A tungsten dispersion strengthened copper-based composite material and a preparation method thereof

Abstract

The application discloses a tungsten dispersion-strengthened copper-based composite material and a preparation method thereof, and belongs to the technical field of copper-based composite material preparation. The method disclosed by the application adopts electrolytic copper powder, soluble tungsten salt and a binder as raw materials to prepare a tungsten-copper composite precursor water-based slurry, uniform dispersion in the Cu powder can be realized in the slurry, in the spray drying granulation process, the W salt is adsorbed on the surface of the Cu powder in the form of nanoparticles, and after reduction, the Cu / W composite powder with uniformly dispersed nano W particles can be prepared; in the preparation of the tungsten dispersion-strengthened copper-based composite material, the nano W particles are dispersedly distributed, the strength of Cu can be significantly improved, meanwhile, the high conductivity of W can also make the Cu-W composite material have high conductivity, and therefore, the high-strength and high-conductivity Cu-W composite material is prepared.

Description

Technical Field

[0001] This invention belongs to the field of copper-based composite material preparation technology, specifically relating to a tungsten dispersion reinforced copper-based composite material and its preparation method. Background Technology

[0002] The rapid advancement of electronic information integration technology has led to a research focus on improving the high-temperature performance of copper-based materials. Secondly, the booming development of cutting-edge technologies requires copper-based materials to maintain both high conductivity and high strength. However, it is usually difficult to achieve both high strength and high conductivity simultaneously in copper-based materials. Therefore, resolving this contradiction has become another key research focus.

[0003] Alloys such as Cu-Cr, Cu-Cr-Zr, and Cu-Ni-Si are widely used in conductor components and leadframe materials due to their high strength and excellent electrical conductivity. However, in recent years, integrated circuits have developed towards large-scale, high reliability, and precision, which has placed higher demands on the high-temperature softening resistance of leadframe materials. Materials must possess characteristics such as softening resistance, high thermal conductivity, and high-temperature low-cycle fatigue resistance at high service temperatures. However, these copper-based materials have poor high-temperature stability. When heated to temperatures above precipitation treatment, the precipitated phase easily coarsens and redissolves, forming a solid solution, causing the previous precipitation strengthening effect to almost completely disappear. Therefore, the high-temperature softening temperature should not exceed 600℃. Adding a second-phase ceramic particle reinforcement phase can hinder dislocation recovery and copper matrix recrystallization at high service temperatures, giving the composite material superior strength and high-temperature performance. However, the physical properties of the dispersed phase particles, such as conductivity, are also factors determining the performance of copper alloys. Typical ceramic phases have very low conductivity, thus significantly reducing the conductivity of the composite material. Therefore, there is an urgent need to develop a new Cu-based composite material with both high softening temperature and high conductivity. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a tungsten dispersion reinforced copper-based composite material and its preparation method, so as to solve the technical problem that existing Cu-based composite materials are difficult to achieve both softening temperature and conductivity that meet the application requirements.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] This invention discloses a method for preparing tungsten dispersion-reinforced copper-based composite materials, comprising the following steps:

[0007] S1: A water-based slurry for tungsten-copper composite precursors was prepared using electrolytic copper powder, soluble tungsten salt, and binder as raw materials.

[0008] S2: The tungsten-copper composite precursor slurry is sequentially subjected to spray granulation and reduction treatment to obtain tungsten dispersion-strengthened copper powder;

[0009] S3: Tungsten dispersion-reinforced copper powder is sequentially pressed, sintered, and plastically deformed to obtain tungsten dispersion-reinforced copper-based composite material.

[0010] Furthermore, in S1, the step of preparing the tungsten-copper composite precursor water-based slurry is as follows:

[0011] Electrolytic copper powder, soluble tungsten salt and binder are mixed and then ball-milled to obtain a water-based slurry of tungsten-copper composite precursor.

