A high-strength, heat-resistant aluminum-iron-silicon alloy and its preparation method

Abstract

This invention relates to a high-strength, heat-resistant aluminum-iron-silicon alloy produced by selective laser melting. The aluminum alloy comprises, by mass percentage: 1.5%-2.7% silicon, 5.6%-6.7% iron, with the balance being Al and unavoidable impurities, the total impurity content being less than or equal to 0.06%. The preparation process includes smelting, gas atomization powdering, and selective laser melting. This invention, through optimizing the alloy composition and preparation process, produces a crack-free, high-density alloy with high-density nano-α atoms within its interior. c -Al 20 The Fe5Si2 strengthening phase yields high-strength, heat-resistant additive manufacturing aluminum alloys that can be used in components operating at high temperatures, such as engine housings and pistons.

Description

Technical Field

[0001] This invention relates to an aluminum-iron-silicon alloy and its preparation method, and more particularly to a high-strength, heat-resistant aluminum-iron-silicon alloy and its selective laser melting preparation method, belonging to the field of non-ferrous metal technology. Background Technology

[0002] Currently, Al-Si alloys widely used in automotive engines typically improve their properties by adding elements such as Mg and Cu. The main strengthening mechanisms are dispersion strengthening of eutectic silicon particles and precipitation strengthening of precipitates. However, engine operating temperatures are generally above 200℃, reaching up to around 350℃. Within this temperature range, both eutectic silicon particles and precipitates undergo significant dissolution and growth, reducing their ability to hinder dislocations and thus lowering the alloy's mechanical properties. Therefore, it is necessary to develop an aluminum alloy that can withstand high temperatures of 200-350℃ to replace Al-Si alloys.

[0003] Most new heat-resistant alloys currently incorporate rare earth elements such as Ce and Sc to improve their heat resistance, primarily by forming Al3Sc and Al in the microstructure. 11 Phases such as Ce3 can resist dislocation and grain boundary migration, thereby improving the room temperature and high temperature mechanical properties of alloys. However, these rare earth elements are national strategic resources, with limited reserves and high prices worldwide.

[0004] Fe and Si are abundant in the Earth's crust, second only to O. Compared to other aluminum alloys, Al-Fe-Si alloys have an inherent cost advantage and extremely high application potential. In this system, Al, Fe, and Si elements form abundant and complex intermediate phases, most of which are Al... 13 Detrimental phases such as Fe4 and β-Al5FeSi, which are flaky and readily form during solidification, are present in Al-Fe-Si alloys. Conversely, it is difficult to obtain a uniform and fine-grained beneficial phase, α-AlFeSi, in the solidified microstructure. Previous research has not yet found an effective solution to these challenges. Consequently, research and applications of Al-Fe-Si alloys are scarce.

[0005] In the prior art, patent CN 113930644 B discloses a heat-resistant aluminum alloy and its preparation method. The alloy contains 4.5%-5.5% iron and 2.8%-3.5% silicon. Fine α-AlFeSi is obtained by heating and quenching in a quartz tube. The resulting alloy has a tensile strength of 252 MPa and an elongation of 15%. However, the samples prepared by this method are limited by the size of the quartz tube and cannot be applied to actual production.

[0006] Selective laser melting is an advanced additive manufacturing technology that uses laser energy to melt powdered metal layer by layer, gradually building complex three-dimensional parts. It is characterized by a very rapid cooling rate (>10). 4 Therefore, materials prepared by selective laser melting (K / s) have microstructures and mechanical properties that are completely different from ordinary casting materials, such as the cellular structure, submicron coral-like structure, and nanoscale precipitates that are very common in aluminum alloys.

