WO2025178645A2

WO2025178645A2 - Novel aluminum alloy for 3d printing powder feedstock

Info

Publication number: WO2025178645A2
Application number: PCT/US2024/033349
Authority: WO
Inventors: Philippe Boichat; Zeqin LIANG; Navid SOHRABI; Aurele Blaise MARIAUX; Vincent MARCLAY
Original assignee: Novelis Inc Canada
Current assignee: Novelis Inc Canada
Priority date: 2023-06-12
Filing date: 2024-06-11
Publication date: 2025-08-28
Anticipated expiration: 2025-12-12
Also published as: WO2025178645A3

Abstract

Described herein is a novel aluminum alloy and aluminum alloy powder for use in additive manufacturing which exhibit improved mechanical properties, such as high strength, and high recyclability. The aluminum alloys described herein exhibit high strength despite having higher amounts of Si and no rare earth metals compared to traditional aluminum alloys used in additive manufacturing. The present disclosure provides a cost-effective alternative to the use of commercial aluminum alloys used for additive manufacturing, such as laser powder-bed fusion processes.

Description

NOVEL ALUMINUM ALLOY FOR 3D PRINTING POWDER FEEDSTOCK

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63/507,564, filed on June 12, 2023, the content of which is hereby incorporated by reference in its entirety.

FIELD

[0002] The present disclosure relates to the fields of material science, material chemistry, metallurgy, aluminum alloys, aluminum fabrication, and related fields. In particular, the present disclosure provides novel aluminum alloy useful in 3D printing powder feedstock having improved mechanical properties.

BACKGROUND

[0003] Aluminum (Al) alloys are often employed as printing material in additive manufacturing using laser powder-bed fusion methods. Typical aluminum alloys used in additive manufacturing applications do not meet the current demands of the industry which include high strength, light weight, recyclability, and additive manufacturing products free of defects. As additive manufacturing is adapted as a method of manufacture in an area including automotive and aerospace, additive manufacturing demands characteristics including small feature sizes and accuracy. It is necessary to control the microstructure of the additive manufacturing product to ensure the product meets strict safety and structural requirements within the industry.

[0004] Previously, aluminum alloys for commercial use in additive manufacturing achieved mechanical properties while comprising high content of elemental components such as rare earth elements. Other such aluminum alloys may combine higher levels of other elemental components like copper or magnesium but such levels may result in heavy cracking in the material during laser-based additive manufacturing processes. While high content rare earth metal alloys may have mechanical properties demanded by additive manufacturing methods, defects are common during processing and the products generated do not have the recyclability sought after in the industry. Such alloys typically use scandium as a grain refiner to obtain additive manufacturing products with fine grain structures. Furthermore, high content of rare earth elements typically increases the price of the aluminum alloy composition. The mechanical properties of the aluminum alloy products produced by additive manufacturing depend not only on the alloy composition but also on the heat treatment processes applied after the additive material is produced. Thus, the industry lacks an aluminum alloy composition specifically designed for additive manufacturing with superior mechanical properties while omitting rare earth elements, which makes the alloy less expensive and more recyclable friendly. The industry also lacks a method for increasing the mechanical strength subsequent to production of the additive manufacturing product.

[0005] There has long been a need in the industry for alloys having superior mechanical properties that also may be processed into powders for use in additive manufacturing methods without the significant defects currently plaguing the industry. Additionally, additive manufacturing methods have long required methods for producing reproducible atomization parameters to meet the demand and provide reproducible printing materials comprising the aluminum alloy composition.

SUMMARY

[0006] Covered embodiments of the present disclosure are defined by the claims, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification, any or all drawings and each claim.

[0007] Provided herein are aluminum alloy compositions useful for the additive manufacturing of products and other applications. The alloys exhibit the strength, microstructure, good processability, and recyclability necessary for the demands of additive manufacture product printing. The aluminum alloys described herein include from 1.0 - 80 wt.% Si, at least 0.50 wt.% Mg, at least 0.10 wt.% Fe, greater than 0.20 wt.% Cu, greater than 0.20 wt.% Mn, at least 0.01 wt.% of at least one of Cr and V, and up to 0.15 wt.% impurities, and Al. The aluminum alloy may further comprise Co, Ti and/or Zr. Throughout this application, all elements are described in weight percentage (wt.%) based on the total weight of the alloy. In some embodiments, the aluminum alloy composition described herein is free from rare earth metals. In another example, the aluminum alloys described herein comprises about 1.0 - 7.0 wt.% Si, 0.50 - 3.0 wt.% Mg, 0.10 - 10.0 wt.% Fe, greater than 0.20 - 2.0 wt.% Cu, greater than 0.20 - 6.0 wt.% Mn, 0.05 - 0.25 wt.% of at least one of Cr and V, up to 0.15 wt.% impurities, and Al. The aluminum alloy may further comprise Co, Ti and/or Zr. In another example, the aluminum alloy composition described herein comprises about 1.0 - 80.0 wt.% Si, 1.0 - 10.0 wt.% Mg, 0.10 - 10.0 wt.% Fe, greater than 0.20 - 2.0 wt.% Cu, greater than 0.20 - 6.0 wt.% Mn, 0.05 - 0.25 wt.% of at least one of Cr and V, up to 0.15 wt.% impurities, and Al. The aluminum alloy may further comprise Co, Ti and/or Zr. [0008] Further provided herein are aluminum alloy powders useful for additive manufacturing of products and other applications. The alloys exhibit the strength, processability, microstructure, and recyclability necessary for the demands of additive manufacture product printing. The aluminum alloy powder described herein may include from 1.0 - 80 wt.% Si, 0.50 - 4.0 wt.% Mg, 0.10 - 10.0 wt.% Fe, greater than 0.20 - 2.0 wt.% Cu, greater than 0.20 - 6.0 wt.% Mn, 0.05 - 0.25 wt.% of at least one of Cr and V, up to 0.15 wt.% impurities, and Al. The aluminum alloy may further comprise Co, Ti and/or Zr. Throughout this application, all elements are described in weight percentage (wt.%) based on the total weight of the alloy. In another example, the aluminum alloy powder composition described herein is free from rare earth metals.

