PREPARATION METHOD FOR W-CU COMPOSITE PLATE WITH CU PHASE IN FINGER-SHAPED GRADIENT DISTRIBUTION

Abstract

A preparation method for a W—Cu composite plate with a Cu phase in finger-shaped gradient distribution is provided. The method includes adding WO.sub.X powder obtained with ammonium metatungstate as a raw material into W powder through a combustion synthesis method, adding a binder and a pore-forming agent to prepare a slurry, then performing tape casting, soaking in water and sintering to obtain a W framework with pores in finger-shaped distribution, and then infiltrating Cu to obtain a target product. The Cu phase in the W—Cu composite material prepared by the present method is distributed in a finger-shaped gradient manner from an infiltration surface to the interior of a specimen, the Cu phase and the W phase are mutually pinned, and the W—Cu interface has good bonding strength. The present method has the characteristics of adjustable material component performance, simple process, low cost, suitability for large-scale production and the like.

Claims

1. A preparation method for a W—Cu composite plate with a Cu phase in a finger-shaped gradient distribution, comprising the following steps: (1) mixing a WO.sub.X powder and a W powder to obtain a powder mixture; adding the powder mixture, a binder polyethersulfone, and a pore-forming agent polyvinyl pyrrolidone into an N-methylpyrrolidone solvent to obtain a first resulting mixture, and uniformly mixing the first resulting mixture by a ball milling in a planetary ball mill to obtain a slurry; wherein the WO.sub.X powder accounts for 50 wt. % or less of a mass of the powder mixture and is not 0; the binder polyethersulfone and the pore-forming agent polyvinyl pyrrolidone each independently account for 1-6% of the mass of the powder mixture; and the slurry has a solid content of 50-85 wt. %; (2) tape-casting the slurry on a PET film to obtain a green body, soaking the green body and the PET film in water together to partially remove the N-methylpyrrolidone solvent, then separating the green body from the PET film, and then drying the green body; (3) pre-sintering the green body at 500-800° C. under a H.sub.2 atmosphere to remove the binder polyethersulfone and reduce the green body, and then performing a heating to 800-2000° C. to sinter the green body to obtain a W framework with finger-shaped distributed pores; and (4) infiltrating Cu into the W framework to obtain a resulting framework, and then cooling the resulting framework along with a furnace to obtain the W—Cu composite plate with the Cu phase in the finger-shaped gradient distribution.

2. The preparation method for the W—Cu composite plate with the Cu phase in the finger-shaped gradient distribution according to claim 1, wherein the WO.sub.X powder is obtained through a combustion synthesis method by taking ammonium metatungstate, ammonium nitrate, glycine, and ethylenediaminetetraacetic acid as raw materials, adding deionized water for a dispersion to obtain a second resulting mixture, and then placing the second resulting mixture into a muffle furnace at a constant temperature of 200° C.

3. The preparation method for the W—Cu composite plate with the Cu phase in the finger-shaped gradient distribution according to claim 1, wherein in the step (1), the ball milling is performed at a rotation speed of 100-400 r/min for 2-48 h.

4. The preparation method for the W—Cu composite plate with the Cu phase in the finger-shaped gradient distribution according to claim 1, wherein in the step (2), the green body obtained through the tape-casting has a thickness of 200 μm-2 mm.

5. The preparation method for the W—Cu composite plate with the Cu phase in the finger-shaped gradient distribution according to claim 1, wherein in the step (2), when the green body and the PET film are soaked in the water together, the PET film is placed at a lower part, the green body is placed at an upper part, and a sample is ensured to be parallel to a horizontal plane, so that a pore distribution in the green body is controlled, and the soaking is performed for 12-48 h.

6. The preparation method for the W—Cu composite plate with the Cu phase in the finger-shaped gradient distribution according to claim 1, wherein in the step (2), when the green body and the PET film are soaked in the water together, an exchange of the water and the N-methylpyrrolidone solvent occurs at an interface of an upper surface of the green body and the water, and the water penetrates into the green body, forming finger-shaped distributed pores.

7. The preparation method for the W—Cu composite plate with the Cu phase in the finger-shaped gradient distribution according to claim 1, wherein in the step (3), the green body is pre-sintered at 500-800° C. for 1-4 h and sintered at 800-2000° C. for 1-4 h.