[0007] However, current selective laser melting (SLM) aluminum alloys with high strength and heat resistance require the addition of elements such as Sc and Zr, and necessitate a certain degree of heat treatment, resulting in high costs and limiting the development of SLM aluminum alloys. Furthermore, many alloy systems are prone to forming large solidification cracks under SLM melting. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a selective laser melting high-strength heat-resistant aluminum alloy with reasonable component ratio, fewer element types, and low cost.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] This invention relates to a heat-resistant, high-strength Al-Fe-Si alloy, wherein the Al-Fe-Si alloy comprises the following components by mass percentage:

[0011] Silicon 1.5%-2.7%,

[0012] Iron 5.6%-6.7%,

[0013] The balance is Al and unavoidable impurities, with the total impurities less than or equal to 0.06%;

[0014] The heat-resistant high-strength Al-Fe-Si alloy includes a heat-resistant high-strength Al-Fe-Si alloy prepared by selective laser melting;

[0015] The heat-resistant, high-strength Al-Fe-Si alloy prepared by selective laser melting contains nano-phase α within its grains. c -Al 20 Fe5Si2, the nanophase α c -Al 20 Fe5Si2 is spherical or ellipsoidal.

[0016] The composition designed in this invention not only yields a crack-free, printed alloy but also enables the formation of high-density nanophases at the nanoscale. In the printed alloy obtained by this invention, the number of nanophases per square meter on any cross-section is greater than 10. 19 One, or even more than 10 20 indivual.

[0017] As a further improvement, the aluminum-silicon alloy comprises the following components by mass percentage:

[0018] Silicon 2.1%-2.7%, iron 5.6%-6.3%.

[0019] As a further improvement, the aluminum-silicon alloy comprises the following components by weight percentage:

[0020] Silicon 2.4%-2.7%, iron 5.9%-6.3%.

[0021] In a preferred embodiment of the present invention, when Si is 2.45–2.68% and Fe is 5.93–6.25%, the tensile strength of the printed product can reach greater than 540 MPa and the yield strength can reach greater than 405 MPa. In particular, when Si is 2.65–2.68% and Fe is 6.2–6.25%, the tensile strength of the printed product can reach greater than 545 MPa and the yield strength can reach greater than 415 MPa.

[0022] As a further improvement, the microstructure of the aluminum-iron-silicon alloy consists of Al grains and nano-α. c -Al 20 Fe5Si2 particles, wherein the Al grain diameter is 5-15 μm, and the nano-α c -Al 20 Fe5Si2 particles have a diameter of less than 30 nm, preferably 10-15 nm.

[0023] This invention discloses a method for preparing a high-strength, heat-resistant aluminum-iron-silicon alloy, comprising using selective laser melting (SLM) to prepare the alloy; during SLM, the laser power is controlled at 300-480W, preferably 350-455W, the scanning speed at 800-1200mm / s, preferably 900-1130mm / s, the scanning interval at 0.1-0.25mm, preferably 0.12-0.21mm, and the powder layer thickness at 0.025-0.035mm, preferably 0.03mm.

[0024] As a further preferred embodiment, the present invention provides a method for preparing a high-strength, heat-resistant aluminum-iron-silicon alloy, comprising preparing the high-strength, heat-resistant aluminum-iron-silicon alloy using a selective laser melting process; wherein the laser power is controlled at 420-480W, preferably 445-455W, more preferably 450W, the scanning speed is 1000-1130mm / s, preferably 1050-1130mm / s, more preferably 1100mm / s, and the scanning interval is 0.15-0.21mm, preferably 0.18-0.21mm, more preferably 0.2mm.

[0025] Preferably, the selective laser melting process includes a selective laser melting process.

[0026] The selective laser melting process used in this invention, combined with its composition, is beneficial to the metastable phase α. c -Al 20 Fe5Si2 is preferentially formed rather than the stable phase α-AlFeSi. Relatively speaking, the metastable phase has a more significant strengthening effect on the alloy.

[0027] The powder used in selective laser melting is the undersize powder that has passed through a 270-mesh sieve.

[0028] In industrial applications, the powder used in selective laser melting is prepared through the following steps:

[0029] Step 1: Ingredients

[0030] Prepare silicon, iron, and aluminum raw materials according to the designed alloy composition;

[0031] Step 2: Smelting

[0032] The alloy raw materials are placed in an induction melting furnace and heated to melt.

