CN114850472B - Method for coating ceramic particles and preparation method of composite material - Google Patents

Abstract

The invention provides a method for coating ceramic particles and a preparation method for composite materials. The coating method includes: mixing ceramic particles with adhesive, adding coating powder, and stirring to obtain ceramic particles coated with coating powder; mixing ceramic particles coated with coating powder with polyvinyl alcohol, and drying to obtain surface Ceramic particles with coating powder and polyvinyl alcohol attached; activating the ceramic particles with coating powder and polyvinyl alcohol attached to the surface, and after activation, electroless plating is performed with a plating solution to obtain ceramic particles coated with coating powder-metal coating. The preparation method of the composite material comprises: preparing coating powder-metal coating-coated ceramic particles; performing pressureless impregnation treatment on the coating powder-metal coating-coated ceramic particles and a metal matrix to obtain a composite material. The method of the invention utilizes the protective layer formed by the polyvinyl alcohol to better coat the coating powder on the surface of the ceramic particles, to better form a reactive interface during the composite process of the ceramic particles and the metal matrix, and to have better bonding performance.

Description

A method for coating ceramic particles and a composite material preparation method

technical field

The invention relates to the technical field of ceramic composite materials, in particular to a method for coating ceramic particles and a method for preparing composite materials.

Background technique

Ceramic particles have the advantages of low density, high strength, wear resistance and corrosion resistance. Metal materials have good plasticity and toughness. Combining ceramic particles with metal materials will produce a kind of metal that has both the advantages of metal and the characteristics of ceramics. , a ceramic/metal matrix composite material with high toughness, high hardness and high oxidation resistance.

However, the preparation of ceramic/metal matrix composites has become quite difficult due to the poor wettability of ceramic particles and metal matrix. Attempts have been made to surface-treat ceramic particles and then recombine them with metal substrates to enhance their wettability. Due to the advantages of simple process, uniform coating, and good bonding with the substrate, the electroless plating technology can not only be plated on metals, but also can be directly plated on the surface of non-conductors such as ceramics, plastics, and glass after pretreatment. At present, It has become a widely used surface treatment technology for ceramic particles, in which Ni, Cu or Fe and their alloys are mainly plated. However, the above-mentioned plating elements diffuse into the molten metal at high temperature and eventually disappear from the ceramic surface. Therefore, some coated powders such as ceramic powders, carbide powders, and metal powders (such as metal titanium) that are stable at high temperatures and form interfaces with high-temperature molten metals have been regarded as new "shells" in core-shell materials. direction of development.

At present, there are mainly two preparation methods for the core-shell structure. The first method uses Ni powder and other metals with a low melting point to be ball-milled, mixed with ceramic particles, and then vacuum sintered. This method can obtain a stable core-shell structure. structure, but this method takes a long time in the process of ball milling and vacuum sintering, and has the disadvantage of long preparation time; in addition, limited by the experimental conditions of high temperature and vacuum, this method also has high preparation temperature, high energy consumption and low output Shortcomings. The second method is to directly bond the coating powder to the surface of ceramic particles by using a binder. This method can obtain such core-shell materials in large quantities, but during the preparation process of ceramic/metal matrix composites, the simply mechanically bonded coated powder is in direct contact with the flowing high-temperature metal, resulting in the surface coated powder being washed away; In addition, due to the long-term high-temperature conditions, the binder in the inner layer will quickly volatilize, and even fall off from the surface of the ceramic particles into the molten metal, which will affect the integrity and uniformity of the coating layer formed by the coating powder to varying degrees. sex.

Contents of the invention

In view of the deficiencies in the prior art, one of the purposes of the present invention is to provide a method for obtaining coating powder-metal coating coated ceramic particles in large quantities at low temperature and in a short period of time, and through the obtained coating The ceramic particles covered by the powder-metal coating and the metal matrix are casted, and a composite material with a complete and uniform interface can be obtained.

