A method of integrally forming a ceramic-aluminum alloy composite fan containment case

Abstract

The application discloses a kind of whole forming methods of ceramic-aluminum alloy composite fan containment case, comprising the following steps: using electric arc additive or casting process to manufacture powder metallurgy mould;The surface roughness and microstructure of ceramic block are optimized by femtosecond laser processing, and the wettability is improved;The ceramic layout is planned by finite element simulation, and the treated ceramic block is placed in the mould;Aluminum alloy powder is filled layer by layer and is densified by pressure;Vacuum sintering is carried out to realize high-strength combination of metal powder and ceramic;Finally, machining and solid solution aging obtain excellent performance composite fan containment case.This method combines femtosecond laser micro-carving and powder metallurgy technology, effectively solves the problem of ceramic-metal composite structure in densification, bonding strength and shape control, significantly improves the stability, lightweight and functionality of fan containment case, meets the high performance demand of modern aero-engine.

Description

Technical Field

[0001] This invention relates to an integral molding method for a ceramic-aluminum alloy composite fan housing, belonging to the field of aerospace manufacturing. Background Technology

[0002] The fan containment casing is a core safety component of an aero-engine. Its main function is to effectively contain high-speed, flying debris in the event of fan blade breakage or detachment, preventing damage to the engine and other critical components. Given the enormous centrifugal force generated by the high-speed rotation of modern aero-engine fan blades, failure of the fan containment casing can lead to serious consequences. Therefore, this component must possess high strength, excellent impact resistance, and lightweight characteristics.

[0003] To meet these requirements, traditional fan housings are typically made of metallic materials such as high-strength steel, titanium alloys, or aluminum alloys. However, with the increasing demands for lightweight design and high thrust-to-weight ratio in aero engines, the limitations of single-metal materials have become increasingly apparent. Although metals possess excellent toughness and ductility, their relatively high density restricts their application in the aerospace field. Metal-ceramic composite materials cleverly combine the high hardness of ceramics with the toughness of metals, significantly improving the impact resistance of the housing and effectively reducing overall weight, perfectly meeting the performance requirements of modern aero engines.

[0004] Against this backdrop, femtosecond laser technology has played a crucial role in the preparation of ceramic-metal composites. Traditional manufacturing techniques, such as casting and welding, while achieving some degree of bonding between ceramics and metals, typically suffer from significant drawbacks. Casting struggles to address stress concentration issues arising from the difference in thermal expansion coefficients between ceramics and metals, leading to insufficient interfacial bonding strength and making the material prone to delamination or cracking. Welding, on the other hand, is susceptible to thermal damage or structural degradation of the ceramic due to high-temperature processing, and the interfacial bonding zone often contains microcracks or porosity, thus reducing the overall performance of the composite material. Furthermore, these traditional processes typically consume large amounts of energy, have low manufacturing precision, and low material utilization, making it difficult to meet the demands of modern aerospace industries for lightweight, high-performance materials.

[0005] Femtosecond laser technology, with its ultrashort pulses and high power density, can form micro- and nano-structures on ceramic surfaces, thereby significantly enhancing the bonding force between metals and ceramics. By engraving microgrooves or micropores on ceramic surfaces using femtosecond lasers, not only is the insufficient interfacial bonding strength in traditional processes effectively overcome, but the overall structural strength and density are also improved, expanding the application potential of composite materials in extreme environments.

[0006] At the same time, powder metallurgy technology has significant advantages over traditional casting or welding processes in terms of material utilization, structural precision and manufacturing efficiency. However, single powder metallurgy processes may still face shortcomings such as uneven interface bonding and high porosity. Summary of the Invention

[0007] The purpose of this invention is to provide an integral molding method for a ceramic-aluminum alloy composite fan housing.

[0008] To address the problems of poor bonding ability, large difference in thermal expansion coefficients, and limited manufacturing shape of traditional ceramic-metal composite fan housings, a method for integral molding of ceramic-aluminum alloy composite fan housings based on femtosecond laser modification of ceramic surfaces and powder metallurgy is provided.

