A method for preparing beryllium-aluminum composite material by electric arc additive manufacturing

Abstract

The application relates to a method for preparing a beryllium-aluminum composite material by adopting electric arc additive manufacturing, and relates to a method for preparing a beryllium-aluminum composite material. In order to solve the problem that solidification cracks are caused by the difference between the thermal physical properties of two phases in the electric arc additive manufacturing process of the beryllium-aluminum composite material. In the process of preparing the beryllium-aluminum composite material by layer-by-layer deposition of the electric arc additive manufacturing, the environmental temperature of the beryllium-aluminum composite material is controlled, and the beryllium-aluminum composite material is controlled to be cooled between adjacent layer deposition, the thermal gradient and the cooling rate in the solidification and cooling process are reduced, the instantaneous stress peak value caused by the rapid shrinkage and the uneven thermal strain is reduced, the crack driving force is reduced, and the problem that the thermal physical properties of the beryllium and aluminum two phases are greatly different is overcome. The preparation period of the method is short, the forming efficiency is high, the cost is low, and the method can meet the manufacturing of large metal components. The near-net forming of the beryllium-aluminum composite material component can also be realized, and the material utilization rate is greatly improved.

Description

Technical Field

[0001] This invention relates to a method for preparing beryllium-aluminum composite materials. Background Technology

[0002] Beryllium-aluminum composites possess properties such as lightweight, high stiffness, and high thermal stability, making them an indispensable key material supporting high-end applications in next-generation electronics, information technology, and national defense. However, due to the scarcity and unique characteristics of beryllium resources, the cost of beryllium-aluminum composites is extremely high. Current traditional casting and powder metallurgy preparation technologies for beryllium-aluminum composites require complex molds and struggle to achieve near-net-shape forming. Component processing relies heavily on subtractive manufacturing processes, especially for the fabrication of complex thin-walled beryllium-aluminum parts, resulting in extremely low material utilization and significant waste of beryllium resources, further increasing costs.

[0003] In contrast, arc additive manufacturing technology can effectively reduce material waste in traditional subtractive manufacturing processes, enabling the customization of high-end parts without the need for molds. Furthermore, it boasts shorter delivery cycles, less machining, and higher material utilization, reducing costs by minimizing beryllium resource consumption. This fundamentally solves the problem of rare beryllium resource depletion.

[0004] However, for beryllium-aluminum composites with a beryllium volume fraction exceeding 50%, the arc additive manufacturing process presents significant challenges compared to conventional aluminum alloys. The key issue lies in the substantial difference in melting points (above 600°C) between the beryllium and aluminum phases, as well as their nearly doubled coefficients of thermal expansion. During solidification, beryllium solidifies first, forming a solid dendritic framework, while aluminum solidifies later. Constrained by the already formed beryllium framework, the later-solidified liquid aluminum experiences strong resistance to shrinkage. Due to the large solidification range, the prolonged presence of the pasty region, and the significant difference in thermal expansion coefficients, this resistance to shrinkage leads to significant tensile stress concentration at the two-phase interface. This stress concentration, especially towards the end of solidification and during subsequent cooling, results in solidification cracks. Summary of the Invention

[0005] To address the problem of solidification cracking caused by the difference in thermophysical properties between the two phases in beryllium-aluminum composite materials during arc additive manufacturing, this invention proposes a method for preparing beryllium-aluminum composite materials using arc additive manufacturing.

[0006] The present invention uses an electric arc additive manufacturing method to prepare beryllium aluminum composite materials, which is carried out according to the following steps:

[0007] 1. Select beryllium-aluminum composite welding wire and perform surface deoxidation and cleaning;

[0008] The beryllium-aluminum composite welding wire is composed of an aluminum matrix and beryllium particle reinforcement.

[0009] The volume fraction of beryllium particle reinforcement in the beryllium-aluminum composite welding wire is 30%-70%.

[0010] 2. Before deposition, the substrate is cleaned, then the substrate is preheated, and heaters are arranged around the substrate.

