NANO beryllium oxide strengthened beryllium-aluminum alloy powder, preparation method, and use

Abstract

The present invention relates to the technical field of beryllium-aluminum alloy powder preparation, and provides nano beryllium oxide strengthened beryllium-aluminum alloy powder, a preparation method, and a use. The method comprises the following steps: step S1, sequentially placing nano beryllium oxide, an aluminum block, and a beryllium ingot into a crucible in a vacuum container for melting, and then performing uniform stirring to obtain a melt; step S2, pouring the melt into a thermal insulation package above an atomization nozzle, wherein the melt flows out through a flow guide pipe at the bottom of the thermal insulation package, and when passing through the atomization nozzle, meets with high-pressure argon to be atomized into tiny droplets, and in an atomization tower, the droplets are rapidly solidified into spherical nano beryllium oxide-containing beryllium-aluminum alloy powder; and step S3, on the basis of powder particle sizes, classifying the nano beryllium oxide-containing beryllium-aluminum alloy powder into grade-1 powder, grade-2 powder and grade-3 powder. In the present invention, the beryllium-aluminum alloy powder is prepared by a method of first melting aluminum in vacuum, and then introducing inert gas to continue to melt beryllium, thereby reducing the content of oxygen in the powder and preventing aluminum evaporation.

Description

Nano beryllium oxide reinforced beryllium aluminum alloy powder, preparation method and application TECHNICAL FIELD

[0001] The application belongs to the technical field of beryllium aluminum alloy preparation, and particularly relates to a nano beryllium oxide reinforced beryllium aluminum alloy powder, a preparation method and application thereof. BACKGROUND

[0002] Beryllium aluminum alloy has high strength, high dimensional stability, light weight and good processing ductility, and is widely used as a key core material in the field of aerospace. The additive manufacturing technology can realize the customized and integrated production of beryllium aluminum alloy, which not only saves the precious beryllium resources, but also realizes the rapid forming of complex structure hollow and thin-walled parts.

[0003] At present, the preparation of beryllium aluminum alloy powder can be mainly prepared by inert gas atomization method and plasma rotating electrode method. Chinese patent CN111570813A adopts the plasma rotating electrode method, and utilizes the electric arc to melt the end face of the beryllium aluminum alloy rod into a liquid film; the liquid film is broken into fine droplets by centrifugal force, and is cooled to obtain the beryllium aluminum alloy powder. The beryllium aluminum alloy rod mainly has two modes, namely, isostatic pressing beryllium aluminum alloy rod and extruded beryllium aluminum alloy rod. In the process of hot isostatic pressing, the oxygen increment of the isostatic pressing beryllium aluminum alloy rod is very large, so that the oxygen content of the prepared powder is too high, which is not conducive to the additive manufacturing of beryllium aluminum alloy; the extruded beryllium aluminum alloy rod is subjected to large deformation, and the internal structure of the beryllium aluminum alloy rod has serious anisotropy, which is not conducive to the uniformity of the powder composition and affects the strength of the beryllium aluminum alloy powder. SUMMARY

[0004] To solve the above technical problems, the application provides a nano beryllium oxide reinforced beryllium aluminum alloy powder, a preparation method and application thereof. In the application, the nano beryllium oxide is used as a reinforcing agent to improve the strength of the beryllium aluminum alloy, and a method of vacuum first and inert gas protection second is used to prepare the beryllium aluminum alloy powder, which can reduce the oxygen content in the powder and avoid the evaporation of aluminum.

[0005] The first aspect of the application discloses a preparation method of a nano beryllium oxide reinforced beryllium aluminum alloy powder, which adopts components including the following mass percentages as raw materials: 30-90% beryllium, 5-70% aluminum and 1-5% nano beryllium oxide.

[0006] The preparation method comprises the following steps:

[0007] Step S1, the nano beryllium oxide, aluminum block and beryllium ingot are sequentially placed in the crucible in the vacuum container, and then are subjected to melting and stirring to obtain a melt;

[0008] The specific process of the melting is as follows:

[0009] After vacuumizing the vacuum container to a vacuum degree of 10-100 Pa, the crucible is heated to 800-850℃, then inert gas is filled until the pressure in the vacuum container reaches 6-8 MPa, the crucible is continuously heated to 1400-1450℃, and then kept for 20-30 min;

[0010] In step S2, the melt is poured into a heat preservation package above an atomizing nozzle, the melt flows out through a flow guide pipe at the bottom of the heat preservation package, and is atomized into fine droplets when meeting high-pressure argon gas through the atomizing nozzle, and the droplets are rapidly solidified into spherical beryllium aluminum alloy powder containing nano beryllium oxide in an atomizing tower;

[0011] In the method, the heat preservation package is preheated and continuously kept warm during the whole atomizing process, and the preheating temperature of the heat preservation package is less than the highest temperature during smelting and greater than the melting point of beryllium metal.