[0009] This invention combines powder metallurgy and femtosecond laser technology, providing a more efficient and precise solution for the manufacturing of fan housings, and significantly improving the uniformity of interface bonding and structural performance.

[0010] The ceramic-metal composite material prepared using femtosecond laser and powder metallurgy technologies has significant advantages in impact resistance, wear resistance, and lightweighting, especially in applications involving repeated impacts or extreme environments. This integrated fan housing manufacturing solution not only overcomes the interface bonding and density defects of existing technologies but also improves manufacturing efficiency, optimizes material utilization and energy consumption, and ultimately significantly enhances the overall efficiency of the engine.

[0011] The technical solution to achieve the purpose of this invention is as follows:

[0012] A method for integral molding of a ceramic-aluminum alloy composite fan housing.

[0013] The above method includes the following steps:

[0014] Step 1: Fabricate a powder metallurgy mold for the cylindrical / funnel-shaped structure of the fan housing.

[0015] Step 2: Improve the wettability of the ceramic block surface by femtosecond laser treatment;

[0016] Step 3: Simulate powder spreading and ceramic block placement for the powder metallurgy pressed body according to the size of the ceramic block. Perform finite element simulation of heating the pressed body to simulate the deformation of the pressed body during the heating process. Design a suitable powder spreading amount and ceramic block spacing based on the deformation data.

[0017] Step 4: Based on the simulation results, lay aluminum alloy powder at the bottom of the mold, and evenly place the ceramic block obtained in Step 2 into the mold according to the simulation data. Inject aluminum alloy powder into the mold and continuously apply pressure to densify it.

[0018] Step 5: Repeat step 4, adding ceramic blocks and powder layer by layer while continuously applying pressure, so that the ceramic layers are staggered until the design height of the fan housing is reached.

[0019] Step 6: Demold and vacuum sinter the composite structure to ensure a tight bond between the metal powder and the ceramic block;

[0020] Step 7: Thin the sintered body and perform subsequent processing according to installation requirements.

[0021] Furthermore, in step 1, the powder metallurgy mold is a simple cylindrical or funnel-shaped mold determined by the actual needs of the fan housing shape and size, with a certain machining allowance reserved, and the inner wall surface of the mold is smooth to facilitate demolding.

[0022] Furthermore, in step 2, the femtosecond laser processing path is either linear or cross-shaped, creating serrated or island-shaped morphologies on each surface of the ceramic pillar to improve surface wettability. The femtosecond laser micro-engraving scanning rate is 40–200 mm / s, the power is 15–30 W, the scanning spacing is 30–100 μm, and the number of scans is 1–3. The ceramic material used is SiC, Al2O3, B4C, etc., and the shape is blocky, spherical, columnar, or conical.

[0023] Furthermore, in step 3, the finite element simulation software can be ANSYS, COMSOL Multiphysics, ABAQUS, MSC Marc, etc.

[0024] Furthermore, in step 4, the powder particle size used is 5000-20000 mesh, the applied pressure is 120-150 MPa, and the pressurization time is 2 hours.

[0025] Furthermore, in step 5, the operation of step 4 is repeated, adding ceramic blocks and powder layer by layer and continuously applying pressure so that the ceramic layers are arranged in an alternating pattern until the design height of the fan housing is reached.

[0026] Furthermore, in step 6, the vacuum degree during sintering is 10. -3 The sintering temperature is 550-610℃ and the sintering time is 1-3 hours.

[0027] Furthermore, in step 7, the sintered body undergoes finishing processes, including thinning, hole machining, and surface treatment. The heating casing is held at 460–480°C for 24 hours, followed by oil quenching, and then heated to 120–160°C and held for 6–10 hours to improve the material's hardness and strength, ensuring that the fan housing casing meets actual service requirements.

[0028] This invention provides a method for preparing ceramic-metal composite structures as described above.

[0029] Compared with the prior art, the present invention has the following significant advantages: (1) economical and efficient, with a solid connection and excellent protection capability; (2) reliable strength, excellent fatigue resistance and long-term stability; (3) extended lifespan and improved efficiency; (4) lightweight design, improved mobility and reduced energy consumption. Attached Figure Description

[0030] Figure 1 A schematic diagram of the integral molding process for the housing of a ceramic-aluminum alloy composite fan.