[0033] Step 3: Powdering

[0034] The molten liquid, which has been kept at a certain temperature for a certain period of time in the second step, is poured into the atomization chamber to produce powder.

[0035] During smelting, the melt is first heated to about 880-920℃, and after melting, it is cooled to 840-860℃ and held for 25-35 minutes.

[0036] During powder preparation, argon is used as the atomizing medium, with an argon pressure of 2.8-3.2 MPa. The powder must pass through a 270-mesh sieve.

[0037] The printing strategy used for selective laser melting is a strip scanning strategy, with the scanning direction between adjacent layers at 67°.

[0038] At room temperature, the tensile strength of the printed aluminum alloy is between 530-550 MPa, the yield strength is between 400-420 MPa, and the elongation is between 4.9-7.5%.

[0039] The printed aluminum alloy is stretched at 350℃, with a tensile strength between 199-215MPa, a yield strength between 172-201MPa, and an elongation between 4-4.5%.

[0040] The printed aluminum alloy, after being heat-exposed at 350°C for 100 hours and then subjected to room temperature tensile testing, exhibits a tensile strength between 350-360 MPa, a yield strength between 270-281 MPa, a strength retention rate greater than or equal to 65%, and an elongation rate between 8.5-14%. In this invention, the strength retention rate of the printed aluminum alloy after heat exposure at 350°C for 100 hours and subsequent room temperature tensile testing is calculated as: (room temperature tensile strength - tensile strength after heat exposure) / room temperature tensile strength × 100%.

[0041] The most prominent substantive features and significant advancements of this invention are mainly reflected in:

[0042] (1) This invention obtains a high-density nanophase α-Al without solidification cracks by rationally adjusting the alloy composition and selective laser melting. 20 The Fe5Si2 aluminum alloy has a good effect on enhancing the mechanical properties of the alloy.

[0043] (2) The alloy of the present invention can achieve a high-strength aluminum alloy with a tensile strength greater than 530 MPa and a yield strength of 407 MPa without the addition of other precipitation strengthening elements.

[0044] (3) The alloy of the present invention can achieve a heat-resistant aluminum alloy with a tensile strength greater than 199 MPa and a yield strength of 172 MPa at 350℃ without the addition of other precipitation strengthening elements.

[0045] (4) The alloy of the present invention can achieve a heat-resistant aluminum alloy with a tensile strength greater than 355MPa and a yield strength greater than 271MPa after being exposed to heat at 350℃ for 100h without the addition of other precipitation strengthening elements.

[0046] (5) The alloy of the present invention has the characteristics of high structural stability and excellent strength, and can be applied to parts that are used at higher temperatures, such as engine pistons or housings.

[0047] (5) The Fe and Si elements contained in the alloy of the present invention have a very obvious cost advantage over strengthening elements such as Sc and Zr, and have obvious commercial advantages. Attached Figure Description

[0048] Appendix Figure 1 The stress-strain curve of the printed aluminum alloy structural component obtained in Example 1 is shown in the room temperature tensile test.

[0049] Appendix Figure 2 The stress-strain curve of the printed aluminum alloy structural component obtained in Example 2 is shown in the room temperature tensile test.

[0050] Appendix Figure 3 The stress-strain curves of the printed aluminum alloy structural component obtained in Example 3 are obtained from a room temperature tensile test.

[0051] Appendix Figure 4 The stress-strain curve of the printed aluminum alloy structural component obtained in Example 1 was obtained after a high-temperature tensile test at 350°C.

[0052] Appendix Figure 5 The stress-strain curve of the printed aluminum alloy structural component obtained in Example 2 is shown in the figure after a high-temperature tensile test at 350°C.

[0053] Appendix Figure 6 The stress-strain curve of the printed aluminum alloy structural component obtained in Example 3 is shown in the tensile test at 350°C.

