mm / s and 400mm / s and power of 230W, 300W and 370W, according to exemplary embodiments of the present application.

[0030] FIG.10 shows optical microscopy images of a printed element using AA7075+Sc unblended (110 pm) printed at speed 1800mm / s, 1100mm / s and 400mm / s and power of 230W, 300W and 370W, according to exemplary embodiments of the present application.

[0031] FIG.11 is a graph of relative density vs volumetric energy density for AA7075-1 , according to exemplary embodiments of the present application.

[0032] FIG.12 shows optical microscopy images of a printed element using AA7075+Sc+Zn+Zr blended (80 pm) printed at speed 1800mm / s, 1100mm / s and400mm / s and power of 230W, 300W and 370W, where * indicates optimal printing parameters, according to exemplary embodiments of the present application.

[0033] FIG.13 shows optical microscopy images of a printed element usingAA7075+Sc+Zn+Zr blended (80 pm) printed at speed 1800mm / s, 1100mm / s and 400mm / s and power of 230W, 300W and 370W, where * indicates optimal printing parameters, according to exemplary embodiments of the present application.

[0034] FIG.14 is a graph of relative density vs volumetric energy density for AA7075-2, according to exemplary embodiments of the present application.

[0035] FIG.15 shows optical microscopy images of a printed element usingAA7075+Sc+Zr blended (80 pm) printed at speed 1800mm / s, 110Omm / s and 400mm / s and power of 230W, 300W and 370W, where * indicates optimal printing parameters, according to exemplary embodiments of the present application.

[0036] FIG.16 shows optical microscopy images of a printed element usingAA7075+Sc+Zr blended (110 pm) printed at speed 1800mm / s, 1100mm / s and 400mm / s and power of 230W, 300W and 370W, where * indicates optimal printing parameters, according to exemplary embodiments of the present application.

[0037] FIG.17 is a graph of relative density vs volumetric energy density forAA7075-3, according to exemplary embodiments of the present application.

[0038] FIG.18 is a graph of Vickers microhardness vs volumetric energy density for AA535-1 ,

[0039] FIG.19 is a graph of Vickers microhardness vs volumetric energy density for AA535-2, according to exemplary embodiments of the present application.

[0040] FIG.20 is a graph of Vickers microhardness vs volumetric energy density for AA7075-1 , according to exemplary embodiments of the present application.

[0041] FIG.21 is a graph of Vickers microhardness vs volumetric energy density for AA7075-2, according to exemplary embodiments of the present application.

[0042] FIG.22 is a graph of Vickers microhardness vs volumetric energy density for AA7075-3, according to exemplary embodiments of the present application.

[0043] FIG.23 is a graph of engineering tensile strength for AA535-2 in the as- built (AB) and heat-treated (HT) conditions using optimal print parameters, according to exemplary embodiments of the present application.

[0044] FIG.24 is a graph of engineering tensile strength for AA7075-2 in the as- built (AB) and heat-treated (HT) conditions using optimal print parameters, according to exemplary embodiments of the present application.

[0045] FIG.25 is a graph of engineering tensile strength for AA7075-3 in the as- built (AB) and heat-treated (HT) conditions using optimal print parameters, according to exemplary embodiments of the present application.DETAILED DESCRIPTIONI. Definitions

[0046] Unless otherwise indicated, the definitions and embodiments described in this and other sections are intended to be applicable to all embodiments and aspects of the present application herein described for which they are suitable as would be understood by a person skilled in the art.

[0047] As used in this application and claim(s), the words "comprising" (and any form of comprising, such as "comprise" and "comprises"), "having" (and any form of having, such as "have" and "has"), "including" (and any form of including, such as "include" and "includes") or "containing" (and any form of containing, such as "contain" and "contains"), are inclusive or open-ended and do not exclude additional, unrecited elements or process steps.

