An additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy and its preparation method

Abstract

The present invention discloses an additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy and a preparation method thereof. By mass fraction, the alloy consists of the following components: Fe: 0.9-3.5 wt%; Ni: 0.9-3.5 wt%; Mn: 0.9-3.5 wt%; Cr: 0.9-3.5 wt%; Zr: 0.6-2.5 wt%; and the balance is Al. In the present invention, a variety of heat-resistant elements are added to the Al alloy, and the alloy composition is optimized to form Al9FeNi and Al6M (Mn, Fe) dispersed phases. On the premise of ensuring the strength of the alloy, the thermal stability of the Al alloy in the medium and high temperature environment is improved. The obtained product parts have fine and uniform grain structures, no cracks, and excellent mechanical properties. While ensuring the mechanical properties at room temperature, they have excellent high-temperature properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and particularly relates to an additively manufactured multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy and a preparation method thereof. Background Art

[0002] Al alloys have excellent properties such as high specific strength, good thermal conductivity, fatigue resistance and corrosion resistance, and are widely used in cutting-edge scientific and technological fields such as space rockets, space shuttles and artificial satellites. With the continuous progress of technology, new pursuits for the high strength, light weight, heat resistance and other characteristics of alloy materials have been continuously put forward. Additive manufacturing technology, with its multiple advantages such as short cycle, high material utilization rate and high design freedom, provides new methods and ideas for solving problems in the face of new requirements under the new situation. Based on the high degree of freedom in alloy composition design in additive manufacturing, relevant research on the additive manufacturing Al alloy system has developed vigorously. Existing research shows that the addition of heat-resistant elements such as Cr, Mn, Ni, Fe, Zr, etc. in Al alloys can provide good solid solution strengthening effects. Certain reactions may also occur between elements and the matrix, and between elements, to form strengthening phases, further refining grains and strengthening mechanical properties, while also possibly improving the heat resistance of the alloy.

[0003] Traditional additively manufactured 4xxx and 7xxx aluminum alloys can meet the use standards of light weight and high strength when serving at room temperature, but their inherent softening problem in the medium and high temperature environment restricts the further development of Al alloys. Therefore, how to optimize the alloy composition to form a higher volume fraction and uniformly dispersed thermally stable nano-phase inside the alloy to improve the thermal stability of Al alloys has become a major research hotspot at present. Summary of the Invention

[0004] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Simplifications or omissions may be made in this part, as well as in the abstract and title of the specification of this application, to avoid obscuring the purpose of this part, the abstract and the title of the specification, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] In view of the above and / or problems existing in the prior art, the present invention is proposed.

[0006] One of the purposes of the present invention is to provide an additively manufactured multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy, and the obtained product parts have fine and uniform grain structures, no cracks, and excellent mechanical properties.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: An additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy, by mass fraction, the alloy consists of the following components: Fe: 0.9 - 3.5 wt%; Ni: 0.9 - 3.5 wt%; Mn: 0.9 - 3.5 wt%; Cr: 0.9 - 3.5 wt%; Zr: 0.6 - 2.5 wt%; the balance is Al.

[0008] As a preferred embodiment of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention, wherein: by mass fraction, the alloy consists of the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the balance is Al.

[0009] As a preferred embodiment of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention, wherein: the alloy has the following properties:

[0010] (a) The tensile strength at room temperature is 470 - 527 MPa, and the elongation at break is 7 - 11%;

[0011] (b) The tensile strength at 200 °C is 310 - 395 MPa;

[0012] (c) The tensile strength at 300 °C is 250 - 329 MPa, and the elongation at break is 5 - 9%;

[0013] (d) The average hardness is 151 - 168 HV0.5.

[0014] Another object of the present invention is to provide a preparation method of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy as described in any one of the above, including,

[0015] Prepare metal raw materials according to mass fraction, and prepare pre-alloy powder through vacuum melting and atomization powder making;

[0016] Perform 3D printing on the pre-alloy powder after mechanical screening and heat preservation drying.