One aspect of the present invention provides a method for coating ceramic particles, which may include the following steps: mixing ceramic particles with an adhesive, adding coating powder, and stirring to obtain ceramic particles coated with coating powder; The powder-coated ceramic particles are mixed with polyvinyl alcohol, and after drying, the ceramic particles with coated powder and polyvinyl alcohol attached to the surface are obtained; the ceramic particles with coated powder and polyvinyl alcohol attached to the surface are activated, and after activation, the plating solution is used for Plating, such as electroless plating, results in coating powder-metal coating coated ceramic particles.

Another aspect of the present invention provides a method for preparing a composite material, which may include the following steps: preparing coating powder-metal coating-coated ceramic particles by the above-mentioned method for coating ceramic particles; coating the coating powder-metal coating The coated ceramic particles are cast with a metal matrix to obtain a composite material.

Compared with the prior art, the beneficial effects of the present invention at least include at least one of the following:

(1) The protective layer formed by polyvinyl alcohol in the method of the present invention can better coat the coating powder on the surface of the ceramic particles, preventing the coating powder from detaching from the ceramic particles and dispersing into the activation solution.

(2) The method of the present invention uses the metal layer formed after electroless plating to protect the coating powder, which can prevent the ceramic particles coated by the coating powder from directly contacting the metal-based liquid at high temperature and affecting the integrity and uniformity of the coating layer. It can make the reactive interface better formed in the composite process of the ceramic particles and the metal base, the bonding performance is better, and the bonding strength of the interface between the ceramic particles and the metal base can be improved.

(3) The method of the present invention can obtain coated powder-metal coating-coated ceramic particles in large quantities at low temperature in a short time.

Description of drawings

The above and other objects and features of the present invention will become clearer through the following description in conjunction with the accompanying drawings, wherein:

Fig. 1 shows the comparison of appearance morphology of ZTA _p -Ti/PVA before and after activation and ZTA _p -Ti before and after activation.

Figure 2 shows the comparison of microscopic morphology of ZTA _p -Ti and ZTA _p -Ti/PVA before and after activation.

Fig. 3 shows the surface distribution diagram of ZTA _p -Ti/PVA@CuNi section elements.

Figure 4 shows the surface distribution of elements at the interface of ZTA _p -Ti/PVA@CuNi/HCCI.

Detailed ways

Hereinafter, a method for coating ceramic particles and a composite material preparation method according to the present invention will be described in detail with reference to the accompanying drawings and exemplary embodiments.

One aspect of the present invention provides a method of coating ceramic particles. In an exemplary embodiment of the method for coating ceramic particles of the present invention, the following steps may be included:

S01, mixing ceramic particles with a binder, adding coating powder, and stirring to obtain ceramic particles coated with coating powder.

S02, mixing ceramic particles coated with coating powder and polyvinyl alcohol, and drying to obtain ceramic particles coated with coating powder and polyvinyl alcohol.

S03, activating the ceramic particles coated with coating powder and polyvinyl alcohol, and performing electroless plating with a plating solution after activation, to obtain ceramic particles coated with coating powder-metal coating.

Further, the ceramic particles may be metal oxide ceramic particles, carbide ceramic particles or boride ceramic particles. For example, it may be ZTA ceramic particles (ZTA _p ), Al ₂ O ₃ ceramic particles, TiC particles, SiC particles, ZrO ₂ ceramic particles, TiB ₂ particles or SiO ₂ ceramic particles. Of course, the types of ceramic particles in the present invention are not limited thereto, and may also be WC particles and the like.

Further, the adhesive may be water glass adhesive or polyvinyl alcohol (PVA) adhesive or the like. The binder is used to adhere the coating powder to the surface of the ceramic particles.

Further, the coating powder can be one or a combination of metal powder, ceramic powder, carbide powder and boride powder. For example, the metal powder may be Ti powder, Ni powder, Cu powder or a mixture thereof, and the like. For example, when the ceramic particles are ZTA _p and the coating powder is Ti powder, the obtained ceramic particles coated with the coating powder are ZTA _p -Ti. Through the coating method of the present invention, non-conductive materials such as ceramic powder and carbide powder can be coated on the surface of ceramic particles under the conditions of low temperature and simple process flow.