[0054] Appendix Figure 7 The stress-strain curve of the printed aluminum alloy structural component obtained in Example 1 after being exposed to heat at 350°C for 100 hours at room temperature is shown in the tensile test at room temperature.

[0055] Appendix Figure 8 The stress-strain curve of the printed aluminum alloy structural component obtained in Example 2 after being exposed to heat at 350°C for 100 hours at room temperature for a tensile test.

[0056] Appendix Figure 9 The stress-strain curve of the printed aluminum alloy structural component obtained in Example 3 after being exposed to heat at 350°C for 100 hours in a room temperature tensile test is shown.

[0057] Appendix Figure 10 The images shown are optical microscope images of the etched aluminum alloy structural component obtained in Example 1 and high-angle annular dark-field images obtained by transmission electron microscopy.

[0058] Appendix Figure 11 The stress-strain curves of the cast aluminum alloy structural component obtained in Comparative Example 1 are shown in the tensile test results.

[0059] Appendix Figure 12 The stress-strain curves of the aluminum alloy structural component obtained in Comparative Example 2 are shown in the room temperature tensile test results.

[0060] Appendix Figure 13 The stress-strain curves of the aluminum alloy structural component obtained in Comparative Example 3 are shown in the room temperature tensile test results.

[0061] From the appendix Figure 1 It can be seen that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 1 has a tensile strength of 548.33 MPa and a yield strength of 418.07 MPa, thus obtaining a high-strength selective laser melting aluminum alloy material.

[0062] From the appendix Figure 2 It can be observed that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 2 has a tensile strength of 542.15 MPa and a yield strength of 409.68 MPa, thus obtaining a high-strength selective laser melting aluminum alloy material.

[0063] From the appendix Figure 3 It can be observed that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 3 has a tensile strength of 534.69 MPa and a yield strength of 407.92 MPa, thus obtaining a high-strength selective laser melting aluminum alloy material.

[0064] From the appendix Figure 4 It can be observed that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 1 has a tensile strength of 213.88 MPa and a yield strength of 200.47 MPa at 350°C, thus obtaining a heat-resistant selective laser melting aluminum alloy material.

[0065] From the appendix Figure 5 It can be observed that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 2 has a tensile strength of 212.41 MPa and a yield strength of 198.17 MPa at 350°C, thus obtaining a heat-resistant selective laser melting aluminum alloy material.

[0066] From the appendix Figure 6 It can be observed that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 3 has a tensile strength of 199.14 MPa and a yield strength of 172.09 MPa at 350°C, thus obtaining a heat-resistant selective laser melting aluminum alloy material.

[0067] From the appendix Figure 7 It can be observed that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 1 has a room temperature tensile strength of 356.06 MPa and a yield strength of 280.77 MPa after being exposed to heat at 350°C for 100 hours, thus obtaining a heat-resistant selective laser melting aluminum alloy material.

[0068] From the appendix Figure 8 It can be observed that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 2 has a room temperature tensile strength of 355.17 MPa and a yield strength of 276.14 MPa after being exposed to heat at 350°C for 100 hours, thus obtaining a heat-resistant selective laser melting aluminum alloy material.

[0069] From the appendix Figure 9 It can be observed that the selective laser melting aluminum alloy structural component obtained under the composition and process of Example 3 has a room temperature tensile strength of 355.59 MPa and a yield strength of 271.25 MPa after being exposed to heat at 350°C for 100 hours, thus obtaining a heat-resistant selective laser melting aluminum alloy material.

[0070] From the appendix Figure 10It can be seen that the printed Al-Fe-Si alloy did not exhibit obvious solidification cracks, indicating that a fine and uniform eutectic structure was formed under this composition. This material composition is highly suitable for selective laser melting. At the nanoscale, high-density nanophase α-Al appeared within the grains of the printed Al-Fe-Si alloy. 20 Fe5Si2, these round or elliptical nanophases, create a great resistance to the movement of dislocations, thereby significantly improving the mechanical properties of the material.

