Mg-Ta metal composite, preparation method and application thereof

Abstract

The application provides a honeycomb structure Mg-Ta metal composite material and a preparation method and application thereof, and relates to the technical field of metal composite material forming. First, a honeycomb porous Ta plate is prepared by using an SLM method, then liquid AZ91 magnesium alloy is used as a filling material and is poured into the honeycomb cells of the honeycomb porous Ta plate under the action of pressure by pressure casting, and the honeycomb structure Mg-Ta metal composite material is obtained after cooling. The preparation method has a short process flow and a simple process, is suitable for the preparation of lightweight Mg-Ta metal composite materials, and has high strength, strong size and mass stability, and is especially suitable for the processing and manufacturing of radiation-resistant lightweight Mg-Ta composite materials for shielding structures of deep space probes.

Description

Technical Field

[0001] This invention relates to the field of metal composite material molding technology, and in particular to a honeycomb structure Mg-Ta metal composite material, its preparation method and application. Background Technology

[0002] With the continuous development of deep space exploration technology, my country's deep space exploration activities are gradually moving towards deeper and farther reaches. However, the high-energy charged particles in the deep space environment have extremely strong penetrating power and are particularly prone to causing space electron radiation, which can damage the delicate electronic components inside spacecraft and hinder the normal progress of exploration activities. NASA has achieved good electron shielding effects by using high atomic number metals such as niobium and tantalum in the "Juno" Jupiter probe. However, considering the impact of spacecraft weight reduction and payload capacity, there is an urgent need to develop a lightweight material that also has the ability to resist high-energy particle radiation to replace high atomic number metals such as niobium and tantalum. This is of great significance for promoting the development of deep space exploration.

[0003] Analysis and calculations of radiation-resistant material systems show that, at the same areal density, a combination of low atomic number (e.g., Mg) and high atomic number (Ta) materials can achieve better shielding than a single high atomic number material, while also effectively reducing weight. However, due to the significant differences in the physicochemical properties of Mg and Ta, they are difficult to obtain through traditional processing methods.

[0004] In the prior art, regarding the preparation and molding of Mg-Ta composite materials, Chinese patent publication CN 116037653A reports a Mg-Ta composite plate and its preparation method. While this method can produce molded Mg-Ta composite plates, it has high requirements for the initial microstructure of the magnesium alloy raw material (AZ-based magnesium alloy plates with bimodal separation non-basal surface texture). Furthermore, the plate preparation process involves steps such as energizing the rolls, multiple cryogenic treatments, and thermal diffusion annealing, resulting in relatively complex processes, high requirements for rolling equipment and process parameters, and low production efficiency. Chinese patent publication CN116372344A reports a method for preparing Mg-Ta layered composite metal plates through hot isostatic pressing diffusion bonding. Although this method can achieve the processing and preparation of Mg-Ta composite plates, it involves the use of Al as an intermediate layer material, similarly resulting in relatively complex processes, high requirements for equipment and process parameters, and low production efficiency. Moreover, the above methods are mostly for preparing Mg-Ta layered composite plates; no method for preparing the Mg-Ta metal composite material described in this paper has been found. Summary of the Invention

[0005] To address the low production efficiency of existing Mg-Ta composite metal material preparation processes and the poor interfacial bonding in the preparation of Mg-Ta dissimilar metal composites using conventional processing methods, this paper proposes a combined SLM (selective laser melting) and pressure casting method for preparing Mg-Ta metal composites. This method enables strong metallurgical bonding at the interface, resulting in Mg-Ta composite metal materials with excellent comprehensive performance, and further promotes the engineering application of this type of composite material.

[0006] One of the objectives of this invention is to provide a method for preparing Mg-Ta metal composite materials.

[0007] The second objective of this invention is to provide a Mg-Ta metal composite material prepared by this method.

[0008] The third objective of this invention is to provide an application of this Mg-Ta metal composite material in the preparation of airborne detectors.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0010] In a first aspect, the present invention provides a method for preparing a Mg-Ta metal composite material, comprising the following steps:

[0011] S1. Honeycomb porous Ta plates were prepared using selective laser melting (SLM); wherein the laser power used in SLM was 400-500W, the scanning rate was 100-150mm / s, and the energy density was 240-450J / mm². 3 ;

[0012] S2. Under a protective atmosphere, the cleaned AZ91 magnesium alloy is melted to obtain molten AZ91 magnesium alloy liquid.