Further, the radial dimension of the coating powder may be 0.1 μm˜10 μm. The size of the coating powder is less than 0.1 μm, and the coating layer formed on the surface of the ceramic particles is too dense, resulting in the infiltration of high-temperature metal liquid during the preparation of composite materials, which affects the composite effect; the size of the coating powder is too large, which affects the uniformity of the coating . For example, the radial dimension of the coated powder may be 0.3 μm˜8 μm or 1 μm˜7 μm.

Furthermore, the purpose of adding polyvinyl alcohol (PVA) is to form a protective film on the surface of the ceramic particles coated by the coating powder, which can prevent the coating powder from detaching from the surface of the ceramic particles and dispersing in the activation solution during the activation process. Make the coating powder better adhere to the surface of the ceramic particles to form a coating layer. Preferably, the mass concentration of PVA can be 1.5%-8.5%. If the mass concentration of PVA is lower than 1.5%, the formed protective film will be too thin, and the coating powder will break away from the surface of the ceramic particles and enter the activation solution during activation, which will not prevent the coating powder from breaking away from the surface of the ceramic particles. Affect the coating layer formed by the coating powder; if the mass concentration of PVA is higher than 8.5%, the formed protective film will be too thick, and the protective film cannot be completely dissolved during activation, affecting the final plating effect, and the protective film is too thick to make The activation effect exists on the protective film, and it does not have an activation effect on the coating powder, which affects the subsequent electroless plating. Form a suitable protective film thickness. During the activation process, part of the protective film will be dissolved, and a part of the undissolved protective film will play a protective role. The activation and residual film are mixed on the surface of the coating powder, which can make the coating powder complete and effective. active. Preferably, the mass concentration of PVA can be 2.5%~3.5% (2.5g/L~3.5g/L). Within this mass concentration range, the thickness of the formed protective film is moderate, which can well prevent the coating powder from detaching from the ceramic particles. At the same time, it will not affect the activation effect of the coating powder. Here, it should be noted that the mass concentration of PVA refers to the mass of PVA/mass of deionized water (for example: the mass concentration of PVA is 3%, when the mass of deionized water is 100g, add 3g of PVA). PVA can be prepared by stirring at 85° C. with a stirring speed of 500 rpm for 6 hours to obtain a viscous clear solution. Of course, the preparation of PVA in the present invention is not limited thereto, it is sufficient to add PVA to deionized water and stir evenly.

Further, after the ceramic particles coated with coating powder are mixed with polyvinyl alcohol, the drying temperature may be 50°C-70°C. Drying in the above temperature range can make polyvinyl alcohol form a protective film on the surface of ceramic particles, and at the same time, it can avoid the ceramic particles from adhering to each other due to the existence of polyvinyl alcohol, so that the bonding between ceramic particles The surface cannot be effectively plated. The drying time can be 1min~2min.

Further, activating the coated powder and polyvinyl alcohol-coated ceramic particles may include using an activation solution to activate at a temperature of 150°C to 200°C, for example, the activation may be performed at 170°C. The purpose of activation is to make the surface of the particles have metal active sites, so that the metal contained in the plating solution can be better plated on the surface of the ceramic particles. The activation solution can be Ni(Ac) ₂ activation solution, and its Ni(Ac) ₂ activation solution can be composed of Ni(Ac) ₂ , NaH ₂ PO ₂ , C ₂ H ₆ O and H ₂ O, wherein, Ni(Ac) _2. The mass concentration ratio of NaH ₂ PO ₂ , C ₂ H ₆ O and H ₂ O can be 1:(0.5~1.5):(10~20):(1~3). For example, it could be 1:1:15:2. The activation time is enough to activate all the ceramic particles coated with the coating powder, which can be adjusted according to the output and the completeness of activation. For example, the activation time can be 20min~30min, for example, 25min. Specifically, for the activation of ceramic particles ZTA _p -Ti/PVA with titanium powder and polyvinyl alcohol attached to the surface, Ni(Ac) ₂ :NaH ₂ PO ₂ :C ₂ H ₆ O:H ₂ O=1:1 : The component with a mass concentration ratio of 15:2 is an activation solution, which is activated at 170° C. for 25 minutes to obtain Ni-activated ZTA _p -Ti/PVA/Ni ²⁺ . Of course, the activation solution can also be PbCl ₂ activation solution or AgNO ₃ activation solution.

