Heat treatment method for synchronously improving strength and plasticity of additive manufacturing Al-Ni-Sc-Zr alloy

Abstract

The invention provides a heat treatment method for synchronously improving the strength and plasticity of an Al-Ni-Sc-Zr alloy manufactured through an additive, and belongs to the field of aluminum alloys. The aluminum alloy comprises 5.0-10.0 wt% of nickel (Ni), not more than 1.0 wt% of scandium (Sc) and not more than 0.5 wt% of zirconium (Zr), with the balance being aluminum. The aluminum alloy is manufactured through a laser powder bed melting technology, the invention further provides a heat treatment method which is simple, short in path and high in efficiency, and the strength and the plasticity effect of the Al-Ni-Sc-Zr alloy subjected to heat treatment and formed through laser powder bed melting (LPBF) are obviously improved.

Description

Technical Field

[0001] The present invention belongs to the field of aluminum alloys, and particularly relates to a heat treatment method for simultaneously improving the strength and plasticity of additively manufactured Al-Ni-Sc-Zr alloys. Background Art

[0002] Additive manufacturing processes generally have high cooling rates and large temperature gradients. Laser powder bed fusion (LPBF) is one of the most common additive manufacturing processes, and the cooling rate range of the LPBF process is between 10 3 ~10 6 ℃ / s, and the temperature gradient can reach up to ~10 7 ℃ / m.

[0003] Al-Ni alloys have advantages such as good formability and high temperature resistance. In order to improve the formability and mechanical properties of additively manufactured aluminum alloys, grain refinement is a commonly used means in additive manufacturing. Elements in groups IIIB-VB such as Sc, Zr, Ti, and Nb are beneficial to the formation of L1 2 structured Al 3 X primary phases, thus promoting the growth of equiaxed grains as nucleation particles. On the basis of Al-Ni alloys, adding elements such as Sc and Zr, during the LPBF forming process, the addition of Sc and Zr elements will promote the formation of fine equiaxed grains at the molten pool boundary. A lower solidification front rate is beneficial to the precipitation of Al 3 (Sc, Zr) primary phases, promoting the nucleation of fine α-Al grains. A large amount of Sc and Zr elements will be dissolved in the α-Al matrix during the rapid solidification process of additive manufacturing. After heat treatment, nano-scale Al 3 (Sc, Zr) particles will precipitate, thereby increasing the mechanical properties of the material.

[0004] Currently, LPBF-formed Al-Mg-Sc-Zr alloys are generally heat-treated at a temperature of 300°C and a holding time of 4 h, while the heat treatment method for LPBF-formed Al-Ni-Sc-Zr alloys has not been disclosed. Based on this, the present invention has studied an LPBF-formed Al-Ni-Sc-Zr alloy, and through a simple short-time heat treatment method, significantly improved the strength and plasticity of the LPBF-formed Al-Ni-Sc-Zr alloy. Summary of the Invention

[0005] To solve the above problems, the present invention provides a high-strength LPBF-formed Al-Ni-Sc-Zr alloy and its heat treatment method.

[0006] On the one hand, the present invention provides a high-strength aluminum alloy, characterized in that the aluminum alloy comprises:

[0007] 5.0 - 10.0 wt% nickel (Ni), not more than 1.0 wt% scandium (Sc), and not more than 0.5 wt% zirconium (Zr).

[0008] In some embodiments, the aluminum alloy comprises 5.0 - 10.0 wt% nickel, for example, it can be 5.0 - 9.0 wt%, 5.0 - 8.0 wt%, 5.0 - 7.0 wt%, 6.0 - 10.0 wt%, 6.0 - 9.0 wt%, 6.0 - 8.0 wt%, 6.0 - 7.0 wt%, or 7.0 - 10.0 wt%. Further, it can be 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, 9.5 wt%, 10.0 wt%, or a range between any two of the foregoing.