[0009] As one non limiting example, the alloy is useful in additive manufacturing, such as powders suitable for the production of products produced via laser powder-bed fusion methods.

[0010] Further provided herein are methods of manufacturing an additive manufactured product comprising the aluminum alloy composition described herein. The methods include steps of preparing an aluminum alloy powder feedstock, the powder feedstock comprising an aluminum having the following composition: from 1.0 - 80 wt.% Si, 0.50 - 4.0 wt.% Mg, 0.10 - 10.0 wt.% Fe, greater than 0.20 - 2.0 wt.% Cu, greater than 0.20 - 6.0 wt.% Mn, 0.05 - 0.25 wt.% of at least one of Cr and V, up to 0.15 wt.% impurities, and Al. The aluminum alloy may further comprise Co, Ti and/or Zr. The method may further include printing successive layers from the powder feedstock to form the additive manufactured product. In another example, the method includes printing of the successive layers, wherein the printing comprises laser powder bed fusion, laser metal deposition, or any suitable method for manufacturing additive products. In another example, the method may include cooling the additive manufactured product at a rate from about 1000 - 1,000,000 °C/second. In another example, the aluminum alloy powder may be atomized via gas, liquid, or ultrasonic atomization methods followed by printing successive layers from the powder feedstock to form the additive manufactured product. The additive material produced may have desirable physical characteristics such as a desired density, hardness, strength, and processability. In another example, the method of producing the additive manufactured product may include a heat treating step subsequent to printing the additive manufactured product and optionally, the heat treated product may not be subject to hot isostatic pressing. In yet another example, the heat treated product is subject to hot isostatic pressing.

[0011] Also provided herein are products obtained according to the methods provided herein. As one non-limiting example, those products may be alloys or alloy powders useful for fabrication into additive manufacturing products.

[0012] Further aspects, objects, and advantages will become apparent upon consideration of the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIGS. 1A-1B provide microscopy images of the microstructure (FIG. 1 A) and arm spacing measurements (FIG. IB) of an example aluminum alloy composition described herein, according to some embodiments described herein.

[0014] FIG. 2 provides a graph of the Vickers hardness and the Brinell hardness of an example aluminum alloy composition cast as ingot and heat treated, according to some embodiments described herein.

[0015] FIGS. 3A-3I provide electron dispersive X-ray spectroscopy (EDX) maps of Example 1 as cast, according to some embodiments described herein.

[0016] FIGS. 4A-4I provide electron dispersive X-ray spectroscopy (EDX) maps of Example 1 after T6 temper, according to some embodiments described herein.

[0017] FIGS. 5A-5B provide an SEM image (FIG. 5 A) and EDX mapping of three independent locations (FIG. 5B) for Example 1, according to some embodiments described herein. DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0018] Described herein are novel aluminum alloy compositions and powders used in additive manufacturing which exhibit high strength and processability. Surprisingly, the aluminum alloys described herein exhibit high strength and processability despite having a lower Si content and being substantially free of rare earth metals, e.g., less than 0.01 wt.% or below a detectable limit. Rare earth metals, including neodymium, scandium, cerium, yttrium, dysprosium, praseodymium, lanthanum, terbium, samarium, europium, gadolinium, promethium, holmium, erbium, thulium, yttrbium, and lutetium, are commonly included in aluminum alloy compositions as they allow for small nucleation sites without generating defects, aiding to refine the microstructure of the alloy and generating a high strength material. The aluminum alloy compositions described herein, substantially free of rare earth metals, have mechanical properties that are stable and maintained throughout the process of additive manufacturing. The present disclosure provides a high strength, cost-effective, and recyclable friendly alternative to the use of current aluminum alloys for additive manufacturing.

[0019] Described herein are methods for manufacturing the products comprising the aluminum alloy compositions which exhibit the strength, processability, powder morphology, and particle size distribution required for manufacture of printable aluminum products. In a non-limiting example, the aluminum alloy described herein may be used in high solidification technologies to print fully dense parts with low or no cracking. In some examples, the additive manufacturing technology may be a laser powder-bed fusion method or laser metal deposition. The alloys described herein include alloying elements that may increase the recyclability of the alloy without limiting the mechanical properties of the alloy product.

Definitions and Descriptions:

[0020] The terms “invention,” “the invention,” “this invention,” and “the present invention” used herein are intended to refer broadly to all of the subject matter of this patent application and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below.

[0021] As used herein, the meaning of “a,” “an,” or “the” includes singular and plural references unless the context clearly dictates otherwise. [0022] All ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g., 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10.

Alloy Compositions

[0023] Aluminum alloy properties are partially determined by the composition of the aluminum alloys. In certain aspects, the alloy composition may influence or even determine whether the alloy will have properties adequate for a desired application.

[0024] Additionally, aluminum alloy powder properties are partially determined by the composition of the aluminum powder. In certain aspects, the powder composition may influence or even determine whether the powder will have properties adequate for a desired application.

[0025] The alloy and powder described herein are novel aluminum compositions. The aluminum compositions exhibit desirable mechanical and physical properties, such as strength, processability, microstructure, and recyclability. The properties of the composition are achieved at least in part due to the elemental composition of the aluminum.

