阅读说明：本技术 一种Cu相呈指状梯度分布的W-Cu复合板的制备方法 (Preparation method of W-Cu composite plate with Cu phases distributed in finger-shaped gradient manner ) 是由 程继贵 周锐 魏邦争 陈鹏起 郑肃 喻新喜 于 2021-10-18 设计创作，主要内容包括：本发明公开了一种Cu相呈指状梯度分布的W-Cu复合板的制备方法,是在W粉中加入以偏钨酸铵为原料通过燃烧合成方法获得的WO-(X)粉末,并加入粘结剂和造孔剂制成浆料,然后通过流延、水中浸泡、烧结获得孔隙呈指状分布的W骨架,再经熔渗Cu获得目标产物。本发明方法制备的W-Cu复合材料中Cu相由熔渗表面至试样内部呈指状梯度分布,且Cu相与W相相互钉扎,W-Cu界面有良好的结合强度；本发明的方法具有材料成分性能可调控、工艺简单、成本低、适合规模化生产等特点。(The invention discloses a preparation method of a W-Cu composite plate with Cu phases distributed in a finger-shaped gradient manner, which is characterized in that ammonium metatungstate is added into W powderWO obtained by combustion synthesis of raw materials X Adding a binder and a pore-forming agent into the powder to prepare slurry, then casting, soaking in water and sintering to obtain a W framework with finger-shaped pores, and infiltrating Cu to obtain a target product. The Cu phase in the W-Cu composite material prepared by the method is distributed in a finger-shaped gradient manner from the infiltration surface to the interior of a sample, the Cu phase and the W phase are mutually pinned, and the W-Cu interface has good bonding strength; the method has the characteristics of adjustable material component performance, simple process, low cost, suitability for large-scale production and the like.)

1. A preparation method of a W-Cu composite plate with Cu phases distributed in a finger-shaped gradient manner is characterized by comprising the following steps:

(1) mixing WO_XMixing the powder and the W powder to obtain a powder mixture; adding the powder mixture, a binder polyether sulfone and a pore-forming agent polyvinylpyrrolidone into an N-methyl pyrrolidone solvent, and uniformly mixing the powder mixture and the binder polyether sulfone together in a planetary ball mill by ball milling to obtain slurry;

(2) casting the slurry on a PET film to obtain a green body, soaking the obtained green body and the PET film in water together to partially remove a solvent N-methylpyrrolidone, then separating the green body from the PET film, and drying;

(3) at H₂Under the atmosphere, pre-sintering the obtained green body at 500-800 ℃ to remove the binder and reduce the green body, and then heating to 800-2000 ℃ to sinter the green body to obtain a W framework with finger-shaped pores;

(4) and infiltrating Cu into the W framework, and then cooling along with the furnace to obtain the W-Cu composite plate with the Cu phase in finger-shaped gradient distribution.

2. The method for preparing a W-Cu composite plate with Cu phase distributed in finger-shaped gradient according to claim 1, wherein the method comprises the following steps: said WO_XThe powder is prepared by taking ammonium metatungstate, ammonium nitrate, glycine and ethylene diamine tetraacetic acid as raw materials, adding deionized water for dispersion, then placing the mixture into a muffle furnace, keeping the temperature at 200 ℃ and performing combustion synthesis.

3. The method for preparing a W-Cu composite plate with Cu phase distributed in finger-shaped gradient according to claim 1, wherein the method comprises the following steps: in step (1), the WO_XThe powder accounts for 0-50 wt% of the mass of the powder mixture; the addition amounts of the polyether sulfone and the polyvinylpyrrolidone are respectively and independently 1-6% of the mass of the powder mixture; the solid content of the slurry is 50-85 wt.%.

4. The method for preparing a W-Cu composite plate with Cu phase distributed in finger-shaped gradient according to claim 1, wherein the method comprises the following steps: in the step (1), the rotation speed of the ball milling is 100-400 r/min, and the ball milling time is 2-48 h.

5. The method for preparing a W-Cu composite plate with Cu phase distributed in finger-shaped gradient according to claim 1, wherein the method comprises the following steps: in the step (2), the thickness of the green body obtained by casting is 200 mu m-2 mm.

6. The method for preparing a W-Cu composite plate with Cu phase distributed in finger-shaped gradient according to claim 1, wherein the method comprises the following steps: in the step (2), when the obtained green body and the PET film are soaked together in water, the PET film is placed below and the green body is placed above, and the sample is ensured to be parallel to the horizontal plane, so that the pore distribution in the green body is controlled, and the soaking time is 12-48 h.