[0009] In some embodiments, the aluminum alloy comprises not more than 1.0 wt% scandium, for example, it can be not more than 0.9 wt%, not more than 0.8 wt%, not more than 0.7 wt%, not more than 0.6 wt%, not more than 0.5 wt%, not more than 0.4 wt%, not more than 0.3 wt%, not more than 0.2 wt%, not more than 0.1 wt%. Further, it can be 0.1 - 1.0 wt%, 0.1 - 0.9 wt%, 0.1 - 0.8 wt%, 0.5 - 0.8 wt%, 0.5 - 1.0 wt%, 0.6 - 1.0 wt%, 0.6 - 0.8 wt%, or 0.6 - 7.0 wt%. Still further, it can be 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, 0.55 wt%, 0.6 wt%, 0.65 wt%, 0.7 wt%, 0.75 wt%, 0.8 wt%, 0.85 wt%, 0.9 wt%, 0.95 wt%, 1.0 wt%, or a range between any two of the foregoing.

[0010] In some embodiments, the aluminum alloy contains no more than 0.5 wt% of zirconium, for example, it can be no more than 0.4 wt%, no more than 0.3 wt%, no more than 0.2 wt%, no more than 0.1 wt%, and further can be 0.05 - 0.5 wt%, 0.05 - 0.4 wt%, 0.05 - 0.3 wt%, 0.1 - 0.4 wt%, 0.1 - 0.3 wt%, 0.1 - 0.2 wt%, 0.05 - 0.2 wt%, 0.05 - 0.1 wt%, 0.2 - 0.3 wt%, 0.2 - 0.4 wt% or 0.2 - 0.5 wt%. Still further, it can be 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt% or the range between any two of the foregoing.

[0011] In some embodiments, the aluminum alloy contains 6.0 - 8.0 wt% of nickel (Ni), preferably 6.0 - 7.0 wt%, and more preferably 6.0 wt%.

[0012] In some embodiments, the aluminum alloy contains no more than 0.9 wt% of scandium (Sc), preferably 0.5 - 0.8 wt%, and more preferably 0.6 wt%.

[0013] In some embodiments, the aluminum alloy contains no more than 0.4 wt% of zirconium (Zr), preferably 0.1 - 0.2 wt% or 0.2 - 0.4 wt%, and more preferably 0.1 wt% or 0.3 wt%.

[0014] In some embodiments, the aluminum alloy contains: 6.0 wt% of nickel, 0.6 wt% of scandium, 0.1 wt% of zirconium.

[0015] In some embodiments, the aluminum alloy contains: 6.0 wt% of nickel, 0.6 wt% of scandium, 0.3 wt% of zirconium.

[0016] In some embodiments, the aluminum alloy further contains aluminum (Al) as the balance and inevitable impurities.

[0017] In some embodiments, the impurities include at least one of boron, titanium, silicon, chromium, vanadium, manganese, magnesium, zinc, phosphorus, lanthanum, calcium, copper, cerium or lithium.

[0018] In some embodiments, the aluminum alloy is prepared by additive manufacturing.

[0019] In some embodiments, the additive manufacturing is a laser powder bed fusion (LPBF) process.

[0020] In some embodiments, the forming parameter of the laser powder bed fusion process, the laser power is 200 - 300 W, for example, it can be 200, 210, 220, 230, 240, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295 or 300 W, preferably 250 - 300 W, more preferably 260 - 285 W.

[0021] In some embodiments, the forming parameter of the laser powder bed fusion process, the scanning speed is 800 - 1800 mm / s, for example, it can be 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800 mm / s, preferably 1000 - 1800 mm / s, more preferably 1300 - 1500 mm / s.

[0022] In some embodiments, the forming parameter of the laser powder bed fusion process, the scanning spacing is 80 - 120 μm, for example, it can be 80, 90, 100, 110 or 120 μm, preferably 80 - 100 μm, more preferably 90 μm.

[0023] In some embodiments, the forming parameter of the laser powder bed fusion process, the layer thickness is 30 - 50 μm, for example, it can be 30, 35, 40, 45, 50 μm, preferably 30 - 40 μm, more preferably 30 μm.

[0024] In some embodiments, the forming parameters of the laser powder bed fusion process are laser power 285 W, scanning speed 1500 mm / s, scanning spacing 90 μm, layer thickness 30 μm;

[0025] In some embodiments, the forming parameters of the laser powder bed fusion process are laser power 260 W, scanning speed 1300 mm / s, scanning spacing 90 μm, layer thickness 30 μm.

