Flux-cored welding wire for manufacturing aircraft engine casing and method for preparing aircraft casing

Abstract

The invention discloses a flux-cored welding wire for manufacturing an aero-engine casing, comprising an alloy sheath and flux-cored powder. The flux-cored wire is composed of the following components (by weight): 15.8% to 18.03% iron powder, 16.6% to 18.95% nickel powder, 14.71% to 16.79% chromium powder, 16.67% to 19.02% cobalt powder, 7.64% to 8.7% aluminum powder, 13.58% to 15.50% molybdenum powder, and 3% to 15% NbC, where the sum of the weight percentages of the above components is 100%. The invention also discloses a method for preparing an aero-engine casing using the flux-cored welding wire. Examples show that the flux-cored welding wire has excellent comprehensive performance, and that using the welding wire 3D printing technology to prepare a high-wear-resistant FeCoNiCrAl-Mx-based high-entropy alloy aero-engine casing not only has good molding quality and high precision, but also saves raw materials and conforms to the concept of green development.

Description

Technical Field

[0001] The invention belongs to the technical field of welding materials and relates to a flux-cored welding wire for manufacturing aircraft engine casings.

[0002] The invention also relates to a method for preparing the aviation engine casing. Background Art

[0003] Modern industry requires structural materials to have high strength, fracture toughness and stiffness, while reducing weight as much as possible. In this case, lightweight high-strength alloys represented by aluminum and titanium, and load-bearing heat-resistant alloys represented by Ni-based high-temperature alloys have become one of the key development materials in new material research and development plans of various countries, and are also important application materials in additive manufacturing. Aluminum alloys and titanium alloys, due to their excellent low density and structural strength, are widely used in aerospace, automobile, machinery manufacturing and other fields, whether using 3D printing or CNC processing. However, titanium has an extremely high melting point, exceeding 1600°C, and is also a typical difficult-to-process material. Although titanium has high high temperature resistance and corrosion resistance, its electrical conductivity is poor, so it is a bad choice in electrical applications. Compared with other lightweight metals (such as aluminum), titanium alloys are also more expensive. Aluminum has the characteristics of low density, high thermal conductivity and easy oxidation, so it is easy to agglomerate and have poor continuity during the 3D printing process, which has a poor impact on the accuracy of the additive manufacturing system.

[0004] High-entropy alloys not only have excellent properties such as high strength, high hardness, high wear and corrosion resistance, and high-temperature oxidation resistance, but can also greatly reduce costs and have a high material utilization rate. Fe-Co-Ni high-entropy alloys have excellent comprehensive performance, flexible composition adjustment, and synergistic performance control of various elements. Excellent corrosion resistance and wear resistance are the most typical characteristics of Fe-Co-Ni high-entropy alloys. Therefore, Fe-Co-Ni high-entropy alloys can be used as an excellent strengthening material and are widely used in oil pipelines, thermal power and aerospace fields, thereby achieving the dual needs of cost reduction and performance improvement, and making outstanding contributions to my country's sustainable development, greening and ecologicalization.

[0005] Modern aerospace components must simultaneously meet a series of stringent requirements such as lightweight, high performance, high reliability, and low cost. In addition, the structure of the components is more complex and the design and manufacturing are more difficult. Through the innovation and development of new aerospace materials and key technologies of 3D printing shape control and controllability, it not only reflects the development direction of lightweight and high performance in material selection, but also highlights the development trend of precision and net forming of 3D printing technology itself, which can realize the integrated 3D printing of materials, structures and performances and the major engineering applications of 3D printing technology in aerospace. Summary of the Invention

[0006] The purpose of the present invention is to provide a flux-cored welding wire for manufacturing aero-engine casings, which has the characteristics of low manufacturing cost and significantly improved product performance.

[0007] Another object of the present invention is to provide a method for preparing an aircraft engine casing.

[0008] The first technical solution adopted by the present invention is a flux-cored welding wire for manufacturing aircraft engine casings, which specifically includes an alloy sheath and flux core powder, with a powder coating rate of 28wt.%-35wt.%.