[0048] The term “consisting” and its derivatives as used herein are intended to be closed terms that specify the presence of the stated features, elements, components, groups, integers, and / or steps, and also exclude the presence of other unstated features, elements, components, groups, integers and / or steps.

[0049] The term “consisting essentially of’, as used herein, is intended to specify the presence of the stated features, elements, components, groups, integers, and / or steps as well as those that do not materially affect the basic and novel characteristic(s) of these features, elements, components, groups, integers, and / or steps.

[0050] The terms "about", “substantially” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies or unless the context suggests otherwise to a person skilled in the art.

[0051] As used in the present application, the singular forms “a”, “an” and “the” include plural references unless the content clearly dictates otherwise.

[0052] In embodiments comprising an “additional” or “second” component, the second component as used herein is different from the other components or first component. A “third” component is different from the other, first, and second components, and further enumerated or “additional” components are similarly different.

[0053] The term “and / or” as used herein means that the listed items are present, or used, individually or in combination. In effect, this term means that “at least one of” or “one or more” of the listed items is used or present.

[0054] The term “suitable” as used herein means that the selection of the particular composition or conditions would depend on the specific steps to be performed, the identity of the components to be transformed and / or the specific use for the compositions, but the selection would be well within the skill of a person trained in the art.II. Material and Compositions of the Application

[0055] It has been shown herein that materials of the present application provide for additive manufacturing components with improved mechanical properties. The methods of the present application further provide for additive manufacturing components with improved mechanical properties.

[0056] Significant strides in the field of 3D printing aluminum and scandium alloy powders have been made, particularly using alloys 7075 and 535, to eliminate microcracks that typically occur when 3D printing powders of this nature. The materials of the present application supersedes previous attempts documented in the literature.

[0057] In some embodiments, advantageous effect of materials of the present application lies in modifying aluminum powders by adding scandium, zirconium, and cerium. By augmenting the powders with these elements, the materials of the present application may effectively eliminate the micro-cracks associated with 3D printing of previously used materials, such as Scalmalloy™, which relied solely on the use of aluminum-scandium powders.

[0058] In some embodiments, advantageous effect of materials of the present application lies in modifying aluminum powders by adding scandium, zirconium, and cerium. By augmenting the powders with these elements, the materials of the present application may be restored to the desired compositions of original alloys prior to an unplanned impoverishment of zirconium, zinc and magnesium during atomization.

[0059] As such, in some embodiments, the materials of the present application addresses the inherent challenges associated with 3D printing aluminum and scandium powders, particularly alloy 7075 and 535, by the addition of scandium, zirconium, and cerium, enabling the production of crack-free components that exhibit superior mechanical properties. Furthermore, incorporating Ce into an alloy is intended to provide the moderation of the solidification curve to approach a near-eutectic freezing range to eliminate solidification cracking, and for the improvement of strength at elevated temperatures.

[0060] In some embodiments, the blending of Zr into the mixture, in an effort to resolve the cracking present, cracking was removed at all energy levels. Similarly, the addition of Ca may mitigate the loss of Mg, which is a significant source of porosity and material anisotropy at various processing conditions, as was illustrated with the testing of CalciScal® as an improvement upon Scalmalloy®.

[0061] Accordingly, the present application includes an aluminum alloy powder comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1 .0 wt%;Mg in an amount of about 1 .0wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 0 wt% to about 3 wt%; andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0062] The present application further includes an aluminum alloy powder for use as an additive manufacturing substrate, comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%,Mg in an amount of about 1 .0wt% to about 5 wt%,Sc in an amount of about 0.25 wt% to about 0.75 wt%,Ce in an amount of about 0 wt% to about 3 wt%, andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0063] Also included is an aluminum alloy powder for use in additive manufacturing of aerospace components, comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%,Mg in an amount of about 1 .0wt% to about 5 wt%,Sc in an amount of about 0.25 wt% to about 0.75 wt%,Ce in an amount of about 0 wt% to about 3 wt%, andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0064] In some embodiments, Zr is in an amount of about 0.6 wt% to about 0.9 wt%. In some embodiments, Zr is in an amount of about 0.7 wt% to about 0.85 wt%.