[0017] As a preferred embodiment of the preparation method of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention, wherein: for the vacuum melting, the melting temperature is 650 - 900 °C, and the air pressure is 0.5 - 0.6 MPa.

[0018] As a preferred embodiment of the preparation method of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention, wherein: for the atomization powder making, it is carried out in an argon atmosphere, and the gas atomization pressure is 7.5 - 8.5 MPa.

[0019] As a preferred embodiment of the preparation method of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention, wherein: after mechanical screening, the average particle size after screening is 15-53 μm.

[0020] As a preferred embodiment of the preparation method of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention, wherein: 3D printing is carried out, and the forming parameters are: the substrate preheating temperature is 200 °C, the laser scanning power is 200-400 W, the scanning speed is 800-1200 W, the layer thickness is 0.02-0.05 mm, the scanning spacing is 0.1-0.2 mm, and the interlayer rotation angle is 67°.

[0021] As a preferred embodiment of the preparation method of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention, wherein: further included is that after additive manufacturing, heat treatment and annealing are carried out on the 3D printed alloy.

[0022] As a preferred embodiment of the preparation method of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention, wherein: the heat treatment temperature is 300-325 °C, the heating rate is 50 °C / min, and the holding time is 5-8 h.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention designs a new type of additive manufacturing special multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy powder, innovates and verifies the composition of the heat-resistant Al alloy, forms Al9FeNi and Al6M (Mn, Fe) dispersed phases, and improves the thermal stability of the Al alloy in the medium and high temperature environment on the premise of ensuring the strength of the alloy. By preparing the Al-Fe-Ni-Mn-Cr-Zr alloy powder through the above scheme and combining it with the optimization of printing parameters, the obtained product parts have fine and uniform grain structures, no cracks, and excellent mechanical properties. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Among them:

[0026] Figure 1 It is a scanning morphology diagram of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy powder prepared in Example 1;

[0027] Figure 2 Metallographic diagram of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy prepared in Example 1;

[0028] Figure 3 Scanning diagram of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy prepared in Example 1;

[0029] Figure 4 Tensile curve of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy prepared in Example 1 at 200 °C. Detailed implementation manners

[0030] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following describes the detailed implementation manners of the present invention in conjunction with the embodiments of the specification.

[0031] Many specific details are set forth in the following description in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0032] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.

[0033] Unless otherwise specified, the raw materials used in the embodiments are all commercially purchased.

[0034] For the high-temperature tensile tests involved in the following embodiments, the heating rate is 10 °C / min, and heat balance is achieved by holding for half an hour before tensile testing.

[0035] Example 1

[0036] Configure the composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy. By mass fraction, it includes the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the balance is Al.

[0037] The preparation method of the above alloy powder is as follows:

[0038] (1) Vacuum melting. Weigh the metal block raw materials according to the mass ratio of each element and place them in a vacuum induction furnace for heating and melting into a pre-alloy. The melting temperature is 800 °C, and the air pressure is 0.6 MPa;

[0039] (2) Atomization powder making: Transfer the above pre-alloy into the atomization tank, and use argon gas to atomize the metal droplets. The atomization pressure is 8 MPa to obtain pre-alloy powder.

[0040] (3) Mechanical screening: Screen the above pre-alloy powder to obtain metal powder with a particle size range of 15 - 53 μm.

[0041] (4) Heat preservation and drying: Put the screened powder into the drying oven, with a heat preservation time of 12 hours and a heat preservation temperature of 90 °C to obtain the raw material powder required for printing. Its powder morphology is as Figure 1 shown.

[0042] The laser parameters for 3D printing of the above powder are as follows: the substrate preheating temperature is 200 °C, the laser scanning power is 350 W, the scanning speed is 1000 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°; to obtain a multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy component.