[0013] S3. Molten AZ91 magnesium alloy liquid is poured into the honeycomb pores of the honeycomb porous Ta plate under pressure as filler, and then cooled.

[0014] S4. The surface of the cast Mg-Ta metal composite material is leveled and cleaned to remove the residual AZ91 magnesium alloy on the surface after casting, so as to obtain a Mg-Ta metal composite material with a honeycomb structure.

[0015] The following is a detailed explanation:

[0016] Step S1:

[0017] In some implementations, step S1 specifically includes the following steps:

[0018] S11. Place the pure Ta powder in a vacuum drying oven for preheating. The preheating time is 0.5-1h and the preheating temperature is 100-200℃.

[0019] S12. Draw a three-dimensional model of the honeycomb porous Ta plate on a computer using three-dimensional design software, and generate a honeycomb porous Ta plate entity.

[0020] S13. The honeycomb porous Ta plate solid is transferred to the slicing software for slicing and then imported into the laser selective melting additive manufacturing equipment.

[0021] S14. Turn on the laser selective melting additive manufacturing equipment, set the printing parameters, and print the honeycomb porous Ta plate to obtain the honeycomb porous Ta plate; the printing parameters include: laser power of 400-500W, scanning rate of 100-150mm / s, and energy density of 240-450J / mm². 3 ;

[0022] Preferably, in step S11, the pure Ta powder has a particle size of 15-45 μm and a purity of ≥99.9%.

[0023] Preferably, in step S12, the honeycomb porous Ta plate has a honeycomb pore wall thickness of 0.5-1mm, the honeycomb pores are regular hexagons with a side length of 5-10mm, and a height of 2-4mm.

[0024] Preferably, in step S12, the honeycomb porous Ta plate has a honeycomb cell wall thickness of 1-1.5 mm, the honeycomb cells are regular hexagons with a side length of 10-15 mm and a height of 5-10 mm, and the inner wall of the honeycomb cells has uniformly distributed hollow holes with a diameter of 1-2 mm.

[0025] Step S2:

[0026] In some embodiments, step S2 specifically includes: placing the cleaned AZ91 magnesium alloy in an induction furnace filled with argon gas for melting, with the temperature controlled in the range of 650 to 700°C; and removing the surface slag from the molten AZ91 magnesium alloy liquid after melting.

[0027] Step S3:

[0028] In some embodiments, the process conditions for step S3 include: being carried out under a protective atmosphere, a casting temperature of 680–700°C, a casting pressure of 15–30 MPa, and natural cooling after casting.

[0029] This can be achieved using a general-purpose die-casting machine.

[0030] Step S4:

[0031] In some implementations, in step S4, a lathe or wire cutting is used to flatten and clean the surface to remove the AZ91 magnesium alloy residue remaining on the surface after casting.

[0032] The principle of this invention is as follows: The honeycomb structure Mg-Ta metal composite material of this invention is prepared by a combined SLM and pressure casting method. First, a honeycomb porous Ta plate is prepared by SLM (laser power 400-500W, scanning rate 100-150mm / s, energy density 240-450J / mm). 3 Secondly, liquid AZ91 magnesium alloy at 680–700℃ is used as filler and cast into the honeycomb lattice of a honeycomb porous Ta plate under pressure using a pressure casting method. All the above steps are carried out under a protective atmosphere, effectively avoiding oxidation at the bonding interface. The SLM method can prepare honeycomb porous Ta plates with excellent microstructure and properties. Simultaneously, casting at a relatively high temperature of 680–700℃ allows for a metallurgical reaction between aluminum and Ta elements in the AZ91 magnesium alloy, resulting in a certain degree of metallurgical bonding at the Mg-Ta interface, ensuring the overall molding of the composite material. The entire process avoids the formation of a surface oxide layer, ensuring the interfacial bonding strength. Furthermore, the process flow is relatively simple, involving SLM and pressure casting. Therefore, this method has high preparation efficiency for Mg-Ta metal composites, is suitable for the preparation of Mg-Ta metal composites, and produces Mg-Ta metal composites with excellent mechanical properties and strong dimensional and quality stability.