[0011] The method for cleaning the substrate is as follows: first, remove oxides and oil stains from the substrate surface, and then clean the substrate surface with anhydrous ethanol or acetone.

[0012] 3. Beryllium aluminum composite material is prepared by layer-by-layer deposition using arc additive manufacturing in an inert gas atmosphere. During the deposition process, the beryllium aluminum composite material is controlled to be in an environment of 200-300℃ using a heater. After each layer is deposited, the beryllium aluminum composite material is cooled to 300-350℃ before the next layer is deposited.

[0013] The process parameters for the arc additive manufacturing are as follows: voltage: 15-20V; current: 150-250A; wire extension: 6-12mm; wire feed speed: 6-10m / min; welding torch moving speed: 5-10mm / s.

[0014] The present invention has the following beneficial effects:

[0015] 1. This invention controls the ambient temperature of the beryllium-aluminum composite material during layer-by-layer deposition in arc additive manufacturing and controls the cooling of the beryllium-aluminum composite material between adjacent deposition layers. This reduces the thermal gradient and cooling rate during solidification and cooling, decreases the instantaneous stress peak caused by rapid shrinkage and uneven thermal strain, and reduces the crack driving force, overcoming the problem of large differences in the thermophysical properties of the beryllium-aluminum two phases. Simultaneously, the plastic deformation capacity of aluminum is greatly enhanced above 200℃. Even when constrained by the beryllium skeleton and subjected to stress, the aluminum phase can coordinate deformation and release stress through local plastic rheology, thereby inhibiting crack initiation and propagation. The difference in total aluminum shrinkage is also significantly reduced, directly decreasing the thermal mismatch stress at the interface, thus achieving crack-free preparation of arc additive beryllium-aluminum composite materials.

[0016] 2. Compared with the traditional beryllium-aluminum composite material preparation process, the method of the present invention can prepare complex beryllium-aluminum composite material components without molds, and the preparation cycle is short.

[0017] 3. If laser additive manufacturing is used, the high reflectivity of aluminum to lasers results in low energy absorption. However, this invention uses arc additive manufacturing, where the aluminum substrate has high energy absorption, achieving a melting efficiency of 3-6 kg / h for a single wire, resulting in high forming efficiency and low cost. Furthermore, it eliminates the need for a large vacuum chamber, enabling the manufacture of large metal components.

[0018] 4. This invention can achieve near-net-shape forming of beryllium aluminum composite components, greatly improving material utilization and significantly reducing the price of beryllium aluminum components.

[0019] 5. This invention utilizes the rapid solidification characteristics of additive manufacturing to refine the grain structure of beryllium aluminum composite materials and simultaneously improve their strength and plasticity. Attached Figure Description

[0020] Figure 1 This is a scanning microstructure of the beryllium aluminum composite material prepared by additive manufacturing in Example 1. Detailed Implementation

[0021] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any reasonable combination of the specific embodiments.

[0022] Specific Implementation Method 1: This implementation method for preparing beryllium-aluminum composite materials using arc additive manufacturing is carried out according to the following steps:

[0023] 1. Select beryllium-aluminum composite welding wire and perform surface deoxidation and cleaning;

[0024] The beryllium-aluminum composite welding wire is composed of an aluminum matrix and beryllium particle reinforcement.

[0025] The volume fraction of beryllium particle reinforcement in the beryllium-aluminum composite welding wire is 30%-70%.

[0026] 2. Before deposition, the substrate is cleaned, then the substrate is preheated, and heaters are arranged around the substrate.

[0027] The method for cleaning the substrate is as follows: first, remove oxides and oil stains from the substrate surface, and then clean the substrate surface with anhydrous ethanol or acetone.

[0028] 3. Beryllium aluminum composite material is prepared by layer-by-layer deposition using arc additive manufacturing in an inert gas atmosphere. During the deposition process, the beryllium aluminum composite material is controlled to be in an environment of 200-300℃ using a heater. After each layer is deposited, the beryllium aluminum composite material is cooled to 300-350℃ before the next layer is deposited.