7. The method for preparing a W-Cu composite plate with Cu phase distributed in finger-shaped gradient according to claim 1, wherein the method comprises the following steps: in step (2), when the resulting green body is soaked in water together with the PET film, exchange of water and N-methylpyrrolidone occurs at the interface of the upper surface of the green body and water, and water permeates into the green body, forming finger-shaped pores.

8. The method for preparing a W-Cu composite plate with Cu phase distributed in finger-shaped gradient according to claim 1, wherein the method comprises the following steps: in the step (3), the pre-sintering time of the obtained green body at 500-800 ℃ is 1-4 h, and the sintering time at 800-2000 ℃ is 1-4 h.

9. The method for preparing a W-Cu composite plate with Cu phase distributed in finger-shaped gradient according to claim 1, wherein the method comprises the following steps: in the step (4), the step of infiltrating Cu into the W framework is to infiltrate Cu into N in an infiltration sintering furnace₂Or H₂Under the protection of atmosphere, placing a pure purple Cu block or an electrolytic Cu powder compact on the surface of a W skeleton with finger-shaped holes, heating to melt Cu, and infiltrating Cu melt into the finger-shaped holes of the W skeleton under the action of capillary force, wherein the temperature range of the infiltrated Cu is 1200-1500 ℃, and the time is 1-4 h.

Technical Field

The invention relates to a preparation method of a W-Cu composite plate with Cu phases distributed in a finger-shaped gradient manner, belonging to the field of preparation of metal-based composite materials.

Background

The Functionally Graded Material (FGM) is a novel heterogeneous composite material with non-uniform variation of material components and gradient variation of performance, which is obtained by continuously changing the structure, composition, density, etc. of two or more materials with different properties to reduce or even eliminate the internal interface. The research of FGM comprises material design, material synthesis (preparation) and material characteristic evaluation, the three parts supplement each other and are all indispensable, and the core part is material preparation.

The W-Cu FGM combines the good electric conductivity, heat conduction and corrosion resistance of Cu and the high hardness, strength and thermal stability of W, and simultaneously gradually transits from high W (pure W) to high Cu (pure Cu) layer along the section, has various excellent performances, and has good application prospects in electronic packaging and aerospace. However, because the melting points of W and Cu are different and are not mutually soluble, the process for preparing the high-density W-Cu FGM by the powder metallurgy process is difficult and the gradient component distribution is difficult to control effectively. At present, the W-Cu gradient material is mostly prepared by a lamination method, the obtained W-Cu gradient composite material is mostly in a laminated structure, an obvious interface still exists between layers, the interface is easy to crack and the like at the interface due to the thermal expansion difference between the layers under an extreme working environment, so that the service life of the W-Cu gradient composite material is influenced, and the W-Cu gradient composite material designed by M.Richou and the like cracks after 972 times of thermal cyclesLike (m.richou, f.gallay, B.Fusion Engineering and Design,2020,157.111610). Weibang et al uses W powder with different particle sizes as raw material, polyvinyl butyral (PVB) as binder and absolute ethyl alcohol as solvent to prepare slurry, then through settling, binder removal and presintering to obtain W skeleton with continuous gradient distribution of pores, then seeping Cu to obtain W-Cu Functionally gradient material (Wei BZ, Yu XX, Chen RZ, et al. A Novel application to fabric W-Cu Functionally gradient material and Infiltratation Method [ J ] (Wei BZ, Yu XX, Chen RZ, et al. A Novel application to Cu Functionally gradient material with Cu content of 28.03% -44.47%]Materials Science and Engineering: A, 2021.). Jiang Da et al compared W, Cu bond strengths between the original interface, the nano-corrugated interface, the micro-cubic interface, and the micro-crater interface, and found that W, Cu micro-crater interfaces improved tensile strength, shear strength, heat transfer capability, thermal stress resistance, and thermal fatigue life of W, Cu joints overall (Jiang D, Long J, Han J, et al. materials Science and Engineering: A,2017,696(JUN.1): 429-.

In summary, most of the current aspects of preparing W-Cu gradient composite materials are layered structures, and the research on W-Cu gradient composite materials with distributed Cu phases in finger-shaped gradient is less.

