A method for preparing a beryllium / aluminum composite filament

Abstract

A method for preparing a beryllium / aluminum composite material filament, which relates to a method for preparing a beryllium / aluminum composite material filament. In order to solve the problems of high production difficulty and long production cycle of the existing beryllium / aluminum composite material filaments. Method: The beryllium / aluminum composite material is prepared by the self-exhaust pressure infiltration method, the beryllium / aluminum composite material and the hot extrusion die are preheated, the beryllium / aluminum composite material rod is prepared by hot extrusion, the beryllium / aluminum composite material rod is annealed, and the beryllium / aluminum composite material filament is prepared by hot rotary forging. The present invention combines the methods of hot extrusion and hot rotary forging to efficiently and low-costly prepare the beryllium / aluminum composite material filament, providing raw materials for preparing beryllium / aluminum composite material components by arc melting additive manufacturing. The yield strength of the prepared filament exceeds 540 MPa, the tensile strength exceeds 660 MPa, and the elongation exceeds 6.5%.

Description

Technical Field

[0001] The present invention relates to a method for preparing a beryllium / aluminum composite material filament. Background Art

[0002] Due to the excellent properties of high specific strength and high specific stiffness, beryllium / aluminum composite materials have attracted much attention in the aerospace field. The main application of beryllium / aluminum composite materials in the aerospace field is complex-shaped thin-walled components. If the components are produced by the method of precision machining of blanks, it will cause a large amount of waste of raw materials. At the same time, the high price of beryllium / aluminum composite materials makes the production cost increase sharply. The preparation of such components can be achieved by precision casting to realize near-net shaping. However, the beryllium / aluminum composite materials prepared by precision casting are prone to typical casting defects such as shrinkage porosity, shrinkage cavity, hot cracking and segregation, resulting in low mechanical properties of the materials and low yield rate. Therefore, it is a promising method to produce complex-shaped thin-walled components by additive manufacturing.

[0003] Due to the toxicity of beryllium powder, additive manufacturing methods using powder as raw materials, such as powder bed sintering, injection molding, etc., are dangerous and not environmentally friendly. Using beryllium / aluminum composite material filaments as raw materials and the method of arc melting is safer. How to produce suitable beryllium / aluminum composite material filaments has become a new problem.

[0004] The cast beryllium / aluminum composite material blank cannot meet the length requirement of the raw material for additive manufacturing. Therefore, it is necessary to process the cast beryllium / aluminum composite material. If it is directly prepared by extrusion, due to the small diameter of the beryllium / aluminum composite material filament for additive manufacturing and the large extrusion ratio, a large extrusion pressure is required, and the production difficulty is high. If the beryllium / aluminum composite material filament is directly produced by rotary forging, due to the limited deformation amount of each rotary forging process, it will lead to many production steps and a long production cycle. Summary of the Invention

[0005] In order to solve the problems of high production difficulty and long production cycle of the existing beryllium / aluminum composite material filaments, the present invention provides a method for preparing beryllium / aluminum composite material filaments, which combines the methods of hot extrusion and hot rotary forging to efficiently and low-costly prepare beryllium / aluminum composite material filaments, and provides raw materials for the preparation of beryllium / aluminum composite material components by arc melting additive manufacturing.

[0006] The method for preparing the beryllium / aluminum composite material filaments of the present invention is carried out according to the following steps:

[0007] Step 1: Preparation of beryllium / aluminum composite material

[0008] Prepare beryllium / aluminum composite materials by the self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite materials is 20% - 70%; the aluminum metal in the beryllium / aluminum composite materials is pure aluminum or aluminum alloy;

[0009] The process of the self-exhaust pressure infiltration method is as follows:

[0010] ①. According to 20 - 70% by volume of beryllium powder and the remaining aluminum metal, load the beryllium powder into a steel mold and press it into a preform. The holding pressure for pressing is 80 - 110 kN, and the holding time is 2 - 4 min. Then, place the steel mold containing the beryllium powder preform into a preheating furnace and preheat it at 510 - 560 °C for 2 h;

[0011] ②. Melt the aluminum metal at a temperature of 820 - 860 °C to obtain liquid aluminum, and then pour the liquid aluminum into the steel mold preheated in step ①;

[0012] ③. Apply a pressure of 20 - 35 MPa and move downward at a speed of 5 mm / min with the press head, so that the liquid aluminum infiltrates into the gaps of the beryllium powder, and hold the pressure at 20 - 35 MPa for 3 - 4 min, and then cool it with circulating water to obtain the beryllium / aluminum composite material;

[0013] Step two: Preheating of the beryllium / aluminum composite material and the hot extrusion mold

[0014] First, preheat the beryllium / aluminum composite material to a temperature of 400 °C - 600 °C, and then keep it warm for 0.5 h - 6 h under the condition of a temperature of 400 °C - 600 °C; The hot extrusion mold is kept warm for 0.5 h - 6 h at a temperature 10 °C - 50 °C lower than the preheating temperature of the beryllium / aluminum composite material;

[0015] Step three: Preparation of beryllium / aluminum composite material rods by hot extrusion