[0043] The microstructure of the obtained component is as Figure 2 shown, and the alloy scanning diagram is as Figure 3 shown, without obvious cracks and obvious hole defects, with high density; high thermal stability. Through the mechanical property test of the components, it can be found that the tensile strength at room temperature is 527 MPa, and the elongation at break exceeds 9.0%; the tensile curve of the alloy at 200 °C is as Figure 4 shown, the tensile strength at 200 °C is 395 MPa, the tensile strength at 300 °C reaches 329 MPa, and the elongation at break exceeds 7.0%. The average hardness reaches 168 HV0.5.

[0044] Perform heat treatment on the above specimens: the heat treatment temperature is 325 °C, and the heat preservation time is 6 h. After heat treatment, the tensile strength at room temperature is increased to 546 MPa.

[0045] Example 2

[0046] Configure the composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention. By mass fraction, it includes the following components: Fe: 2.5 wt%; Ni: 2.5 wt%; Mn: 2.5 wt%; Cr: 2.5 wt%; Zr: 1 wt%; the rest is Al.

[0047] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0048] The laser parameters for 3D printing of the above powder are as follows: the substrate preheating temperature is 200°C, the laser scanning power is 350 W, the scanning speed is 1000 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°

[0049] The obtained component has no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 515 MPa, the elongation at break is 8.5%, the tensile strength at 200°C is 368 MPa, the tensile strength at 300°C reaches 307 MPa, and the elongation at break is 6.3%. The average hardness reaches 162 HV0.5.

[0050] Example 3

[0051] Configure the composition of the multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy for additive manufacturing according to the present invention. By mass fraction, it includes the following components: Fe: 3 wt%; Ni: 3 wt%; Mn: 3 wt%; Cr: 3 wt%; Zr: 0.9 wt%; the balance is Al.

[0052] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0053] The laser parameters for 3D printing of the above powder are as follows: the substrate preheating temperature is 200°C, the laser scanning power is 350 W, the scanning speed is 1000 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°

[0054] The obtained component has no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 481 MPa, the elongation at break is 7.2%, the tensile strength at 200°C is 322 MPa, the tensile strength at 300°C reaches 269 MPa, and the elongation at break is 5.0%. The average hardness reaches 154 HV0.5.

[0055] Example 4

[0056] Configure the composition of the multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy for additive manufacturing according to the present invention. By mass fraction, it includes the following components: Fe: 1.5 wt%; Ni: 1.5 wt%; Mn: 1.5 wt%; Cr: 1.5 wt%; Zr: 1 wt%; the balance is Al.

[0057] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0058] The laser parameters for 3D printing the above powder are as follows: the substrate preheating temperature is 200°C, the laser scanning power is 350 W, the scanning speed is 1000 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°.

[0059] The obtained component has no obvious cracks, no obvious hole defects, and high density; it has high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 518 MPa, the elongation at break is 9.5%, the tensile strength at 200°C is 346 MPa, the tensile strength at 300°C reaches 292 MPa, and the elongation at break is 7.5%. The average hardness reaches 151 HV0.5.

[0060] Example 5

[0061] Configure the composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy described in the present invention. By mass fraction, it includes the following components: Fe: 1 wt%; Ni: 1 wt%; Mn: 1 wt%; Cr: 1 wt%; Zr: 1 wt%; the rest is Al.

[0062] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0063] The laser parameters for 3D printing the above powder are as follows: the substrate preheating temperature is 200°C, the laser scanning power is 350 W, the scanning speed is 1000 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°.

[0064] The obtained component has no obvious cracks, no obvious hole defects, and high density; it has high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 492 MPa, the elongation at break exceeds 10.2%, the tensile strength at 200°C is 337 MPa, the tensile strength at 300°C reaches 283 MPa, and the elongation at break exceeds 9%. The average hardness reaches 157 HV0.5.