[0033] Secondly, the present invention provides a Mg-Ta metal composite material, which is prepared by the above-described preparation method.

[0034] Thirdly, the present invention also provides an application of Mg-Ta metal composite material in the preparation of airborne detectors.

[0035] Beneficial effects

[0036] 1. The honeycomb structure Mg-Ta metal composite material of the present invention adopts a combined preparation method of SLM + pressure casting. The SLM method realizes the preparation of honeycomb porous Ta plate, and then the combined pressure casting method fills the honeycomb pores of the honeycomb porous Ta plate with magnesium alloy, realizing the effective composite of magnesium alloy and pure Ta, which can significantly improve the quality of the plate and improve the aerospace carrying capacity.

[0037] 2. The preparation method of the honeycomb structure Mg-Ta metal composite material of the present invention has significant advantages over traditional solid-state composite methods such as rolling diffusion bonding, including shorter production cycle, fewer steps, and avoidance of surface oxidation. Furthermore, due to the use of AZ91 magnesium alloy with high Al content (the aluminum content in AZ91 magnesium alloy is 9%) and the selection of a higher casting temperature, the mutual diffusion of Al and Ta atoms can be promoted, forming a better interfacial metallurgical bonding effect, thus solving the problem of difficult metallurgical bonding between Ta and Mg alloy.

[0038] 3. The honeycomb structure Mg-Ta metal composite material of the present invention is particularly suitable for the processing and manufacturing of radiation-resistant lightweight composite materials for shielding structures of deep space probes.

[0039] The present invention has been described in detail above; however, the above embodiments are merely illustrative in nature and are not intended to limit the invention. Furthermore, this document is not limited to the foregoing prior art or the invention itself, or to any theory described in the following embodiments. Attached Figure Description

[0040] Figure 1 A process flow diagram for preparing the honeycomb structure Mg-Ta metal composite material of the present invention is shown;

[0041] Figure 2 A schematic diagram of the honeycomb structure Mg-Ta metal composite material of the present invention is shown. Detailed Implementation

[0042] The present invention will be further described below with reference to the embodiments. It should be noted that the following embodiments are provided for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0043] like Figure 1 , Figure 2 As shown, the method for preparing honeycomb structure Mg-Ta metal composite material by SLM + pressure casting includes the following steps:

[0044] Step 1: Preheat the pure Ta powder in a vacuum drying oven;

[0045] Step 2: Draw a 3D model of the honeycomb porous Ta plate on a computer using 3D design software to generate a honeycomb porous Ta plate entity;

[0046] Step 3: Transfer the honeycomb porous Ta plate solid to the slicing software for slicing processing, and then import it into the laser selective melting additive manufacturing equipment;

[0047] Step 4: Turn on the laser selective melting additive manufacturing equipment, set the printing parameters, and print the honeycomb porous Ta plate to obtain the honeycomb porous Ta plate.

[0048] Step 5: Under a protective atmosphere, melt the cleaned AZ91 magnesium alloy to obtain molten AZ91 magnesium alloy liquid;

[0049] Step 6: The molten AZ91 magnesium alloy liquid is poured into the honeycomb lattice of the honeycomb porous Ta plate under pressure as filler, and then cooled.

[0050] Step 7: After casting, the well-filled Mg-Ta metal composite material (AZ91 magnesium alloy fills the honeycomb cavity) is smoothed and cleaned to remove the residual AZ91 magnesium alloy on the surface after casting, thus obtaining a Mg-Ta metal composite material with a honeycomb structure.

[0051] In the above technical solution, both pure Ta powder and AZ91 magnesium alloy can be commercially available. The pure Ta powder has a particle size of 15-45μm and a purity of ≥99.9%.

[0052] In the above technical solution, in step one, the preheating time is 0.5-1 hour and the preheating temperature is 100-200℃;

[0053] In the above technical solution, in step four, the laser power is 400-500W, the scanning rate is 100-150mm / s, and the energy density is 240-450J / mm. 3 The inner wall of a honeycomb structure may or may not have holes.