[0009] The first technical solution of the present invention is also characterized in that:

[0010] The flux core comprises, by mass percentage, 15.8% to 18.03% iron powder, 16.6% to 18.95% nickel powder, 14.71% to 16.79% chromium powder, 16.67% to 19.02% cobalt powder, 7.64% to 8.7% aluminum powder, 13.58% to 15.50% molybdenum powder, and 3% to 15% NbC, and the sum of the mass percentages of the above components is 100%;

[0011] The alloy belt skin is a Fe-Co-Ni alloy belt.

[0012] The second technical solution adopted by the present invention is a method for preparing an aircraft engine casing, using a flux-cored welding wire for manufacturing an aircraft engine casing, which is specifically implemented by the following steps:

[0013] Step 1: 3D modeling of the 3D printed structural component is performed using Pro E modeling software, and then 15.8% to 18.03% of iron powder, 16.6% to 18.95% of nickel powder, 14.71% to 16.79% of chromium powder, 16.67% to 19.02% of cobalt powder, 7.64% to 8.7% of aluminum powder, 13.58% to 15.50% of molybdenum powder, and 3% to 15% of NbC are weighed, where the sum of the mass percentages of the above components is 100%;

[0014] Step 2: The Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine, and the mixed powder obtained in step 1 is then filled into the U-shaped welding strip and rolled into an O-shape; the surface of the welding strip is then wiped clean with anhydrous ethanol, and the diameter of the thick welding wire is gradually reduced; finally, anhydrous ethanol is used to remove impurities and oil stains on the surface of the welding wire and the wire is coiled;

[0015] Step 3: Cut the welding wire obtained in step 2 to obtain the appropriate length, perform 3D printing surfacing and cooling, and obtain the required FeCoNiCrMo after surfacing. 0.5 Al-NbC x High entropy alloy engine casing, the cladding substrate is martensitic stainless steel;

[0016] Step 4: The component obtained by 3D printing in step 3 is polished and modified by wire electric discharge cutting and CNC lathe to ensure its surface roughness and accuracy.

[0017] The second technical solution adopted by the present invention is also characterized in that:

[0018] In step 1, the weighed alloy powders are mixed uniformly and dried, and 99.9% pure Ar gas is introduced throughout the drying process, with an Ar gas flow rate of 2 L / min to 3 L / min, a drying temperature of 200° C. to 250° C., and a drying time of 2.2 h to 2.5 h;

[0019] In step 2, the thick welding wire is gradually reduced in diameter to obtain a 1.20 mm welding wire;

[0020] In step 3, the welding process adopts 3D printing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 15L / min to 20L / min;

[0021] Wherein the welding method in step 3 adopts multi-layer multi-pass welding;

[0022] The welding process parameters in step 3 are: stacking current of 145A to 155A, arc voltage of 21V to 23V, welding speed of 0.18m / min to 0.21m / min, and interlayer cooling temperature of 100℃ to 200℃.

[0023] The beneficial effects of the present invention are:

[0024] Compared with solid welding wire, the flux-cored welding wire for 3D printing used in the present invention has a simple production process, convenient operation, high controllability of composition, flexible adjustment, and low cost. The flux-cored welding wire has higher heat transfer efficiency and higher welding efficiency during the cladding process.

[0025] Secondly, in the flux-cored welding wire of the present invention, the Ni and Cr elements can play a good solid solution strengthening role, which directly determines the corrosion resistance and wear resistance of the alloy. In addition, the presence of Cr and Ni elements can reduce the precipitation of brittle phases; the Co element can increase the hardness of the alloy to a certain extent, thereby improving the wear resistance of the alloy; a dense oxide film can be formed on the surface of the Al element, thereby effectively improving the wear resistance and corrosion resistance of the alloy; the Fe element can inhibit the segregation phenomenon between the substrate and the engine housing during the welding process; the addition of the Mo element can effectively inhibit the precipitation of brittle phases and improve the overall performance of the substrate; at the same time, the addition of NbC can be evenly dispersed in the engine housing and play a role of dispersion strengthening, thereby improving the overall performance of the engine housing;

[0026] Furthermore, the FeCoNiCrMo in the present invention 0.5 Al-NbCx High-entropy alloy matched flux-cored welding wire is used in 3D printing technology. The engine casing has excellent molding quality, without obvious defects such as cracks and pores. The arc smoke and dust are small during the welding process, making a huge contribution to the green development strategy.