[0065] Example 6

[0066] Configure the composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy described in the present invention. By mass fraction, it includes the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 1 wt%; Cr: 1 wt%; Zr: 1 wt%; the rest is Al.

[0067] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0068] The laser parameters for 3D printing the above powder are as follows: the substrate preheating temperature is 200°C, the laser scanning power is 350W, the scanning speed is 1000mm / min, the layer thickness is 0.02mm, the scanning spacing is 0.2mm, and the interlayer rotation angle is 67°.

[0069] The obtained component has no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 521MPa, the tensile strength at 200°C is 323MPa, and the tensile strength at 300°C reaches 280MPa. The average hardness reaches 161HV0.5.

[0070] Example 7

[0071] Configure the multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy composition of the present invention. By mass fraction, it includes the following components: Fe: 1wt%; Ni: 1wt%; Mn: 2wt%; Cr: 2wt%; Zr: 1wt%; the rest is Al.

[0072] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0073] The laser parameters for 3D printing the above powder are as follows: the substrate preheating temperature is 200°C, the laser scanning power is 350W, the scanning speed is 1000mm / min, the layer thickness is 0.02mm, the scanning spacing is 0.2mm, and the interlayer rotation angle is 67°.

[0074] The obtained component has no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 472MPa, the tensile strength at 200°C is 304MPa, and the tensile strength at 300°C reaches 262MPa. The average hardness reaches 153HV0.5.

[0075] Example 8

[0076] Configure the multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy composition of the present invention. By mass fraction, it includes the following components: Fe: 1.5wt%; Ni: 1.5wt%; Mn: 2wt%; Cr: 2wt%; Zr: 1wt%; the rest is Al.

[0077] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0078] The laser parameters for 3D printing the above powder are as follows: the substrate preheating temperature is 200°C, the laser scanning power is 350W, the scanning speed is 1000mm / min, the layer thickness is 0.02mm, the scanning spacing is 0.2mm, and the interlayer rotation angle is 67°.

[0079] The obtained components have no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the components, it can be found that the tensile strength at room temperature is 491 MPa, the tensile strength at 200 °C is 312 MPa, and the tensile strength at 300 °C reaches 269 MPa. The average hardness reaches 157 HV0.5.

[0080] Example 9

[0081] Configure the composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy described in the present invention. By mass fraction, it includes the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the rest is Al.

[0082] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0083] The laser parameters for 3D printing of the above powder are: the substrate preheating temperature is 200 °C, the laser scanning power is 400 W, the scanning speed is 1000 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°.

[0084] The obtained components have no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the components, it can be found that the tensile strength at room temperature is 476 MPa.

[0085] Example 10

[0086] Configure the composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy described in the present invention. By mass fraction, it includes the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the rest is Al.

[0087] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0088] The laser parameters for 3D printing of the above powder are: the substrate preheating temperature is 200 °C, the laser scanning power is 350 W, the scanning speed is 800 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°.

[0089] The obtained components have no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the components, it can be found that the tensile strength at room temperature is 473 MPa.

[0090] Example 11

[0091] The multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy component specimens obtained in Example 1 were respectively subjected to the following heat treatment experiments.

[0092] (1) The heat treatment temperature was 275 °C and the holding time was 6 h; after heat treatment, the tensile strength at room temperature was 531 MPa.

[0093] (2) The heat treatment temperature was 375 °C and the holding time was 6 h; after heat treatment, the tensile strength at room temperature was 508 MPa.

[0094] (3) The heat treatment temperature was 325 °C and the holding time was 8 h; after heat treatment, the tensile strength at room temperature was 535 MPa.

[0095] (4) The heat treatment temperature was 325 °C and the holding time was 10 h; after heat treatment, the tensile strength at room temperature was 519 MPa.

[0096] Comparative Example 1

[0097] The composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy described in the present invention was configured. By mass fraction, it included the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the balance was Al.

[0098] The raw material powder required for printing was obtained by using the same preparation method as in Example 1.

