W-Cu gradient composite material containing pure W layer and preparation method of W-Cu gradient composite material

Abstract

The invention discloses a W-Cu gradient composite material containing a pure W layer and a preparation method of the W-Cu gradient composite material, and belongs to the technical field of tungsten-copper composites.The preparation method comprises the steps that W powder is dried for 6-8 h at the temperature of 150-160 DEG C, the pretreated W-Cu gradient composite material is preheated for 2 h at the temperature of 200-300 DEG C, then the dried W powder is laid at the W-rich end of the W-Cu gradient composite material, and the W-Cu gradient composite material containing the pure W layer is obtained; performing laser cladding on the W-Cu gradient composite material paved with the W powder in a protective gas atmosphere to obtain a W-Cu gradient composite material containing a pure W layer; the pure W layer is prepared on the surface of the W-Cu gradient material through the laser cladding method, diffusion of Cu can be effectively restrained, the density of the pure W layer is improved, and meanwhile the high-purity characteristic of the pure W layer is guaranteed; the preparation method has the characteristics of high efficiency, flexible processing and accuracy, and is suitable for industrial popularization and application.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tungsten-copper composite materials, and particularly relates to a W-Cu gradient composite material containing a pure W layer and a preparation method thereof. BACKGROUND

[0002] The W-Cu gradient composite material has high melting point, high strength and low expansion characteristics of W (tungsten) and high thermal conductivity and electrical conductivity of Cu (copper), and through design of continuous composition transition from the high-thermal-conductivity zone (Cu-rich end) to the high-strength heat-resistant zone (W-rich end), the thermal stress concentration can be effectively relieved, and the structural reliability under extreme thermal cycling can be improved. In the high-temperature thermal management field, the W-Cu gradient composite material has irreplaceable application value. However, the highest W content of the gradient layer of the current W-Cu gradient composite material is usually limited by the traditional preparation process (such as powder metallurgy and infiltration method), and it is difficult to realize a 100% pure W surface layer, which restricts the load capacity of the material at ultra-high temperature.

[0003] In the existing preparation process of the W-Cu gradient composite material, the formation of the pure W layer faces the following technical bottlenecks: Infiltration method defects: the molten Cu-based liquid phase diffuses along the interlayer interface in the infiltration process, causing passive dilution of the W content at the W-rich end and destroying the preset composition gradient. Powder layering method defects: due to the difference between the thermal expansion coefficients and the sintering shrinkage rates of adjacent gradient layers, stress concentration occurs between the layers, causing interface delamination or macroscopic cracking failure of the material during the sintering stage.

[0004] A Chinese patent with the publication number CN113976885A discloses a preparation method of a W-Cu gradient composite material. The method uses a melting-infiltration-welding and hot isostatic pressing method to prepare the W-Cu gradient composite material. The tungsten element in the raw material used in the method has a mass percentage upper limit of 95%, and the composite layered structure does not contain a single-component dense tungsten layer; in the melting-infiltration-welding process, the copper-based molten liquid phase diffuses and penetrates along the interlayer gap, causing a decrease in the W content.

[0005] A Chinese patent with the publication number CN118045994A discloses a preparation method of a W-Cu gradient composite material. The method mixes W powder and Cu powder according to a preset ratio, and obtains the W-Cu gradient composite material through static pressing and sintering. However, the W percentage content at the heat-resistant end has an upper limit of 97%, and there is no pure W region in the gradient interval.

[0006] In summary, the preparation of the pure W layer of the W-Cu gradient composite material is limited by the process, which affects the actual application of the W-Cu gradient composite material in specific fields. Therefore, it is urgent to develop a short-time and high-efficiency preparation method of the W-Cu gradient composite material containing a pure W layer and capable of meeting performance requirements. SUMMARY

[0007] The application aims to provide a W-Cu gradient composite material containing a pure W layer and a preparation method thereof.

[0008] The application can achieve the above-mentioned purpose by the following technical solutions. The W-Cu gradient composite material containing a pure W layer is composed of a W-Cu gradient composite material and a pure W layer cladded on the W-rich end of the W-Cu gradient composite material, wherein the density of the pure W layer is 95.2%-99.1%, and the Vickers hardness is 310.7-349.2 HV.