[0027] The second technical solution of the present invention, the method for preparing an aero-engine casing, has the following technical advantages:

[0028] First, laser cladding or vacuum melting processes suffer from severe material waste and burnout, resulting in low density of the formed workpiece, severe segregation, numerous defects, and low efficiency. 3D printing technology offers a higher material utilization rate and a more precise welding process. Large aircraft engine casings fabricated using this method exhibit excellent molding, a distinct metallic luster, and a distinct fish-scale pattern, with good bonding between the substrate and the engine casing.

[0029] Secondly, 3D printing technology is suitable for a variety of harsh and complex working conditions, with low investment costs and flexible program control operations. It can greatly promote the response and call for low energy consumption, high efficiency, high precision, and green development in the field of engine casing preparation, laying a solid foundation for industrial innovation and development.

[0030] Finally, FeCoNiCrMo 0.5 Al-NbC x High-entropy alloy is matched with flux-cored welding wire for 3D printing. The surface of the engine casing is glossy, showing regular fish-scale patterns, without defects such as collapse cracks. Using 3D printing technology, the protective gas is 99.9% pure Ar gas, which can avoid contact with air or impurities during the welding process, inhibit the possibility of oxidation of the molten pool, and reduce the splashing of molten droplets during the welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FeCoNiCrMo prepared by the method of the present invention 0.5 Al-NbC x Schematic diagram of high entropy alloy engine casing modeling;

[0032] Figure 2 FeCoNiCrMo prepared by the method of the present invention 0.5 Al-NbC x Schematic diagram of high-entropy alloy engine casing modeling. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] The present invention provides a flux-cored welding wire for manufacturing aircraft engine casings. The flux-cored welding wire comprises an alloy strip and a flux core powder. The flux core is composed of the following components (by weight): 15.8% to 18.03% iron powder, 16.6% to 18.95% nickel powder, 14.71% to 16.79% chromium powder, 16.67% to 19.02% cobalt powder, 7.64% to 8.7% aluminum powder, 13.58% to 15.50% molybdenum powder, and 3% to 15% NbC, with the sum of the mass percentages of the above components being 100%. The alloy strip is made of an Fe-Co-Ni alloy strip; the alloy powder filling rate is 28% to 35% by weight;

[0035] The roles and functions of each component in flux-cored welding wire are as follows:

[0036] Ni and Cr elements can play a good role in solid solution strengthening, which directly determines the corrosion resistance and wear resistance of the engine casing alloy. In addition, the presence of Cr and Ni elements will reduce the precipitation of brittle phases.

[0037] The Co element increases the hardness of the alloy to a certain extent, thereby improving the wear resistance of the alloy;

[0038] A dense oxide film will form on the surface of the Al element, thus effectively improving the wear resistance and corrosion resistance of the alloy;

[0039] The addition of Mo element can effectively inhibit the precipitation of brittle phase and improve the overall performance of the matrix;

[0040] The Fe element can suppress the segregation between the substrate and the engine housing during welding;

[0041] The addition of NbC can be evenly dispersed in the engine casing and play a role of dispersion strengthening, thereby improving the overall performance of the engine casing.