[0099] The laser parameters for 3D printing of the above powder were: the substrate preheating temperature was 200 °C, the laser scanning power was 250 W, the scanning speed was 1000 mm / min, the layer thickness was 0.02 mm, the scanning spacing was 0.2 mm, and the interlayer rotation angle was 67°.

[0100] The obtained component had no obvious cracks, no obvious pore defects, high density; and high thermal stability. Through the mechanical property test of the component, it was found that the tensile strength at room temperature was 363 MPa.

[0101] Comparative Example 2

[0102] The composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy described in the present invention was configured. By mass fraction, it included the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the balance was Al.

[0103] The raw material powder required for printing was obtained by using the same preparation method as in Example 1.

[0104] The laser parameters for 3D printing the above powder are as follows: the substrate preheating temperature is 200 °C, the laser scanning power is 300 W, the scanning speed is 1000 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°.

[0105] The obtained component has no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 453 MPa.

[0106] Comparative Example 3

[0107] Configure the multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy composition of the present invention. By mass fraction, it includes the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the rest is Al.

[0108] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0109] The laser parameters for 3D printing the above powder are as follows: the substrate preheating temperature is 200 °C, the laser scanning power is 450 W, the scanning speed is 1000 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°.

[0110] The obtained component has no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 398 MPa.

[0111] Comparative Example 4

[0112] Configure the multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy composition of the present invention. By mass fraction, it includes the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the rest is Al.

[0113] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0114] The laser parameters for 3D printing the above powder are as follows: the substrate preheating temperature is 200 °C, the laser scanning power is 350 W, the scanning speed is 1200 mm / min, the layer thickness is 0.02 mm, the scanning spacing is 0.2 mm, and the interlayer rotation angle is 67°.

[0115] The obtained component has no obvious cracks, no obvious hole defects, high density, and high thermal stability. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is 465 MPa.

[0116] Comparative Example 5

[0117] Configure the composition of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy of the present invention. By mass fraction, it includes the following components: Fe: 4wt%; Ni: 4wt%; Mn: 2wt%; Cr: 2wt%; Zr: 1wt%; the balance is Al.

[0118] Use the same preparation method as in Example 1 to obtain the raw material powder required for printing.

[0119] The laser parameters for 3D printing of the above powder are: the substrate preheating temperature is 200°C, the laser scanning power is 350W, the scanning speed is 1000mm / min, the layer thickness is 0.02mm, the scanning spacing is 0.2mm, and the interlayer rotation angle is 67°.

[0120] The obtained component has serious cracking phenomenon. Through the mechanical property test of the component, it can be found that the tensile strength at room temperature is only 324MPa.

[0121] The present invention discloses an additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy and its preparation method. The metal powder, by mass percentage, consists of the following components: Fe: 0.9 - 3.5wt%; Ni: 0.9 - 3.5wt%; Mn: 0.9 - 3.5wt%; Cr: 0.9 - 3.5wt%; Zr: 0.6 - 2.5wt%; the balance is Al. After melting and atomizing the above powder to obtain pre-alloy powder, the product obtained by additive manufacturing has fine and uniform structure, no cracks, almost no pore defects, excellent mechanical properties and thermal stability. The tensile strength at room temperature is 470 - 527MPa, and the elongation at break exceeds 7 - 11%; the tensile strength at 200°C is 310 - 395MPa; the tensile strength at 300°C is 250 - 329MPa, and the elongation at break exceeds 5 - 9%; the average hardness is 151 - 168HV0.5. After heat treatment, the tensile strength is further increased to 546MPa.