[0009] The application further provides a preparation method of the W-Cu gradient composite material containing a pure W layer. The W powder is dried at 150-160 DEG C for 6-8 h, the pretreated W-Cu gradient composite material is preheated at 200-300 DEG C for 2 h, the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W-Cu gradient composite material laid with the W powder is cladded by laser in a protective gas atmosphere to obtain the W-Cu gradient composite material containing a pure W layer.

[0010] Further, the parameters of the laser cladding are as follows: the laser power is 3.5-5.5 kW, the spot diameter is 2-3 mm, and the scanning speed is 4-6 mm / s.

[0011] Further, the pretreatment method of the W-Cu gradient composite material is as follows: the surface of the W-Cu gradient composite material is polished by using 1200-mesh sandpaper, and then the surface of the W-rich end of the W-Cu gradient composite material is cleaned by ultrasonic cleaning with anhydrous ethanol as a medium to remove the oxide layer and other contaminants on the surface of the W-rich end of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0012] Further, the average particle size of the W powder is 100 mu m, and the purity of the W powder is greater than or equal to 99.99%.

[0013] Further, the W content of the W-rich end of the W-Cu gradient composite material is 3wt%-10wt%.

[0014] Further, the laying thickness of the W powder is 1 mm.

[0015] Further, the protective gas used in the laser cladding is argon, and the flow rate of the protective gas is 15 L / min.

[0016] The application has the following beneficial effects. 1. The present application prepares a pure W layer on the surface of a W-Cu gradient material by a laser cladding method, and effectively overcomes the copper phase infiltration problem between adjacent component layers caused by long-time sintering in the conventional W-Cu gradient composite material preparation process by precisely controlling the laser cladding parameters and selectively targeting the tungsten powder particle size, thereby improving the density of the pure W layer while ensuring its high purity characteristics.

[0017] 2. The present application can prepare a pure W layer of the desired thickness through repeated powder laying and cladding processes, and has the characteristics of high efficiency, flexible processing and accuracy, and is suitable for industrial popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Figure 1 is an SEM morphology diagram of a W-Cu gradient composite material containing a pure W layer according to Embodiment 1 of the present application.

[0019] Figure 2 Figure 2 is an SEM morphology diagram of a W-Cu gradient composite material containing a pure W layer according to Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0021] Embodiment 1: The present embodiment provides a W-Cu gradient composite material containing a pure W layer, which is prepared by the following preparation method: S1: The surface of the W-Cu gradient composite material is polished with 1200 mesh sandpaper, and then ultrasonic cleaning is performed with anhydrous ethanol as the medium to remove the oxidation layer and other contaminants on the W-rich end surface of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0022] S2: The W powder with an average particle size of 100 μm is placed in a drying oven and dried at 160℃ for 8h, and the purity of the W powder is ≥99.99%.

[0023] S3: The pretreated W-Cu gradient composite material is preheated at 250℃ for 2h, and then the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 3wt%, and the laying thickness of the W powder is 1mm.

[0024] S4: The W-Cu gradient composite material with W powder laid thereon is subjected to laser cladding to obtain a W-Cu gradient composite material containing a pure W layer.

[0025] The parameters of laser cladding are as follows: laser power is 3.5 kW, spot diameter is 2 mm, scanning speed is 4 mm / s, flow rate of protective gas is 15 L / min, and the protective gas used is argon.

[0026] The W-Cu gradient composite material prepared in Example 1 was observed for morphology by using a Hitachi SU8020 cold field emission scanning electron microscope (see Figure 1 ).

[0027] As shown in Figure 1 , the prepared W-Cu gradient composite material with a pure W layer has a smooth surface, no cracks, good combination of the pure W layer and the W-Cu gradient composite material, no Cu element penetration, and high purity of composition.

[0028] As shown in Figure 1 , the prepared W-Cu gradient composite material with a pure W layer has a smooth surface, no cracks, good combination of the pure W layer and the W-Cu gradient composite material, no Cu element penetration, and high purity of composition.

[0029] Example 2: The present example provides a W-Cu gradient composite material with a pure W layer, which is prepared by the following preparation method: S1: The surface of the W-Cu gradient composite material is polished by using 1200 mesh sandpaper, and then ultrasonic cleaning is performed by using anhydrous ethanol as the medium to remove the oxide layer and other contaminants on the W-rich end surface of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0030] S2: The W powder with an average particle size of 100 μm is placed in a drying box and dried at 155°C for 7 h, and the purity of the W powder is ≥99.99%.