[0042] The present invention also provides a method for preparing a high wear-resistant large-scale aircraft engine casing, which adopts a 3D printing technology to prepare a high wear-resistant large-scale aircraft engine casing using FeCoNiCrMo 0.5 Al-NbC x High entropy alloy matched with flux-cored wire to prepare aircraft engine casing, such as Figure 1 The specific steps are as follows:

[0043] Step 1, such as Figure 2As shown, the 3D printed structural parts were three-dimensionally modeled using Pro E modeling software, and 15.8% to 18.03% iron powder, 16.6% to 18.95% nickel powder, 14.71% to 16.79% chromium powder, 16.67% to 19.02% cobalt powder, 7.64% to 8.7% aluminum powder, 13.58% to 15.50% molybdenum powder, and 3% to 15% NbC were weighed, and the sum of the mass percentages of the above components was 100%; then the weighed alloy powders were mixed evenly and dried, and the drying was carried out in a vacuum tube furnace, 99.9% Ar gas was continuously introduced, the Ar gas flow rate was 2 L / min to 3 L / min, the drying temperature was 200° C. to 250° C., and the drying time was 2.2 h to 2.5 h;

[0044] Step 2: First, the Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine. Then, the dry mixed powder obtained in step 1 is filled into the U-shaped welding strip and rolled into an O-shape. The powder feeding speed is adjusted according to the actual situation. Then, the surface of the welding strip is wiped clean with anhydrous ethanol, and the thick welding wire is gradually reduced to obtain a 1.20 mm welding wire. Finally, the impurities and oil on the surface of the welding wire are cleaned with anhydrous ethanol and the wire is coiled.

[0045] Step 3: Cut the welding wire obtained in step 2 to obtain a suitable length, perform 3D printing and cool it. The stacking current is 145A-155A, the arc voltage is 21V-23V, the welding speed is 0.18m / min-0.21m / min, and the interlayer cooling temperature is 100℃-200℃. The welding process adopts 3D printing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 15L / min-20L / min. The welding method adopts multi-pass multi-layer cladding. After the cladding is completed, the required FeCoNiCrMo 0.5 Al-NbC x High entropy alloy aero-engine casing, the cladding substrate is martensitic stainless steel;

[0046] Step 4: The 3D printed components are polished and modified by wire-cutting and CNC lathe to ensure their surface roughness and accuracy.

[0047] Example 1

[0048] Step 1: Use Pro E modeling software to perform three-dimensional modeling of the 3D printed structural parts. Weigh 18.04% iron powder, 18.95% nickel powder, 16.79% chromium powder, 19.02% cobalt powder, 8.7% Al powder, 15.50% molybdenum powder, and 5% NbC powder. The sum of the mass percentages of the above components is 100%; the weighed alloy powders are mixed evenly and dried. The drying is carried out in a vacuum tube furnace, and 99.9% Ar gas is continuously introduced at an Ar gas flow rate of 2L / min to 3L / min. The drying temperature is 200℃ to 250℃ and the drying time is 2.2h to 2.5h.

[0049] Step 2: First, the Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine. Then, the dry mixed powder obtained in step 1 is filled into the U-shaped welding strip and rolled into an O-shape. The powder feeding speed is adjusted according to the actual situation. Then, the surface of the welding strip is wiped clean with anhydrous ethanol, and the thick welding wire is gradually reduced to obtain a 1.20 mm welding wire. Finally, the impurities and oil on the surface of the welding wire are cleaned with anhydrous ethanol and the wire is coiled.

[0050] Step 3: Cut the welding wire obtained in step 2 to obtain the appropriate length, perform 3D printing and cool it. The stacking current is 145A-155A, the arc voltage is 21V-23V, the welding speed is 0.18m / min-0.21m / min, and the interlayer cooling temperature is 100℃-200℃. The welding process adopts 3D printing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 15L / min-20L / min. The welding method adopts multi-pass multi-layer cladding. After the cladding is completed, the required FeCoNiCrMo 0.5 Al-NbC x High entropy alloy aero-engine casing, the cladding substrate is 304 stainless steel;

[0051] Step 4: The 3D printed components are polished and modified by wire-cutting and CNC lathe to ensure their surface roughness and accuracy.

[0052] After the welding test, the engine casing was subjected to a mechanical performance test; the test results showed that the average hardness was 707.3HV 0.2 The wear amount is 7 mg, the average friction coefficient is 0.26, and the mechanical properties are in line with expectations. The experimental results show that the Fe-Co-Ni high entropy alloy aero-engine casing of the present invention has excellent comprehensive performance, and its performance is comparable to or even better than that of forgings and castings, and is suitable for the preparation and modification of large aero-engine casings.