[0031] Figure 2 Schematic diagram of ceramic femtosecond laser micro-engraving surface structure. (a) Linear path; (b) Cross-shaped path.

[0032] Figure 3 A cross-sectional schematic diagram of the ceramic-aluminum alloy composite fan housing.

[0033] Figure 4 This is a schematic diagram showing the staggered arrangement of ceramic blocks between different layers on the circumferential surface of the casing. Detailed Implementation

[0034] Combination Figure 2 , Figure 3 , Figure 4 A method for integrally molding a ceramic-aluminum alloy composite fan housing, the method comprising the following steps:

[0035] Step 1: Fabricate a powder metallurgy mold for the cylindrical / funnel-shaped structure of the fan housing.

[0036] Step 2: Use a femtosecond laser to process the cleaned ceramic block surface, engraving patterns such as... Figure 2 The island-shaped or sawtooth-shaped morphology;

[0037] Step 3: Simulate powder spreading and ceramic block placement for the powder metallurgy pressed body according to the size of the ceramic block. Perform finite element simulation of heating the pressed body to simulate the deformation of the pressed body during the heating process. Design a suitable powder spreading amount and ceramic block spacing based on the deformation data.

[0038] Step 4: Based on the simulation results, lay aluminum alloy powder at the bottom of the mold, and evenly place the ceramic block obtained in Step 2 into the mold according to the simulation data. Inject aluminum alloy powder into the mold and continuously apply pressure to densify it.

[0039] Step 5: Repeat step 4, adding ceramic blocks and powder layer by layer while continuously applying pressure to create a bond between the ceramic layers. Figure 4 The staggered arrangement shown continues until the fan-enclosed casing is designed to be the highest possible height.

[0040] Step 6: Demold and vacuum sinter the composite structure to ensure a tight bond between the metal powder and the ceramic block, resulting in the desired product. Figure 3 The ceramic-aluminum alloy composite sintered body shown;

[0041] Step 7: Thin the sintered body and perform subsequent processing according to installation requirements.

[0042] The above describes the specific selection of process parameters and conditions for the method of the present invention:

[0043] Step 1: The powder metallurgy mold is a simple cylindrical or funnel-shaped mold determined by the actual needs of the fan housing shape and size. A certain machining allowance is reserved, and the inner wall surface of the mold is smooth for easy demolding.

[0044] Step 2: Improve the wettability of the ceramic block surface by femtosecond laser treatment. The processing path of the femtosecond laser is a straight line or a cross shape. The micro-engraving scanning rate is 40-200 mm / s, the power is 15-30 W, the scanning spacing is 30-100 μm, and the number of scans is 1-3. The surface morphology of each ceramic column is serrated or island-shaped. The ceramic material is SiC, Al2O3, B4C, etc., and the shape is block, spherical, columnar or conical.

[0045] Step 3: Simulate powder spreading and ceramic block placement for the powder metallurgy pressed body according to the ceramic block size. Perform finite element simulation of heating the pressed body to simulate the deformation of the pressed body during the heating process. Design appropriate powder spreading amount and ceramic block spacing based on deformation data. Finite element simulation software used includes ANSYS, COMSOL Multiphysics, ABAQUS, MSC Marc, etc.

[0046] Step 4: Based on the simulation results, lay aluminum alloy powder at the bottom of the mold, and evenly place the ceramic block obtained in Step 2 into the mold according to the simulation data. Inject aluminum alloy powder into the mold and continuously pressurize it to make it dense. The powder particle size is 5000-20000 mesh, the applied pressure is 120-150MPa, and the pressurization time is 2 hours.

[0047] Step 5: Repeat step 4, adding ceramic blocks and powder layer by layer while continuously applying pressure, so that the ceramic layers are staggered until the design height of the fan housing is reached.