[0026] In some embodiments, the yield strength of the as - printed aluminum alloy is not less than 300 MPa, for example, it can be not less than 310 MPa, not less than 320 MPa, not less than 330 MPa, not less than 340 MPa, not less than 350 MPa. In some preferred embodiments, the yield strength of the as - printed aluminum alloy is not less than 330 MPa.

[0027] In some preferred embodiments, the yield strength of the as-printed aluminum alloy is 300 - 400 MPa. For example, it can be 300 - 380 MPa, 310 - 380 MPa, 310 - 360 MPa, 310 - 350 MPa, 330 - 400 MPa, 330 - 380 MPa, 330 - 360 MPa, or 330 - 350 MPa. Further, it can be 300 MPa, 310 MPa, 320 MPa, 330 MPa, 334 MPa, 340 MPa, 350 MPa, 360 MPa, 365 MPa, 370 MPa, 380 MPa, 390 MPa, or 400 MPa.

[0028] In some embodiments, the tensile strength of the as-printed aluminum alloy is not less than 400 MPa. For example, it can be not less than 410 MPa, not less than 420 MPa, not less than 430 MPa, not less than 440 MPa, or not less than 450 MPa. In some preferred embodiments, the tensile strength of the as-printed aluminum alloy is not less than 420 MPa.

[0029] In some preferred embodiments, the tensile strength of the as-printed aluminum alloy is 400 - 500 MPa. For example, it can be 410 - 500 MPa, 420 - 500 MPa, 420 - 480 MPa, 420 - 460 MPa, 400 - 480 MPa, 400 - 460 MPa. Further, it can be 400 MPa, 405 MPa, 410 MPa, 415 MPa, 420 MPa, 425 MPa, 426 MPa, 430 MPa, 435 MPa, 440 MPa, 445 MPa, 450 MPa, 455 MPa, 459 MPa, 460 MPa, 465 MPa, 470 MPa, 475 MPa, 477 MPa, 480 MPa, 490 MPa, or 500 MPa.

[0030] In some embodiments, the elongation at break of the as-printed aluminum alloy is not less than 5%. For example, it can be not less than 5.5% or not less than 6%. In some preferred embodiments, the elongation at break of the as-printed aluminum alloy is not less than 6%.

[0031] In some preferred embodiments, the elongation at break of the as-printed aluminum alloy is 5% - 8%. For example, it can be 5% - 7%, 5% - 6%, 6% - 8%, 6% - 7%. Further, it can be 5%, 5.2%, 5.5%, 5.8%, 6%, 6.4%, 6.5%, 7%, 7.5%, or 8%.

[0032] In some embodiments, the aluminum alloy can be further heat-treated;

[0033] In some embodiments, the heat treatment comprises the following steps:

[0034] (1) Heat up the heat treatment furnace, then place the Al-Ni-Sc-Zr alloy formed part prepared by LPBF in the heating furnace, and keep it at a constant temperature after the temperature rises to the target temperature;

[0035] (2) Take out the heat-treated Al-Ni-Sc-Zr alloy formed part from the heat treatment furnace and cool it to room temperature in the air.

[0036] In some embodiments, the heating temperature is 250 - 400 °C, for example, it can be 250 °C, 275 °C, 300 °C, 325 °C, 350 °C, 375 °C or 400 °C, and preferably 275 - 375 °C.

[0037] In some embodiments, the heating rate is 5 - 15 °C / min, for example, it can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 °C / min, and preferably 10 °C / min.

[0038] In some embodiments, the holding time is 1 min - 2 h, for example, it can be 1 min, 2 min, 3 min, 4 min, 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, 1 h or 2 h, and preferably 3 min - 1 h.

[0039] In some preferred embodiments, the heating temperature of the heat treatment is 350 °C, the heating rate is 10 °C / min, and the holding time is 15 min.

[0040] In some preferred embodiments, the heating temperature of the heat treatment is 350 °C, the heating rate is 10 °C / min, and the holding time is 3 min.

[0041] In some preferred embodiments, the heating temperature of the heat treatment is 300 °C, the heating rate is 10 °C / min, and the holding time is 30 min.