[0031] S3: The pretreated W-Cu gradient composite material is preheated at 200°C for 2 h, and then the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 10 wt%, and the laying thickness of the W powder is 1 mm.

[0032] S4: The W-Cu gradient composite material with the laid W powder is subjected to laser cladding to obtain a W-Cu gradient composite material with a pure W layer.

[0033] The parameters of laser cladding are as follows: laser power is 3.5 kW, spot diameter is 2.5 mm, scanning speed is 5 mm / s, flow rate of protective gas is 15 L / min, and the protective gas used is argon.

[0034] Example 3: The present example provides a W-Cu gradient composite material with a pure W layer, which is prepared by the following preparation method: S1: polish the surface of the W-Cu gradient composite material with 1200 mesh sandpaper, and then perform ultrasonic cleaning with anhydrous ethanol as the medium to remove the oxide layer and other contaminants on the W-rich end surface of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0035] S2: place W powder with an average particle size of 100 pm into a drying box and dry at 150°C for 6h, and the purity of the W powder is greater than or equal to 99.99%.

[0036] S3: preheat the pretreated W-Cu gradient composite material at 200°C for 2h, and then lay the dried W powder on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 5wt%, and the laying thickness of the W powder is 1mm.

[0037] S4: perform laser cladding on the W-Cu gradient composite material with W powder laid thereon to obtain a W-Cu gradient composite material containing a pure W layer.

[0038] The laser cladding parameters are: laser power is 3.5kW, spot diameter is 3mm, scanning speed is 6mm / s, flow rate of protective gas is 15L / min, and the protective gas used is argon.

[0039] Example 4: A W-Cu gradient composite material containing a pure W layer is provided, which is prepared by the following preparation method: S1: polish the surface of the W-Cu gradient composite material with 1200 mesh sandpaper, and then perform ultrasonic cleaning with anhydrous ethanol as the medium to remove the oxide layer and other contaminants on the W-rich end surface of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0040] S2: place W powder with an average particle size of 100 pm into a drying box and dry at 150°C for 6h, and the purity of the W powder is greater than or equal to 99.99%.

[0041] S3: preheat the pretreated W-Cu gradient composite material at 250°C for 2h, and then lay the dried W powder on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 5wt%, and the laying thickness of the W powder is 1mm.

[0042] S4: perform laser cladding on the W-Cu gradient composite material with W powder laid thereon to obtain a W-Cu gradient composite material containing a pure W layer.

[0043] The laser cladding parameters are: laser power is 4.5kW, spot diameter is 2.5mm, scanning speed is 4mm / s, flow rate of protective gas is 15L / min, and the protective gas used is argon.

[0044] Embodiment 5: The embodiment provides a W-Cu gradient composite material containing a pure W layer, which is prepared by the following method: S1: The surface of the W-Cu gradient composite material is polished by using 1200-mesh sandpaper, and then ultrasonic cleaning is performed by using anhydrous ethanol as a medium to remove the oxide layer and other contaminants on the surface of the W-rich end of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0045] S2: The W powder with an average particle size of 100 μm is placed in a drying box and dried at 150°C for 6 h, and the purity of the W powder is ≥99.99%.

[0046] S3: The pretreated W-Cu gradient composite material is preheated at 250°C for 2 h, and then the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 5 wt%, and the laying thickness of the W powder is 1 mm.

[0047] S4: The W-Cu gradient composite material laid with the W powder is subjected to laser cladding to obtain the W-Cu gradient composite material containing a pure W layer.

[0048] The parameters of the laser cladding are as follows: the laser power is 4.5 kW, the spot diameter is 3 mm, the scanning speed is 5 mm / s, the flow rate of the protective gas is 15 L / min, and the protective gas used is argon.

[0049] Embodiment 6: The embodiment provides a W-Cu gradient composite material containing a pure W layer, which is prepared by the following method: S1: The surface of the W-Cu gradient composite material is polished by using 1200-mesh sandpaper, and then ultrasonic cleaning is performed by using anhydrous ethanol as a medium to remove the oxide layer and other contaminants on the surface of the W-rich end of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0050] S2: The W powder with an average particle size of 100 μm is placed in a drying box and dried at 150°C for 6 h, and the purity of the W powder is ≥99.99%.