[0048] Step Six: Demolding and vacuum sintering the composite structure to ensure a tight bond between the metal powder and the ceramic block. The vacuum level during sintering is 10. -3 Pa or above, sintering temperature 550-610℃, sintering time 1-3 hours;

[0049] Step 7: Perform finishing on the sintered body, including thinning, hole machining, and surface treatment. Heat the casing and hold it at 460–480°C for 24 hours, then perform oil quenching, and reheat to 120–160°C and hold for 6–10 hours to improve the hardness and strength of the material, ensuring that the fan housing casing meets the actual service requirements.

[0050] The invention will be further described below with reference to examples:

[0051] Example 1

[0052] Taking a simple fan housing casing with a diameter of 600mm, a height of 290mm, and a wall thickness of 5mm at its thinnest point, manufactured using 7A52 aluminum alloy powder and SiC ceramic cylinders with dimensions of Ф30mm×3mm as an example:

[0053] 1. Make a simple cylindrical mold for the fan housing casing with a diameter of 600mm, a height of 300mm, and a wall thickness of 10mm, and ensure that the inner wall surface of the mold is smooth.

[0054] 2. Femtosecond laser micro-engraving was performed on the surface of a columnar ceramic block. Three sets of variables were set, all using a cross-shaped path, scanning once, with a laser frequency of 1000kHz. Specific parameter settings are as follows: Variable group 1: scanning speed 100mm / s, laser power 20W, 22W, 24W, 26W, scanning interval 50μm; Variable group 2: scanning speed 100mm / s, laser power 22W, scanning interval 30μm, 50μm, 70μm, 90μm; Variable group 3: scanning speed 50mm / s, 100mm / s, 150mm / s, 200mm / s, laser power 22W, scanning interval 50μm. The processing results are as follows: surface roughness Sa for variable group 1 are 3.37 μm, 4.82 μm, 5.52 μm, and 6.61 μm; for variable group 2, the surface roughness Sa are 3.21 μm, 4.82 μm, 4.52 μm, and 3.90 μm; and for variable group 3, the surface roughness Sa are 6.57 μm, 4.82 μm, 3.23 μm, and 2.29 μm. Based on the above data, the process parameters of 100 mm / s scanning speed, 20 W laser power, and 50 μm scanning spacing yield the best results.

[0055] 3. Based on the dimensions of the ceramic blocks, the powder metallurgy pressing process was simulated, including powder spreading and placement. The deformation of the pressed body during the heating process was simulated using the finite element simulation software ANSYS. The powder layer thickness was set to 1 mm, and the following parameters were used: thermal conductivity: SiC 58.6 W / (m·K), 7A52 132 W / (m·K); elastic modulus: SiC 426 GPa, 7A52 68 GPa; Poisson's ratio: SiC 0.27, 7A52 0.33; coefficient of thermal expansion: SiC 4.4 × 10⁻⁶. -6 / ℃, 7A52 is taken as 24×10 -6 At a temperature of 837K, with a grid width of 2mm and no load applied to either end of the part, frictionless supports were used. When the ceramic block spacing was 10mm, the maximum thermal stress at the ceramic edge was 58MPa. When the ceramic block spacing was reduced to 4mm, the maximum thermal stress increased to 63MPa. Considering both thermal stress and the overall protective effect on the workpiece, a ceramic block spacing of 4mm was subsequently chosen.

[0056] 4. Based on the simulation results, lay aluminum alloy powder at the bottom of the mold, and put the ceramic block obtained in step 2 into the mold evenly according to the simulation data. Inject 10,000-mesh aluminum alloy powder into the mold, apply pressure of 150 MPa, and continue to apply pressure for 2 hours.

[0057] 5. Repeat step 4, adding ceramic blocks and powder layer by layer while continuously applying pressure, so that the ceramic layers are staggered until the design height of the fan housing is reached.