[0012] In step S3, the beryllium aluminum alloy powder containing nano beryllium oxide is divided into first-grade powder, second-grade powder and third-grade powder according to the particle size.

[0013] The particle size of the first-grade powder is 80-150 μm.

[0014] The particle size of the second-grade powder is 20-80 μm.

[0015] The particle size of the third-grade powder is less than 20 μm.

[0016] According to the preparation method of the first aspect of the present application, the total yield of the first-grade powder and the second-grade powder is greater than 90%.

[0017] According to the preparation method of the first aspect of the present application, in step S1, the nano beryllium oxide is placed at the bottom of the crucible.

[0018] According to the preparation method of the first aspect of the present application, in step S1, the material of the crucible is alumina.

[0019] According to the preparation method of the first aspect of the present application, in step S2, the heat preservation package is preheated to 1280-1300℃ and kept warm during the whole atomizing process.

[0020] The heat preservation package comprises an alumina intermediate package, a graphite sleeve and a heat preservation sleeve which are detachably connected in sequence.

[0021] The graphite sleeve is nested in the outer layer of the alumina intermediate package, and the heat preservation sleeve is nested in the outer layer of the graphite sleeve.

[0022] According to the preparation method of the first aspect of the present application, in step S2, the material of the flow guide pipe is beryllium oxide.

[0023] The diameter of the guide pipe is 2-4 mm.

[0024] According to the preparation method of the first aspect of the application, the pressure of the argon is 2-7 MPa and the purity is greater than 99.5% in the step S2.

[0025] According to the preparation method of the first aspect of the application, the purity of the nano beryllium oxide is greater than 99.5% and the average particle size is less than 20 nm; the purity of the aluminum block is greater than 99.5%; and the purity of the beryllium ingot is greater than 99.0%.

[0026] The second aspect of the application discloses a nano beryllium oxide reinforced beryllium aluminum alloy powder.

[0027] The third aspect of the application discloses an application of the nano beryllium oxide reinforced beryllium aluminum alloy powder in laser additive manufacturing.

[0028] The powder feeding mode is synchronous powder feeding, the laser power is 1500 W-2500 W, the scanning interval is 1.0-2.0 mm, and the scanning rate is 1-6 mm / s.

[0029] According to the application of the third aspect of the application, the tensile strength of the beryllium aluminum alloy is greater than or equal to 350 MPa, the yield strength is greater than or equal to 240 MPa, and the elongation rate is greater than or equal to 4.9%.

[0030] In summary, the scheme provided in the application has the following technical effects:

[0031] The nano beryllium oxide is added as a reinforcing agent in the raw material, the beryllium oxide cannot be dissolved in beryllium metal or aluminum metal, and is attached to the grain boundary to realize a dispersion strengthening of the material; meanwhile, the beryllium aluminum alloy powder is prepared by adopting the method of first vacuumizing to melt the aluminum and then introducing inert gas to continue melting the beryllium, so that the oxygen content in the powder can be reduced and the evaporation of the aluminum can be avoided.

[0032] In addition, the beryllium aluminum alloy is prepared by adopting the laser additive manufacturing method, the particle size requirement range is wide, and the utilization rate of the powder is high. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0034] Fig. 1(a) is a CT photo of the interior of the nano beryllium oxide reinforced beryllium aluminum alloy prepared in Example 1 of the present application (scanning along the length direction).

[0035] Fig. 1(b) is a CT photo of the interior of the nano beryllium oxide reinforced beryllium aluminum alloy prepared in Example 1 of the present application (scanning along the width direction).

[0036] Fig. 2 is a particle size distribution diagram of the nano beryllium oxide reinforced beryllium aluminum alloy powder prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present application.

[0038] The first aspect of the present embodiment provides a preparation method of a nano beryllium oxide reinforced beryllium aluminum alloy powder, which uses components including the following mass percentages as raw materials: 30-90% beryllium, 5-70% aluminum, and 1-5% nano beryllium oxide.