[0026] In some examples, an aluminum alloy as described herein can have the following elemental composition as provided in Table 1.

Table 1

[0027] In some examples, the aluminum alloy powder as described herein can have the following elemental composition as provided in Table 2.

Table 2

Silicon (Si)

[0028] In some examples, the aluminum alloy described herein includes Si in an amount of from 1.0 % to 80.0 % (e.g., from 1.3 to 80 %, from 1.3 % to 50.0. %, from 1.3 % to 20.0 %, from 1.3 % to 30.0 %, or from 1.3 % to 7.0%) based on the total weight of the alloy. For example, the alloy can include 1.0 %, 1.3 % 2.0 %, 3.0 %, 4.0 %, 5.0 %, 6.0 %, 7.0 %, 8.0 %,

9.0 %, 10.0 %, 11.0 %, 12.0 %, 13.0 %, 14.0 %, 15.0 %, 16.0 %, 17.0 %, 18.0 %, 19.0 %

20.0 %, 21.0 %, 22.0 %, 23.0 %, 24.0 %, 25.0 %, 26.0 %, 27.0 %, 28.0 %, 29.0 %, 30.0 %,

31.0 %, 32.0 %, 33.0 %, 34.0 %, 35.0 %, 36.0 %, 37.0 %, 38.0 %, 39.0 %, 40.0 %, 41.0 %,

42.0 %, 43.0 %, 44.0 %, 45.0 %, 46.0 %, 47.0 %, 48.0 %, 49.0 %, 50.0 %, 51.0 %, 52.0 %,

53.0 %, 54.0 %, 55.0 %, 56.0 %, 57.0 %, 58.0 %, 59.0 %, 60.0 %, 61.0 %, 62.0 %, 63.0 %, 64.0 %, 65.0 %, 66.0 %, 67.0 %, 68.0 %, 69.0 %, 70.0 %, 71.0 %, 72.0 %, 73.0 %, 74.0 %,

75.0 %, 76.0 %, 77.0 %, 78.0 %, 79.0 %, or 80.0 % Si. All expressed in wt.%.

Iron (Fe)

[0029] In some examples, the aluminum alloy described herein also includes Fe in an amount of from 0.10 % to 10.0 % (e.g., from 0.10 % to 5.0 %, from 0.50 % to 8.0 %, or from 0.10 % to 2.0 %) based on the total weight of the alloy. For example, the alloy can include

0.10 %, 0.20 %, 0.30 %, 0.40 %, 0.50 %, 0.60 %, 0.70 %, 0.80 %, 0.90 %, 1.0 %, 1.1 %, 1.2

%, 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2 %, 2.3 %, 2.4 %, 2.5

%, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, 3.4 %, 3.5 %, 3.6 %, 3.7 %, 3.8

%, 3.9 %, 4.0 %, 4.1 %, 4.2 %, 4.3 %, 4.4 %, 4.5 %, 4.6 %, 4.7 %, 4.8 %, 4.9 %, 5.0 %, 5.1

%, 5.2 %, 5.3 %, 5.4 %, 5.5 %, 5.6 %, 5.7 %, 5.8 %, 5.9 %, 6.0 %, 6.1 %, 6.2 %, 6.3 %, 6.4

%, 6.5 %, 6.6 %, 6.7 %, 6.8 %, 6.9 %, 7.0 %, 7.1 %, 7.2 %, 7.3 %, 7.4 %, 7.5 %, 7.6 %, 7.7

%, 7.8 %, 7.9 %, 8.0 %, 8.1 %, 8.2 %, 8.3 %, 8.4 %, 8.5 %, 8.6 %, 8.7 %, 8.8 %, 8.9 %, 9.0

%, 9.1 %, 9.2 %, 9.3 %, 9.4 %, 9.5 %, 9.6 %, 9.7 %, 9.8 %, 9.9 %, or 10.0 % Fe. All expressed in wt.%.

Copper (Cu)

[0030] In some examples, the aluminum alloy described herein includes Cu in an amount of from greater than 0.20 % to 2.00 % (e.g., from 0.21 % to 1.50 %, from 0.21 % to 1.25 %, or from 0.21 % to 1.0 %) based on the total weight of the alloy. For example, the alloy can include 0.25 %, 0.30 %, 0.40 %, 0.50 %, 0.60 %, 0.70 %, 0.80 %, 0.90 %, 1.0 %, 1.10 %, 1.20 %, 1.30 %, 1.40 %, 1.50 %, 1.60 %, 1.70 %, 1.80 %, 1.90 %, or 2.0 % Cu. All expressed in wt.%.

Manganese (Mn)

[0031] In some examples, the aluminum alloy described herein may include Mn in an amount of from greater than 0.20 % to 6.0 % (e.g., from 0.21 % to 5.0 %, from 0.21 % to 4.0 %, from 0.21 % to 2.0 %, or from 0.21 % to 1.0 %) based on the total weight of the alloy. For example, the alloy can include 0.25 %, 0.30 %, 0.40 %, 0.50 %, 0.60 %, 0.70 %, 0.80 %, 0.90

%, 1.0 %, 1.1 %, 1.2 %, 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2

%, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, 3.4 %, 3.5

%, 3.6 %, 3.7 %, 3.8 %, 3.9 %, 4.0 %, 4.1 %, 4.2 %, 4.3 %, 4.4 %, 4.5 %, 4.6 %, 4.7 %, 4.8

%, 4.9 %, 5.0 %, 5.1 %, 5.2 %, 5.3 %, 5.4 %, 5.5 %, 5.6 %, 5.7 %, 5.8 %, 5.9 %, or 6.0 %