[0058] 6. Demold the composite structure and place it in a vacuum sintering furnace for vacuum sintering to ensure a tight bond between the metal powder and the ceramic block. The vacuum level during sintering is 10. -3 After sintering, the sample was cooled in the furnace to room temperature and then removed from the vacuum chamber. Electrical discharge machining (EDM) measurements showed that when the sintering time was 3 hours and the sintering temperature increased from 580°C to 600°C, the joint shear strength linearly increased from 18.1 MPa to 24.4 MPa. As the sintering temperature continued to rise, the joint strength began to decrease. When the sintering temperature was 600°C and the sintering time increased from 1 hour to 3 hours, the joint shear strength linearly increased from 16.0 MPa to 24.4 MPa. Finally, the optimal joint shear strength was achieved using a liquid-solid composite process with one scan, a repetition frequency of 1000 kHz, a femtosecond laser power of 22 W, a scanning speed of 100 mm / s, a processing spacing of 50 μm, a sintering time of 3 hours, and a sintering temperature of 600°C.

[0059] 7. Thin the sintered body, heat the casing, hold it at 460-480℃ for 24 hours, then quench it in oil, heat it to 150℃ and hold it for 8 hours, and after cooling, obtain the fan housing casing that meets the requirements.

Claims

1. A method for integrally molding a ceramic-aluminum alloy composite fan housing, characterized in that, The method includes the following steps: Step 1: Fabricate a powder metallurgy mold for the cylindrical / funnel-shaped structure of the fan housing. Step 2: Improve the wettability of the ceramic block surface by femtosecond laser treatment; Step 3: Simulate powder spreading and ceramic block placement for the powder metallurgy pressed body according to the size of the ceramic block. Perform finite element simulation of heating the pressed body to simulate the deformation of the pressed body during the heating process. Design a suitable powder spreading amount and ceramic block spacing based on the deformation data. Step 4: Based on the simulation results, lay aluminum alloy powder at the bottom of the mold, and evenly place the ceramic block obtained in Step 2 into the mold according to the simulation data. Inject aluminum alloy powder into the mold and continuously apply pressure to densify it. Step 5: Repeat step 4, adding ceramic blocks and powder layer by layer while continuously applying pressure, so that the ceramic layers are staggered until the design height of the fan housing is reached. Step 6: Demold and vacuum sinter the composite structure to ensure a tight bond between the metal powder and the ceramic block; Step 7: Thin the sintered body and perform subsequent processing according to installation requirements.

2. The integral molding method for a ceramic-aluminum alloy composite fan housing according to claim 1, characterized in that, In step 1, the powder metallurgy mold is a simple cylindrical or funnel-shaped mold determined according to the actual needs of the fan housing shape and size, with a certain machining allowance reserved, and the inner wall surface of the mold is smooth to facilitate demolding.

3. The integral molding method for a ceramic-aluminum alloy composite fan housing according to claim 1, characterized in that, In step 2, the femtosecond laser processing path is a straight line or a cross shape, and sawtooth or island-shaped morphology is processed on each surface of the ceramic column to improve the wettability of the ceramic surface; the femtosecond laser micro-engraving scanning rate is 40-200mm / s, the power is 15-30W, the scanning interval is 30-100μm, and the number of scans is 1-3; the ceramic material is SiC, Al2O3 or B4C, and the shape is block, spherical, columnar or conical.

4. The integral molding method for a ceramic-aluminum alloy composite fan housing according to claim 1, characterized in that, In step 3, the finite element simulation software used is ANSYS, COMSOL Multiphysics, ABAQUS, or MSC Marc.

5. The integral molding method for a ceramic-aluminum alloy composite fan housing according to claim 1, characterized in that, In step 4, the powder used has a particle size of 5000-20000 mesh, the applied pressure is 120-150 MPa, and the pressurization time is 2 hours.

6. The integral molding method for a ceramic-aluminum alloy composite fan housing according to claim 1, characterized in that, In step 6, the vacuum degree during sintering is 10. -3 The sintering temperature is 550-610℃ and the sintering time is 1-3 hours.

7. The integral molding method for a ceramic-aluminum alloy composite fan housing according to claim 1, characterized in that, In step 7, the sintered body is machined by turning, including thinning of the outer shape, machining of holes and surface treatment; finally, solution aging treatment is performed, which requires heating the casing and holding it at a temperature range of 460-480℃ for 24 hours, followed by oil quenching, and then heating to 120-160℃ and holding for 6-10 hours to improve the hardness and strength of the material and ensure that the fan housing casing meets the actual service requirements.

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