[0065] In some embodiments, Mg is in an amount of about 1 .5 wt% to about 4.5 wt%. In some embodiments, Mg is in an amount of about 2.5 wt% to about 4.0 wt%.

[0066] In some embodiments, Sc is in an amount of about 0.35 wt% to about 0.7 wt%. In some embodiments, Sc is in an amount of about 0.45 wt% to about 0.65 wt%.

[0067] In some embodiments, Ce is in an amount of about 0.1 wt% to about 2.75 wt%. In some embodiments, Ce is in an amount of about 0.5 wt% to about 2.5 wt%.

[0068] In some embodiments, Zn is in an amount of about 0.06 wt% to about 3.0 wt%. In some embodiments, Zn is in an amount of about 0.07 wt% to about 2.5 wt%.

[0069] In some embodiments, the aluminum alloy powder has an average particle size of about 15 pm to about 90 pm. In some embodiments, the aluminum alloy powder has an average particle size of about 20 pm to about 65 pm.

[0070] In some embodiments, the aluminum alloy powder of the present application is for use as a substrate in additive manufacturing of aerospace components.

[0071] In some embodiments, the aluminum alloy powder of the present application may also comprise other elements in trace amounts, such as H, Si, Ti, Mn, Fe, Cu, etc.

[0072] In some embodiments, the aluminum alloy powder of the present application is obtained from modification of AA535 aluminum alloy powder.

[0073] The normal composition of AA535 being:Element Symbol Average PreferredRange %Manganese Mn 0.1Silicon Si 0.2Phosphorus P 0.57Magnesium Mg 7.5Copper Cu 0.1Iron Fe 0.15Titanium Ti 0.25Aluminum Al Balance

[0074] The typical composition of AA7075 comprises about 5.6-6.1 % zinc, 2.1 -2.5% magnesium, 1.2-1 .6% copper, and less than a half percent of silicon, iron,manganese, titanium, chromium, and other metals. AA7075 aluminium alloy's composition may be produced in many tempers, such as 7075-0, 7075-T6, 7075-T651 .III. Methods and Uses of the Application

[0075] The materials of the application have been shown to be useful in additive manufacturing of components with improved mechanical properties.

[0076] Accordingly, included is a method of additive manufacturing aerospace components comprising: providing an aluminum alloy powder of the present application as a substrate; melting and fusing the substrate to additively manufacture the aerospace components.

[0077] Also included is a method for reducing microcracking and / or porosity of additive manufacturing components, the method comprising: providing an aluminum alloy powder of the present application as a substrate; melting and fusing the substrate to additively manufacture the components.

[0078] Previously, 3D printing using traditional materials led to reveal the presence of grain growth detrimentally affecting the strength and elongation made possible by very small grains inherent to AM and rapid solidification.

[0079] In some embodiments, the present application focused on identifying the printing conditions for achieving the present improved results. By meticulously fine- tuning parameters such as laser power, laser scanning speed, layer thickness, powder particle size, and hatch spacing, an environment conducive to the successful 3D printing of the modified metal powders of the application was created. Additionally, efforts have been directed towards reducing the oxygen content within the printing chamber, a factor that has been found to impact the quality of the printed components. As such, the meticulous determination of printing parameters achieved a level of precision and reliability previously unattainable in this field.

[0080] Without being bound to theory, to be used in production applications at a greater scale, the material needs to tolerate higher scanning speeds without introducing a higher defect density. In some embodiments, materials of the present application have shown to be suitable across a range of laser energy levels at1800mm / s scanning speed, which is approaching a feasible range for component production following the addition of Zr, which also resolved the cracking, indicating the transition to refined grains from the combination of a sufficient amount of Sc and Zr.