Mn. All expressed in wt.%. Magnesium (Mg)

[0032] In some examples, the aluminum alloy described herein may include Mg in an amount of from 0.50 % to 4.0 % (e.g., from 0.75 % to 3.75 %, from 0.50 % to 3.50 %, from 0.50 % to 3.25 %, from 0.50 % to 3.0 %, or from 0.50 % to 2.0 %). For example, the alloy described herein can include Mg in an amount from 0.50 %, 0.60 %, 0.70 %, 0.80 %, 0.90 %, 1.0 %, 1.1 %, 1.2 %, 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1 %, 2.2 %,

2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, 3.4 %, 3.5 %,

3.6 %, 3.7 %, 3.8 %, 3.9 %, 4.0 %, 4.1 %, 4.2 %, 4.3 %, 4.4 %, 4.5 %, 4.6 %, 4.7 %, 4.8 %,

4.9 %, 5.0 %, 5.1 %, 5.2 %, 5.3 %, 5.4 %, 5.5 %, 5.6 %, 5.7 %, 5.8 %, 5.9 %, 6.0 %, 6.1 %,

6.2 %, 6.3 %, 6.4 %, 6.5 %, 6.6 %, 6.7 %, 6.8 %, 6.9 %, 7.0 %, 7.1 %, 7.2 %, 7.3 %, 7.4 %.

7.5 %, 7.6 %, 7.7 %, 7.8 %, 7.9 %, 8.0 %, 8.1 %, 8.2 %, 8.3 %, 8.4 %, 8.5 %, 8.6 %, 8.7 %,

8.8 %, 8.9 %, 9.0 %, 9.1 %, 9.2 %, 9.3 %, 9.4 %, 9.5 %, 9.6 %, 9.7 %, 9.8 %, 9.9 %, or 10.0

% Mg. All expressed in wt.%.

Chromium (Cr)

[0033] In some examples, the aluminum alloy described herein includes Cr in an amount of up to 0.25 % or in an amount of at least 0.01 %, (e.g., from 0.01 % to 0.25 %, from 0.01 % to 0.20 %, from 0.01 % to 0.15 %, from 0.02 % to 0.25 %, from 0.02 % to 0.20 %, from 0.05 % to 0.15 %, from 0.06 % to 0.15 %, from 0.08 % to 0.15 %, or from 0.10 % to 0.15 %) based on the total weight of the alloy. For example, the alloy can include 0.01 %, 0.02 %, 0.03 %, 0.04 %, 0.05 %, 0.06 %, 0.07 %, 0.08 %, 0.09 %, 0.10 %, 0.11 %, 0.12 %, 0.13 %, 0.14 %, 0.15 %, 0.16 %, 0.17 %, 0.18 %, 0.19 %, 0.20 %, 0.21 %, 0.22 %, 0.23 %, 0.24 %, or 0.25 % Cr. In some cases, Cr is not present in the alloy (i.e., 0 %). In some cases, Cr is not present when V is present. All expressed in wt.%.

Vanadium (V)

[0034] In some examples, the aluminum alloy described herein includes V in an amount of up to 0.25 % and/or at least 0.01 %, (e.g., from 0.01 % to 0.25 %, from 0.01 % to 0.20 %, from 0.01 % to 0.15 %, from 0.02 % to 0.25 %, from 0.02 % to 0.20 %, from 0.05 % to 0.15 %, from 0.06 % to 0.15 %, from 0.08 % to 0.15 %, or from 0.10 % to 0.15 %) based on the total weight of the alloy. For example, the alloy can include 0.01 %, 0.02 %, 0.03 %, 0.04 %,

0.05 %, 0.06 %, 0.07 %, 0.08 %, 0.09 %, 0.10 %, 0.11 %, 0.12 %, 0.13 %, 0.14 %, 0.15 %

0.16 %, 0.17 %, 0.18 %, 0.19 %, 0.20 %, 0.21 %, 0.22 %, 0.23 %, 0.24 %, or 0.25 % V. In some cases, V is not present in the alloy (i.e., 0 %). In some cases, V is not present when Cr is present. All expressed in wt.%.

Zinc (Zn)

[0035] In some examples, the aluminum alloy described herein includes Zn in an amount of 0.01 % to 0.40 % (e.g., from 0.01 % to 0.40 %, from 0.01 % to 0.30 %, from 0.01 % to 0.20 %, or from 0.01 % to 0.15 %) based on the total weight of the alloy. For example, the alloy can include 0.01 %, 0.02 %, 0.03 %, 0.04 %, 0.05 %, 0.06 %, 0.07 %, 0.08 %, 0.09 %, 0.10

%, 0.11 %, 0.12 %, 0.13 %, 0.14 %, 0.15 %, 0.16 %, 0.17 %, 0.18 %, 0.19 %, 0.20 %, 0.21

%, 0.22 %, 0.23 %, 0.24 %, 0.25 %, 0.26 %, 0.27 %, 0.28 %, 0.29 %, 0.30 %, 0.31 %, 0.32

%, 0.33 %, 0.34 %, 0.35 %, 0.36 %, 0.37 %, 0.38 %, 0.39 %, or 0.40 % Zn. In some cases, Zn is not present in the alloy (i.e., 0 %). All expressed in wt.%.