[0039] In the present embodiment, the nano beryllium oxide is mainly used for realizing dispersion strengthening of the beryllium aluminum alloy material, thereby improving the strength of the alloy. However, too high content of the nano beryllium oxide will reduce the elongation and other properties of the beryllium aluminum alloy. Therefore, the content of the nano beryllium oxide is limited to 1-5% in the present embodiment.

[0040] The preparation method comprises the following steps:

[0041] Step S1, the nano beryllium oxide, aluminum block and beryllium ingot are sequentially put into the crucible in the vacuum container, then the melting and stirring are performed to obtain a melt.

[0042] Step S2, the melt is poured into the heat preservation bag above the atomizing nozzle, the melt flows out through the flow guide pipe at the bottom of the heat preservation bag, and meets the high pressure argon gas when passing through the atomizing nozzle to be atomized into fine droplets. The droplets are rapidly solidified into spherical beryllium aluminum alloy powder containing nano beryllium oxide in the atomizing tower.

[0043] Step S3, according to the powder particle size, the beryllium aluminum alloy powder containing nano beryllium oxide is divided into first grade powder, second grade powder and third grade powder.

[0044] In step S1, the nano beryllium oxide, aluminum block and beryllium ingot are sequentially placed in the crucible in the vacuum container, then the melting is carried out and the stirring is uniform, so as to obtain the melt.

[0045] In some embodiments, the specific process of the melting is as follows:

[0046] After the vacuum degree of the vacuum container is 10-100 Pa, the crucible is heated to 800-850℃, then the inert gas is filled until the pressure in the vacuum container reaches 6-8 MPa, the crucible is continuously heated to 1400-1450℃, and then the temperature is kept for 20-30 min.

[0047] In this embodiment, the aluminum block is first completely melted at a temperature of 800-850℃ in a vacuum state, then the inert gas is introduced to make the container pressure reach 5-8 MPa, and then the temperature is continuously increased to 1350-1550℃ to make the beryllium ingot continue to melt. Melting aluminum in a vacuum state can avoid oxidation of aluminum or beryllium, effectively reduce the oxygen content in the alloy, and on the other hand, some impurity elements can be volatilized under vacuum melting, thereby improving the purity of the alloy. After that, the inert gas is introduced to prevent the liquid aluminum metal from volatilizing in the continuous vacuum state, and to avoid the splashing of beryllium after melting.

[0048] In addition, through experiments, if the vacuum degree is too high, the beryllium aluminum alloy will splash during the melting process, and if the vacuum degree is too low, the beryllium aluminum alloy will be oxidized, therefore, the vacuum degree is selected to be 10-100 Pa in this embodiment.

[0049] In some embodiments, the nano beryllium oxide is placed at the bottom of the crucible, so as to avoid the nano beryllium oxide from being sucked away during the vacuumizing.

[0050] Preferably, the aluminum block is placed between the nano beryllium oxide and the beryllium ingot.

[0051] In the melting process, the low-melting-point aluminum blocks are placed below the beryllium ingots, mainly to take advantage of the density difference between the metals to make them better distributed and mixed during the melting process. Specifically, the low-melting-point aluminum metal has a lower density and will float on the surface of the metal melt during melting. If the low-melting-point aluminum blocks are placed on the upper layer of the high-melting-point beryllium ingots, the molten aluminum formed after the first melting will form a cluster on the surface of the melt, resulting in uneven alloy composition and quality problems. Placing the low-melting-point aluminum blocks below the beryllium ingots allows them to gradually melt during the melting process and be evenly distributed throughout the melt as the metal liquid flows, which can improve the uniformity of the alloy composition and reduce segregation and inclusion problems. In addition, placing the low-melting-point aluminum blocks below the beryllium ingots can also prevent aluminum from evaporating or losing too early during the melting process, thereby ensuring the quality and yield of the metal melting.

[0052] In some embodiments, the inert gas is argon or helium. From a cost perspective, argon is preferred.

[0053] It should be noted that nitrogen cannot be used as a protective gas during the melting process in this embodiment to avoid the reaction between aluminum and nitrogen under high temperature and high pressure conditions.

[0054] In some embodiments, the purity of the nano beryllium oxide is greater than 99.5%, and the average particle size is less than 20 nm; the purity of the aluminum blocks is greater than 99.5%; and the purity of the beryllium ingots is greater than 99.0%.