[0054] In step five of the above technical solution, the cleaned AZ91 magnesium alloy is placed in an induction furnace filled with argon gas for melting; the temperature is controlled within the range of 650–700°C, and the surface slag of the molten magnesium alloy is removed after melting. However, it should be noted that there are no other specific requirements for the melting equipment, and other melting methods well known to those skilled in the art are also applicable to this invention.

[0055] In step six of the above technical solution, it is preferable to use pressure casting to cast liquid AZ91 magnesium alloy as filler into the honeycomb pores of the honeycomb porous Ta plate under pressure. The preferred pressure casting process conditions are: carried out under a protective atmosphere, casting temperature of 680-700℃, and natural cooling after casting. However, it should be noted that there are no other specific requirements for the equipment, and other casting methods known to those skilled in the art are also applicable to this invention.

[0056] In the above technical solution, step seven preferably uses a lathe or wire cutting to flatten and clean the surface, removing the AZ91 magnesium alloy residue on the surface after casting. However, it should be noted that other surface flattening and cleaning processes known to those skilled in the art are also applicable to this invention.

[0057] The terminology used in this invention generally has the meanings commonly understood by those skilled in the art, unless otherwise stated. To enable those skilled in the art to better understand the technical solutions of this invention, the invention will be further described in detail below with reference to embodiments.

[0058] In the following embodiments, various processes and methods not described in detail are conventional methods known in the art. Unless otherwise specified, the materials, reagents, apparatus, instruments, equipment, etc., used in the following embodiments are commercially available.

[0059] The laser selective melting additive manufacturing equipment comes from the SLM-250 laser selective melting 3D printing equipment from North China University of Technology.

[0060] The pressure casting equipment is from L.K. DCC280 die casting machine;

[0061] The pure Ta powder is commercially available high-purity Ta powder with a particle size of 15-45 μm and a purity of ≥99.9%.

[0062] AZ91 magnesium alloy is a commercially available AZ91 magnesium alloy ingot.

[0063] Example 1

[0064] The method for preparing honeycomb structured Mg-Ta metal composite material by SLM + pressure casting includes the following steps:

[0065] Step 1: Place the pure Ta powder (particle size of pure Ta powder is 15-45μm, purity ≥99.9%) in a vacuum drying oven for preheating for 1 hour at a temperature of 200℃.

[0066] Step 2: Draw a 3D model of the honeycomb porous Ta plate on a computer using 3D design software to generate a honeycomb porous Ta plate entity;

[0067] Step 3: Transfer the honeycomb porous Ta plate solid to the slicing software for slicing processing, and then import it into the laser selective melting additive manufacturing equipment;

[0068] Step 4: Turn on the laser selective melting additive manufacturing equipment, set the printing parameters, and print the honeycomb porous Ta plate to obtain the honeycomb porous Ta plate. The printing parameters include: laser power of 500W, scanning rate of 150mm / s, and energy density of 450J / mm². 3 The honeycomb cell wall thickness is 1mm, and the honeycomb cell is a regular hexagon with a side length of 5mm and a height of 4mm.

[0069] Step 5: Under a protective atmosphere, melt the clean AZ91 magnesium alloy to obtain molten AZ91 magnesium alloy liquid (temperature controlled within the range of 650-700℃). After melting, remove the surface slag from the molten magnesium alloy liquid.

[0070] Step 6: Liquid AZ91 magnesium alloy is used as filler and cast into the honeycomb cells of the honeycomb porous Ta plate under pressure (under a protective atmosphere, casting temperature is 680-700℃, and it is naturally cooled after casting).

[0071] Step 7: After casting, the well-filled Mg-Ta metal composite material is cleaned using a lathe or wire cutting machine to remove the residual AZ91 magnesium alloy on the surface, thus obtaining a Mg-Ta metal composite material with a honeycomb structure.

[0072] Example 2

[0073] The method for preparing honeycomb structured Mg-Ta metal composite material by SLM + pressure casting includes the following steps:

[0074] Step 1: Place the pure Ta powder (particle size of pure Ta powder is 15-45μm, purity ≥99.9%) in a vacuum drying oven for preheating for 0.5h at a temperature of 100℃.