Disclosure of Invention

The invention aims to provide a preparation method of a W-Cu composite plate with a Cu phase in finger-shaped gradient distribution, which comprises the steps of firstly preparing a W framework with finger-shaped pore distribution, and then putting the W framework in an infiltration sintering furnace and an N phase₂Or H₂Under the protection of atmosphere, a purple Cu block or a Cu powder compact is placed on the surface of a W framework with finger-shaped holes, and heated to melt Cu, a Cu melt is infiltrated into the finger-shaped holes of the W framework under the action of capillary force, and finally, a composite plate with Cu phases distributed in a finger-shaped gradient manner from the infiltration surface to the interior of a sample is obtained, and the Cu phase and the W phase are mutually pinned, so that an W, Cu interface has good bonding strength.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a W-Cu composite plate with Cu phases distributed in a finger-shaped gradient manner is characterized by comprising the following steps:

(1) mixing WO_XMixing the powder and the W powder to obtain a powder mixture; adding the powder mixture, a binder polyether sulfone and a pore-forming agent polyvinylpyrrolidone into an N-methyl pyrrolidone solvent, and uniformly mixing the powder mixture and the binder polyether sulfone together in a planetary ball mill by ball milling to obtain slurry;

(2) casting the slurry on a PET film to obtain a green body, soaking the obtained green body and the PET film in water together to partially remove a solvent N-methylpyrrolidone, then separating the green body from the PET film, and drying;

(3) at H₂Under the atmosphere, pre-sintering the obtained green body at 500-800 ℃ to remove the binder and reduce the green body, and then heating to 800-2000 ℃ to sinter the green body to obtain a W framework with finger-shaped pores;

(4) and infiltrating Cu into the W framework, and then cooling along with the furnace to obtain the W-Cu composite plate with the Cu phase in finger-shaped gradient distribution.

Further, said WO_XThe powder is prepared by taking ammonium metatungstate, ammonium nitrate, glycine and ethylene diamine tetraacetic acid as raw materials, adding deionized water for dispersion, then placing the mixture into a muffle furnace, keeping the temperature at 200 ℃ and performing combustion synthesis. By using WO_XThe purpose of the powder is to prevent carbon remaining in the material after binder removal and reduction from forming excess WC with W, thereby affecting the properties of the final material; said WO_XThe powder is obtained by combustion synthesis using ammonium metatungstate as raw material, and the WO obtained in this way_XThe powder has special surface structure and highest chemical activity, and is suitable for producing superfine tungsten powder and various nanometer tungsten compounds.

Further, in step (1), the WO_XThe powder accounts for 0-50 wt% of the mass of the powder mixture; the addition amounts of the polyether sulfone and the polyvinylpyrrolidone are respectively and independently 1-6% of the mass of the powder mixture; the solid content of the slurry is 50-85 wt.%.

Further, in the step (1), the rotation speed of the ball milling is 100-400 r/min, and the ball milling time is 2-48 h.

Further, in the step (2), the thickness of the green body obtained by casting is 200 μm to 2 mm.

Further, in the step (2), when the obtained green body and the PET film are soaked in water together, the PET film is placed below and the green body is placed above, and the sample is ensured to be parallel to the horizontal plane, so that the pore distribution in the green body is controlled, and the soaking time is 12-48 h.

Further, in step (2), when the resulting green body is soaked in water together with the PET film, exchange of water and N-methylpyrrolidone occurs at the interface of the upper surface of the green body and water, and water penetrates into the green body, forming finger-shaped pores.

Further, in the step (3), the pre-sintering time of the obtained green body at 500-800 ℃ is 1-4 h, the sintering time at 800-2000 ℃ is 1-4 h, and the gradient component distribution in the final W-Cu composite board is controlled by controlling the framework sintering temperature.

Further, in the step (4), the W framework is infiltrated with Cu in an infiltration sintering furnace in N₂Or H₂Under the protection of atmosphere, placing a pure purple Cu block or an electrolytic Cu powder compact on the surface of a W skeleton with finger-shaped holes, heating to melt Cu, and infiltrating Cu melt into the finger-shaped holes of the W skeleton under the action of capillary force, wherein the temperature range of the infiltrated Cu is 1200-1500 ℃, and the time is 1-4 h.

The invention has the beneficial effects that:

1. the Cu phase in the W-Cu composite material prepared by the method is distributed in a finger-shaped gradient manner from the infiltration surface to the interior of a sample, the Cu phase and the W phase are mutually pinned, and the W-Cu interface has good bonding strength; the method has the characteristics of adjustable material component performance, simple process, low cost, suitability for large-scale production and the like.

2. The invention uses ammonium metatungstate as raw material to prepare WO by a combustion synthesis method_XPowder, low cost of raw material, easy obtaining, obtained WO_XThe powder has special surface structure and highest chemical activity, and is suitable for producing superfine tungsten powder and various nanometer tungsten compounds.