[0016] Load the preheated beryllium / aluminum composite material into the hot extrusion mold and perform hot extrusion with a press. The hot extrusion rate is 30 - 120 mm / min, and multiple beryllium / aluminum composite material rods are obtained at one time;

[0017] In the extrusion mold, the extrusion nozzle is a multi-hole extrusion nozzle with a pore diameter of 3 mm - 10 mm and the number of pores is 2 - 10; The diameter of the preheated beryllium / aluminum composite material is 34 - 36 mm;

[0018] Step four: Annealing treatment of the beryllium / aluminum composite material rods

[0019] Heat the beryllium / aluminum composite material rods obtained in step three to 200 - 600 °C, and then keep it warm for 0.5 h - 6 h under the condition of a temperature of 200 - 600 °C;

[0020] Step five: Preparation of beryllium / aluminum composite material filaments by hot rotary forging

[0021] Use a rotary forging machine to perform multi-pass rotary forging on the beryllium / aluminum composite material rods to obtain beryllium / aluminum composite material filaments with a diameter of 1 - 2.5 mm;

[0022] The multi-pass rotary forging process is as follows: the rotary forging temperature is 200 - 600 °C, the deformation amount per pass is 1% - 10%, the feeding rate is 10 - 200 mm / min, the rotary forging frequency is 10 - 100 Hz, and annealing treatment is carried out after each pass of rotary forging. The annealing temperature is the same as the rotary forging temperature, and the annealing time is 19 - 21 min.

[0023] The present invention has the following beneficial effects:

[0024] 1. The present invention processes the beryllium / aluminum composite material rod after hot extrusion by using the multi-pass rotary forging method at medium and high temperatures, avoiding the disadvantages of low elongation and poor workability of the beryllium / aluminum composite material at room temperature, and annealing the beryllium / aluminum composite material between processing passes to eliminate work hardening and improve the workability of the material, thereby preparing a beryllium / aluminum composite material filament that can be used for additive manufacturing.

[0025] 2. The present invention first extrudes the cast beryllium / aluminum composite material to obtain a rod-shaped beryllium / aluminum composite material, and then further reduces the diameter of the rod by rotary forging to obtain a beryllium / aluminum composite material filament, which can achieve efficient and low-cost preparation. This method has a simple process, is easy to operate, the composite material has excellent properties, and is easy to realize industrial production and application.

[0026] 3. The high-strength and tough beryllium / aluminum composite material prepared by the present invention has excellent properties. Multi-pass deformation is carried out at medium and high temperatures, and annealing treatment is carried out during each pass of deformation to improve the deformation ability of the material and ensure the integrity of the material. After extrusion processing, the matrix grains can be refined, and at the same time, the reinforcing bodies are oriented, improving the material properties. In the subsequent multi-pass rotary forging process, the matrix grains can be further refined to produce ultrafine grains, and at the same time, the aspect ratio of the reinforcing bodies is increased, improving the load transfer strengthening ability and further improving the material properties. The yield strength exceeds 540 MPa, the tensile strength exceeds 660 MPa, and the elongation exceeds 6.5%. Description of the Drawings

[0027] Figure 1 The beryllium / aluminum composite material filament prepared in Example 1. Detailed Embodiments

[0028] The technical solution of the present invention is not limited to the following specific embodiments, and also includes any reasonable combination between specific embodiments.

[0029] Specific Embodiment 1: The preparation method of the beryllium / aluminum composite material filament in this embodiment is carried out according to the following steps:

[0030] Step 1: Preparation of the beryllium / aluminum composite material

[0031] The beryllium / aluminum composite material is prepared by the self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite material is 20% to 70%; the aluminum metal in the beryllium / aluminum composite material is pure aluminum or aluminum alloy;

[0032] The process of the self-exhaust pressure infiltration method is as follows:

[0033] ①. According to 20-70% by volume of beryllium powder and the remaining aluminum metal, the beryllium powder is loaded into a steel mold and pressed into a preform. The holding pressure for pressing is 80-110 kN, and the holding time is 2-4 min; then the steel mold containing the beryllium powder preform is placed in a preheating furnace and preheated at 510-560 °C for 2 h;

[0034] ②. The aluminum metal is melted at a temperature of 820-860 °C to obtain liquid aluminum, and then the liquid aluminum is poured into the steel mold preheated in step ①;

[0035] ③. The pressure head applies a pressure of 20-35 MPa and moves downward at a speed of 5 mm / min, so that the liquid aluminum infiltrates into the gaps of the beryllium powder, and is held under a pressure of 20-35 MPa for 3-4 min, and then is cooled by circulating water to obtain the beryllium / aluminum composite material;

[0036] Step two: Preheating of the beryllium / aluminum composite material and the hot extrusion mold

[0037] First, the beryllium / aluminum composite material is preheated to a temperature of 400 °C to 600 °C, and then held at a temperature of 400 °C to 600 °C for 0.5 h to 6 h; the hot extrusion mold is held at a temperature 10 °C to 50 °C lower than the preheating temperature of the beryllium / aluminum composite material for 0.5 h to 6 h;

[0038] Step three: Hot extrusion to prepare beryllium / aluminum composite material rods