[0071] From the appendix Figure 11 As can be seen, under the preparation process of Comparative Example 1, the room temperature tensile strength of the alloy is 184.65 MPa, the yield strength is 99.4 MPa, and the elongation is only 3.70%. Even though the alloy composition falls within the range of this design, the different preparation process severely reduces the mechanical properties and ductility of the alloy.

[0072] From the appendix Figure 12 As can be seen, under the composition of Comparative Example 2, the room temperature tensile strength of the alloy is 167.65 MPa, the yield strength is 142.06 MPa, and the elongation is only 0.88%. The Fe and Si elements in the alloy are not within the designed range, which will lead to large solidification cracks during selective laser melting, and the formation of coarse second phases will severely damage the mechanical properties and ductility of the alloy.

[0073] From the appendix Figure 13 As can be seen, under the composition and printing process of Comparative Example 3, the room temperature tensile strength of the alloy is 477.24 MPa, the yield strength is 357.37 MPa, and the elongation is only 1.55%. The laser power and scanning rate used in the printing were not within the design range. Inappropriate scanning parameters will form large hot cracks in the alloy during selective laser melting, reducing the mechanical properties of the alloy. Detailed Implementation

[0074] This invention provides a heat-resistant, high-strength Al-Fe-Si alloy and its preparation method, wherein the alloy contains 1.5%-2.7% silicon by mass percentage.

[0075] Iron 5.6%-6.7%,

[0076] The balance is Al and unavoidable impurities, with the total impurities less than or equal to 0.06%.

[0077] The present invention also provides a corresponding preparation method:

[0078] (1) Batching: Prepare silicon, iron and aluminum raw materials according to the designed alloy composition;

[0079] (2) Melting: The alloy raw materials are placed in an induction melting furnace and heated to melt. The melt is first heated to about 900°C, and then cooled to 850°C and held for 30 minutes.

[0080] (3) Powder making: Pour the molten liquid that has been kept at a certain temperature into the atomization chamber to make powder. Argon gas is used as the gas atomization medium. The argon gas pressure is 3MPa. The powder made needs to pass through a 270-mesh sieve.

[0081] (4) Selective laser melting: Cooled powder is added to a selective laser melting equipment to print aluminum alloy castings.

[0082] Example 1

[0083] The alloy consists of 5.95 wt% iron, 2.31 wt% silicon, with the remainder being Al and unavoidable impurities. The alloy is prepared according to the composition ratio and then melted in an induction melting furnace at approximately 900°C. After melting, the temperature is lowered to 850°C and held for 30 minutes. The molten metal is then poured into an atomization chamber to form powder, using argon gas as the atomization medium at a pressure of 3 MPa. The cooled powder is passed through a 270-mesh sieve and added to a selective laser melting (SLM) machine to print aluminum alloy structural parts. The printing parameters are: laser power 450W, scanning speed 1100 mm / s, scanning interval 0.2 mm, and powder layer thickness 0.03 mm. After forming, the sample is removed from the printer and subjected to a tensile test.

[0084] Table 1 Tensile properties of the sample from Example 1

[0085] state tensile strength Yield strength elongation room temperature stretching 548.33MPa 418.09MPa 6.02％ 350℃ stretching 213.88MPa 200.47MPa 4.40％ Tensile testing at room temperature after 100 hours of heat exposure at 350℃ 356.06MPa 280.77MPa 8.98％

[0086] Example 2

[0087] The alloy consists of 5.83 wt% iron, 2.36 wt% silicon, with the remainder being Al and unavoidable impurities. The alloy is prepared according to the composition ratio, then melted in an induction melting furnace at approximately 900°C. After melting, it is cooled to 850°C and held for 30 minutes. The molten metal is then poured into an atomization chamber to form powder, using argon gas as the atomization medium at a pressure of 3 MPa. The cooled powder is passed through a 270-mesh sieve and added to a selective laser melting (SLM) machine to print aluminum alloy structural parts. The printing parameters are: laser power 350W, scanning speed 900 mm / s, scanning interval 0.2 mm, and powder layer thickness 0.03 mm. After forming, the sample is removed from the printer and subjected to a tensile test.