[0012] In the water-based slurry of the tungsten-copper composite precursor, the mass fraction of electrolytic copper powder is 30% to 60%, and the mass fraction of binder is 0.25% to 1.75%.

[0013] Further, in S1, the particle size of the electrolytic copper powder is 0.5–50 μm; the soluble tungsten salt is ammonium metatungstate; and the binder is at least one of PVA, PVB, and PEG.

[0014] Furthermore, in S1, the amount of the soluble tungsten salt used satisfies the requirement that the converted elemental W accounts for 1% to 10% of the total mass of W and Cu.

[0015] Furthermore, in S2, the spray granulation is carried out by a centrifugal spray dryer; during the spray granulation, the inlet temperature of the centrifugal spray dryer is 180-300℃, the outlet temperature is 110-150℃, and the rotation speed of the rotary atomizer is 8000-12000 r / min.

[0016] Furthermore, in S2, the reduction process is carried out in a hydrogen atmosphere; the reduction temperature of the hydrogen is 700-850°C, and the holding time is 1-3 hours.

[0017] Furthermore, in S3, the sintering method is vacuum hot pressing sintering; the temperature of the vacuum hot pressing sintering is 900-1050℃, and the holding time is 10-60min.

[0018] Furthermore, in S3, the plastic deformation treatment method is at least one of hot rolling, hot extrusion, and hot forging.

[0019] Furthermore, the deformation amount of the plastic processing deformation treatment is 20% to 99%.

[0020] The present invention also discloses a tungsten dispersion-reinforced copper-based composite material prepared by the above preparation method.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention discloses a method for preparing tungsten dispersion-reinforced copper-based composite materials. The method uses electrolytic copper powder, soluble tungsten salt, and a binder as raw materials to prepare a water-based slurry of tungsten-copper composite precursor. Uniform dispersion of tungsten salt in Cu powder can be achieved in the slurry. During spray drying and granulation, tungsten salt is adsorbed onto the surface of Cu powder in the form of nanoparticles. After reduction, a Cu / W composite powder with uniformly dispersed nanoparticles of tungsten salt can be prepared. Compared with existing technologies, this method produces finer and more uniformly distributed tungsten salt particles in situ during the calcination process after spray drying, resulting in better dispersion reinforcement.

[0023] The present invention also discloses a tungsten dispersion-reinforced copper-based composite material prepared by the above method. The nano-W particles in the tungsten dispersion-reinforced copper-based composite material prepared by the present invention are dispersedly distributed, which can significantly improve the strength of Cu. At the same time, the high conductivity of W can also give the Cu-W composite material high conductivity. The softening temperature exceeds 1000℃. Therefore, the prepared material is a high-strength and high-conductivity Cu-W composite material. Detailed Implementation

[0024] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0025] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0026] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0027] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0028] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0029] This invention provides a method for preparing tungsten dispersion-reinforced copper-based composite materials, comprising the following steps:

[0030] Step 1: Electrolytic copper powder with a mass fraction of 30% to 60%, ammonium metatungstate with a conversion W content of 1% to 10% of the total mass of W and Cu, and PVA with a mass fraction of 0.25% to 1.75%, are ball-milled to prepare a tungsten-copper composite precursor water-based slurry.

[0031] Step 2: Spray granulation of the tungsten-copper composite precursor slurry prepared in Step 1 using a centrifugal spray dryer;

[0032] Step 3: Reduce the powder obtained by spray granulation in step 2 in a hydrogen atmosphere to obtain tungsten dispersion reinforced copper powder;

[0033] Step 4: Tungsten dispersion-reinforced copper powder is pressed and sintered to obtain tungsten dispersion-reinforced copper-based composite material;

[0034] Step 5: The composite material obtained in Step 4 is subjected to plastic deformation to obtain a fully dense tungsten dispersion reinforced copper-based composite material.