[0042] In some embodiments, the yield strength of the heat-treated aluminum alloy is not less than 400 MPa, for example, it can be not less than 410 MPa, not less than 420 MPa, not less than 430 MPa, not less than 440 MPa, not less than 450 MPa, not less than 460 MPa, not less than 470 MPa. In some preferred embodiments, the yield strength of the heat-treated aluminum alloy is not less than 440 MPa.

[0043] In some preferred embodiments, the yield strength of the heat-treated aluminum alloy is 400 - 500 MPa, for example, it can be 400 - 420 MPa, 400 - 430 MPa, 400 - 450 MPa, 400 - 470 MPa, 400 - 480 MPa, 410 - 500 MPa, 410 - 490 MPa, 410 - 480 MPa, 420 - 400 MPa, 440 - 500 MPa, 460 - 500 MPa, 470 - 500 MPa, 470 - 480 MPa, and further can be 480 MPa, 400 - 460 MPa, and further can be 400 MPa, 405 MPa, 410 MPa, 415 MPa, 420 MPa, 421 MPa, 425 MPa, 428 MPa, 430 MPa, 435 MPa, 440 MPa, 445 MPa, 446 MPa, 450 MPa, 455 MPa, 460 MPa, 464 MPa, 465 MPa, 470 MPa, 475 MPa, 480 MPa, 490 MPa or 500 MPa.

[0044] In some embodiments, the tensile strength of the heat-treated aluminum alloy is not less than 400 MPa, for example, it can be not less than 420 MPa, not less than 440 MPa, not less than 450 MPa, not less than 460 MPa, not less than 470 MPa, not less than 480 MPa, not less than 490 MPa, not less than 500 MPa, not less than 510 MPa, not less than 520 MPa, not less than 530 MPa. In some preferred embodiments, the tensile strength of the heat-treated aluminum alloy is not less than 450 MPa.

[0045] In some preferred embodiments, the tensile strength of the heat-treated aluminum alloy is 400 - 600 MPa, for example, it can be 400 - 550 MPa, 450 - 550 MPa, 480 - 550 MPa, 490 - 550 MPa, 500 - 600 MPa, 500 - 550 MPa, 480 - 600 MPa, 480 - 550 MPa, 480 - 540 MPa, 480 - 530 MPa, 480 - 500 MPa, 480 - 490 MPa, 500 - 540 MPa, for example, it can be 450 MPa, 458 MPa, 460 MPa, 470 MPa, 480 MPa, 481 MPa, 485 MPa, 490 MPa, 500 MPa, 501 MPa, 510 MPa, 520 MPa, 530 MPa, 540 MPa, 550 MPa, 560 MPa, 570 MPa, 580 MPa, 590 MPa, 493 MPa or 600 MPa.

[0046] In some embodiments, the elongation at break of the heat-treated aluminum alloy is not less than 8%, for example, it can be not less than 9%, not less than 10%, not less than 11%, not less than 12%, not less than 13%, not less than 14%, or not less than 15%. In some preferred embodiments, the elongation at break of the heat-treated aluminum alloy is not less than 10%.

[0047] In some alternative embodiments, the elongation at break of the heat-treated aluminum alloy is 8% - 16%, for example, it can be 8% - 10%, 8% - 11%, 8% - 12%, 8% - 13%, 8% - 14%, 8% - 15%, 9% - 12%, 9% - 13%, 9% - 14%, 9% - 15%, 9% - 16%, 10% - 15%, 10% - 16%, 11% - 15%, 11% - 16%, 12% - 15%, 12% - 16%, 13% - 15%, 13% - 16%, 14% - 15%, 14% - 16%, and further can be 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.3%, 11.5%, 12%, 12.5%, 13%, 13.5%, 13.6%, 14%, 14.5%, 14.7%, 15%, 15.2%, 15.5% or 16%.

[0048] On the other hand, the present invention also provides a heat treatment method for preparing Al-Ni-Sc-Zr alloy by LPBF. First, the Al-Ni-Sc-Zr alloy is prepared by the LPBF process, and then the Al-Ni-Sc-Zr is directly aged and heat-treated. Among them, the heat treatment includes the following steps:

[0049] (1) Heat up the heat treatment furnace, and then place the formed part of the Al-Ni-Sc-Zr alloy prepared by LPBF in the heating furnace. After the temperature rises to the target temperature, keep it warm.