[0053] Example 2

[0054] Step 1, three-dimensional modeling of the 3D printed structural parts is performed using Pro E modeling software, and 17.49% iron powder, 18.37% nickel powder, 16.28% chromium powder, 18.45% cobalt powder, 8.4% Al powder, 15.01% molybdenum powder, and 6% NbC powder are weighed. The sum of the mass percentages of the above components is 100%. The weighed alloy powders are mixed evenly and dried. The drying is carried out in a vacuum tube furnace, and 99.9% Ar gas is continuously introduced with an Ar gas flow rate of 2L / min to 3L / min. The drying temperature is 200°C to 250°C and the drying time is 2.2h to 2.5h.

[0055] Step 2: First, the Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine. Then, the dry mixed powder obtained in step 1 is filled into the U-shaped welding strip and rolled into an O-shape. The powder feeding speed is adjusted according to the actual situation. Then, the surface of the welding strip is wiped clean with anhydrous ethanol, and the thick welding wire is gradually reduced to obtain a 1.20 mm welding wire. Finally, the impurities and oil on the surface of the welding wire are cleaned with anhydrous ethanol and the wire is coiled.

[0056] Step 3: Cut the welding wire obtained in step 2 to obtain a suitable length, perform 3D printing technology and cool it. The stacking current is 145A-155A, the arc voltage is 21V-23V, the welding speed is 0.18m / min-0.21m / min, the interlayer cooling temperature is 100℃-200℃, the welding process adopts 3D printing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 15L / min-20L / min; the welding method adopts multi-pass multi-layer cladding, and the required FeCoNiCrMo is obtained after the cladding is completed. 0.5 Al-NbC x High entropy alloy aero-engine casing, the cladding substrate is martensitic stainless steel;

[0057] Step 4: The 3D printed components are polished and modified by wire-cutting and CNC lathe to ensure their surface roughness and accuracy.

[0058] After the welding test, the engine casing was subjected to mechanical performance testing. The test results showed that the average hardness was 703.4HV 0.2 The wear amount is 9 mg, the average friction coefficient is 0.19, and the mechanical properties are in line with expectations. The experimental results show that the Fe-Co-Ni high entropy alloy aviation engine casing of the present invention has excellent comprehensive performance, and the performance is equal to or even better than that of forgings and castings, and is suitable for the preparation and modification of large aviation engine casings.

[0059] Example 3

[0060] Step 1, three-dimensional modeling of the 3D printed structural part is performed using Pro E modeling software; 16.73% iron powder, 17.58% nickel powder, 15.57% chromium powder, 17.65% cobalt powder, 8.1% Al powder, 14.37% molybdenum powder, and 10% NbC powder are weighed, and the sum of the mass percentages of the components above is 100%. The weighed alloy powders are mixed evenly and dried. The drying is carried out in a vacuum tube furnace, and 99.9% Ar gas is continuously introduced with an Ar gas flow rate of 2L / min to 3L / min. The drying temperature is 200°C to 250°C and the drying time is 2.2h to 2.5h.

[0061] Step 2: First, the Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine. Then, the dry mixed powder obtained in step 1 is filled into the U-shaped welding strip and rolled into an O-shape. The powder feeding speed is adjusted according to the actual situation. Then, the surface of the welding strip is wiped clean with anhydrous ethanol, and the thick welding wire is gradually reduced to obtain a 1.20 mm welding wire. Finally, the impurities and oil on the surface of the welding wire are cleaned with anhydrous ethanol and the wire is coiled.