[0035] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0036] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0037] Example 1

[0038] A method for preparing a tungsten dispersion-reinforced copper-based composite material includes the following steps:

[0039] Step 1: 30% electrolytic copper powder, 5% ammonium metatungstate (converted W to form W by the total mass of W and Cu), and 1% PVA are ball-milled to prepare a tungsten-copper composite precursor water-based slurry.

[0040] Step 2: The tungsten-copper composite precursor water-based slurry prepared in Step 1 is spray-granulated using a centrifugal spray dryer with an inlet temperature of 240℃, an outlet temperature of 120℃, and a rotary atomizer speed of 10000 r / min.

[0041] Step 3: Reduce the powder obtained by spray granulation in step 2 in a hydrogen atmosphere for 2 hours at a reduction temperature of 700℃ to obtain tungsten dispersion reinforced copper powder.

[0042] Step 4: Vacuum hot pressing sintering of tungsten dispersion reinforced copper powder at a temperature of 950℃ and a holding time of 30min. Then, the resulting composite material is rolled and deformed to obtain a fully dense tungsten dispersion reinforced copper matrix composite material. The rolling process is hot rolling at 900℃ with a deformation amount of 20%.

[0043] Tests showed that the tungsten dispersion reinforced copper matrix composite material obtained in this case had a hardness of 133HB and a softening temperature of 1045℃.

[0044] Example 2

[0045] A method for preparing a tungsten dispersion-reinforced copper-based composite material includes the following steps:

[0046] Step 1: Electrolytic copper powder with a mass fraction of 40%, ammonium metatungstate with a conversion W content of 2% of the total mass of W and Cu, and PVA with a mass fraction of 1% are ball-milled to prepare a tungsten-copper composite precursor water-based slurry.

[0047] Step 2: The tungsten-copper composite precursor water-based slurry prepared in Step 1 is spray-granulated using a centrifugal spray dryer with an inlet temperature of 240℃, an outlet temperature of 120℃, and a rotary atomizer speed of 10000 r / min.

[0048] Step 3: Reduce the powder obtained by spray granulation in step 2 in a hydrogen atmosphere for 2 hours at a reduction temperature of 700℃ to obtain tungsten dispersion reinforced copper powder.

[0049] Step 4: Vacuum hot pressing sintering of tungsten dispersion reinforced copper powder at a temperature of 950℃ and a holding time of 30min. Then, the resulting composite material is rolled and deformed to obtain a fully dense tungsten dispersion reinforced copper matrix composite material. The rolling process is hot rolling at 900℃ with a deformation amount of 20%.

[0050] Tests showed that the tungsten dispersion reinforced copper matrix composite material obtained in this case had a hardness of 128 HB and a softening temperature of 1000℃.

[0051] Example 3

[0052] A method for preparing a tungsten dispersion-reinforced copper-based composite material includes the following steps:

[0053] Step 1: Electrolytic copper powder with a mass fraction of 50%, ammonium metatungstate with a conversion W content of 3% of the total mass of W and Cu, and PVA with a mass fraction of 1% are ball-milled to prepare a tungsten-copper composite precursor water-based slurry.

[0054] Step 2: The tungsten-copper composite precursor water-based slurry prepared in Step 1 is spray-granulated using a centrifugal spray dryer with an inlet temperature of 240℃, an outlet temperature of 120℃, and a rotary atomizer speed of 10000 r / min.

[0055] Step 3: Reduce the powder obtained by spray granulation in step 2 in a hydrogen atmosphere for 2 hours at a reduction temperature of 700℃ to obtain tungsten dispersion reinforced copper powder.

[0056] Step 4: Vacuum hot pressing sintering of tungsten dispersion reinforced copper powder at a temperature of 950℃ and a holding time of 30min. The resulting composite material is then rolled and deformed to obtain a fully dense tungsten dispersion reinforced copper matrix composite material. The rolling process is hot rolling at 900℃ with a deformation amount of 20%.