[0081] In some embodiments, the method further comprises removing ambient oxygen, for example within an additive manufacturing chamber when conducting the additive manufacturing.

[0082] In some embodiments, the method further comprises reducing the average particle size of the aluminum alloy powder to about 15 pm to about 70 pm, prior to blending.

[0083] In some embodiments, the melting and fusing is at a temperature of about 600 °C to about 850 °C.

[0084] In some embodiments, the melting and fusing is conducted by a powder bed fusion process. In some embodiments, the powder bed fusion process comprises direct metal la-ser sintering (DMLS), selective laser melting (SLM) or electron beam melting (EBM).

[0085] In some embodiments, the melting and fusing is provided by a laser. In some embodiments, the laser is operated at a power of about 100 W to about 500 W. In some embodiments, the laser is operated at a power of about 200 W to about 400 W. In some embodiments, the laser is operated at a scanning speed of about 100 mm / s to about 3000 mm / s. In some embodiments, the laser is operated at a scanning speed of about 400 mm / s to about 2000 mm / s. In some embodiments, the laser is operated at a scanning speed of about 100 mm / s to about 1000 mm / s.

[0086] In some embodiments, the method comprises depositing the substrate at a hatch spacing of about 0.1 mm to about 0.2 mm. In some embodiments, the depositing is made layer by layer. In some embodiments, the depositing is made layer by layer at a layer thickness of about 20 pm to about 100 pm.

[0087] In some embodiments, the additive manufacturing components produced by the method of the present application have increased strength, corrosion resistance and / or thermal conductivity.

[0088] Also included is use of AA535 aluminum alloy powder for preparing an aluminum alloy powder suitable for additive manufacturing of aerospace components.

[0089] The present application further includes use of AA535 aluminum alloy powder for preparing an aluminum alloy powder suitable for use as a substrate for additive manufacturing.

[0090] Further provided is use of an aluminum alloy powder of the present application for additive manufacturing aerospace components.

[0091] Also included is use of an aluminum alloy powder of the present application as a substrate for additive manufacturing.

[0092] Further included is use of an aluminum alloy powder of the present application for reducing microcracking in additive manufacturing components, for reducing porosity in additive manufacturing components, for increasing strength in additive manufacturing components, for increasing corrosion resistance in additive manufacturing components, and / or for increasing thermal conductivity in additive manufacturing components.IV. Methods of Preparing the Compositions of the Application

[0093] Also included is a method of manufacturing an aluminum alloy powder of the present application, the method comprising, blending an AA535 aluminum alloy powder with at least one of zirconium dihydride or scandium oxide to generate the aluminum alloy powder.

[0094] The present application further includes a method of manufacturing an aluminum alloy powder for use as an additive manufacturing substrate, the method comprising, blending an AA535 aluminum alloy powder with at least one of zirconium dihydride or scandium oxide to generate the aluminum alloy powder, wherein the aluminum alloy powder comprises:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%;Mg in an amount of about 1 .0 wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 0 wt% to about 3 wt%; andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0095] The present application also includes a method of manufacturing an aluminum alloy powder for use in additive manufacturing of aerospace components, the method comprising, blending an AA535 aluminum alloy powder with at least one of zirconium dihydride or scandium oxide to generate the aluminum alloy powder, wherein the aluminum alloy powder comprises:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1 .0 wt%;Mg in an amount of about 1 .0wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 0 wt% to about 3 wt%; andZn in an amount of about 0.05 wt% to about 3.5 wt%.

[0096] In some embodiments, the blending is with zirconium dihydride.

[0097] In some embodiments, the method further comprises doping the AA535 aluminum alloy powder with at least one of Sc and Ce prior to the blending.

[0098] In some embodiments, the AA535 aluminum alloy powder and the zirconium dihydride are blended in a ratio of about 100:1 to about 150:1. In some embodiments, the AA535 aluminum alloy powder and the zirconium dihydride are blended in a ratio of about 120:1 to about 135:1.