[0062] Step 3: Cut the welding wire obtained in step 2 to obtain the appropriate length, perform 3D printing technology and cool it. The stacking current is 145A~155A, the arc voltage is 21V~23V, the welding speed is 0.18m / min~0.21m / min, and the interlayer cooling temperature is 100℃~200℃. The welding process adopts 3D printing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 15L / min~20L / min; the welding method adopts multi-pass multi-layer cladding. After the cladding is completed, the required FeCoNiCrMo 0.5 Al-NbC x High entropy alloy aero-engine casing, the cladding substrate is martensitic stainless steel;

[0063] Step 4: The 3D printed components are polished and modified by wire-cutting and CNC lathe to ensure their surface roughness and accuracy.

[0064] After the welding test, the engine casing was subjected to a mechanical performance test. The test results showed that the average hardness was 688.2HV 0.2 The wear loss is 14 mg, the average friction coefficient is 0.33, and the mechanical properties are in line with expectations. The experimental results show that the Fe-Co-Ni high entropy alloy aero-engine casing of the present invention has excellent comprehensive performance, and its performance is comparable to or even better than that of forgings and castings, and is suitable for the preparation and modification of large aero-engine casings;

[0065] Example 4

[0066] Step 1, three-dimensional modeling of the 3D printed structural parts is performed using Pro E modeling software, and 16.36% iron powder, 17.19% nickel powder, 15.23% chromium powder, 17.26% cobalt powder, 7.91% Al powder, 14.05% molybdenum powder, and 12% NbC powder are weighed. The sum of the mass percentages of the above components is 100%. The weighed alloy powders are mixed evenly and dried. The drying is carried out in a vacuum tube furnace, and 99.9% Ar gas is continuously introduced with an Ar gas flow rate of 2L / min to 3L / min. The drying temperature is 200°C to 250°C and the drying time is 2.2h to 2.5h.

[0067] Step 2: First, the Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine, and then the dry mixed powder obtained in step 1 is filled into the U-shaped welding strip and rolled into an O-shape. The powder feeding speed is adjusted according to the actual situation; then, the surface of the welding strip is wiped clean with anhydrous ethanol, and the thick welding wire is gradually reduced to obtain a 1.20 mm welding wire; finally, the impurities and oil on the surface of the welding wire are removed with anhydrous ethanol and the wire is coiled.

[0068] Step 3: Cut the welding wire obtained in step 2 to obtain a suitable length, perform 3D printing technology and cool it. The stacking current is 145A-155A, the arc voltage is 21V-23V, the welding speed is 0.18m / min-0.21m / min, the interlayer cooling temperature is 100℃-200℃, the welding process adopts 3D printing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 15L / min-20L / min; the welding method adopts multi-pass multi-layer cladding, and the required FeCoNiCrMo is obtained after the cladding is completed. 0.5 Al-NbC x High entropy alloy aero-engine casing, the cladding substrate is martensitic stainless steel;

[0069] Step 4: The 3D printed components are polished and modified by wire-cutting and CNC lathe to ensure their surface roughness and accuracy.

[0070] After the welding test, the engine casing was subjected to a mechanical performance test; the test results showed that the average hardness was 690.1HV 0.2 The wear amount is 12 mg, the average friction coefficient is 0.38, and the mechanical properties are in line with expectations. The experimental results show that the Fe-Co-Ni high entropy alloy aviation engine casing of the present invention has excellent comprehensive performance, and the performance is equal to or even better than that of forgings and castings, and is suitable for the preparation and modification of large aviation engine casings.

[0071] Example 5

[0072] Step 1: Use Pro E modeling software to perform three-dimensional modeling of the 3D printed structural parts. Weigh 15.80% iron powder, 16.60% nickel powder, 14.71% chromium powder, 6.67% cobalt powder, 7.64% Al powder, 13.58% molybdenum powder, and 15% NbC powder. The sum of the mass percentages of the above components is 100%. The weighed alloy powders are mixed evenly and dried. The drying is carried out in a vacuum tube furnace. 99.9% Ar gas is continuously introduced at an Ar gas flow rate of 2L / min to 3L / min. The drying temperature is 200℃ to 250℃ and the drying time is 2.2h to 2.5h.