[0050] (2) Take out the formed part of the heat-treated Al-Ni-Sc-Zr alloy from the heat treatment furnace and cool it to room temperature in the air.

[0051] In some embodiments, the heating temperature is 250 - 400 °C, for example, it can be 250 °C, 275 °C, 300 °C, 325 °C, 350 °C, 375 °C or 400 °C, and preferably 275 - 375 °C.

[0052] In some embodiments, the heating rate is 5 - 15 °C / min, for example, it can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 °C / min, and preferably 10 °C / min.

[0053] In some embodiments, the heat preservation time is 1 min - 2 h, for example, it can be 1 min, 2 min, 3 min, 4 min, 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, 1 h or 2 h, and preferably it is 3 min - 1 h.

[0054] In some preferred embodiments, the heating temperature for the heat treatment is 350 °C, the heating rate is 10 °C / min, and the heat preservation time is 15 min.

[0055] In some preferred embodiments, the heating temperature for the heat treatment is 350 °C, the heating rate is 10 °C / min, and the heat preservation time is 3 min.

[0056] In some preferred embodiments, the heating temperature for the heat treatment is 300 °C, the heating rate is 10 °C / min, and the heat preservation time is 30 min.

[0057] In some embodiments, the yield strength of the aluminum alloy after heat treatment is increased by at least 20%, for example, it can be at least 21%, at least 22%, at least 23%, at least 24%, at least 25%, at least 26%, at least 27%, at least 28%, at least 29%, at least 30%.

[0058] In some preferred embodiments, the yield strength of the aluminum alloy after heat treatment is increased by 20% - 40%, for example, it can be 20%, 21%, 22%, 22.3%, 23%, 24%, 25%, 26%, 26.9%, 27%, 27.1%, 27.4%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 34.3%, 35%, 36%, 37%, 38%, 39% or 40%.

[0059] In some embodiments, the tensile strength of the aluminum alloy after heat treatment is increased by at least 5%, for example, it can be at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11%, at least 12%, at least 13%, at least 14%, at least 15%.

[0060] In some preferred embodiments, the tensile strength of the aluminum alloy after heat treatment is increased by 5% - 20%, for example, it can be 5%, 5.4%, 6%, 7%, 7.5%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 15.5%, 16%, 17%, 18%, 19% or 20%.

[0061] In some embodiments, the elongation at break of the aluminum alloy after heat treatment is increased by at least 60%, for example, it can be at least 70%, at least 80%, at least 90%, at least 100%, at least 110%, at least 120%, at least 130%, at least 140%, at least 150%, at least 160%.

[0062] In some preferred embodiments, the tensile strength of the aluminum alloy after heat treatment is increased by 60% - 200%, for example, it can be 60%, 64%, 70%, 80%, 90%, 95%, 100%, 110%, 120%, 130%, 140%, 150%, 160%, 161%, 162%, 170%, 180%, 190% or 200%.

[0063] On the other hand, the present invention provides an aluminum alloy component, wherein at least a part of the aluminum alloy component comprises the above-mentioned aluminum alloy or the aluminum alloy prepared by the above method.

[0064] On the other hand, the present invention provides the use of the above-mentioned aluminum alloy, the aluminum alloy prepared by the above method or the above-mentioned aluminum alloy component in automobiles or aerospace equipment.

[0065] Advantages of the present invention

[0066] The Al-Ni-Sc-Zr alloy of the present invention has high strength. At the same time, the heat treatment method of the present invention is simple and efficient in operation, and the effect of simultaneously improving the strength and plasticity of the LPBF-formed Al-Ni-Sc-Zr alloy is obvious. Detailed embodiments

[0067] For the purpose of clear and concise description, features are described herein as part of the same or separate embodiments. However, it will be understood that the scope of the present disclosure may include some embodiments having combinations of all or some of the described features. The technical solutions of the present invention will be described clearly and completely below. Obviously, all other embodiments obtained by those of ordinary skill in the art based on the specific embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0068] I. Definitions

[0069] In the present invention, unless otherwise specified, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. And the relevant terms and laboratory operation steps used herein are all widely used terms and conventional steps in the corresponding fields. At the same time, for a better understanding of the present invention, the definitions and explanations of relevant terms are provided below.