[0055] The smaller the particle size of the nano beryllium oxide, the more obvious the dispersion strengthening effect, so the average particle size of the nano beryllium oxide used in this embodiment is less than 20 nm.

[0056] In some embodiments, the material of the crucible is alumina.

[0057] Alumina crucibles are selected for beryllium-aluminum alloy melting instead of beryllium oxide or other material crucibles, mainly because alumina crucibles meet the use requirements while avoiding material contamination, and the cost of alumina crucibles is lower than that of beryllium oxide crucibles.

[0058] In step S2, the melt is poured into a heat preservation package above the atomizing nozzle, the melt flows out through the flow guide pipe at the bottom of the heat preservation package, and when passing through the atomizing nozzle, it meets high-pressure argon gas and is atomized into fine droplets. The droplets rapidly solidify into spherical beryllium-aluminum alloy powder containing nano beryllium oxide in the atomizing tower.

[0059] In some embodiments, the heat preservation package is preheated and continuously heated throughout the atomization process, and the preheating temperature of the heat preservation package is less than the highest temperature during melting and greater than the melting point of beryllium metal.

[0060] In some embodiments, the heat preservation package is preheated to 1280-1300℃ and continuously preserved during the whole atomization process to ensure that the melt does not condense.

[0061] The temperature of the heat preservation package in this process is also the temperature at which the melt is cast into the heat preservation package and atomization begins. The role of this process is to prevent the melt from having a large temperature drop, which would result in a decrease in viscosity and affect the atomization effect. This process does not require a very high temperature, but only a temperature higher than the melting point of the metal.

[0062] In some embodiments, the heat preservation package comprises an alumina tundish, a graphite sleeve and a heat preservation sleeve which are sequentially detachably connected.

[0063] The graphite sleeve is nested in the outer layer of the alumina tundish, and the heat preservation sleeve is nested in the outer layer of the graphite sleeve.

[0064] Specifically, the wall thickness of the graphite sleeve is 20-25 mm, and the wall thickness of the heat preservation sleeve is 15-20 mm. The material of the heat preservation sleeve is alumina fiber.

[0065] In this embodiment, the graphite sleeve and the heat preservation sleeve are sequentially nested in the outer layer of the alumina tundish to better preserve the melt. In the long atomization process, the temperature of the melt in the tundish decreases, resulting in the precipitation of some alloy particles and reducing the purity of the final alloy. In addition, the material of the outermost heat preservation sleeve is preferably alumina fiber, which can further ensure the purity of the beryllium aluminum alloy.

[0066] In some embodiments, the material of the flow guide pipe is beryllium oxide. The diameter of the flow guide pipe is 2-4 mm.

[0067] The beryllium oxide flow guide pipe of this embodiment is durable and reusable, while flow guide pipes made of other materials are disposable. Through multiple experiments, it has been found that selecting a 2-4 mm flow guide pipe can effectively improve the yield of powders with a particle size of 20-150 μm.

[0068] In some embodiments, the pressure of the argon gas is 2-7 MPa, and the purity is greater than 99.5%.

[0069] In this embodiment, the pressure of the argon gas during atomization is selected to match the diameter of the flow guide pipe. The larger the diameter of the flow guide pipe, the more melt flows down per unit time, and more argon gas is needed for gasification. Therefore, the two need to be matched.

[0070] In step S3, the beryllium aluminum alloy powder containing nano beryllium oxide is divided into first, second and third powders according to the particle size of the powder.

[0071] In some embodiments, the particle size of the primary powder is 80-150 μm; the particle size of the secondary powder is 20-80 μm; and the particle size of the tertiary powder is <20 μm.

[0072] In some embodiments, the total yield of the primary powder and the secondary powder is greater than 90%.

[0073] The second aspect of the embodiment provides a nano-beryllium oxide reinforced beryllium aluminum alloy powder. The nano-beryllium oxide reinforced beryllium aluminum alloy powder comprises, by weight percentage, 30-90% beryllium, 5-70% aluminum, and 1-5% nano-beryllium oxide.

[0074] The third aspect of the embodiment provides an application of the nano-beryllium oxide reinforced beryllium aluminum alloy powder in laser additive manufacturing. Specifically, the nano-beryllium oxide reinforced beryllium aluminum alloy powder with a particle size of 20-150 μm is 3D printed into a beryllium aluminum alloy by using a laser additive manufacturing method.