[0099] In some embodiments, the AA535 aluminum alloy powder and the scandium oxide are blended in a ratio of about 1000:1 to about 450:1. In some embodiments, the AA535 aluminum alloy powder and the scandium oxide are blended in a ratio of about 900:1 to about 500:1 In some embodiments, the AA535 aluminum alloy powder and the scandium oxide are blended in a ratio of about 800:1 to about 550:1.EXAMPLES

[0100] The following non-limiting examples are illustrative of the present application.General MethodsThe following appellations were used in the examples and figures:Generic Process Parameters for additive manufacturing

[0101] One suitable 3D printing process for aluminum alloys is powder bed fusion, which utilizes a focused heat source like a laser or electron beam to selectively melt and fuse powder particles layer-by-layer.

[0102] Typical range of process parameters:• Laser power: 100-500 W• Laser scanning speed: 100-1000 mm / s• Hatch spacing: 0.1 -0.2 mm• Layer thickness: 20-100 pm• Powder particle size: 15-62 pm• Powder bed temperature: Room temperature for SLM / DMLS, 600-850°C for EBMExample 1 - Modified AA535

[0103] The blending process of AA535 with ZrH2 provided an aluminum alloy powder having the following composition:FINAL Mass »> 2715 g Wt. % At. %0.02% 0.45%0.00% 0.00%Mg 3.98% 4.52%91 .46% 93.59%Si 0.09% 0.09%Ca 0.00% 0.00%Sc 0.56% 0.34%Ti 0.15% 0.09%V 0.00% 0.00%Cr 0.00% 0.00%Mn 0.11 % 0.05%Fe 0.09% 0.04%Ni 0.00% 0.00%Cu 0.14% 0.06%Zn 0.10% 0.04%Zr 0.76% 0.22%Ag 0.00% 0.00%Ce 2.55% 0.50%

[0104] Data was collected using the Archimedes method for measuring relative density and optical images of material generated by Laser Powder Bed Fusion (FIG.1 & FIG.8), with the latter being processed using Imaged to determine the relative pore volume fraction. The images shown in FIG.2, FIG.3, FIG.5 and FIG.6 are from optical microscopy (OM) observations, where optimal parameters (*) represents those that have an absence of cracking and a reduced porosity, that were processed to create the plots shown in FIG.4 and FIG.7, which are only representative of the processing of OM images, not other relative density measures. In particular, the key contrast between the unblended (AA535-1 ) and blended (AA535-2) varieties is the reduction in defect density, with the near-complete subtraction of cracking in the blended formulation (AA535-2).Example 2 - Modified AA7075

[0105] The blending process of AA7075 with ZrH2 provided an aluminum alloy powder having the following composition:FINAL Mass »> 4149 g wt. % at. %H 0.01 % 0.37%O 0.00% 0.00%Mg 1.45% 1.67%Al 91.80% 94.97%Si 0.07% 0.07%Ca 0.00% 0.00%Sc 0.61% 0.38%Ti 0.00% 0.00%V 0.00% 0.00%Cr 0.14% 0.07%Mn 0.05% 0.03%Fe 0.09% 0.04%Ni 0.00% 0.00%Cu 1.76% 0.77%Zn 3.41 % 1.46%Zr 0.62% 0.18%Ag 0.00% 0.00%Ce 0.00% 0.00%

[0106] Data was collected using the Archimedes method for measuring relative density and optical images, with the latter being processed using Imaged to determine the relative pore volume fraction. The images shown in FIG.9, FIG.10, FIG.12, FIG.13, FIG.15 and FIG.16 are from OM observations, where optimal parameters (*) represents those that have an absence of cracking and a reduced porosity, that were processed to create the plots shown in FIG. 11 and FIG.17, which are only representative of processing of OM images, not other relative density measures. In particular, the key contrast between the unblended (AA7075-1 ) and blended (AA7075- 2, and AA7075-3) varieties is the near-complete subtraction of cracking in the blendedformulations, with the second round of modifications (in AA7075-3) minimizing the pore volume fraction relative to the previous blend (AA7075-2).Example 3 - Mechanical Properties Testing

[0107] The ASTM G69 method measures the corrosion potential of aluminum alloys. The compositions of the present application show reduced discoloration after exposures compared to undoped alloys.