Cobalt (Co)

[0036] In some examples, the aluminum alloy described herein may include Co in an amount of from 0.10 % to 6.0 % (e.g., from 0.10 % to 5.0 %, from 0.10 % to 4.0 %, from

0.10 % to 2.0 %, or from 0.20 % to 1.0 %) based on the total weight of the alloy. For example, the alloy can include 0.10 %, 0.20 %, 0.30 %, 0.40 %, 0.50 %, 0.60 %, 0.70 %, 0.80

%, 0.90 %, 1.0 %, 1.1 %, 1.2 %, 1.3 %, 1.4 %, 1.5 %, 1.6 %, 1.7 %, 1.8 %, 1.9 %, 2.0 %, 2.1

%, 2.2 %, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3.0 %, 3.1 %, 3.2 %, 3.3 %, 3.4

%, 3.5 %, 3.6 %, 3.7 %, 3.8 %, 3.9 %, 4.0 %, 4.1 %, 4.2 %, 4.3 %, 4.4 %, 4.5 %, 4.6 %, 4.7

%, 4.8 %, 4.9 %, 5.0 %, 5.1 %, 5.2 %, 5.3 %, 5.4 %, 5.5 %, 5.6 %, 5.7 %, 5.8 %, 5.9 %, or

6.0 % Co. All expressed in wt.%.

Titanium (Ti)

[0037] In some examples, the aluminum alloy described herein includes Ti in an amount of 0.01 % to 0.40 % (e.g., from 0.01 % to 0.40 %, from 0.01 % to 0.30 %, from 0.01 % to 0.20 %, or from 0.01 % to 0.15 %) based on the total weight of the alloy. For example, the alloy can include 0.01 %, 0.02 %, 0.03 %, 0.04 %, 0.05 %, 0.06 %, 0.07 %, 0.08 %, 0.09 %, 0.10

%, 0.33 %, 0.34 %, 0.35 %, 0.36 %, 0.37 %, 0.38 %, 0.39 %, or 0.40 % Ti. In some cases, Ti is not present in the alloy (i.e., 0 %). Zirconium (Zr)

[0038] In some examples, the aluminum alloy described herein may include Zr in an amount of from 0.10 % to 6.0 % (e.g., from 0.10 % to 5.0 %, from 0.10 % to 4.0 %, from 0.10 % to 2.0 %, or from 0.10 % to 1.0 %) based on the total weight of the alloy. For example, the alloy can include 0.10 %, 0.20 %, 0.30 %, 0.40 %, 0.50 %, 0.60 %, 0.70 %, 0.80

6.0 % Mn. All expressed in wt.%.

[0039] In some embodiments, the novel aluminum alloys described herein include both Zr and Ti in amounts of at least 0.50 wt.% (each). The ratio of Zr to Ti may range from 1 : 10 to 10: 1, e.g., from 1 :5 to 5: 1, from 1 :3 to 3: 1, from 1 :2 to 2: 1, or approximately 1 : 1.

[0040] In some embodiments, the novel aluminum alloys described herein can include Cr and V. Alternatively, in some embodiments, the aluminum alloys described herein can include Cr or V in an amount of at least 0.01 % and/or up to 0.25 %. The Al content may make up the balance or remainder of the alloy.

Minor Elements

[0041] Optionally, the aluminum alloys described herein may further include other minor elements, sometimes referred to as impurities, in amounts of 0.05 % or below, 0.04 % or below, 0.03 % or below, 0.02 % or below, or 0.01 % or below. These impurities may include, but are not limited to, Ni, Hf, Sn, Ga, Ca, Bi, Na, Pb, or combinations thereof. Accordingly, Ni, Hf, Sn, Ga, Ca, Bi, Na, or Pb, may be present in alloys in amounts of 0.05 % or below, 0.04 % or below, 0.03 % or below, 0.02 % or below, or 0.01 % or below. The sum of all impurities does not exceed 0.15 % (e.g., 0.1 %). All expressed in wt.%. The remaining percentage of each alloy can be aluminum. In some embodiments, each of these components may be specifically excluded.

[0042] The aluminum alloys described herein can contain at least 5 wt.% recycled content, at least 10 wt.% recycled content, at least 15 wt.%, at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.%, at least 40 wt.%, at least 45 wt.%, at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, or at least 95 wt.% recycled content. Properties

[0043] The aluminum alloy products described herein exhibit excellent properties, particularly when produced according to the methods described herein. In some embodiments, the aluminum alloy products described herein exhibit improved properties compared to aluminum alloy articles subjected to conventional laser powder-bed fusion or other additive manufacturing processes. Beneficially, the methods described herein produce aluminum alloy products that have excellent mechanical properties.

[0044] The additive manufacturing products comprising an aluminum alloy according to the methods described herein exhibit exceptional tensile strength. In particular, the tensile strength of the aluminum alloy products comprising the alloy composition described herein achieves service strength requirements to satisfy design criteria in additive manufacturing applications. For example, an aluminum alloy article can achieve excellent service strength for automotive applications.

[0045] In some examples, the portion of the additive manufactured product comprising the aluminum alloy composition described herein can have a tensile strength (Rm) of at least 350 MPa (e.g., from 350 MPa to 550 MPa, from 360 MPa to 540 MPa, from 370 MPa to 530 MPa, or from 390 MPa to 520 MPa) when the additive manufacturing product is processed according to the methods described herein. For example, additive manufacturing product comprising the aluminum alloy can have a tensile strength of 350 MPa or greater, 360 MPa or greater, 370 MPa or greater, 380 MPa or greater, 390 MPa or greater, 400 MPa or greater, 410 MPa or greater, 420 MPa or greater, 430 MPa or greater, 440 MPa or greater, 450 MPa, 460 MPa or greater, 470 MPa or greater, 480 MPa or greater, 490 MPa or greater, 500 MPa or greater, 510 MPa or greater, 520 MPa or greater, 530 MPa or greater, 540 MPa or greater, or 550 MPa or greater.