[0029] The process parameters for the arc additive manufacturing are as follows: voltage: 15-20V; current: 150-250A; wire extension: 6-12mm; wire feed speed: 6-10m / min; welding torch moving speed: 5-10mm / s.

[0030] This embodiment has the following beneficial effects:

[0031] 1. This embodiment controls the ambient temperature of the beryllium-aluminum composite material during the layer-by-layer deposition process in arc additive manufacturing, and controls the cooling of the beryllium-aluminum composite material between adjacent layers. This reduces the thermal gradient and cooling rate during solidification and cooling, decreases the instantaneous stress peak caused by rapid shrinkage and uneven thermal strain, and reduces the crack driving force, overcoming the problem of large differences in the thermophysical properties of the beryllium-aluminum two phases. Simultaneously, the plastic deformation capacity of aluminum is greatly enhanced above 200℃. Even when constrained by the beryllium skeleton and subjected to stress, the aluminum phase can coordinate deformation and release stress through local plastic rheology, thereby inhibiting crack initiation and propagation. The difference in total aluminum shrinkage is also significantly reduced, directly decreasing the thermal mismatch stress at the interface, thus achieving crack-free preparation of arc additive beryllium-aluminum composite materials.

[0032] 2. Compared with the traditional beryllium-aluminum composite material preparation process, the method of this embodiment can prepare complex beryllium-aluminum composite material components without molds, and the preparation cycle is short.

[0033] 3. If laser additive manufacturing is used, the high reflectivity of aluminum to lasers results in low energy absorption. However, this embodiment uses arc additive manufacturing, where the aluminum substrate has high energy absorption, achieving a melting efficiency of 3-6 kg / h for a single filament, resulting in high forming efficiency and low cost. Furthermore, it eliminates the need for a large vacuum chamber, allowing for the manufacture of large metal components.

[0034] 4. This implementation method can achieve near-net-shape forming of beryllium aluminum composite components, which greatly improves material utilization and can significantly reduce the price of beryllium aluminum components.

[0035] 5. This embodiment utilizes the rapid solidification characteristics of additive manufacturing to refine the grain structure of beryllium aluminum composite materials and simultaneously improve their strength and plasticity.

[0036] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the cleaning in step one uses anhydrous ethanol.

[0037] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 or 2 in that the volume fraction of beryllium particle reinforcement in the beryllium aluminum composite welding wire described in step 1 is 50%.

[0038] Specific Implementation Method Four: This implementation method differs from one of the specific implementation methods one to three in that the volume fraction of beryllium particle reinforcement in the beryllium aluminum composite welding wire described in step one is 60%.

[0039] Specific Implementation Method 5: This implementation method differs from one of the specific implementation methods 1 to 4 in that the particle size of the beryllium particle reinforcement in the beryllium aluminum composite welding wire described in step 1 is 10μm-800μm.

[0040] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the composition of the aluminum matrix in Step One is: Mg 0.01-0.05wt%, Si 0.01-0.25%, Fe 0.01-0.4%, Mn 0.01-0.02%, Cu 0.01-0.04%, O 0.05-0.5%, with the balance being Al.

[0041] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the diameter of the beryllium aluminum composite welding wire in Step One is 1-1.6mm.

[0042] Specific Implementation Method Eight: This implementation method differs from one of the specific implementation methods one to seven in that the temperature for preheating the substrate in step two is 200-300℃.

[0043] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the inert gas atmosphere described in step three is argon or a mixture of argon and helium.

[0044] Specific Implementation Method 10: This implementation method differs from Specific Implementation Methods 1 to 9 in that the gas flow rate of the inert gas in step 3 is 15-25 L / min.

[0045] Example 1

[0046] This embodiment uses an electric arc additive manufacturing method to prepare beryllium-aluminum composite materials, which is carried out according to the following steps:

[0047] 1. Select beryllium-aluminum composite welding wire and perform surface deoxidation and cleaning;

[0048] The cleaning process uses anhydrous ethanol.