[0108] The Laser Flash Thermal Diffusivity (TD) measurements are designed to measure thermal transmission. The compositions of the present application show an increased transmission of heat compared to the undoped alloys.Example 4 - Tensile strength

[0109] Samples were printed with the profile of ASTM E8 subsize tensile specimens, cut to roughly 4.5mm thickness via wire-EDM, leaving the printed side-skin in place. Samples were tested until failure at a strain rate of roughly 2mm / min in a MTS Criterion Model 43 50kN testing apparatus.

[0110] For optical imaging and relative density, the samples were mounted in bakelite, grinding and polishing performed. Keyence microscope was used to obtain stitched images and the images were processed via thresholding using Imaged and graphed in Excel. Results are shown in FIG. 14 and FIG. 17 and illustrate the relative density of printed material (Y-axis) as a function of the energy imparted to the powders (X-axis) for two hatch distances, demonstrating a broad range.

[0111] For microhardness test results, the same samples from imaging were used. Clemens automatic tester was used, following ASTM specifications for microhardness measurements in a grid of 5x5 indents, with indents overlapping with defects removed. Results were collected and graphed in Excel. Results are shown in FIG.18, FIG.19, FIG.20, FIG.21 and FIG.22. It can be seen that the range of Vickers microhardness shows only slight variation over a broad range of energy imparted to the powders.

[0112] For tensile testing, samples were printed with the profile of ASTM E8 subsize tensile specimens, cut to roughly 4.5mm thickness via wire-EDM, leaving theprinted side-skin in place. Samples were tested until failure at a strain rate of roughly 2mm / min in a MTS Criterion Model 43 50kN testing apparatus. Results were collected and graphed in Excel, as shown in Tables 1 -5 below and in FIG. 23, FIG.24 and FIG.25, from which can be seen the residual metal composition of the coupons and their tensile strengths in as-built and in temperature-treated forms.

[0113] Table 1 : Engineering tensile strength (peak, mean, and range for UTS and Elongation) for AA535-2 in the as-built and heat-treated conditions using optimal print parameters

[0114] Table 2: Concentration of key elements in the optimal printed tensile coupons determined via ICP-OES measurements for AA535-2

[0115] Table 3: Engineering tensile strength for AA7075-2 in the as-built (AB) and heat-treated (HT) conditions using optimal print parameters

[0116] Table 4: Engineering tensile strength (peak, mean, and range for UTS and Elongation) for AA7075-3 in the as-built and heat-treated conditions using optimal print parameters

[0117] Table 5: Concentration of key elements in the optimal printed tensile coupons determined via ICP-OES measurements for AA7075-2 and AA7075-3

[0118] While the applicant's teachings described herein are in conjunction with various embodiments for illustrative purposes, it is not intended that the applicant's teachings be limited to such embodiments as the embodiments described herein are intended to be examples. On the contrary, the applicant's teachings described and illustrated herein encompass various alternatives, modifications, and equivalents,without departing from the embodiments described herein, the general scope of which is defined in the appended claims.

Claims

CLAIMS :

1. An aluminum alloy powder comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%;Mg in an amount of about 1.0 wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 0 wt% to about 3 wt%; andZn in an amount of about 0.05 wt% to about 3.5 wt%.

2. An aluminum alloy powder for use as an additive manufacturing substrate, comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%,Mg in an amount of about 1.0 wt% to about 5 wt%,Sc in an amount of about 0.25 wt% to about 0.75 wt%,Ce in an amount of about 0 wt% to about 3 wt%, andZn in an amount of about 0.05 wt% to about 3.5 wt%.