[0075] Step 2: Draw a 3D model of the honeycomb porous Ta plate on a computer using 3D design software to generate a honeycomb porous Ta plate entity;

[0076] Step 3: Transfer the honeycomb porous Ta plate solid to the slicing software for slicing processing, and then import it into the laser selective melting additive manufacturing equipment;

[0077] Step 4: Turn on the laser selective melting additive manufacturing equipment, set the printing parameters, and print the honeycomb porous Ta plate to obtain the honeycomb porous Ta plate. The printing parameters include: laser power of 400W, scanning rate of 100mm / s, and energy density of 240J / mm². 3 The honeycomb cell wall thickness is 1.5mm, the honeycomb cell is a regular hexagon with a side length of 10mm and a height of 5mm, and the inner wall of the honeycomb cell has evenly distributed hollow holes with a diameter of 1-2mm.

[0078] Step 5: Under a protective atmosphere, melt the clean AZ91 magnesium alloy to obtain molten AZ91 magnesium alloy liquid (temperature controlled within the range of 650-700℃). After melting, remove the surface slag from the molten magnesium alloy liquid.

[0079] Step 6: Liquid AZ91 magnesium alloy is used as filler and cast into the honeycomb cells of the honeycomb porous Ta plate under pressure (under a protective atmosphere, casting temperature is 680-700℃, and it is naturally cooled after casting).

[0080] Step 7: After casting, the well-filled Mg-Ta metal composite material is cleaned using a lathe or wire cutting machine to remove the residual AZ91 magnesium alloy on the surface, thus obtaining a Mg-Ta metal composite material with a honeycomb structure.

[0081] Compared to Example 1, adding holes to the inner wall of the honeycomb structure can further reduce the weight of the material and facilitate the subsequent tight bonding of Ta material and AZ91 magnesium alloy.

[0082] Comparative Example 1

[0083] The only difference between this comparative example and Example 1 is that the AZ91 magnesium alloy is replaced with the AZ31 magnesium alloy.

[0084] Comparative Example 2

[0085] The only difference between this comparative example and Example 1 is that it was cast under no pressure.

[0086] Comparative Example 3

[0087] The only difference between this comparative example and Example 1 is that the honeycomb cell wall thickness is 2mm and the honeycomb cell is a regular hexagon with a side length of 10mm.

[0088] Comparative Example 4

[0089] The only difference between this comparative example and Example 1 is that the SLM process parameters are different, with a scanning rate of 200-250 mm / s.

[0090] The honeycomb structure Mg-Ta metal composite materials prepared in Examples 1-2 and Comparative Examples 1-4 were tested, and the results are as follows.

[0091] The surface and internal quality of the prepared honeycomb structure Mg-Ta metal composite material were observed by field emission electron microscopy (SEM). The compressive strength was tested using a universal testing machine. It was found that the honeycomb structure Mg-Ta metal composite material prepared in Example 1 had good surface quality, good honeycomb pore filling, good bonding between the Mg and Ta dissimilar metal interfaces, and a compressive strength of 120 MPa. The AZ91-Ta interface diffusion width was 2 μm, indicating good interfacial bonding.

[0092] The prepared honeycomb structure Mg-Ta metal composite material was subjected to surface and internal quality tests, compressive strength tests, and field emission electron microscopy (SEM) observation. It was found that the honeycomb structure Mg-Ta metal composite material prepared in Example 2 had good surface quality, good honeycomb pore filling, good bonding between the Mg and Ta dissimilar metal interfaces, a compressive strength of 100 MPa, and an AZ91-Ta interface diffusion width of 2 μm, indicating good interfacial bonding.

[0093] The honeycomb structure Mg-Ta metal composite material prepared in Comparative Example 1 has good surface quality and good honeycomb pore filling. However, the bonding between the Mg and Ta dissimilar metal interfaces is poor. The compressive strength of the Mg-Ta metal composite material is 85 MPa, and the diffusion width of the AZ31-Ta interface is 0 μm. There is no metallurgical bonding at the interface, indicating that the use of AZ91 magnesium alloy can effectively improve the interfacial bonding ability.

[0094] The honeycomb structure Mg-Ta metal composite material prepared in Comparative Example 2 has poor surface quality and many macroscopic casting defects. The honeycomb cells are not fully filled, and there are many gaps and pores. The compressive strength of the Mg-Ta metal composite material is 80 MPa, indicating that pressure casting can effectively improve the filling ability of magnesium alloy and promote the successful preparation of honeycomb structure Mg-Ta metal composite material.