[0075] In some embodiments, the powder feeding mode is synchronous powder feeding; the laser power is 1500-2500 W; the scanning interval is 1.0-2.0 mm; and the scanning rate is 1-6 mm / s.

[0076] In some embodiments, the beryllium aluminum alloy has a tensile strength of greater than or equal to 350 MPa, a yield strength of greater than or equal to 240 MPa, and an elongation of greater than or equal to 4.9%.

[0077] Embodiment 1

[0078] (1) The nano-beryllium oxide powder (purity higher than 99.5 wt.%, content of 5 wt.%), aluminum block (purity higher than 99.5 wt.%, content of 65 wt.%), and beryllium ingot (purity higher than 99.0 wt.%, content of 30 wt.%) are sequentially placed in an alumina crucible in a vacuum container, and then subjected to smelting and stirring to obtain a melt;

[0079] In the process, the nano-beryllium oxide is placed at the bottom of the alumina crucible.

[0080] The specific process of smelting is as follows:

[0081] After the vacuum degree of the vacuum container is 10-100 Pa, the crucible is heated to 825 ℃, then argon is filled until the pressure in the vacuum container reaches 8 MPa, and then the crucible is heated to 1425 ℃, and then kept for 25 min.

[0082] (2) pouring the melt into a heat preservation package above an atomizing nozzle, the melt flowing out through a 3mm beryllium oxide flow guide pipe at the bottom of the heat preservation package, being atomized into fine droplets when meeting argon with a pressure of 3MPa and a purity of 99.5% through the atomizing nozzle, and the droplets rapidly solidifying into spherical nano beryllium oxide reinforced beryllium aluminum alloy powder in an atomizing tower;

[0083] wherein the heat preservation package is preheated at 1290℃ and continuously preserved during the whole atomizing process;

[0084] According to the powder particle size, the nano beryllium oxide reinforced beryllium aluminum alloy powder is divided into first grade powder with a particle size of 80-150um, second grade powder with a particle size of 20-80um and third grade powder with a particle size of <20um; Fig. 2 is a particle size distribution diagram of the nano beryllium oxide reinforced beryllium aluminum alloy powder prepared in Example 1. As can be seen from Fig. 2, the total yield of the first grade powder and the second grade powder in the nano beryllium oxide reinforced beryllium aluminum alloy powder prepared in Example 1 is greater than 90%.

[0085] (3) using a laser additive manufacturing method to 3D print the nano beryllium oxide reinforced beryllium aluminum alloy powder with a particle size of 20-150um to obtain the nano beryllium oxide reinforced beryllium aluminum alloy;

[0086] wherein the powder feeding mode is synchronous powder feeding; the laser power is 2000W, the scanning interval is 1.5mm and the scanning rate is 3mm / s.

[0087] The beryllium aluminum alloy obtained in Example 1 is subjected to mechanical property testing, and the results are shown in Table 1.

[0088] Table 1 Mechanical properties of the nano beryllium oxide reinforced beryllium aluminum alloy of Example 1

[0089] The nano beryllium oxide reinforced beryllium aluminum alloy obtained in Example 1 is subjected to CT scanning, and the results are shown in Fig. 1(a) and Fig. 1(b). In this embodiment, the nano beryllium oxide reinforced beryllium aluminum alloy additive manufacturing is realized by using the synchronous powder feeding mode, and the material after forming is dense inside. According to the results of CT characterization, there is no obvious defect in the alloy.

[0090] Example 2

[0091] (1) putting nano beryllium oxide powder (purity higher than 99.5wt.%, content of 1wt.%), aluminum block (purity higher than 99.5wt.%, 37wt.%) and beryllium ingot (purity higher than 99.0wt.%, content of 62wt.%) into an alumina crucible in a vacuum container in sequence, then melting and stirring uniformly to obtain a melt;

[0092] wherein the nano beryllium oxide is placed at the bottom of the alumina crucible;

[0093] The specific process of smelting is as follows:

[0094] After the vacuum degree of the vacuum container is 10-100 Pa, the crucible is heated to 850℃, then argon is filled until the pressure in the vacuum container reaches 5 MPa, the crucible is continuously heated to 1450℃, and then kept for 20 min.