[0039] The preheated beryllium / aluminum composite material is loaded into the hot extrusion mold, and hot extrusion is carried out with a press. The hot extrusion rate is 30-120 mm / min, and multiple beryllium / aluminum composite material rods are obtained at one time;

[0040] In the extrusion mold, the extrusion nozzle is a multi-hole extrusion nozzle, the aperture is 3 mm to 10 mm, and the number of holes is 2 to 10; the diameter of the preheated beryllium / aluminum composite material is 34-36 mm;

[0041] Step four: Annealing treatment of the beryllium / aluminum composite material rods

[0042] The beryllium / aluminum composite material rods obtained in step three are heated to 200-600 °C, and then held at a temperature of 200-600 °C for 0.5 h to 6 h;

[0043] Step five: Hot swaging to prepare beryllium / aluminum composite material filaments

[0044] The beryllium / aluminum composite material rod is subjected to multi-pass rotary swaging using a rotary swaging machine to obtain beryllium / aluminum composite material filaments with a diameter of 1 - 2.5 mm;

[0045] The multi-pass rotary swaging process is as follows: the rotary swaging temperature is 200 - 600 °C, the deformation amount per pass is 1% - 10%, the feeding rate is 10 - 200 mm / min, the rotary swaging frequency is 10 - 100 Hz, and annealing treatment is carried out after each pass of rotary swaging. The annealing temperature is the same as the rotary swaging temperature, and the annealing time is 19 - 21 min.

[0046] This embodiment has the following beneficial effects:

[0047] 1. In this embodiment, the beryllium / aluminum composite material rod after hot extrusion is processed by multi-pass rotary swaging at medium and high temperatures, avoiding the disadvantages of low elongation and poor workability of the beryllium / aluminum composite material at room temperature. Annealing is carried out on the beryllium / aluminum composite material between processing passes to eliminate work hardening and improve the workability of the material, and beryllium / aluminum composite material filaments that can be used for additive manufacturing are prepared;

[0048] 2. In this embodiment, the as-cast beryllium / aluminum composite material is first extruded to obtain a rod-shaped beryllium / aluminum composite material, and then the diameter of the rod is further reduced by rotary swaging to obtain beryllium / aluminum composite material filaments, which can achieve high-efficiency and low-cost preparation. This method has a simple process, is easy to operate, has excellent composite material properties, and is easy to realize industrial production and application.

[0049] 3. The high-strength and tough beryllium / aluminum composite material prepared in this embodiment has excellent properties. Multi-pass deformation is carried out at medium and high temperatures, and annealing treatment is carried out during each pass of deformation to improve the deformation ability of the material and ensure the integrity of the material. After extrusion processing, the matrix grains can be refined, and at the same time, the reinforcement is oriented, improving the material properties. In the subsequent multi-pass rotary swaging process, the matrix grains can be further refined to produce ultrafine grains, and at the same time, the aspect ratio of the reinforcement is increased, improving the load transfer strengthening ability and further improving the material properties. The yield strength exceeds 540 MPa, the tensile strength exceeds 660 MPa, and the elongation exceeds 6.5%.

[0050] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is that the purity of the beryllium powder described in Step 1 is greater than 99%, and the average particle size is 5 - 800 μm.

[0051] Specific Embodiment 3: The difference between this embodiment and Specific Embodiment 1 or 2 is that the beryllium powder described in Step 1 is one or several of irregular shapes, spherical shapes, and beryllium turning chips in any ratio combination.

[0052] Specific Embodiment 4: The difference between this embodiment and any one of Embodiments 1 to 3 is that the process of the self-exhausting pressure infiltration method in Step 1 is as follows:

[0053] ①. According to 50% by volume of beryllium powder and the remaining aluminum metal, the beryllium powder is loaded into a steel mold and pressed into a preform. The holding pressure for pressing is 100 kN, and the holding time is 4 min. Then, the steel mold containing the beryllium powder preform is placed in a preheating furnace and preheated at 520 °C for 2 h.

[0054] ②. The aluminum metal is melted at a temperature of 820 °C to obtain liquid aluminum, and then the liquid aluminum is poured into the steel mold preheated in Step ①.

[0055] ③. The press head applies a pressure of 25 MPa and moves downward at a speed of 5 mm / min to make the liquid aluminum infiltrate into the gaps of the beryllium powder, and holds the pressure at 25 MPa for 3 min, and then cools it with circulating water to obtain a beryllium / aluminum composite material.