[0049] The beryllium-aluminum composite welding wire is composed of an aluminum matrix and beryllium particle reinforcement.

[0050] The volume fraction of beryllium particle reinforcement in the beryllium-aluminum composite welding wire is 40%.

[0051] The beryllium particle reinforcement in the beryllium-aluminum composite welding wire has a particle size of 40-100 μm;

[0052] The composition of the aluminum matrix is: 0.02% Mg, 0.1% Si, 0.3% Fe, 0.01% Mn, 0.02% Cu, 0.4% O, with the balance being Al;

[0053] The diameter of the beryllium-aluminum composite welding wire is 1.6 mm;

[0054] The preparation method of the beryllium aluminum composite welding wire is as follows:

[0055] Step (1): Preparation of beryllium / aluminum composite material

[0056] Beryllium / aluminum composites were prepared using a self-venting pressure infiltration method.

[0057] ① After the beryllium particle reinforcement and aluminum matrix are mixed evenly, they are loaded into a steel mold and pressed into a preform. The pressing pressure is 100kN and the holding time is 2min. Then the steel mold containing the preform is placed in a preheating furnace and preheated at 510℃ for 2h.

[0058] ② Melt the aluminum substrate at a temperature of 850℃ to obtain liquid aluminum, and then pour the liquid aluminum into the steel mold that was preheated in step ①;

[0059] ③ The pressure head is applied at 20MPa and moves downward at a speed of 5mm / min, and is held at 30MPa for 3min. Then it is cooled by circulating water to obtain beryllium / aluminum composite material.

[0060] Step (2): Preheating of beryllium / aluminum composite material and hot extrusion die

[0061] First, preheat the beryllium / aluminum composite material to 500℃, and then keep it at 500℃ for 1 hour; keep the hot extrusion die at 50℃ lower than the preheating temperature of the beryllium / aluminum composite material for 1 hour.

[0062] Step (3): Hot extrusion preparation of beryllium / aluminum composite rods

[0063] The preheated beryllium / aluminum composite material is loaded into a hot extrusion die and hot extruded using a press at a rate of 60 mm / min to obtain multiple beryllium / aluminum composite material rods in one go.

[0064] In the extrusion die, the extrusion nozzle is a multi-hole extrusion nozzle with a diameter of 5 mm and a number of 4 holes; the diameter of the preheated beryllium / aluminum composite material is 36 mm;

[0065] Step (4): Annealing treatment of beryllium / aluminum composite rods

[0066] The beryllium / aluminum composite rod obtained in step (3) is heated to 400°C and then kept at 400°C for 2 hours.

[0067] Step (5): Hot spinning forging to prepare beryllium / aluminum composite filaments

[0068] Beryllium / aluminum composite bars are subjected to multi-pass rotary forging using a rotary forging machine. The multi-pass rotary forging process is as follows: the rotary forging temperature is 300℃, the deformation per pass is 10%, the feed rate is 100mm / min, the rotary forging frequency is 50Hz, and annealing is performed after each pass of rotary forging at the same temperature as the rotary forging temperature for 20min.

[0069] 2. Before deposition, the substrate is cleaned, then the substrate is preheated, and heaters are arranged around the substrate.

[0070] The method for cleaning the substrate is as follows: first, remove oxides and oil stains from the substrate surface, and then clean the substrate surface with anhydrous ethanol.

[0071] The substrate is preheated at a temperature of 200°C.

[0072] 3. Beryllium aluminum composite material was prepared by layer-by-layer deposition using arc additive manufacturing in an inert gas atmosphere. During the deposition process, the beryllium aluminum composite material was kept at 200°C by a heater. After each layer was deposited, the beryllium aluminum composite material was cooled to 300°C before the next layer was deposited.