[0095] (2) The melt is poured into the heat preservation bag above the atomizing nozzle, the melt flows out through the 4mm beryllium oxide flow guide pipe at the bottom of the heat preservation bag, and is atomized into fine droplets when meeting the argon with a pressure of 4 MPa and a purity of 99.5% through the atomizing nozzle, and the droplets are rapidly solidified into spherical nano beryllium oxide reinforced beryllium aluminum alloy powder in the atomizing tower;

[0096] The heat preservation bag is preheated to 1300℃ and continuously kept during the whole atomizing process.

[0097] According to the powder particle size, the nano beryllium oxide reinforced beryllium aluminum alloy powder is divided into first grade powder with a particle size of 80-150μm, second grade powder with a particle size of 20-80μm and third grade powder with a particle size of <20μm.

[0098] The total yield of the first grade powder and the second grade powder in the nano beryllium oxide reinforced beryllium aluminum alloy powder prepared in Example 2 is greater than 89%.

[0099] (3) The nano beryllium oxide reinforced beryllium aluminum alloy powder with a particle size of 20-150um is 3D printed by using the laser additive manufacturing method to obtain the nano beryllium oxide reinforced beryllium aluminum alloy;

[0100] The powder feeding mode is synchronous powder feeding; the laser power is 1500W, the scanning interval is 1.0mm, and the scanning rate is 1mm / s.

[0101] The mechanical property test is performed on the nano beryllium oxide reinforced beryllium aluminum alloy obtained in Example 2, and the results are shown in Table 2.

[0102] Table 2 Mechanical properties of the nano beryllium oxide reinforced beryllium aluminum alloy of Example 2

[0103] Example 3

[0104] (1) The nano beryllium oxide powder (purity higher than 99.5wt.%, content 3wt.%), aluminum block (purity higher than 99.5wt.%, 10wt.%) and beryllium ingot (purity higher than 99.0wt.%, content 87wt.%) are sequentially put into the alumina crucible in the vacuum container, then smelting is performed and stirring is uniformly performed to obtain a melt;

[0105] The nano beryllium oxide is placed at the bottom of the alumina crucible;

[0106] The specific process of smelting is as follows:

[0107] After the vacuum container is vacuumized to a vacuum degree of 10-100 Pa, the crucible is heated to 800 DEG C, then argon is filled until the pressure in the vacuum container reaches 8 MPa, and then the crucible is continuously heated to 1400 DEG C and kept for 30 min.

[0108] (2) The melt is poured into the heat preservation bag above the atomizing nozzle, the melt flows out through the 2mm beryllium oxide flow guide pipe at the bottom of the heat preservation bag, and is atomized into fine droplets when meeting the argon with a pressure of 2 MPa and a purity of 99.5% through the atomizing nozzle, and the droplets are rapidly solidified into spherical nano beryllium oxide reinforced beryllium aluminum alloy powder in the atomizing tower;

[0109] The heat preservation bag is preheated to 1280 DEG C and continuously kept during the whole atomizing process.

[0110] According to the powder particle size, the nano beryllium oxide reinforced beryllium aluminum alloy powder is divided into first grade powder with a particle size of 80-150um, second grade powder with a particle size of 20-80um and third grade powder with a particle size of less than 20um.

[0111] The total yield of the first grade powder and the second grade powder in the nano beryllium oxide reinforced beryllium aluminum alloy powder prepared in Example 3 is greater than 93%.

[0112] (3) The nano beryllium oxide reinforced beryllium aluminum alloy powder with a particle size of 20-150um is 3D printed by using a laser additive manufacturing method, and the nano beryllium oxide reinforced beryllium aluminum alloy is obtained.

[0113] The powder feeding mode is synchronous powder feeding, the laser power is 2500W, the scanning interval is 2.0mm, and the scanning rate is 6mm / s.

[0114] The nano beryllium oxide reinforced beryllium aluminum alloy obtained in Example 3 is subjected to mechanical property testing, and the results are shown in Table 3.

[0115] Table 3 Mechanical properties of the nano beryllium oxide reinforced beryllium aluminum alloy of Example 3

[0116] Therefore, the scheme provided by the application has the following technical effects:

[0117] The present application adds nano-beryllium oxide as a reinforcing agent in raw materials, the beryllium oxide cannot dissolve in beryllium metal or aluminum metal, and adheres to the grain boundary to realize dispersion strengthening of the material; meanwhile, the beryllium aluminum alloy powder is prepared by the method of first vacuuming to melt the aluminum and then introducing inert gas to continue melting the beryllium, which can reduce the oxygen content in the powder and avoid evaporation of the aluminum.