3. An aluminum alloy powder for use in additive manufacturing of aerospace components, comprising:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%,Mg in an amount of about 1.0 wt% to about 5 wt%,Sc in an amount of about 0.25 wt% to about 0.75 wt%,Ce in an amount of about 0 wt% to about 3 wt%, andZn in an amount of about 0.05 wt% to about 3.5 wt%.

4. The aluminum alloy powder of any one of claims 1 to 3, wherein Zr is in an amount of about 0.6 wt% to about 0.9 wt%.

5. The aluminum alloy powder of any one of claims 1 to 3, wherein Zr is in an amount of about 0.7 wt% to about 0.85 wt%.

6. The aluminum alloy powder of any one of claims 1 to 5, wherein Mg is in an amount of about 1.5 wt% to about 4.5 wt%.

7. The aluminum alloy powder of any one of claims 1 to 5, wherein Mg is in an amount of about 2.5 wt% to about 4.0 wt%.

8. The aluminum alloy powder of any one of claims 1 to 7, wherein Sc is in an amount of about 0.35 wt% to about 0.7 wt%9. The aluminum alloy powder of any one of claims 1 to 7, wherein Sc is in an amount of about 0.45 wt% to about 0.65 wt%.

10. The aluminum alloy powder of any one of claims 1 to 9, wherein Ce is in an amount of about 0.1 wt% to about 2.75 wt%.

11. The aluminum alloy powder of any one of claims 1 to 9, wherein Ce is in an amount of about 0.5 wt% to about 2.5 wt%.

12. The aluminum alloy powder of any one of claims 1 to 11, wherein Zn is in an amount of about 0.06 wt% to about 3 wt%.

13. The aluminum alloy powder of any one of claims 1 to 11, wherein Zn is in an amount of about 0.07 wt% to about 2.5 wt%.

14. The aluminum alloy powder of any one of claims 1 to 13, wherein the aluminum alloy powder has an average particle size of about 15 pm to about 90 pm.

15. The aluminum alloy powder of any one of claims 1 to 13, wherein the aluminum alloy powder has an average particle size of about 20 pm to about 65 pm.

16. The aluminum alloy powder of any one of claims 1 to 15, for use as a substrate in additive manufacturing of aerospace components.

17. A method of manufacturing an aluminum alloy powder as defined in any one of claims 1 to 15, the method comprising, blending an AA535 aluminum alloy powder doped with at least one metal with at least one of zirconium dihydride or scandium oxide to generate the aluminum alloy powder.

18. A method of manufacturing an aluminum alloy powder for use as an additive manufacturing substrate, the method comprising, blending an AA535 aluminum alloy powder doped with at least one metal with at least one of zirconium dihydride or scandium oxide to generate the aluminum alloy powder, wherein the aluminum alloy powder comprises:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%;Mg in an amount of about 2.5 wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 1.5 wt% to about 3 wt%; and Zn in an amount of about 0.05 wt% to about 0.2 wt%.

19. A method of manufacturing an aluminum alloy powder for use in additive manufacturing of aerospace components, the method comprising, blending an AA535 aluminum alloy powder doped with at least one metal with at least one of zirconium dihydride or scandium oxide to generate the aluminum alloy powder, wherein the aluminum alloy powder comprises:Al in an amount of about 90 wt% to about 94 wt.%;Zr in an amount of about 0.5 wt% to about 1.0 wt%;Mg in an amount of about 2.5 wt% to about 5 wt%;Sc in an amount of about 0.25 wt% to about 0.75 wt%;Ce in an amount of about 1.5 wt% to about 3 wt%; and Zn in an amount of about 0.05 wt% to about 0.2 wt%.