3. The W skeleton obtained by unidirectional water seepage and binder removal pre-sintering has a special structure with finger-shaped pores.

4. The method of the invention can control the gradient distribution by controlling the solid content and thus the size of the finger-shaped pores: when the solid content is smaller, the diffusion speed of the solution is higher, the number of formed new cores is large, the size is small, and the formed pore structure is spongy; when the solid content is larger, the diffusion speed of the solution is slower, the formed new nucleus continuously grows up, and the formed pore structure is a finger-shaped pore.

5. In the method, the W framework with finger-shaped pore distribution is obtained by removing the binder and a reduction process, the finger-shaped pores are from small to large, the fine-grained W powder has better sintering activity and can be dense at a lower temperature, so the pore distribution range in the W framework can be expanded by controlling the sintering process, a gradient material for transition from a pure W layer to a W-Cu layer can be obtained, and the working stability of the material at a high temperature is met.

Drawings

FIG. 1 is a schematic structural diagram of a W-Cu composite plate with Cu phases distributed in a finger-shaped gradient manner;

FIG. 2 shows WO obtained in example 1_XSEM photograph of the powder;

FIG. 3 is an SEM photograph of the W skeleton obtained in example 1;

FIG. 4 is an SEM photograph of the W-Cu composite plate obtained in example 1;

FIG. 5 shows the EDS spectrum and the content distribution of the W-Cu composite plate obtained in example 1.

Detailed Description

The following embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are provided for implementing the technical solution of the present invention, and provide detailed embodiments and specific procedures, but the scope of the present invention is not limited to the following embodiments.

Example 1

(1) Mixing ammonium metatungstate, ammonium nitrate, glycine and ethylenediamine tetraacetic acid, adding deionized water for dispersion, and then putting the mixture into a muffle furnace to burn for 2 hours at a constant temperature of 200 ℃ in an air atmosphere to obtain WO_XPowder; the mass ratio of ammonium metatungstate to ammonium nitrate to glycine to ethylenediamine tetraacetic acid to deionized water is 12:19.2:7:0.7: 50. FIG. 2 shows the WO obtained_XSEM photograph of the powder shows that the obtained powder is in the shape of short rod, the diameter is 0.5-2 μm, and the length is 2-10 μm.

Weighing WO_X50g of powder, 100g of 0.8 mu m W powder, 4g of polyether sulfone, 2.67g of polyvinylpyrrolidone and 26.7g of N-methylpyrrolidone are added into a ball milling tank together, the ball-material ratio is 1:5, the ball milling is carried out for 12 hours, and the rotating speed is 400r/min, so that slurry with the solid content of 82% is obtained.

(2) Casting the obtained slurry on a PET film to obtain a green body with the thickness of 2mm, soaking the obtained green body and the PET film in water together to partially remove the solvent N-methylpyrrolidone, soaking the PET film at the lower part and the green body at the upper part and ensuring that the sample is parallel to the horizontal plane, thereby controlling the pore distribution in the green body, wherein the soaking time is 24h, water and N-methylpyrrolidone exchange occurs at the interface of the upper surface of the green body and the water during soaking, and the water permeates into the green body to form finger-shaped pores.

After soaking, separating the green body from the PET film, and then drying.

(3) At H₂Under the atmosphere, the obtained green body is pre-sintered for 4 hours at 500 ℃ to remove the binder and reduce, and then the temperature is raised to 800 ℃ to sinter for 2 hours to obtain the W framework with the finger-shaped distribution of pores. FIG. 3 is an SEM photograph of the resulting W skeleton, showing that the finger-shaped pores are decreasing in size from top to bottom.

(4) In an infiltration sintering furnace, in N₂Under the protection of atmosphere, placing a pure purple Cu block on the surface of a W framework with finger-shaped holes, heating to melt Cu, and infiltrating Cu melt into the finger-shaped holes of the W framework under the action of capillary force, wherein the temperature of the infiltrated Cu is 1300 ℃, and the time is 2 hours.

Fig. 4 is an SEM photograph of the W-Cu composite plate obtained in the present embodiment, which shows that the Cu phase is distributed in a finger-like gradient, and the gradient is gradually increased from top to bottom.

Fig. 5 is an EDS spectrum and content distribution of the W-Cu composite plate obtained in this example, and it can be seen that the W phase and the Cu phase are well bonded.

The present invention is not limited to the above exemplary embodiments, and any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.