[0118] In addition, the present application uses the laser additive manufacturing method to prepare the beryllium aluminum alloy, the particle size requirement range is wide, and the utilization rate of the powder is high.

[0119] Please note that the technical features of the above embodiments can be combined in any way, and in order to make the description simple, all possible combinations of the technical features in the above embodiments have not been described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application. The above embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as the limitation of the patent scope of the present application. It should be pointed out that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A method of producing a nano beryllium oxide reinforced beryllium aluminum alloy powder, characterized by, The preparation method adopts components including the following mass percentages as raw materials: 30-90% beryllium, 5-70% aluminum, and 1-5% nano beryllium oxide; The method comprises the following steps: In step S1, nano beryllium oxide, aluminum blocks, and beryllium ingots are sequentially placed in a crucible in a vacuum container, and then smelting and stirring are performed to obtain a melt; The specific process of smelting is as follows: After the vacuum degree of the vacuum container is 10-100 Pa, the crucible is heated to 800-850℃, and then inert gas is filled until the pressure in the vacuum container reaches 6-8 MPa, and then the crucible is continuously heated to 1400-1450℃, and then heat preservation is performed for 20-30 min; In step S2, the melt is poured into a heat preservation package above an atomizing nozzle, the melt flows out through a flow guide pipe at the bottom of the heat preservation package, and when passing through the atomizing nozzle, the melt is atomized into fine droplets by high-pressure argon gas, and the droplets are rapidly solidified into spherical beryllium aluminum alloy powder containing nano beryllium oxide in an atomizing tower; The heat preservation package is preheated and continuously heat preserved during the entire atomizing process, and the preheating temperature of the heat preservation package is less than the highest temperature during smelting and greater than the melting point of beryllium metal; In step S3, the beryllium aluminum alloy powder containing nano beryllium oxide is divided into first-level powder, second-level powder, and third-level powder according to the particle size; The particle size of the first-level powder is 80-150 μm; The particle size of the second-level powder is 20-80 μm; The particle size of the third-level powder is less than 20 μm.

2. The production method according to claim 1, characterized by, The total yield of the first-level powder and the second-level powder is greater than 90%.

3. The preparation method according to claim 1, characterized in that, In step S1, the nano beryllium oxide is placed at the bottom of the crucible.

4. The method of claim 1, wherein, In step S1, the material of the crucible is alumina.

5. The preparation method according to claim 1, characterized in that, In step S2, the heat preservation package is preheated to 1280-1300℃ and continuously heat preserved during the entire atomizing process; The heat preservation package comprises an alumina intermediate package, a graphite sleeve, and a heat preservation sleeve which are sequentially and detachably connected; The graphite sleeve is nested in the outer layer of the alumina intermediate package, and the heat preservation sleeve is nested in the outer layer of the graphite sleeve.

6. The method of claim 1, wherein, In step S2, the material of the flow guide pipe is beryllium oxide; The diameter of the flow guide pipe is 2-4 mm.

7. The preparation method according to claim 1, characterized in that, In step S2, the pressure of the argon gas is 2-7 MPa, and the purity is greater than 99.5%.

8. A nano-boroia powder of a beryllium-aluminum alloy strengthened with beryllium oxide, prepared by the method according to any one of claims 1 to 7, characterized in that The nano beryllium oxide reinforced beryllium aluminum alloy powder comprises, by weight percentage, 30-90% beryllium, 5-70% aluminum, and 1-5% nano beryllium oxide.

9. Use of the nano-boroxyride reinforced beryllium aluminum alloy powder of claim 1 in laser additive manufacturing, characterized in that, The nano beryllium oxide reinforced beryllium aluminum alloy powder with a particle size of 20-150 μm is 3D printed by a laser additive manufacturing method to form a beryllium aluminum alloy; The laser power is 1500-2500 W, the scanning interval is 1.0-2.0 mm, and the scanning rate is 1-6 mm / s.

10. Use according to claim 9, characterized in that, The tensile strength of the beryllium aluminum alloy is greater than or equal to 350 MPa, the yield strength is greater than or equal to 240 MPa, and the elongation is greater than or equal to 4.9%.

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