[0057] Tests showed that the tungsten dispersion reinforced copper matrix composite material obtained in this case had a hardness of 119HB and a softening temperature of 1020℃.

[0058] Example 4

[0059] A method for preparing a tungsten dispersion-reinforced copper-based composite material includes the following steps:

[0060] Step 1: Electrolytic copper powder with a mass fraction of 60%, ammonium metatungstate with a conversion W content of 3% of the total mass of W and Cu, and PVA with a mass fraction of 1% are ball-milled to prepare a tungsten-copper composite precursor water-based slurry.

[0061] Step 2: The tungsten-copper composite precursor water-based slurry prepared in Step 1 is spray-granulated using a centrifugal spray dryer with an inlet temperature of 240℃, an outlet temperature of 120℃, and a rotary atomizer speed of 10000 r / min.

[0062] Step 3: Reduce the powder obtained by spray granulation in step 2 in a hydrogen atmosphere for 2 hours at a reduction temperature of 700℃ to obtain tungsten dispersion reinforced copper powder.

[0063] Step 4: Vacuum hot pressing sintering of tungsten dispersion reinforced copper powder at a temperature of 950℃ and a holding time of 30min. Then, the resulting composite material is rolled and deformed to obtain a fully dense tungsten dispersion reinforced copper matrix composite material. The rolling process is hot rolling at 900℃ with a deformation amount of 20%.

[0064] Tests showed that the tungsten dispersion reinforced copper matrix composite material obtained in this case has a hardness of 115HB and a high softening temperature of 1020℃.

[0065] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a tungsten dispersion-reinforced copper-based composite material, characterized in that, Includes the following steps: S1: A water-based slurry for tungsten-copper composite precursors was prepared using electrolytic copper powder, soluble tungsten salt, and binder as raw materials. The steps for preparing the tungsten-copper composite precursor water-based slurry are as follows: Electrolytic copper powder, soluble tungsten salt and binder are mixed and then ball-milled to obtain a water-based slurry of tungsten-copper composite precursor. In the tungsten-copper composite precursor water-based slurry, the mass fraction of electrolytic copper powder is 30%~60%, and the mass fraction of binder is 0.25~1.75%; the particle size of the electrolytic copper powder is 0.5~50μm; the soluble tungsten salt is ammonium metatungstate; the amount of the soluble tungsten salt used is such that the converted W element accounts for 1%~10% of the total mass of W and Cu. S2: The tungsten-copper composite precursor slurry is sequentially subjected to spray granulation and reduction treatment to obtain tungsten dispersion-strengthened copper powder; S3: Tungsten dispersion-reinforced copper powder is sequentially pressed, sintered, and plastically deformed to obtain tungsten dispersion-reinforced copper-based composite material; the sintering method is vacuum hot pressing sintering; the temperature of vacuum hot pressing sintering is 900~1050℃, and the holding time is 10~60min; the deformation amount of plastic deformation treatment is 20%~99%.

2. The method for preparing a tungsten dispersion-reinforced copper-based composite material according to claim 1, characterized in that, In S1, the adhesive is at least one of PVA, PVB, and PEG; In S2, the spray granulation is carried out by a centrifugal spray dryer; during the spray granulation, the inlet temperature of the centrifugal spray dryer is 180~300℃, the outlet temperature is 110~150℃, and the rotation speed of the rotary atomizer is 8000~12000r / min.

3. The method for preparing a tungsten dispersion-reinforced copper-based composite material according to claim 1, characterized in that, In S2, the reduction process is carried out in a hydrogen atmosphere; the reduction temperature of the hydrogen is 700~850℃, and the holding time is 1~3h.

4. The method for preparing a tungsten dispersion-reinforced copper-based composite material according to claim 1, characterized in that, In S3, the plastic deformation treatment method is at least one of hot rolling, hot extrusion, and hot forging.

5. A tungsten dispersion-reinforced copper-based composite material, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 4.