[0070] As used herein and unless otherwise specified, the term "about" or "approximately" means within plus or minus 10% of a given value or range. In cases where an integer is required, the term means within plus or minus 10% of a given value or range, rounded up or down to the nearest integer.

[0071] In the description herein, reference to "some embodiments", "some implementations" or "some embodiments" describes a subset of all possible embodiments, but it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0072] As used herein and unless otherwise specified, the terms "comprising", "including", "having", "containing", including their grammatical equivalents, are generally to be understood as open-ended and non-limiting, e.g., not excluding other unrecited elements or steps.

[0073] As used herein, the term "wt%" represents the weight ratio and the proportion of a substance in a mixture. For example, 5.0 - 10.0 wt% nickel (Ni) means that the weight percentage of Ni element in the total weight of all elements of the alloy is 5.0 - 10.0 wt%.

[0074] As used herein, the term "aluminum alloy" refers to an alloy based on aluminum with a certain amount of other alloying elements added.

[0075] As used herein, the term "additive manufacturing" (AM) refers to any process that produces a three-dimensional object and includes the step of sequentially forming one layer of the shape of the object at a time. For example, AM processes include three-dimensional printing (3DP) processes, laser net shaping manufacturing, direct metal laser sintering (DMLS), direct metal laser melting (DMLM), laser powder bed fusion process (LPBF), freeform fabrication, etc. Without limiting to a specific type of AM process, energy beams such as electron beams or electromagnetic radiation such as laser beams are used to sinter or melt powder materials. AM processes can use metal powder materials or wires as raw materials. Additive manufacturing is a method of manufacturing a physical object from a digital object by adding materials layer by layer, and the thickness of each added layer is about dozens or hundreds of micrometers.

[0076] As used herein, the term "laser powder bed fusion process" is an additive manufacturing technology for manufacturing metal components. Its basic principle is to use a high-energy laser beam to melt metal powder layer by layer according to the path planned in the three-dimensional model slices, making it solidify and metallurgically bond, thereby forming a three-dimensional entity. This process has the characteristics of high material utilization rate, high density of the formed parts, and high manufacturing accuracy.

[0077] Ⅱ. Examples

[0078] The present invention will be described in detail below through specific embodiments. It should be understood that the following embodiments are only for explanation and illustration, and do not limit the scope of the present invention in any form.

[0079] The raw materials and equipment used in the specific implementation scheme of the present disclosure are all known products and are obtained by purchasing commercially available products.

[0080] The yield strength, tensile strength, and elongation at break are measured according to GB / T 228.1-2021.

[0081] Example 1

[0082] An LPBF-formed Al-Ni-Sc-Zr alloy, the powder used is prepared by a vacuum atomization process, and the mass fractions of its components are as follows: 6 wt% Ni, 0.6 wt% Sc, 0.1 wt% Zr, and the rest is Al. Its forming parameters are as follows: laser power 285 W, scanning speed 1500 mm / s, scanning spacing 90 μm, layer thickness 30 μm. The as-printed Al-Ni-Sc-Zr alloy is obtained, with a yield strength of 350 MPa, a tensile strength of 459 MPa, and an elongation at break of 5.8%.

[0083] This example provides a heat treatment method for an LPBF-formed Al-Ni-Sc-Zr alloy, and the steps are as follows:

[0084] 1. Heat the heat treatment furnace to 350 °C at a heating rate of 10 °C / min, then place the Al-Ni-Sc-Zr alloy prepared by LPBF in the heat treatment furnace. After the temperature rises to 350 °C, hold for 15 min.

[0085] 2. After the holding process ends, take out the Al-Ni-Sc-Zr alloy from the heat treatment furnace and cool it to room temperature in the air.

[0086] For the LPBF-formed Al-Ni-Sc-Zr alloy after heat treatment, its yield strength is 446 MPa, its tensile strength is 485 MPa, and its elongation at break is 15.2%. After heat treatment, both the strength and plasticity of the LPBF-formed Al-Ni-Sc-Zr alloy are improved.

[0087] Example 2

[0088] The difference between this example and Example 1 is that the heat treatment furnace is heated to 350 °C and the holding time is 3 min. Others are the same as in Example 1.