[0088] Table 2 Tensile properties of samples from Example 2

[0089] state tensile strength Yield strength elongation room temperature stretching 542.15MPa 409.68MPa 7.14％ 350℃ stretching 212.41MPa 198.17 MPa 4.11％ Tensile testing at room temperature after 100 hours of heat exposure at 350℃ 355.17MPa 276.14 MPa 10.51％

[0090] Example 3

[0091] The alloy consists of 5.71 wt% iron, 2.46 wt% silicon, with the remainder being Al and unavoidable impurities. The alloy is prepared according to the composition ratio, then melted in an induction melting furnace at approximately 900°C. After melting, it is cooled to 850°C and held for 30 minutes. The molten metal is then poured into an atomization chamber to form powder, using argon gas as the atomization medium at a pressure of 3 MPa. The cooled powder is passed through a 270-mesh sieve and added to a selective laser melting (SLM) machine to print aluminum alloy structural parts. The printing parameters are: laser power 400W, scanning speed 1000 mm / s, scanning interval 0.12 mm, and powder layer thickness 0.03 mm. After forming, the sample is removed from the printer and subjected to tensile testing.

[0092] Table 3 Tensile properties of samples from Example 3

[0093] state tensile strength Yield strength elongation room temperature stretching 534.69MPa 407.92MPa 4.99％ 350℃ stretching 199.14 MPa 172.09 MPa 4.01％ Tensile testing at room temperature after 100 hours of heat exposure at 350℃ 355.59MPa 271.25MPa 13.70％

[0094] Comparative Example 1

[0095] The alloy consists of 5.88 wt% iron, 2.52 wt% silicon, with the remainder being Al and unavoidable impurities. The alloy was prepared according to the composition ratio, and then melted in an induction melting furnace and held at 750℃ for 30 minutes. After refining three times, the molten aluminum alloy was die-cast under a pressure of 20 MPa with a vacuum maintained at 110 mba. After cooling, the sample was removed from the die-casting machine and subjected to tensile testing.

[0096] Table 4. Room temperature tensile properties of the as-cast samples from Comparative Example 1

[0097] tensile strength Yield strength elongation 184.65MPa 99.4MPa 3.70％

[0098] Comparative Example 2

[0099] The composition consists of 1.79 wt% iron, 4.5 wt% silicon, with the remainder being Al and unavoidable impurities. The alloy is prepared according to the composition ratio, and then melted in an induction melting furnace at approximately 900°C. After melting, the temperature is lowered to 850°C and held for 30 minutes. The molten metal is then poured into an atomization chamber to form powder, using argon gas as the atomization medium at a pressure of 3 MPa. The cooled powder is passed through a 270-mesh sieve and added to a selective laser melting (SLM) machine to print aluminum alloy structural parts. The printing parameters are: laser power 450W, scanning speed 1100 mm / s, scanning interval 0.2 mm, and powder layer thickness 0.03 mm. After forming, the sample is removed from the printer and subjected to tensile testing.

[0100] Table 5. Room temperature tensile properties of the printed samples from Comparative Example 2

[0101] tensile strength Yield strength elongation 167.65MPa 142.06MPa 0.88％

[0102] Comparative Example 3

[0103] The alloy consists of 5.99 wt% iron, 2.66 wt% silicon, with the remainder being Al and unavoidable impurities. The alloy is prepared according to the composition ratio and then melted in an induction melting furnace at approximately 900°C. After melting, the temperature is lowered to 850°C and held for 30 minutes. The molten metal is then poured into an atomization chamber to form powder, using argon gas as the atomization medium at a pressure of 3 MPa. The cooled powder is passed through a 270-mesh sieve and added to a selective laser melting (SLM) machine to print aluminum alloy structural parts. The printing parameters are: laser power 200W, scanning speed 750 mm / s, scanning interval 0.3 mm, and powder layer thickness 0.03 mm. After forming, the sample is removed from the printer and subjected to a tensile test.