[0051] S3: The pretreated W-Cu gradient composite material is preheated at 250°C for 2 h, and then the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 5 wt%, and the laying thickness of the W powder is 1 mm.

[0052] S4: The W-Cu gradient composite material laid with the W powder is subjected to laser cladding to obtain the W-Cu gradient composite material containing a pure W layer.

[0053] The parameters of laser cladding are as follows: laser power is 4.5 kW, spot diameter is 2 mm, scanning speed is 6 mm / s, flow rate of protective gas is 15 L / min, and the protective gas used is argon.

[0054] Embodiment 7: The embodiment provides a W-Cu gradient composite material containing a pure W layer, which is prepared by the following preparation method. S1: The surface of the W-Cu gradient composite material is polished by using 1200-mesh sandpaper, and then ultrasonic cleaning is performed by using anhydrous ethanol as a medium to remove the oxide layer and other contaminants on the surface of the W-rich end of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0055] S2: The W powder with an average particle size of 100 μm is placed in a drying box and dried at 150°C for 6 h, and the purity of the W powder is ≥99.99%.

[0056] S3: The pretreated W-Cu gradient composite material is preheated at 250°C for 2 h, and then the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 5 wt%, and the laying thickness of the W powder is 1 mm.

[0057] S4: The W-Cu gradient composite material laid with the W powder is subjected to laser cladding to obtain the W-Cu gradient composite material containing a pure W layer.

[0058] The parameters of laser cladding are as follows: laser power is 5.5 kW, spot diameter is 3 mm, scanning speed is 4 mm / s, flow rate of protective gas is 15 L / min, and the protective gas used is argon.

[0059] Embodiment 8: The embodiment provides a W-Cu gradient composite material containing a pure W layer, which is prepared by the following preparation method. S1: The surface of the W-Cu gradient composite material is polished by using 1200-mesh sandpaper, and then ultrasonic cleaning is performed by using anhydrous ethanol as a medium to remove the oxide layer and other contaminants on the surface of the W-rich end of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0060] S2: The W powder with an average particle size of 100 μm is placed in a drying box and dried at 150°C for 6 h, and the purity of the W powder is ≥99.99%.

[0061] S3: The pretreated W-Cu gradient composite material is preheated at 250°C for 2 h, and then the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 5 wt%, and the laying thickness of the W powder is 1 mm.

[0062] S4: laser cladding the W-Cu gradient composite material on which the W powder is laid to obtain the W-Cu gradient composite material containing a pure W layer.

[0063] The parameters of the laser cladding are as follows: the laser power is 5.5 kW, the spot diameter is 2 mm, the scanning speed is 5 mm / s, the flow rate of the protective gas is 15 L / min, and the protective gas used is argon.

[0064] Embodiment 9: The embodiment provides a W-Cu gradient composite material containing a pure W layer, which is prepared by the following preparation method. S1: The surface of the W-Cu gradient composite material is polished by using 1200-mesh sandpaper, and then ultrasonic cleaning is performed by using anhydrous ethanol as a medium to remove the oxide layer and other contaminants on the W-rich end surface of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

[0065] S2: The W powder with an average particle size of 100 μm is placed in a drying box and dried at 150 °C for 6 h, and the purity of the W powder is ≥ 99.99%.

[0066] S3: The pretreated W-Cu gradient composite material is preheated at 250 °C for 2 h, and then the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W content of the W-rich end is 5 wt%, and the laying thickness of the W powder is 1 mm.

[0067] S4: The W-Cu gradient composite material on which the W powder is laid is subjected to laser cladding to obtain the W-Cu gradient composite material containing a pure W layer.

[0068] The parameters of the laser cladding are as follows: the laser power is 5.5 kW, the spot diameter is 2.5 mm, the scanning speed is 6 mm / s, the flow rate of the protective gas is 15 L / min, and the protective gas used is argon.

[0069] Comparative Example 1: The difference from Embodiment 1 is that the average particle size of the W powder in step S2 is adjusted to 150 μm.

[0070] Comparative Example 2: The difference from Embodiment 1 is that the average particle size of the W powder in step S2 is adjusted to 50 μm.

[0071] The morphology of the W-Cu gradient composite material containing a pure W layer prepared in Comparative Example 2 is observed by using a Hitachi SU8020 cold field emission scanning electron microscope (see Figure 2 ).