20. The method of any one of claims 17 to 19, further comprising doping the AA535 aluminum alloy powder with at least one of Sc and Ce prior to the blending.

21. The method of any one of claims 17 to 20, wherein the AA535 aluminum alloy powder and the zirconium dihydride are blended in a ratio of about 100:1 to about 150:1.

22. The method of any one of claims 17 to 20, wherein the AA535 aluminum alloy powder and the zirconium dihydride are blended in a ratio of about 120:1 to about 135:1.

23. The method of any one of claims 17 to 20, wherein the AA535 aluminum alloy powder and the scandium oxide are blended in a ratio of about 1000:1 to about 450:1.

24. A method of additive manufacturing aerospace components comprising: providing an aluminum alloy powder as defined in any one of claims 1 to 15 as a substrate; melting and fusing the substrate to additively manufacture the aerospace components.

25. A method for reducing microcracking and / or porosity of additive manufacturing components, the method comprising: providing an aluminum alloy powder as defined in any one of claims 1 to 15 as a substrate; melting and fusing the substrate to additively manufacture the components.

26. The method of claim 24 or 25, further comprising removing ambient oxygen.

27. The method of any one of claims 24 to 26, further comprising reducing the average particle size of the aluminum alloy powder to about 15 pm to about 70 pm.

28. The method of any one of claims 24 to 27, wherein the melting and fusing is at a temperature of about 600 °C to about 850 °C.

29. The method of any one of claims 24 to 27, wherein the melting and fusing is conducted by a powder bed fusion process.

30. The method of claim 29, wherein the powder bed fusion process comprises direct metal laser sintering (DMLS), selective laser melting (SLM) or electron beam melting (EBM).

31. The method of any one of claims 24 to 28, wherein the melting and fusing is provided by a laser.

32. The method of claim 30, comprising operating the laser at a power of about 100 W to about 500 W.

33. The method of claim 30, comprising operating the laser at a power of about 200 W to about 400 W.

34. The method of any one of claims 31 to 33, comprising operating the laser at a scanning speed of about 100 mm / s to about 3000 mm / s.

35. The method of any one of claims 31 to 33, comprising operating the laser at a scanning speed of about 400 mm / s to about 2000 mm / s.

36. The method of any one of claims 31 to 33, comprising operating the laser at a scanning speed of about 100 mm / s to about 1000 mm / s.

37. The method of any one of claims 24 to 35, comprising depositing the substrate at a hatch spacing of about 0.1 mm to about 0.2 mm.

38. The method of claim 37, wherein the depositing is made layer by layer.

39. The method of claim 37 or 38, wherein the depositing is made layer by layer at a layer thickness of about 20 pm to about 100 pm.

40. The method of any one of claims 24 to 39, wherein the additive manufacturing components have increased strength, corrosion resistance and / or thermal conductivity.

41. Use of AA535 aluminum alloy powder for preparing an aluminum alloy powder suitable for additive manufacturing of aerospace components.

42. Use of AA535 aluminum alloy powder for preparing an aluminum alloy powder suitable for use as a substrate for additive manufacturing.

43. Use of an aluminum alloy powder as defined in any one of claims 1 to 15 for additive manufacturing aerospace components.

44. Use of an aluminum alloy powder as defined in any one of claims 1 to 15 as a substrate for additive manufacturing.

45. Use of an aluminum alloy powder as defined in any one of claims 1 to 15 for reducing microcracking in additive manufacturing components.

46. Use of an aluminum alloy powder as defined in any one of claims 1 to 15 for reducing porosity in additive manufacturing components.

47. Use of an aluminum alloy powder as defined in any one of claims 1 to 15 for increasing strength in additive manufacturing components.

48. Use of an aluminum alloy powder as defined in any one of claims 1 to 15 for increasing corrosion resistance in additive manufacturing components.

49. Use of an aluminum alloy powder as defined in any one of claims 1 to 15 for increasing thermal conductivity in additive manufacturing components.

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