[0073] Step 2: First, the Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine. Then, the dry mixed powder obtained in step 1 is filled into the U-shaped welding strip and rolled into an O-shape. The powder feeding speed is adjusted according to the actual situation. Then, the surface of the welding strip is wiped clean with anhydrous ethanol, and the thick welding wire is gradually reduced to obtain a 1.47 mm welding wire. Finally, the impurities and oil on the surface of the welding wire are cleaned with anhydrous ethanol and the wire is coiled.

[0074] Step 3: Cut the welding wire obtained in step 2 to obtain a suitable length, perform 3D printing technology and cool it. The stacking current is 145A-155A, the arc voltage is 21V-23V, the welding speed is 0.18m / min-0.21m / min, and the interlayer cooling temperature is 100℃-200℃. The welding process adopts 3D printing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 15L / min-20L / min. The welding method adopts multi-pass multi-layer cladding. After the cladding is completed, the required FeCoNiCrMo 0.5 Al-NbC x High entropy alloy aero-engine casing, the cladding substrate is martensitic stainless steel;

[0075] Step 4: The 3D printed components are polished and modified by wire-cutting and CNC lathe to ensure their surface roughness and accuracy.

[0076] After the welding test, the engine casing was subjected to mechanical performance testing. The test results showed that the average hardness was 721.2HV 0.2 The wear amount is 4 mg, the average friction coefficient is 0.18, and the mechanical properties are in line with expectations. The experimental results show that the Fe-Co-Ni high entropy alloy aviation engine casing of the present invention has excellent comprehensive performance, and the performance is equal to or even better than that of forgings and castings, and is suitable for the preparation and modification of large aviation engine casings.

Claims

1. A method for preparing an aircraft engine casing, characterized in that: Please follow the steps below to implement: Step 1: A flux-cored welding wire for manufacturing an aircraft engine casing includes an alloy sheath and flux-cored powder, with a powder coating rate of 28wt.%-35wt.%. A 3D-printed structural component is three-dimensionally modeled using Pro E modeling software. The flux-cored powder is then weighed according to mass percentage: iron powder 15.8%-18.03%, nickel powder 16.6%-18.95%, chromium powder 14.71%-16.79%, cobalt powder 16.67%-19.02%, aluminum powder 7.64%-8.7%, molybdenum powder 13.58%-15.50%, and NbC 3%-15%, where the sum of the mass percentages of the above components is 100%. Step 2: The Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine, and the mixed powder obtained in step 1 is then filled into the U-shaped welding strip and rolled into an O-shape; the surface of the welding strip is then wiped clean with anhydrous ethanol, and the diameter of the thick welding wire is gradually reduced; finally, anhydrous ethanol is used to remove impurities and oil stains on the surface of the welding wire and the wire is coiled; Step 3: Cut the welding wire obtained in step 2 to obtain the appropriate length, perform 3D printing surfacing and cooling, and obtain the required FeCoNiCrMo after surfacing. 0.5 Al-NbC x High entropy alloy engine casing, the cladding substrate is martensitic stainless steel; The stacking current is 145A~155A, the arc voltage is 21V~23V, the welding speed is 0.18m / min~0.21m / min, and the interlayer cooling temperature is 100℃~200℃; Step 4: The component obtained by 3D printing in step 3 is polished and modified by wire electric discharge cutting and CNC lathe to ensure its surface roughness and accuracy.

2. The method for preparing an aircraft engine casing according to claim 1, wherein: In step 1, the weighed alloy powder is mixed evenly and dried. 99.9% pure Ar gas is introduced throughout the drying process, with an Ar gas flow rate of 2 L / min to 3 L / min, a drying temperature of 200° C. to 250° C., and a drying time of 2.2 h to 2.5 h.

3. The method for preparing an aircraft engine casing according to claim 1, wherein: In step 2, the thick welding wire is gradually reduced in diameter to obtain a 1.20 mm welding wire.

4. The method for preparing an aircraft engine casing according to claim 1, wherein: The welding process in step 3 adopts 3D printing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 15 L / min~20 L / min.

5. The method for preparing an aircraft engine casing according to claim 1, wherein: The welding method in step 3 adopts multi-layer multi-pass welding.

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