[0046] In some examples, the portion of the additive manufactured product comprising the aluminum alloy composition described herein can have a yield strength (Rp 0.2) of at least 300 MPa (e.g., from 300 MPa to 500 MPa, from 320 MPa to 500 MPa, from 350 MPa to 450 MPa, or from 300 MPa to 400 MPa) when the additive manufacturing product is processed according to the methods described herein. For example, additive manufacturing product comprising the aluminum alloy can have a yield strength of 300 MPa or greater, 310 MPa or greater, 320 MPa or greater, 330 MPa or greater, 340 MPa or greater, 350 MPa or greater, 360 MPa or greater, 370 MPa or greater, 380 MPa or greater, 390 MPa or greater, 400 MPa or greater, 410 MPa or greater, 420 MPa or greater, 430 MPa or greater, 440 MPa or greater, 450 MPa, 460 MPa or greater, 470 MPa or greater, 480 MPa or greater, 490 MPa or greater, or 500 MPa or greater.

[0047] In some examples, the additive manufacturing product may exhibit exceptional hardness. Methods for measuring the hardness of a material can include the Vickers hardness test (ASTM E384). In particular, the Vickers hardness HV10 of the additive manufacturing product comprising the aluminum alloy composition described herein achieves mechanical strength requirements to satisfy design criteria in additive manufacturing applications. For example, an additive manufacturing product can achieve excellent strength requirements for automotive applications.

[0048] In some examples, the additive manufacturing product comprising the aluminum alloy composition described herein can have a Vickers hardness of 100 HV or greater (e.g., from 100 HV to 250 HV, from 110 HV to 180 HV, from 120 HV to 250 HV, or from 150 HV to 250 HV) when the additive manufacturing product is processed according to the methods described herein. For example, the additive manufacturing product comprising the aluminum alloy composition described herein can have a Vickers hardness of 100 HV or greater, 110 HV or greater, 120 HV or greater, 130 HV or greater, 140 HV or greater, 150 HV or greater, 160 HV or greater, 170 HV or greater, 180 HV or greater, 190 or greater, 200 HV or greater, 210 HV or greater, 220 HV or greater, 230 HV or greater, 240 HV or greater, or 250 HV.

[0049] In some examples, the additive manufacturing product comprising the aluminum alloy composition described herein can have a density of 99% or greater (e.g., from 99% to 100%, from 99.1% to 99.8%, from 99.2% to 100%, or from 99.3% to 100%) when the additive manufacturing product is processed according to the methods described herein. The density may be measured by gas picnometer and the Archimedes method and image analysis of cross-sections of fabricated parts. For example, the additive manufacturing product comprising the aluminum alloy composition described herein can have a density of 99% or greater, 99.1% or greater, 99.2% or greater, 99.3% or greater, 99.4% or greater, 99.5% or greater, 99.6% or greater, 99.7% or greater, 99.8% or greater, 99.9% or greater, or 100%.

[0050] In some examples, the portion of the additive manufacturing product comprising the aluminum alloy described herein can have a tensile elongation of 2% or greater (e.g., from 2% to 20%, from 5% to 20%, or from 6% to 20%) when the additive manufacturing product comprising the aluminum alloy composition described herein is processed according to the methods described herein. For example, the additive manufacturing product comprising the aluminum alloy described herein can have a tensile elongation of 2 % or greater, 3 % or greater, 4 % or greater, 5% or greater, 6% or greater, 7% or greater, 8% or greater, 9% or greater, 10% or greater, 11% or greater, 12% or greater, 13% or greater, 14% or greater, 15% or greater, 16% or greater, 17% or greater, 18% or greater, 19% or greater, or 20%.

Methods

[0051] Methods of producing an aluminum alloy product by additive manufacturing are also described herein. In some examples, the method includes one or more steps for generating an aluminum alloy powder used in additive manufacturing.

[0052] Generally, the aluminum alloy may be cast and then atomized. The aluminum alloy may undergo atomization to generate a powder. In brief, powder atomization is a process by which atomized powder is produced by the dispersion of a molten material into particles by a rapidly moving gas or liquid stream or by mechanical dispersion. In some examples, the powder aluminum alloy may be used for 3D printing of additive manufacturing products, such as automotive or aerospace parts. The methods employed for generating the product may include laser powder-bed fusion, laser metal deposition, or any other additive manufacturing method known to one skilled in the art. In some examples, the laser powder bed fusion or laser metal deposition may have a cooling rate such as from 1,000 to 1,000,000 °C/second.

[0053] In some embodiments, the powder produced may be sieved or classified after production to obtain the desired particle size distribution. Alternatively, in some embodiments, the powder produced may not be sieved after production prior to being used in 3D printing.

[0054] The atomization process may include the steps of melting the aluminum cast product in a furnace, such as a vacuum furnace. In some aspects, the atomization process is ultrasonic atomization. The aluminum alloy may subjected to induction heating with plasma in the furnace to form an aluminum alloy liquid. The aluminum alloy liquid may then be passed through a nozzle for gas or water atomization. For example, the melted aluminum cast product can be poured from the primary vacuum melt container into a holding chamber positioned above a nozzle. The nozzle inlet into the collection chamber may come in contact with multiple ports for gas flow injection. Optionally, the gas flow may be interchangeable with a liquid for forming the particulate. The nozzle may inject the molten aluminum into the path of the gas. The gas expansion zone may generate small aluminum particulates when undergoing rapid solidification. In some embodiments, the solidification rate may be from 1000 °C/second to 100,000 °C/second. Lab casting may allow for further use in defining 3D printing parameters for the alloy composition described herein.