[0095] The honeycomb structure Mg-Ta metal composite material prepared in Comparative Example 3 has good surface quality, good honeycomb cell filling, and good bonding between the Mg and Ta dissimilar metal interfaces. The compressive strength of the Mg-Ta metal composite material is 90 MPa, and the overall weight of the plate is significantly increased. This indicates that the appropriate honeycomb cell wall thickness and honeycomb cell size are key factors in the overall lightweight manufacturing of the plate.

[0096] The honeycomb structure Mg-Ta metal composite material prepared in Comparative Example 4 has good surface quality, good honeycomb pore filling, and good bonding between the Mg and Ta dissimilar metal interfaces. The compressive strength of the Mg-Ta metal composite material is 100 MPa. Due to the increase in scanning speed, there are more pore defects inside the SLM structure, indicating that the SLM scanning rate is a key factor in the controllable manufacturing of the overall quality of the plate.

[0097] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and substance defined by the claims of the present invention; and such modifications or substitutions are still within the scope defined by the claims of the present invention.

Claims

1. A method for producing a Mg-Ta metal composite, characterized by, The method comprises the following steps: S1, preparing a honeycomb porous Ta plate by using a laser selective melting method; S2, melting the surface-cleaned AZ91 magnesium alloy under a protective atmosphere to obtain a molten AZ91 magnesium alloy liquid; S3, pouring the molten AZ91 magnesium alloy liquid as a filler into the honeycomb cells of the honeycomb porous Ta plate under the action of pressure and cooling; S4, performing surface leveling and cleaning on the poured Mg-Ta metal composite material to remove the residual AZ91 magnesium alloy on the surface after pouring, and obtaining a Mg-Ta metal composite material with a honeycomb structure; Step S1 specifically comprises the following steps: S11, preheating the pure Ta powder in a vacuum drying box, the preheating time is 0.5-1h, and the preheating temperature is 100-200℃; S12, drawing a three-dimensional model of the honeycomb porous Ta plate on a computer through a three-dimensional design software to generate a honeycomb porous Ta plate entity; S13, transmitting the honeycomb porous Ta plate entity to a slicing software for slicing processing and then importing into a laser selective melting additive manufacturing equipment; S14, turn on the laser selective melting additive manufacturing equipment, set the printing parameters, print the honeycomb porous Ta plate entity, and obtain the honeycomb porous Ta plate; wherein the printing parameters include: the laser power is 400-500 W, the scanning speed is 100-150 mm / s, and the energy density is 240-450 J / mm 3 ; In step S12, the honeycomb cell wall thickness of the honeycomb porous Ta plate is 0.5-1mm, the honeycomb cell is a regular hexagon with a side length of 5-10mm, and the height of the honeycomb cell is 2-4mm; or The honeycomb cell wall thickness of the honeycomb porous Ta plate is 1-1.5mm, the honeycomb cell is a regular hexagon with a side length of 10-15mm, the height is 5-10mm, and the inner wall of the honeycomb cell is uniformly distributed with hollow holes with a diameter of 1-2mm; The process conditions of step S3 include: being carried out under a protective atmosphere, the pouring temperature is 680-700℃, the pouring pressure is 15-30MPa, and the natural cooling after pouring.

2. The production method according to claim 1, characterized by, In step S11, the particle size of the pure Ta powder is 15-45μm, and the purity is ≥99.9%.

3. The preparation method according to claim 1, characterized in that, Step S2 specifically comprises: placing the surface-cleaned AZ91 magnesium alloy in an induction furnace with argon flowing to melt, the temperature is controlled in the range of 650-700℃; and removing the surface dross of the molten AZ91 magnesium alloy liquid after melting.

4. The preparation method according to claim 1, characterized in that, In step S4, a lathe or a wire cutting machine is used for surface leveling and cleaning to remove the residual AZ91 magnesium alloy on the surface after pouring.

5. A Mg-Ta metal composite material prepared by the preparation method of any one of claims 1-4.

6. An application of the Mg-Ta metal composite material of claim 5 in preparing an aviation detector.

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