[0056] Specific Embodiment 5: The difference between this embodiment and any one of Embodiments 1 to 4 is that the aluminum alloy in Step 1 is one or any ratio combination of several of Al-Si alloy, Al-Cu alloy, Al-Mg alloy, Al-Si-Cu alloy, Al-Si-Mg alloy, Al-Cu-Mg alloy, Al-Zn-Cu alloy, Al-Zn-Mg-Cu alloy, Al-Be alloy, Al-Li alloy, and Al-Si-Cu-Mg alloy; the mass fraction of Si in the Al-Si alloy is 0.5% - 25%; the mass fraction of Cu in the Al-Cu alloy is 0.5% - 53%; the mass fraction of Mg in the Al-Mg alloy is 0.5% - 38%; the mass fraction of Si in the Al-Si-Cu alloy is 0.5% - 25%, and the mass fraction of Cu is 0.5% - 53%; the mass fraction of Si in the Al-Si-Mg alloy is 0.5% - 25%, and the mass fraction of Mg is 0.5% - 38%; the mass fraction of Cu in the Al-Cu-Mg alloy is 0.5% - 53%, and the mass fraction of Mg is 0.5% - 38%; the mass fraction of Zn in the Al-Zn-Cu alloy is 0.5% - 55%, and the mass fraction of Cu is 0.5% - 53%; the mass fraction of Zn in the Al-Zn-Mg-Cu alloy is 0.5% - 55%, the mass fraction of Mg is 0.5% - 38%, and the mass fraction of Cu is 0.5% - 53%; the mass fraction of Be in the Al-Be alloy is 0.5% - 20%; the mass fraction of Li in the Al-Li alloy is 0.5% - 35%; the mass fraction of Si in the Al-Si-Cu-Mg alloy is 0.5% - 25%, the mass fraction of Cu is 0.5% - 53%, and the mass fraction of Mg is 0.5% - 38%.

[0057] Embodiment Six: The difference between this embodiment and any one of Embodiments One to Five is as follows: In Step Two, the beryllium / aluminum composite material is preheated to a temperature of 530 °C and then held at 530 °C for 2 h; the hot extrusion die is held at 510 °C for 3 h.

[0058] Embodiment Seven: The difference between this embodiment and any one of Embodiments One to Six is as follows: In Step Three, the preheated beryllium / aluminum composite material is loaded into the hot extrusion die and hot extruded with a press at a hot extrusion rate of 50 mm / min to obtain multiple beryllium / aluminum composite material rods at one time.

[0059] Embodiment Eight: The difference between this embodiment and any one of Embodiments One to Seven is as follows: In the extrusion die in Step Three, the extrusion nozzle is a multi-hole extrusion nozzle with a pore diameter of 4 mm and the number of pores is 4; the diameter of the preheated beryllium / aluminum composite material is 35 mm.

[0060] Embodiment Nine: The difference between this embodiment and any one of Embodiments One to Eight is as follows: In Step Four, the beryllium / aluminum composite material rod obtained in Step Three is heated to 540 °C and then held at 540 °C for 2 h.

[0061] Embodiment Ten: The difference between this embodiment and any one of Embodiments One to Nine is as follows: In Step Five, the multi-pass rotary forging process is as follows: the rotary forging temperature is 540 °C, the deformation amount per pass is 3%, the feeding rate is 60 mm / min, the rotary forging frequency is 30 Hz, and annealing treatment is carried out after each pass of rotary forging. The annealing temperature is the same as the rotary forging temperature, and the annealing time is 19 - 21 min.

[0062] Example 1

[0063] The preparation method of the beryllium / aluminum composite material filament in this example is carried out according to the following steps:

[0064] Step One: Preparation of the beryllium / aluminum composite material

[0065] The beryllium / aluminum composite material is prepared by the self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite material is 50%; the aluminum metal in the beryllium / aluminum composite material is aluminum alloy.

[0066] The purity of the beryllium powder is greater than 99%, and the average particle size is 500 μm; the beryllium powder is beryllium turning chips.

[0067] The process of the self-exhaust pressure infiltration method is as follows:

[0068] ①. 50% by volume of beryllium powder and the balance aluminum metal. The beryllium powder is loaded into a steel mold and pressed into a preform. The holding pressure during pressing is 100 kN and the holding time is 4 min. Then, the steel mold containing the beryllium powder preform is placed in a preheating furnace and preheated at 520 °C for 2 h.

[0069] ②. The aluminum metal is melted at a temperature of 820 °C to obtain liquid aluminum, and then the liquid aluminum is poured into the steel mold preheated in step ①.

[0070] ③. The punch applies a pressure of 25 MPa and moves downward at a speed of 5 mm / min, causing the liquid aluminum to infiltrate into the gaps of the beryllium powder, and holding the pressure at 25 MPa for 3 min. Then, it is cooled by circulating water to obtain the beryllium / aluminum composite material.

[0071] The aluminum alloy is Al-4.3Cu-1.5Mg.

[0072] Step 2: Preheating of the beryllium / aluminum composite material and the hot extrusion die

[0073] First, the beryllium / aluminum composite material is preheated to a temperature of 530 °C, and then held at 530 °C for 2 h. The hot extrusion die is held at 510 °C for 3 h.

[0074] Step 3: Preparation of beryllium / aluminum composite material rods by hot extrusion

[0075] The preheated beryllium / aluminum composite material is loaded into the hot extrusion die and hot extruded using a press. The hot extrusion rate is 50 mm / min, and multiple beryllium / aluminum composite material rods are obtained at one time.

[0076] In the extrusion die, the extrusion nozzle is a multi-hole extrusion nozzle with a pore diameter of 4 mm and the number of pores is 4. The diameter of the preheated beryllium / aluminum composite material is 35 mm.

[0077] Step 4: Annealing treatment of beryllium / aluminum composite material rods

[0078] The beryllium / aluminum composite material rods obtained in step 3 are heated to 540 °C and then held at 540 °C for 2 h.