8. The preparation method for the W—Cu composite plate with the Cu phase in the finger-shaped gradient distribution according to claim 1, wherein in the step (4), the step of infiltrating the Cu into the W framework is that a pure purple Cu block or an electrolytic Cu powder pressed compact is placed on a surface of the W framework with the finger-shaped distributed pores in an infiltration sintering furnace under a protection of a N.sub.2 or H.sub.2 atmosphere, the heating is performed to melt the Cu to obtain a Cu melt, the Cu melt is infiltrated into the finger-shaped distributed pores of the W framework under an action of a capillary force, and an infiltration of the Cu is performed at 1200-1500° C. for 1-4 h.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a schematic structural diagram of a W—Cu composite plate with a Cu phase in finger-shaped gradient distribution;

[0028] FIG. 2 is an SEM photograph of the WO.sub.X powder obtained in Example 1;

[0029] FIG. 3 is an SEM photograph of the W framework obtained in Example 1;

[0030] FIG. 4 is an SEM photograph of the W—Cu composite plate obtained in Example 1; and

[0031] FIG. 5 shows the EDS pattern and content distribution of the W—Cu composite panel obtained in Example 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The following examples are described in detail with reference to the accompanying drawings, and the following examples are implemented on the premise of the technical solution of the present invention, and give detailed embodiments and specific operation procedures. However, the protection scope of the present invention is not limited to the following examples.

Example 1

[0033] (1) Ammonium metatungstate, ammonium nitrate, glycine and ethylenediaminetetraacetic acid were mixed and added with deionized water for dispersion, and then the mixture was placed into a muffle furnace at a constant temperature of 200° C. for 2 h under the air atmosphere to obtain WO.sub.X powder; wherein the mass ratio of ammonium metatungstate, ammonium nitrate, glycine, ethylenediaminetetraacetic acid and deionized water is 12:19.2:7:0.7:50. FIG. 2 is an SEM photograph of the obtained WO.sub.X powder, and it can be seen that the obtained powder is in short rod-shaped and has a diameter of 0.5 to 2 μm and a length of 2 to 10 μm.

[0034] 50 g of the WO.sub.X powder, 100 g of 0.8 μm W powder, 4 g of polyethersulfone, 2.67 g of polyvinyl pyrrolidone and 26.7 g of N-methylpyrrolidone were weighed and added into a ball milling tank for ball milling for 12 h at a ball-material ratio of 1:5 and a rotating speed of 400 r/min to obtain a slurry with the solid content of 82%.

[0035] (2) The obtained slurry was tape-casted on a PET film to obtain a green body with a thickness of 2 mm, and the obtained green body and the PET film were soaked in water together to partially remove the solvent N-methylpyrrolidone, wherein the PET film was placed at the lower part, the green body was placed at the upper part, and the sample was ensured to be parallel to the horizontal plane so as to control the pore distribution in the green body, the soaking was performed for 24 h, the exchange of water and N-methylpyrrolidone occurs at the interface of an upper surface of the green body and water, and water penetrates into the green body, forming finger-shaped pores.

[0036] After the soaking was completed, the green body was separated from the PET film and then dried.

[0037] (3) The obtained green body was pre-sintered at 500° C. for 4 h under H.sub.2 atmosphere to remove the binder and reduce the green body, and then the green body was heated to 800° C. and sintered for 2 h to obtain a W framework with finger-shaped distributed pores. FIG. 3 is an SEM photograph of the obtained W framework, and it can be seen that the finger-shaped pores are increased in size from top to bottom.

[0038] (4) A pure purple Cu block was placed on the surface of the W framework with finger-shaped pores in an infiltration sintering furnace under the protection of N.sub.2 atmosphere and heated to melt Cu, the Cu melt was infiltrated into the finger-shaped pores of the W framework under the action of capillary force, and the infiltration of Cu was performed at 1300° C. for 2 h.

[0039] FIG. 4 is an SEM photograph of the W—Cu composite plate obtained in the Example, and it can be seen that the Cu phase is distributed in a finger-shaped gradient, and the gradient is gradually increased from top to bottom.

[0040] FIG. 5 shows the EDS pattern and content distribution of the W—Cu composite plate obtained in the Example, and it can be seen that the W phase and the Cu phase are well bonded to each other.

[0041] The above mentioned contents are only exemplary examples of the present invention and are not intended to limit the present invention. Any modification, equivalent substitution, improvement and the like made within the spirit and principle of the present invention shall all fall within the scope of protection of the present invention.