[0122] Under the conditions of rapid solidification and non-equilibrium solidification unique to additive manufacturing, the alloying elements used for modification in the Al alloy act together to form strengthening phases with good thermal stability, and the strengthening phases can produce a certain pinning effect in the alloy, thereby enhancing the stability and mechanical properties of the alloy in medium and high temperature environments. In addition, due to the interaction between different atoms and lattice distortion, the effective diffusion rate of atoms is affected, resulting in a weak retarded diffusion effect, thereby reducing the grain coarsening and recrystallization tendency of the alloy at high temperatures and improving its thermal stability. The combined action of Fe and Ni elements lies in their slow diffusion effect in the Al alloy. Under the optimal process parameters, rapid solidification can promote the uniform distribution of the eutectic Al9FeNi phase, promote the refinement of the microstructure, and produce a precipitation strengthening effect. The Al9FeNi phase still has good thermal stability at 300 °C, thereby enhancing the thermal stability of the Al alloy at 300-400 °C. The role of Fe and Mn elements is to form Al6M (Mn, Fe) dispersed particles, increase the recrystallization temperature, and significantly refine the recrystallized grains. The role of Cr and Zr elements is to utilize the rapid solidification characteristics of additive manufacturing technology to dissolve in the Al alloy under non-equilibrium solidification conditions to form a multi-phase solid solution structure, effectively refine the grain size, and produce a certain solid solution strengthening effect.

[0123] In addition, the interaction of the above several elements can also produce a new strengthening and heat-resistant effect, further enhancing the mechanical properties and heat resistance of the Al-Fe-Ni-Mn-Cr-Zr alloy.

[0124] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. An additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy, characterized in that: By mass fraction, the alloy consists of the following components: Fe: 0.9 - 3.5 wt%; Ni: 0.9 - 3.5 wt%; Mn: 0.9 - 3.5 wt%; Cr: 0.9 - 3.5 wt%; Zr: 0.6 - 2.5 wt%; the balance is Al.

2. The additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy according to claim 1, wherein: By mass fraction, the alloy consists of the following components: Fe: 2 wt%; Ni: 2 wt%; Mn: 2 wt%; Cr: 2 wt%; Zr: 1 wt%; the balance is Al.

3. The additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy according to claim 1, characterized in that: The alloy has the following properties: (a) The tensile strength at room temperature is 470 - 527 MPa, and the elongation at break is 7 - 11%; (b) The tensile strength at 200 °C is 310 - 395 MPa; (c) The tensile strength at 300 °C is 250 - 329 MPa, and the elongation at break is 5 - 9%; (d) The average hardness is 151 - 168 HV0.

5.

4. The preparation method of the additive manufacturing multi-component heat-resistant Al-Fe-Ni-Mn-Cr-Zr alloy according to any one of claims 1 to 3, characterized in that: Including, Prepare metal raw materials by mass fraction, and prepare pre-alloy powder after vacuum melting and atomization powder making; Perform 3D printing on the pre-alloy powder after mechanical screening and heat preservation drying.

5. The preparation method according to claim 4, characterized in that: For the vacuum melting, the melting temperature is 650 - 900 °C, and the air pressure is 0.5 - 0.6 MPa.

6. The preparation method according to claim 5, characterized in that: For the atomization powder making, it is carried out in an argon atmosphere, and the gas atomization pressure is 7.5 - 8.5 MPa.

7. The preparation method according to claim 6, characterized in that: For the mechanical screening, the average particle size after screening is 15 - 53 μm.

8. The preparation method according to claim 4, characterized in that: For the 3D printing, the forming parameters are: the substrate preheating temperature is 200 °C, the laser scanning power is 200 - 400 W, the scanning speed is 800 - 1200 W, the layer thickness is 0.02 - 0.05 mm, the scanning spacing is 0.1 - 0.2 mm, and the interlayer rotation angle is 67°.

9. The preparation method according to any one of claims 4 to 8, characterized in that: It also includes that after additive manufacturing, heat treatment and annealing are carried out on the 3D printed alloy.

10. The preparation method according to claim 9, characterized in that: The heat treatment temperature is 300 - 325 °C, the heating rate is 50 °C / min, and the holding time is 5 - 8 h.

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