[0073] The process parameters for the arc additive manufacturing are: voltage: 16V; current: 220A; wire extension: 10mm; wire feed speed: 6m / min; welding torch moving speed: 8mm / s;

[0074] The inert gas atmosphere is argon, and the gas flow rate is 15 L / min;

[0075] Figure 1 The image shows the scanning microstructure of the beryllium-aluminum composite material prepared by additive manufacturing in Example 1. The beryllium-aluminum composite material prepared in Example 1 exhibits no obvious defects such as pores or cracks, displaying a dense metallurgical microstructure. It has a tensile strength of 405 MPa, a yield strength of 360 MPa, and an elongation of 4%, demonstrating good strength and toughness. In this example, the melting efficiency of a single wire can reach 3-6 kg / h, resulting in high forming efficiency.

[0076] Example 2

[0077] This embodiment uses an electric arc additive manufacturing method to prepare beryllium-aluminum composite materials, which is carried out according to the following steps:

[0078] 1. Select beryllium-aluminum composite welding wire and perform surface deoxidation and cleaning;

[0079] The cleaning process uses anhydrous ethanol.

[0080] The beryllium-aluminum composite welding wire is composed of an aluminum matrix and beryllium particle reinforcement.

[0081] The volume fraction of beryllium particle reinforcement in the beryllium-aluminum composite welding wire is 50%.

[0082] The beryllium particle reinforcement in the beryllium-aluminum composite welding wire has a particle size of 80-200 μm;

[0083] The composition of the aluminum matrix is: 0.01% Mg, 0.1% Si, 0.2% Fe, 0.01% Mn, 0.04% Cu, 0.5% O, with the balance being Al;

[0084] The diameter of the beryllium-aluminum composite welding wire is 1.6 mm;

[0085] 2. Before deposition, the substrate is cleaned, then the substrate is preheated, and heaters are arranged around the substrate.

[0086] The method for cleaning the substrate is as follows: first, remove oxides and oil stains from the substrate surface, and then clean the substrate surface with anhydrous ethanol.

[0087] The substrate is preheated at a temperature of 250°C.

[0088] III. Beryllium aluminum composite material was prepared by layer-by-layer deposition using arc additive manufacturing in an inert gas atmosphere. During the deposition process, the beryllium aluminum composite material was kept at 250°C by a heater. After each layer was deposited, the beryllium aluminum composite material was cooled to 320°C before the next layer was deposited.

[0089] The process parameters for the arc additive manufacturing are: voltage: 17V; current: 240A; wire extension: 10mm; wire feed speed: 8m / min; welding torch moving speed: 8mm / s;

[0090] The inert gas atmosphere is argon, and the gas flow rate is 15 L / min;

[0091] The beryllium-aluminum composite material prepared by additive manufacturing in Example 2 has a tensile strength of 480 MPa, a yield strength of 440 MPa, and an elongation of 3.2%, exhibiting good strength and toughness.

[0092] Example 3

[0093] This embodiment uses an electric arc additive manufacturing method to prepare beryllium-aluminum composite materials, which is carried out according to the following steps:

[0094] 1. Select beryllium-aluminum composite welding wire and perform surface deoxidation and cleaning;

[0095] The cleaning process uses anhydrous ethanol.

[0096] The beryllium-aluminum composite welding wire is composed of an aluminum matrix and beryllium particle reinforcement.

[0097] The volume fraction of beryllium particle reinforcement in the beryllium-aluminum composite welding wire is 60%.

[0098] The beryllium particle reinforcement in the beryllium-aluminum composite welding wire has a particle size of 100μm-300μm;

[0099] The composition of the aluminum matrix is ​​as follows: Mg 0.02%, Si 0.2%, Fe 0.1%, Mn 0.01%, Cu 0.04%, O 0.3%, with the balance being Al;

[0100] The diameter of the beryllium-aluminum composite welding wire is 1.2 mm;

[0101] 2. Before deposition, the substrate is cleaned, then the substrate is preheated, and heaters are arranged around the substrate.

[0102] The method for cleaning the substrate is as follows: first, remove oxides and oil stains from the substrate surface, and then clean the substrate surface with anhydrous ethanol.