[0079] Step 5: Preparation of beryllium / aluminum composite material filaments by hot rotary forging

[0080] The beryllium / aluminum composite material rods are subjected to multi-pass rotary forging using a rotary forging machine to obtain beryllium / aluminum composite material filaments with a diameter of 2 mm.

[0081] The multi-pass rotary forging process is as follows: the rotary forging temperature is 540 °C, the deformation amount per pass is 3%, the feeding rate is 60 mm / min, the rotary forging frequency is 30 Hz, and annealing treatment is carried out after each pass of rotary forging. The annealing temperature is the same as the rotary forging temperature and the annealing time is 20 min.

[0082] The yield strength of the beryllium / aluminum composite filaments prepared in this example is 572 MPa, the tensile strength is 685 MPa, and the elongation is 6.9%.

[0083] Example 2

[0084] The preparation method of the beryllium / aluminum composite filaments in this example is carried out according to the following steps:

[0085] Step 1: Preparation of beryllium / aluminum composite

[0086] The beryllium / aluminum composite is prepared by the self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite is 40%; the aluminum metal in the beryllium / aluminum composite is aluminum alloy;

[0087] The purity of the beryllium powder is greater than 99%, and the average particle size is 80 μm; the beryllium powder is irregular in shape.

[0088] The process of the self-exhaust pressure infiltration method is as follows:

[0089] ①. According to 40% by volume of beryllium powder and the remaining aluminum metal, the beryllium powder is loaded into a steel mold and pressed into a preform. The holding pressure for pressing is 80 kN, and the holding time is 2 min; then the steel mold containing the beryllium powder preform is placed in a preheating furnace and preheated at 510 °C for 2 h;

[0090] ②. The aluminum metal is melted at a temperature of 820 °C to obtain liquid aluminum, and then the liquid aluminum is poured into the steel mold preheated in step ①;

[0091] ③. The punch applies a pressure of 20 MPa and moves downward at a speed of 5 mm / min to make the liquid aluminum infiltrate into the gaps of the beryllium powder, and holds the pressure at 20 MPa for 3 min, and then cools by circulating water to obtain the beryllium / aluminum composite;

[0092] The aluminum alloy is Al-1.2Mg-0.8Si;

[0093] Step 2: Preheating of beryllium / aluminum composite and hot extrusion die

[0094] First, preheat the beryllium / aluminum composite to a temperature of 520 °C, and then keep it at a temperature of 520 °C for 2 h; the hot extrusion die is kept at 500 °C for 3 h;

[0095] Step 3: Hot extrusion to prepare beryllium / aluminum composite rods

[0096] Load the preheated beryllium / aluminum composite into the hot extrusion die and perform hot extrusion with a press. The hot extrusion rate is 80 mm / min, and multiple beryllium / aluminum composite rods are obtained at one time;

[0097] In the extrusion die, the extrusion nozzle is a multi-hole extrusion nozzle with a pore diameter of 5 mm and the number of pores is 5; the diameter of the preheated beryllium / aluminum composite material is 35 mm;

[0098] Step Four: Annealing treatment of the beryllium / aluminum composite material rod

[0099] Heat the beryllium / aluminum composite material rod obtained in Step Three to 500 °C, and then keep it at 500 °C for 2.5 h;

[0100] Step Five: Preparing beryllium / aluminum composite material fine wires by hot rotary forging

[0101] Use a rotary forging machine to perform multi-pass rotary forging on the beryllium / aluminum composite material rod to obtain beryllium / aluminum composite material fine wires with a diameter of 2.2 mm;

[0102] The multi-pass rotary forging process is as follows: the rotary forging temperature is 500 °C, the deformation amount per pass is 5%, the feeding rate is 50 mm / min, the rotary forging frequency is 40 Hz, and annealing treatment is performed after each pass of rotary forging. The annealing temperature is the same as the rotary forging temperature, and the annealing time is 20 min;

[0103] The yield strength of the beryllium / aluminum composite material fine wires prepared in this embodiment is 547 MPa, the tensile strength is 665 MPa, and the elongation is 7.7%;

[0104] Example 3

[0105] The preparation method of the beryllium / aluminum composite material fine wires in this embodiment is carried out according to the following steps:

[0106] Step One: Preparation of the beryllium / aluminum composite material

[0107] Prepare the beryllium / aluminum composite material by the self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite material is 45%; the aluminum metal in the beryllium / aluminum composite material is aluminum alloy;

[0108] The purity of the beryllium powder is greater than 99%, and the average particle size is 60 μm; the beryllium powder is spherical beryllium powder.