[0104] Table 6. Room temperature tensile properties of the printed samples from Comparative Example 3

[0105] tensile strength Yield strength elongation 477.24MPa 357.37MPa 1.55％ .

Claims

1. A heat-resistant, high-strength Al-Fe-Si alloy, characterized in that; The Al-Fe-Si alloy contains the following components by mass percentage: Silicon 1.5% - 2.7%, Iron 5.6% - 6.7%, The balance consists of Al and unavoidable impurities, with the total impurities less than or equal to 0.06%. The heat-resistant high-strength Al-Fe-Si alloy is a heat-resistant high-strength Al-Fe-Si alloy prepared by selective laser melting; The heat-resistant, high-strength Al-Fe-Si alloy prepared by selective laser melting contains nano-phase α within its grains. c -Al 20 Fe5Si2, the nanophase α c -Al 20 Fe5Si2 is spherical or ellipsoidal; The microstructure of the aluminum-iron-silicon alloy consists of Al grains and nano-α. c -Al 20 Fe5Si2 particles, wherein the Al grain diameter is 5-15 μm, and the nano-α... c -Al 20 Fe5Si2 particles have a diameter of less than 30 nm; After selective laser melting, the tensile strength of the printed aluminum alloy is between 530-550 MPa, the yield strength is between 400-420 MPa, and the elongation is between 4.9-7.5%. The printed aluminum alloy was stretched at 350℃, and the tensile strength was between 199-215 MPa, the yield strength was between 172-201 MPa, and the elongation was maintained between 4-4.5%. After being heat-exposed at 350℃ for 100 h, the printed aluminum alloy was subjected to room temperature tensile testing. The tensile strength was between 350-360 MPa, the yield strength was between 270-281 MPa, the strength retention rate was greater than or equal to 65%, and the elongation was maintained between 8.5-14%.

2. The heat-resistant high-strength Al-Fe-Si alloy according to claim 1, characterized in that; The aluminum-iron-silicon alloy comprises the following components by mass percentage: Silicon 2.1% - 2.7%, iron 5.6% - 6.3%.

3. The heat-resistant high-strength Al-Fe-Si alloy according to claim 1, characterized in that; The aluminum-iron-silicon alloy comprises the following components by mass percentage: Silicon 2.4% - 2.7%, iron 5.9% - 6.3%.

4. A method for preparing a high-strength, heat-resistant aluminum-iron-silicon alloy as described in any one of claims 1-3, characterized in that: This includes the preparation of high-strength, heat-resistant aluminum-iron-silicon alloys using selective laser melting (SLM). During SLM, the laser power is controlled at 300-480W, the scanning speed at 800-1200mm / s, the scanning interval at 0.1-0.25mm, and the powder layer thickness at 0.025-0.035mm.

5. The method for preparing a heat-resistant, high-strength Al-Fe-Si alloy according to claim 4, characterized in that: The powder used in selective laser melting is the undersize powder that has passed through a 270-mesh sieve.

6. The method for preparing a heat-resistant, high-strength Al-Fe-Si alloy according to claim 4, characterized in that: The powder used in selective laser melting is prepared through the following steps: Step 1: Ingredients Prepare silicon, iron, and aluminum raw materials according to the designed alloy composition; Step 2: Smelting The alloy raw materials are placed in an induction melting furnace and heated to melt. Step 3: Powdering The molten liquid, which was kept at a certain temperature for a certain period of time in the second step, was poured into the atomization chamber to make powder. The powder was then sieved to obtain the powder used for selective laser melting.

7. The method for preparing a heat-resistant, high-strength Al-Fe-Si alloy according to claim 4, characterized in that: The printing strategy used for selective laser melting is a strip scanning strategy, with the scanning direction between adjacent layers at 67°.

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