[0072] As shown in Figure 2 , the left pure W layer of the prepared W-Cu gradient composite material containing a pure W layer is rough due to the too small powder particle size, and has defects such as holes, agglomeration, and cracks, thereby causing a low material density.

[0073] The W-Cu gradient composite materials containing pure W layer in Example 1-Example 9 and Comparative Example 1-Comparative Example 2 were tested, the density of the pure tungsten layer was detected by scanning electron microscopy, and the Vickers hardness of the pure tungsten layer was detected according to GB / T 4340.1-2024, and the results are shown in Table 1: Table 1 Test results of pure tungsten layer performance As can be seen from the data in Table 1, the density of the W-Cu gradient composite materials containing pure W layer prepared in Example 1-Example 9 is 95.2%-99.1%, and the Vickers hardness is 310.7HV-349.2HV.

[0074] The density and hardness of the materials prepared in Example 3, Example 8 and Example 9 are obviously smaller than those of the materials prepared in other examples. This is because the laser energy is low, the scanning speed is fast, the spot diameter is large, and the energy is relatively dispersed in Example 3, which leads to incomplete sintering of the W powder, so the density and density are relatively low. In Example 8 and Example 9, the laser power is high, which leads to excessive melting depth of the material and increases the dilution rate of the material to the coating, so the density and density are relatively low.

[0075] The density and hardness of the materials prepared in Comparative Example 1 and Comparative Example 2 are smaller than those of the material prepared in Example 1. This is because when the powder particle size is too large, the required energy increases, the internal temperature rises slowly, which leads to incomplete sintering of the W powder, so the density and density are relatively low. When the powder particle size is too small, the specific surface area increases, the energy absorption efficiency is high, which leads to excessive melting depth of the material and increases the dilution rate of the material to the coating and promotes the generation of defects, and the powder particle size is too small to cause agglomeration phenomenon, so the density and density are relatively low.

[0076] It should be noted that in this paper, terms such as "including", "containing" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0077] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the present application.

Claims

1. A method for producing a W-Cu gradient composite material containing a pure W layer, characterized by, Comprising the following steps: The W powder is dried at 150-160 DEG C for 6-8h, the pretreated W-Cu gradient composite material is preheated at 200-300 DEG C for 2h, the dried W powder is laid on the W-rich end of the W-Cu gradient composite material, and the W-Cu gradient composite material laid with the W powder is subjected to laser cladding in a protective gas atmosphere to obtain a W-Cu gradient composite material containing a pure W layer. The parameters of the laser cladding are as follows: laser power is 3.5-5.5kW, spot diameter is 2-3mm, and scanning speed is 4-6mm / s.

2. The method for preparing a W-Cu gradient composite material containing a pure W layer according to claim 1, characterized in that, The pretreatment method of the W-Cu gradient composite material is as follows: The surface of the W-Cu gradient composite material is polished with 1200 mesh sandpaper, and then ultrasonic cleaning is performed with anhydrous ethanol as the medium to remove the oxide layer and other contaminants on the W-rich end surface of the W-Cu gradient composite material, thereby completing the pretreatment of the W-Cu gradient composite material.

3. The method for preparing a W-Cu gradient composite material containing a pure W layer according to claim 1, characterized in that, The average particle size of the W powder is 100μm, and the purity of the W powder is ≥99.99%.

4. The method for preparing a W-Cu gradient composite material containing a pure W layer according to claim 1, characterized in that, The W content of the W-rich end of the W-Cu gradient composite material is 3wt%-10wt%.

5. The method for preparing a W-Cu gradient composite material containing a pure W layer according to claim 1, characterized in that, The laying thickness of the W powder is 1mm.

6. The method for preparing a W-Cu gradient composite material containing a pure W layer according to claim 1, characterized in that, The protective gas is argon, and the flow rate of the protective gas is 15L / min.

7. The method for preparing a W-Cu gradient composite material containing a pure W layer according to claim 1, characterized in that, The density of the pure W layer is 95.2%-99.1%.

8. The method for preparing a W-Cu gradient composite material containing a pure W layer according to claim 1, characterized in that, The Vickers hardness of the pure W layer is 310.7-349.2HV.

9. A W-Cu gradient composite material containing a pure W layer, characterized by, Prepared by the preparation method of any one of claims 1-8.

Images