[0109] The process of the self-exhaust pressure infiltration method is as follows:

[0110] ①. Load the beryllium powder into a steel die according to 45% by volume of beryllium powder and the remaining aluminum metal, and press it into a preform. The holding pressure for pressing is 90 kN, and the holding time is 3 min; then put the steel die containing the beryllium powder preform into a preheating furnace and preheat it at 530 °C for 2 h;

[0111] ②. Melt the aluminum metal at 840 °C to obtain liquid aluminum, and then pour the liquid aluminum into the steel die preheated in Step ①;

[0112] ③ Apply a pressure of 30 MPa and move downward at a speed of 5 mm / min with the indenter, so that the liquid aluminum infiltrates into the gaps of the beryllium powder, and hold the pressure for 3 min under a pressure of 30 MPa, and then cool by circulating water to obtain the beryllium / aluminum composite material;

[0113] The aluminum alloy is an Al-Cu alloy, and the mass fraction of Cu is 10%;

[0114] Step 2: Preheating of the beryllium / aluminum composite material and the hot extrusion die

[0115] First, preheat the beryllium / aluminum composite material to a temperature of 540 °C, and then hold the temperature for 2 h at 540 °C; the hot extrusion die is held at 520 °C for 3 h;

[0116] Step 3: Preparation of beryllium / aluminum composite material rods by hot extrusion

[0117] Load the preheated beryllium / aluminum composite material into the hot extrusion die, and perform hot extrusion with a press. The hot extrusion rate is 80 mm / min, and multiple beryllium / aluminum composite material rods are obtained at one time;

[0118] In the extrusion die, the extrusion nozzle is a multi-hole extrusion nozzle with a pore diameter of 6 mm and the number of pores is 4; the diameter of the preheated beryllium / aluminum composite material is 35 mm;

[0119] Step 4: Annealing treatment of the beryllium / aluminum composite material rods

[0120] Heat the beryllium / aluminum composite material rods obtained in Step 3 to 480 °C, and then hold the temperature for 3 h at 480 °C;

[0121] Step 5: Preparation of beryllium / aluminum composite material filaments by hot rotary forging

[0122] Use a rotary forging machine to perform multi-pass rotary forging on the beryllium / aluminum composite material rods to obtain beryllium / aluminum composite material filaments with a diameter of 2.4 mm;

[0123] The multi-pass rotary forging process is as follows: the rotary forging temperature is 480 °C, the deformation amount per pass is 6%, the feeding rate is 45 mm / min, the rotary forging frequency is 50 Hz, and annealing treatment is performed after each pass of rotary forging. The annealing temperature is the same as the rotary forging temperature, and the annealing time is 20 min;

[0124] The yield strength of the beryllium / aluminum composite material filaments prepared in this example is 569 MPa, the tensile strength is 674 MPa, and the elongation is 7.2%;

[0125] Example 4

[0126] The preparation method of the beryllium / aluminum composite material filaments in this example is carried out according to the following steps:

[0127] Step 1: Preparation of beryllium / aluminum composite material

[0128] The beryllium / aluminum composite material is prepared by self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite material is 60%; the aluminum metal in the beryllium / aluminum composite material is aluminum alloy;

[0129] The purity of the beryllium powder is greater than 99%, and the average particle size is 100μm; the beryllium powder is in irregular shape.

[0130] The process of the self-exhaust pressure infiltration method is as follows:

[0131] ①. According to 60% volume fraction of beryllium powder and the remaining aluminum metal, load the beryllium powder into a steel mold and press it into a preform. The holding pressure for pressing is 110kN, and the holding time is 3min; then put the steel mold with the beryllium powder preform into a preheating furnace and preheat it at 560℃ for 2h;

[0132] ②. Melt the aluminum metal at 840℃ to obtain liquid aluminum, and then pour the liquid aluminum into the steel mold preheated in step ①;

[0133] ③. The press head applies a pressure of 25MPa and moves downward at a speed of 5mm / min to make the liquid aluminum infiltrate into the gaps of the beryllium powder, and hold the pressure at 25MPa for 3min, and then cool it by circulating water to obtain the beryllium / aluminum composite material;

[0134] The aluminum alloy is Al-6.1Zn-2.9Mg-2Cu;

[0135] Step 2: Preheating of beryllium / aluminum composite material and hot extrusion die

[0136] First, preheat the beryllium / aluminum composite material to 530℃, and then keep it at 530℃ for 2h; the hot extrusion die is kept at 510℃ for 3h;

[0137] Step 3: Hot extrusion to prepare beryllium / aluminum composite material rods

[0138] Load the preheated beryllium / aluminum composite material into the hot extrusion die and perform hot extrusion with a press. The hot extrusion rate is 80mm / min, and multiple beryllium / aluminum composite material rods are obtained at one time;

[0139] In the extrusion die, the extrusion nozzle is a multi-hole extrusion nozzle with a pore diameter of 4mm and the number of pores is 5; the diameter of the preheated beryllium / aluminum composite material is 35mm;

[0140] Step 4: Annealing treatment of beryllium / aluminum composite material rods

[0141] Heat the beryllium / aluminum composite rods obtained in Step 3 to 300 °C, and then hold the temperature at 300 °C for 4 h;

[0142] Step 5: Hot rotary forging to prepare beryllium / aluminum composite filaments

[0143] Use a rotary forging machine to perform multi-pass rotary forging on the beryllium / aluminum composite rods to obtain beryllium / aluminum composite filaments with a diameter of 1.5 mm;

[0144] The multi-pass rotary forging process is as follows: the rotary forging temperature is 300 °C, the deformation amount per pass is 3%, the feeding rate is 70 mm / min, the rotary forging frequency is 60 Hz, and annealing treatment is carried out after each pass of rotary forging. The annealing temperature is the same as the rotary forging temperature, and the annealing time is 20 min;

[0145] The yield strength of the beryllium / aluminum composite filaments prepared in this example is 608 MPa, the tensile strength is 716 MPa, and the elongation is 6.5%;

[0146] Example 5

[0147] The preparation method of the beryllium / aluminum composite filaments in this example is carried out according to the following steps:

[0148] Step 1: Preparation of beryllium / aluminum composite

[0149] Prepare beryllium / aluminum composite by self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite is 55%; the aluminum metal in the beryllium / aluminum composite is aluminum alloy;

[0150] The purity of the beryllium powder is greater than 99%, and the average particle size is 300 μm; the beryllium powder is beryllium turning chips.