[0103] The substrate is preheated at a temperature of 250°C.

[0104] III. Beryllium aluminum composite material was prepared by layer-by-layer deposition using arc additive manufacturing in an inert gas atmosphere. During the deposition process, the beryllium aluminum composite material was kept at 250°C by a heater. After each layer was deposited, the beryllium aluminum composite material was cooled to 320°C before the next layer was deposited.

[0105] The process parameters for the arc additive manufacturing are: voltage: 15V; current: 200A; wire extension: 10mm; wire feed speed: 10m / min; welding torch moving speed: 10mm / s;

[0106] The inert gas atmosphere is argon, and the gas flow rate is 15 L / min;

[0107] The beryllium-aluminum composite material prepared by additive manufacturing in Example 3 has a tensile strength of 440 MPa, a yield strength of 380 MPa, and an elongation of 3%, exhibiting good strength and toughness.

Claims

1. A method for preparing beryllium-aluminum composite materials using arc additive manufacturing, characterized in that: The method for preparing beryllium-aluminum composite materials using arc additive manufacturing is carried out according to the following steps:

1. Select beryllium-aluminum composite welding wire and perform surface deoxidation and cleaning; The beryllium-aluminum composite welding wire is composed of an aluminum matrix and beryllium particle reinforcement. The volume fraction of beryllium particle reinforcement in the beryllium-aluminum composite welding wire is 50%-70%.

2. Before deposition, the substrate is cleaned, then the substrate is preheated, and heaters are arranged around the substrate. The method for cleaning the substrate is as follows: first, remove oxides and oil stains from the substrate surface, and then clean the substrate surface with anhydrous ethanol or acetone.

3. Beryllium aluminum composite material is prepared by layer-by-layer deposition using arc additive manufacturing in an inert gas atmosphere. During the deposition process, the beryllium aluminum composite material is controlled to be in an environment of 200-300℃ using a heater. After each layer is deposited, the beryllium aluminum composite material is cooled to 300-350℃ before the next layer is deposited. The process parameters for the electric arc additive manufacturing are: voltage: 15-20V; Current: 150-250A; wire extension: 6-12mm; wire feed speed: 6-10m / min; welding torch moving speed: 5-10mm / s.

2. The method for preparing beryllium-aluminum composite materials using arc additive manufacturing according to claim 1, characterized in that: The cleaning process described in step one uses anhydrous ethanol.

3. The method for preparing beryllium-aluminum composite materials using arc additive manufacturing according to claim 1, characterized in that: The volume fraction of beryllium particle reinforcement in the beryllium aluminum composite welding wire described in step one is 60%.

4. The method for preparing beryllium-aluminum composite materials using arc additive manufacturing according to claim 1, characterized in that: The beryllium particle reinforcement in the beryllium-aluminum composite welding wire described in step one has a particle size of 10μm-800μm.

5. The method for preparing beryllium-aluminum composite materials using arc additive manufacturing according to claim 1, characterized in that: The composition of the aluminum matrix in step one is as follows: Mg 0.01-0.05wt%, Si 0.01-0.25%, Fe 0.01-0.4%, Mn 0.01-0.02%, Cu 0.01-0.04%, O 0.05-0.5%, with the balance being Al.

6. The method for preparing beryllium-aluminum composite materials using arc additive manufacturing according to claim 1, characterized in that: The diameter of the beryllium-aluminum composite welding wire mentioned in step one is 1-1.6 mm.

7. The method for preparing beryllium-aluminum composite materials using arc additive manufacturing according to claim 1, characterized in that: The substrate preheating temperature in step two is 200-300℃.

8. The method for preparing beryllium-aluminum composite materials using arc additive manufacturing according to claim 1, characterized in that: The inert gas atmosphere described in step three is argon or a mixture of argon and helium.

9. The method for preparing beryllium-aluminum composite materials using arc additive manufacturing according to claim 1, characterized in that: Step 3: The inert gas flow rate is 15-25 L / min.

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