[0055] Following production of the powder, the powder may be used for additive manufacturing.

EXAMPLES

Example 1

[0056] Sample aluminum alloy articles were tested to determine the effects of the aluminum alloy composition and atomization or printability on the properties of the aluminum alloy products. The additive manufacturing products comprising the aluminum alloy composition described herein were tested for mechanical and morphological properties (e.g., strength, formability, density, and electron mapping of microstructure).

[0057] The aluminum alloy composition described herein was compared to two currently available aluminum alloys used in additive manufacturing. Comparative Example 1 was prepared from a conventional A357 alloy that does not include any Cr or V (0 wt.%) and Comparative Example 2 was prepared from a conventional AA6016 alloy that does not have any Cr or V (0 wt.%). Example 1 was prepared from an aluminum alloy described herein with different elemental compositions (i.e., Cr and V were added, and an increase amount of Si and other key components). Table 3 provides the wt.% of the alloying elements in each of Comparative Examples 1 and 2 as well as Example 1. As shown below, Example 1 has a greater Fe, Cu, Mn and Mg content, while omitting Zn and Ti and including Cr and V.

Table 3 [0058] FIGS. 1A-1B provide microscopy images of the microstructure analysis (1A) and the arm spacing measurement (IB) according to some embodiments described herein. The alloy composition was cast into 10x100x220 mm thick ingots for analysis of the physical properties of the ingots. The microstructure of the aluminum alloy composition demonstrated both porous regions (solid arrow) and precipitate formation (dashed arrow). The arm spacing measurement was used to assess the solidification rate of the alloy composition.

[0059] Sample aluminum alloy compositions were tested to determine the single sheet track (SST) and single hatching track (SHT) as compared to a commercial casting alloy composition and a wrought alloy composition. Analysis of the horizontal and cross section observations were made to assess the printability of the novel alloy composition. The parameters determined herein define the criteria to assess good alloy candidates to be atomized and further used. [0060] FIG. 2 provides a graph of the Vickers hardness and the Brinell hardness of an example aluminum alloy composition cast as ingot and heat treated, according to some embodiments described herein. The alloy described herein after printing had a 25-30% higher hardness when compared to commercially available powder alloy compositions. The results demonstrate heat treating the alloy to achieve a T5 temper did not improve or alter the hardness of the alloy after printing. When at a T6 temper, the alloy had an increased hardness after printing, while the T6 temper increased to 4 hours in fact decreased the hardness slightly when compared to the 2-hour T6 temper. The results indicate that the alloy can have improved mechanical properties over the standard alloy. Additionally, the results indicate that the alloy composition may be printed and heated in an oven without pressure to increase the mechanical properties. For example, the aluminum alloy described herein may be used to manufacture an automotive part, when the automotive part undergoes painting and required to bake in an oven, the baking process may increase the mechanical properties of the part. In some embodiments, the mechanical properties of the additive manufactured product may increase during a secondary processing step of the product.

[0061] To investigate the microstructure of the aluminum alloy composition at cast, electron dispersive x-ray spectroscopy (EDX) maps of Example 1 were prepared (FIGS. SA- 31). The microstructure of Example 1 shows pockets of different elements within the alloy film. For example, the results indicate pockets of elemental Fe and Mn as indicated by the dashed arrow (FIG. 3 A). The image indicates webbing of Si, Mg, Cu, and Fe (solid arrow) throughout the selected field including areas of dense Mg (dotted arrow) and Si (small- dashed arrow). FIGS. 3B - 31 show elemental mapping for Al, Si, Mg, Cu, Fe, Mn, V, and Cr. The EDX mapping shows that the aluminum alloy at cast has minimal uniformity throughout with pockets of concentrated elements.

[0062] To investigate the microstructure of the alloy composition following heat treatment, the aluminum alloy composition was cast and followed by heat treatment to achieve a T6 temper at 530 °C for 2 hours WQ and 200 °C for 4 hours. FIGS. 4A-4I provide electron dispersive X-ray spectroscopy (EDX) maps of Example 1 after achieving T6 temper, according to some embodiments described herein. The EDX mapping demonstrates that the T6 temper may alter the microstructure of the alloy composition when compared to the alloy after casting as seen in FIGS. 3A-3I). The results demonstrate that Fe, Mn, V, Cr, Cu and Cr spread throughout the microstructure of the alloy composition. The results indicate that under temper conditions without pressure, the microstructure of the aluminum alloy may be altered. The alteration may impart beneficial mechanical properties on the aluminum alloy such as increased.

[0063] To further investigate the microstructure of the aluminum alloy composition following laser powder-bed fusion, SEM and Electron dispersive X-ray spectroscopy(EDX) mapping for 3 distinct areas were further investigated. FIGS. 5A-5B provide an SEM image (FIG. 5 A) and EDX mapping information (FIG.5B) for Example 1, according to some embodiments described herein. The results indicate that the aluminum alloy composition after laser powder-bed fusion showed relatively homogeneous dispersion of the elements disclosed in the composition. Interestingly, Fe was found predominantly in the clear zone while little Fe was mapped in the dark area of the bed fusion. Other elements, such as Mn and V, demonstrated a similar trend in their dispersion. Elemental Mg and Cu demonstrated the inverse effect (i.e., the clear zone elemental composition contained less Cu and Mg when compared to the dark zone).

Illustrations

[0064] Illustration 1 is an aluminum alloy comprising from 1.0 to 80 wt.% Si; at least 0.50 wt.% Mg; at least 0.10 wt.% Fe; greater than 0.20 wt.% Cu; greater than 0.20 wt.% Mn; at least 0.01 wt.% of at least one of Cr and V; up to 0.15 wt.% impurities; and Al.