[0089] For the LPBF-formed Al-Ni-Sc-Zr alloy after heat treatment in this example, its yield strength is 470 MPa, its tensile strength is 530 MPa, and its elongation at break is 11.3%.

[0090] Example 3

[0091] The difference between this example and Example 1 is that the heat treatment furnace is heated to 300 °C and the heat preservation time is 30 min. Others are the same as in Example 1.

[0092] For the LPBF-formed Al-Ni-Sc-Zr alloy after heat treatment in this example, its yield strength is 428 MPa, tensile strength is 481 MPa, and elongation at break is 9.5%.

[0093] As shown in Table 1, the alloys after heat treatment in the above three examples are compared with the as-printed alloys to obtain the relative values of yield strength, tensile strength, and elongation at break: relative value = (value after heat treatment - value of as-printed state) / value of as-printed state × 100%. It can be seen that the yield strength, tensile strength, and elongation at break have all increased significantly.

[0094] Table 1. Effects of alloy after heat treatment

[0095] Example 1 Example 2 Example 3 Yield strength 27.4％ 34.3％ 22.3％ Tensile strength 5.4％ 15.5％ 4.8％ Elongation at break 162.1％ 94.8％ 63.8％

[0096] Example 4

[0097] The difference between this example and Example 1 is that the mass fractions of the Al-Ni-Sc-Zr alloy components are as follows: 6 wt% Ni; 0.6 wt% Sc; 0.3 wt% Zr; the rest is Al. The as-printed Al-Ni-Sc-Zr alloy is obtained, and its yield strength is 365 MPa, tensile strength is 477 MPa, and elongation at break is 5.2%. Others are the same as in Example 1.

[0098] For the LPBF-formed Al-Ni-Sc-Zr alloy after heat treatment in this example, its yield strength is 464 MPa, tensile strength is 501 MPa, and elongation at break is 13.6%. Among them, the yield strength has increased by 27.1% relative to that before heat treatment, the tensile strength has increased by 5.0% relative to that before heat treatment, and the elongation at break has increased by 161.5% relative to that before heat treatment.

[0099] Example 5

[0100] The difference between this example and Example 1 is that the LPBF forming process is as follows: laser power 260 W, scanning speed 1300 mm / s, scanning spacing 90 μm, layer thickness 30 μm. The as-printed Al-Ni-Sc-Zr alloy is obtained, and its yield strength is 334 MPa, tensile strength is 426 MPa, and elongation at break is 6.4%. Others are the same as in Example 1.

[0101] In this embodiment, the LPBF-formed Al-Ni-Sc-Zr alloy after heat treatment has a yield strength of 421 MPa, a tensile strength of 458 MPa, and an elongation at break of 14.7%. Among them, the yield strength is increased by 26.9% compared with that before heat treatment, the tensile strength is increased by 7.5% compared with that before heat treatment, and the elongation at break is increased by 129.7% compared with that before heat treatment.

[0102] The specific embodiments of the present invention have been described in detail above, but they are only examples, and the present invention is not limited to the above-described specific embodiments. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of the present invention are covered by the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A high-strength aluminum alloy, characterized in that: The aluminum alloy comprises: 5.0-10.0wt% of nickel (Ni), not more than 1.0wt% of scandium (Sc) and not more than 0.5wt% of zirconium (Zr).

2. The aluminum alloy according to claim 1, comprising 6.0-8.0 wt% nickel (Ni), preferably 6.0-7.0 wt%, more preferably 6.0 wt%; Preferably, the aluminum alloy contains no more than 0.9 wt % scandium (Sc), preferably 0.5-0.8 wt %, more preferably 0.6 wt %; Preferably, the aluminum alloy contains no more than 0.4 wt% zirconium (Zr), preferably 0.1-0.2 wt% or 0.2-0.4 wt%, more preferably 0.1 wt% or 0.3 wt%; Preferably, the aluminum alloy comprises 6.0 wt % nickel, 0.6 wt % scandium, and 0.1 wt % zirconium; Preferably, the aluminum alloy contains 6.0 wt % nickel, 0.6 wt % scandium, and 0.3 wt % zirconium.