[0151] The process of the self-exhaust pressure infiltration method is as follows:

[0152] ①. Load the beryllium powder into a steel mold and press it into a preform according to 55% by volume of beryllium powder and the remaining aluminum metal. The holding pressure for pressing is 100 kN, and the holding time is 3 min; then put the steel mold with the beryllium powder preform into a preheating furnace and preheat it at 550 °C for 2 h;

[0153] ②. Melt the aluminum metal at 850 °C to obtain liquid aluminum, and then pour the liquid aluminum into the steel mold preheated in Step ①;

[0154] ③. The punch applies a pressure of 35 MPa and moves downward at a speed of 5 mm / min to make the liquid aluminum infiltrate into the gaps of the beryllium powder, and hold the pressure at 35 MPa for 4 min, and then cool it by circulating water to obtain the beryllium / aluminum composite;

[0155] The aluminum alloy is Al-4.9Mg;

[0156] Step 2: Preheating of beryllium / aluminum composite material and the hot extrusion die

[0157] First, preheat the beryllium / aluminum composite material to a temperature of 540°C, and then keep it at this temperature for 2 h; keep the hot extrusion die at a temperature 510°C lower than the preheating temperature of the beryllium / aluminum composite material for 3 h;

[0158] Step 3: Preparation of beryllium / aluminum composite material rods by hot extrusion

[0159] Load the preheated beryllium / aluminum composite material into the hot extrusion die, and perform hot extrusion with a press. The hot extrusion rate is 60 mm / min, and multiple beryllium / aluminum composite material rods are obtained at one time;

[0160] In the said extrusion die, the extrusion nozzle is a multi-hole extrusion nozzle with a pore diameter of 5 mm and the number of pores is 5; the diameter of the preheated beryllium / aluminum composite material is 35 mm;

[0161] Step 4: Annealing treatment of beryllium / aluminum composite material rods

[0162] Heat the beryllium / aluminum composite material rods obtained in Step 3 to 240°C, and then keep it at this temperature for 4.5 h;

[0163] Step 5: Preparation of beryllium / aluminum composite material filaments by hot swaging

[0164] Use a swaging machine to perform multi-pass swaging on the beryllium / aluminum composite material rods to obtain beryllium / aluminum composite material filaments with a diameter of 1.8 mm;

[0165] The said multi-pass swaging process is: the swaging temperature is 240°C, the deformation amount per pass is 6%, the feeding rate is 80 mm / min, the swaging frequency is 60 Hz, and annealing treatment is performed after each pass of swaging. The annealing temperature is the same as the swaging temperature, and the annealing time is 20 min;

[0166] The yield strength of the beryllium / aluminum composite material filaments prepared in this embodiment is 597 MPa, the tensile strength is 694 MPa, and the elongation is 6.7%.

Claims

1. A method for preparing beryllium / aluminum composite filaments, characterized in that: The preparation method of beryllium / aluminum composite filaments is carried out according to the following steps: Step 1: Preparation of Be / Aluminum Composite Materials The beryllium / aluminum composite material is prepared by a self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite material is 20% to 70%; the aluminum metal in the beryllium / aluminum composite material is pure aluminum or aluminum alloy; The process of the self-exhaust pressure infiltration method is: ①, according to the volume fraction of 20-70% beryllium powder and the balance of aluminum metal, the beryllium powder is loaded into a steel mold and pressed into a preform, the holding pressure is 80-110kN, and the holding time is 2-4min; then the steel mold containing the beryllium powder preform is placed in a preheating furnace and preheated at 510-560℃ for 2h; ②, melt the aluminum metal at a temperature of 820-860°C to obtain liquid aluminum, and then pour the liquid aluminum into the steel mold preheated in step ①; ③. The pressure head applies a pressure of 20-35MPa and moves downward at a speed of 5mm / min, so that the liquid aluminum penetrates into the gaps of the beryllium powder, and maintains the pressure at 20-35MPa for 3-4min, and then cools by circulating water to obtain a beryllium / aluminum composite material; Step 2: Preheating of Be / Aluminum Composite Material and Hot Extrusion Die Firstly, the beryllium / aluminum composite material is preheated to a temperature of 400°C to 600°C, and then kept at a temperature of 400°C to 600°C for 0.5h to 6h; the hot extrusion die is kept at a temperature 10°C to 50°C lower than the preheating temperature of the beryllium / aluminum composite material for 0.5h to 6h; Step 3: Preparation of Be / Aluminum Composite Rods by Hot Extrusion The preheated beryllium / aluminum composite material is loaded into a hot extrusion die, and hot extruded by a press machine at a hot extrusion rate of 30 to 120 mm / min to obtain a plurality of beryllium / aluminum composite material rods at one time; In the extrusion die, the extrusion nozzle is a multi-hole extrusion nozzle, the hole diameter is 3mm-10mm, and the number of holes is 2-10; the diameter of the preheated beryllium / aluminum composite material is 34-36mm; Step 4: Annealing of Be / Aluminum Composite Bars The beryllium / aluminum composite material rod obtained in step 3 is heated to 200-600° C., and then kept at 200-600° C. for 0.5-6 hours; Step 5: Preparation of Be / Aluminum Composite Wires by Hot Forging The beryllium / aluminum composite material rod is subjected to multiple passes of rotary forging using a rotary forging machine to obtain beryllium / aluminum composite material filaments having a diameter of 1 to 2.5 mm; The multi-pass rotary forging process is as follows: the rotary forging temperature is 200-600°C, the deformation amount of each pass is 1%-10%, the feed rate is 10-200mm / min, the rotary forging frequency is 10-100Hz, and annealing is performed after each rotary forging. The annealing temperature is the same as the rotary forging temperature, and the annealing time is 19-21min.

2. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: The beryllium powder described in step 1 has a purity greater than 99% and an average particle size of 5 to 800 μm.

3. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: The beryllium powder in step 1 is in the form of irregular shape, spherical shape, and beryllium turning chips, or any combination of the two.

4. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: The process of the self-exhaust pressure infiltration method in step 1 is: ①, according to the volume fraction of 50% beryllium powder and the rest of aluminum metal, the beryllium powder is loaded into a steel mold and pressed into a preform. The holding pressure of the pressing is 100kN and the holding time is 4min. Then the steel mold containing the beryllium powder preform is placed in a preheating furnace and preheated at 520℃ for 2h; ②, melt the aluminum metal at a temperature of 820°C to obtain liquid aluminum, and then pour the liquid aluminum into the steel mold preheated in step ①; ③. The pressure head applies a pressure of 25 MPa and moves downward at a speed of 5 mm / min to make the liquid aluminum infiltrate into the gaps of the beryllium powder, and maintains the pressure at 25 MPa for 3 minutes, and then cools by circulating water to obtain a beryllium / aluminum composite material.

5. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: Step 1: The aluminum alloy is one of Al-Si alloy, Al-Cu alloy, Al-Mg alloy, Al-Si-Cu alloy, Al-Si-Mg alloy, Al-Cu-Mg alloy, Al-Zn-Cu alloy, Al-Zn-Mg-Cu alloy, Al-Be alloy, Al-Li alloy and Al-Si-Cu-Mg alloy, or any combination of several thereof; the mass fraction of Si in the Al-Si alloy is 0.5% to 25%; the mass fraction of Cu in the Al-Cu alloy is 0.5% to 53%; the mass fraction of Mg in the Al-Mg alloy is 0.5% to 38%; the mass fraction of Si in the Al-Si-Cu alloy is 0.5% to 25%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Si in the Al-Si-Mg alloy is 0.5% to 25%, The mass fraction of Mg is 0.5% to 38%; the mass fraction of Cu in the Al-Cu-Mg alloy is 0.5% to 53%, and the mass fraction of Mg is 0.5% to 38%; the mass fraction of Zn in the Al-Zn-Cu alloy is 0.5% to 55%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Zn in the Al-Zn-Mg-Cu alloy is 0.5% to 55%, the mass fraction of Mg is 0.5% to 38%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Be in the Al-Be alloy is 0.5% to 20%; the mass fraction of Li in the Al-Li alloy is 0.5% to 35%; the mass fraction of Si in the Al-Si-Cu-Mg alloy is 0.5% to 25%, the mass fraction of Cu is 0.5% to 53%, and the mass fraction of Mg is 0.5% to 38%.

6. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: Step 2: preheating the beryllium / aluminum composite material to a temperature of 530° C., and then keeping the temperature at 530° C. for 2 hours; The hot extrusion die was kept at 510°C for 3 h.

7. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: Step 3: Load the preheated beryllium / aluminum composite material into a hot extrusion die, and use a press to perform hot extrusion at a hot extrusion rate of 50 mm / min to obtain a plurality of beryllium / aluminum composite material rods at one time.

8. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: In the extrusion die of step 3, the extrusion nozzle is a multi-hole extrusion nozzle with a hole diameter of 4 mm and 4 holes; the diameter of the preheated beryllium / aluminum composite material is 35 mm.

9. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: Step 4: Heat the beryllium / aluminum composite material rod obtained in step 3 to 540° C., and then keep the temperature at 540° C. for 2 hours.

10. The method for preparing beryllium / aluminum composite filaments according to claim 1, characterized in that: The multi-pass rotary forging process in step 5 is as follows: the rotary forging temperature is 540°C, the deformation amount of each pass is 3%, the feed rate is 60mm / min, the rotary forging frequency is 30Hz, and annealing is performed after each rotary forging. The annealing temperature is the same as the rotary forging temperature, and the annealing time is 19 to 21min.

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