[0065] Illustration 2 is the aluminum alloy of any preceding or subsequent illustration, wherein the aluminum alloy further comprises at least one of Co, Zr, Ti, and combinations thereof, optionally in an amount of at least 0.2 wt.% each. [0066] Illustration 3 is the aluminum alloy of any preceding or subsequent illustration, wherein the Si is present from 1.0 to 7 wt.%.

[0067] Illustration 4 is the aluminum alloy of any preceding or subsequent illustration, wherein the Mg is present from 0.50 to 10 wt.%.

[0068] Illustration 5 is a method for manufacturing an additive manufactured product, the method comprising: preparing an aluminum alloy powder feedstock, the powder feedstock comprising an aluminum alloy according to any of Illustrations 1-4, and printing successive layers from the powder feedstock to form the additive manufactured product.

[0069] Illustration 6 is the method of any preceding or subsequent illustration, wherein the printing comprises laser powder-bed fusion.

[0070] Illustration 7 is the method of any preceding or subsequent illustration, wherein the printing comprises laser metal deposition.

[0071] Illustration 8 is the method of any preceding or subsequent illustration, wherein following printing, the additive manufactured product is cooled at a rate from 1000-1,000,000 °C/sec.

[0072] Illustration 9 is the method of any preceding or subsequent illustration, wherein the aluminum alloy powder feedstock is gas atomized prior to the step of printing successive layers from the powder feedstock to form the additive manufactured product.

[0073] Illustration 10 is the method of any preceding or subsequent illustration, wherein the aluminum alloy powder feedstock is liquid atomized prior to the step of printing successive layers from the powder feedstock to form the additive manufactured product.

[0074] Illustration 11 is the method of any preceding or subsequent illustration, wherein the aluminum alloy powder feedstock is ultrasonic atomized prior to the step of printing successive layers from the powder feedstock to form the additive manufactured product.

[0075] Illustration 12 is the method of any preceding or subsequent illustration, wherein the density of the additive manufactured product is greater than 99%.

[0076] Illustration 13 is the method of any preceding or subsequent illustration, wherein the Vickers hardness HV10 of the additive manufactured product is greater than 100 HV. [0077] Illustration 14 is the method of any preceding or subsequent illustration, wherein the method further comprises heat treating the additive manufactured product to form a heat treated product.

[0078] Illustration 15 is the method of any preceding or subsequent illustration, wherein the heat treated product has an elongation of greater than 2% to 20%.

[0079] Illustration 16 is the method of any preceding or subsequent illustration, wherein the heat treated product is not subjected to hot isostatic pressing.

[0080] Illustration 17 is the method of any preceding or subsequent illustration, wherein the additive manufactured product has a tensile strength (Rm) of at least 350 MPa.

[0081] Illustration 18 is the method of any preceding or subsequent illustration, wherein the additive manufactured product has a yield strength (Rp 0.2) of at least 300 MPa.

[0082] All patents, publications and abstracts cited above are incorporated herein by reference in their entireties. Various embodiments of the invention have been described in fulfillment of the various objectives of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptions thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined in the following claims.

Claims

WHAT IS CLAIMED IS:

1. An aluminum alloy comprising: from 1.0 to 80 wt.% Si; at least 0.50 wt.% Mg; at least 0.10 wt.% Fe; greater than 0.20 wt.% Cu; greater than 0.20 wt.% Mn; at least 0.01 wt.% of at least one of Cr and V; up to 0.15 wt.% impurities; and

Al.

2. The alloy according to claim 1, wherein the aluminum alloy further comprises at least one of Co, Zr, Ti, and combinations thereof, optionally in an amount of at least 0.1 wt.% each.

3. The alloy according to claim 1 or 2, wherein the Si is present from 1.0 to 7 wt.%.

4. The alloy according to one of claims 1-3, wherein the Mg is present from 0.5 to 10 wt.%.

5. A method for manufacturing an additive manufactured product, the method comprising: a) preparing an aluminum alloy powder feedstock, the powder feedstock comprising an aluminum alloy according to any of claims 1-4; and b) printing successive layers from the powder feedstock to form the additive manufactured product.

6. The method according to claim 5, wherein the printing comprises laser powder bed fusion.

7. The method according to claim 5, wherein the printing comprises laser metal deposition.

8. The method according to one of claims 5-7, wherein following the printing, the additive manufactured product is cooled at a rate from 1000-1,000,000 °C/sec.

9. The method according to one of claims 6-9, wherein the aluminum alloy powder feedstock is gas atomized prior to step b).

10. The method according to one of claims 6-9, wherein the aluminum alloy powder feedstock is liquid atomized prior to step b).

11. The method according to one of claims 6-9, wherein the aluminum alloy powder feedstock is ultrasonic atomized prior to step b).

12. The method according to one of claims 6-12, wherein the additive manufactured product has a density of greater than 99%.

13. The method according to claim 6, wherein the additive manufactured product has a Vickers hardness HV10 of greater than 100 HV.

14. The method according to one of claims 5-13, further comprising: c) heat treating the additive manufactured product to form a heat-treated product.

15. The method according to claim 14, wherein the heat-treated product has an elongation of greater than 2% to 20%.

16. The method according to one of claims 5-17, wherein the heat-treated product is not subjected to hot isostatic pressing.

17. The method according to one of claims 5-16, wherein the additive manufactured product has a tensile strength (Rm) of at least 350 MPa.

18. The method according to one of claims 5-17, wherein the additive manufactured product has a yield strength (Rp 0.2) of at least 300 MPa.