3. The aluminum alloy according to claim 1 or 2, wherein: The aluminum alloy further contains aluminum (Al) and inevitable impurities as the balance; Preferably, the impurities include at least one of boron, titanium, silicon, chromium, vanadium, manganese, magnesium, zinc, phosphorus, lanthanum, calcium, copper, cerium or lithium.

4. The aluminum alloy according to any one of claims 1 to 3, wherein: The aluminum alloy is prepared by additive manufacturing; Preferably, the additive manufacturing is a laser powder bed fusion (LPBF) process; Preferably, the laser powder bed fusion process forming parameter laser power is 200-300W, preferably 250-300W, more preferably 260-285W; Preferably, the laser powder bed fusion process forming parameter scanning rate is 800-1800 mm / s, preferably 1000-1800 mm / s, more preferably 1300-1500 mm / s; Preferably, the laser powder bed fusion process forming parameter scanning interval is 80-120 μm, preferably 80-100 μm, more preferably 90 μm; Preferably, the layer thickness of the laser powder bed fusion process forming parameter is 30-50 μm, preferably 30-40 μm, more preferably 30 μm; Preferably, the forming parameters of the laser powder bed fusion process are laser power 285W, scanning speed 1500mm / s, scanning spacing 90μm, and layer thickness 30μm; Preferably, the forming parameters of the laser powder bed fusion process are: laser power 260W, scanning speed 1300mm / s, scanning spacing 90μm, and layer thickness 30μm.

5. The aluminum alloy according to claim 4, wherein: The aluminum alloy may be further heat treated.

6. The aluminum alloy according to claim 5, wherein The heat treatment comprises the following steps: (1) The heat treatment furnace is heated, and the Al-Ni-Sc-Zr alloy formed part prepared by LPBF is placed in the heating furnace, and the temperature is kept after it reaches the target temperature; (2) taking the Al-Ni-Sc-Zr alloy formed part after the heat treatment from the heat treatment furnace and cooling it to room temperature in air; Preferably, the heating temperature is 250-400°C, more preferably 275-375°C; Preferably, the heating rate is 5-15°C / min, more preferably 10°C / min; Preferably, the insulation time is 1 min-2 h, more preferably 3 min-1 h.

7. The aluminum alloy according to claim 6, wherein: The heat-treated aluminum alloy satisfies at least one of the following conditions: (1) The yield strength of the aluminum alloy after the heat treatment is not less than 400 MPa; (2) The tensile strength of the aluminum alloy after the heat treatment is not less than 400 MPa; (3) the elongation at break of the aluminum alloy after the heat treatment is not less than 8%; Preferably, the yield strength of the aluminum alloy after heat treatment is not less than 440 MPa; Preferably, the yield strength of the aluminum alloy after heat treatment is 400-500 MPa; Preferably, the tensile strength of the aluminum alloy after heat treatment is not less than 450 MPa; Preferably, the tensile strength of the aluminum alloy after heat treatment is 400-600 MPa; Preferably, the elongation at break of the aluminum alloy after the heat treatment is not less than 10%; Preferably, the elongation at break of the aluminum alloy after the heat treatment is 8%-16%.

8. A heat treatment method for preparing Al-Ni-Sc-Zr alloy by LPBF, wherein: The heat treatment comprises the following steps: (1) The heat treatment furnace is heated, and the Al-Ni-Sc-Zr alloy formed part prepared by LPBF is placed in the heating furnace, and the temperature is kept after it reaches the target temperature; (2) taking the Al-Ni-Sc-Zr alloy formed part after the heat treatment from the heat treatment furnace and cooling it to room temperature in air; Preferably, the heating temperature is 250-400°C, more preferably 275-375°C; Preferably, the heating rate is 5-15°C / min, more preferably 10°C / min; Preferably, the insulation time is 1 min-2 h, more preferably 3 min-1 h.

9. An aluminum alloy component, wherein: At least a portion of the aluminum alloy component comprises the aluminum alloy according to any one of claims 1 to 7 or the aluminum alloy prepared by the method according to claim 8.

10. Use of the aluminum alloy according to any one of claims 1 to 7, the aluminum alloy prepared by the method according to claim 8, or the aluminum alloy component according to claim 9 in automobiles or aerospace equipment.