Further, the plating solution may be a plating solution containing Ni element and/or Cu element. For example, the plating solution may contain nickel sulfate, or copper sulfate, or a mixture of nickel sulfate and copper sulfate.

For example, for CuNi alloy as the metal coating, the plating solution can contain nickel sulfate (NiSO ₄ ·6H ₂ O), copper sulfate (CuSO ₄ ·5H ₂ O), sodium citrate (C ₆ H ₅ Na ₃ O ₇ ·2H ₂ O), sodium hypophosphite (NaH ₂ PO ₂ •H ₂ O), boric acid (H ₃ BO ₃ ) and choline chloride-ethylene glycol (ChCl-EG), where the concentration of nickel sulfate in the plating solution can be 25g/L~35g/L, the concentration of copper sulfate (CuSO ₄ ·5H ₂ O) can be 25g/L~35g/L, the concentration of sodium citrate (C ₆ H ₅ Na ₃ O ₇ ·2H ₂ O) It can be 28g/L~33g/L, the concentration of sodium hypophosphite (NaH ₂ PO ₂ ·H ₂ O) can be 27g/L~38g/L, and the concentration of boric acid (H ₃ BO ₃ ) can be 13g/L~ 17g/L and the concentration of choline chloride-ethylene glycol (ChCl-EG) can be 0g/L~40g/L. After mixing the coating powder and ceramic particles coated with polyvinyl alcohol with the above plating solution, adjust the pH to 9~10, and perform electroless plating at a speed of 80rpm~120rpm and a temperature of 50°C~80°C for 30min~70min. For example, the concentration of nickel sulfate in the plating solution can be 30g/L, the concentration of copper sulfate (CuSO ₄ ·5H ₂ O) can be 30g/L, sodium citrate (C ₆ H ₅ Na ₃ O ₇ ·2H ₂ O) The concentration can be 30g/L, the concentration of sodium hypophosphite (NaH ₂ PO ₂ •H ₂ O) can be 32g/L, the concentration of boric acid (H ₃ BO ₃ ) can be 15g/L and choline chloride-B The concentration of diol (ChCl-EG) can be 25g/L. After mixing the coating powder and ceramic particles coated with polyvinyl alcohol with the above plating solution, adjust the pH to 9.2, and perform electroless plating for 50 minutes at a rotation speed of 100 rpm and a temperature of 65°C. For example, ZTA _p -Ti/PVA/Ni ²⁺ activated by Ni can be plated with the above-mentioned plating solution to obtain ZTA coated with Ti-CuNi, that is, ZTA _p -Ti/PVA@CuNi.

Another aspect of the present invention provides a composite material preparation method. In an exemplary embodiment of the composite material preparation method of the present invention, the following steps may be included:

S100, mixing ceramic particles and binder, adding coating powder, and stirring to obtain ceramic particles coated with coating powder.

S101, mixing ceramic particles coated with coating powder and polyvinyl alcohol, and drying to obtain ceramic particles coated with coating powder and polyvinyl alcohol.

S102, activating the coating powder and the ceramic particles coated with polyvinyl alcohol, and performing electroless plating with a metal-containing plating solution to obtain coating powder-metal coating coated ceramic particles.

S103, casting the ceramic particles coated with the coating powder-metal coating and the metal matrix to obtain a composite material.

The steps S100-S102 are the same as the above-mentioned S01-S03, and will not be described again here. At present, in the process of preparing ceramic/metal matrix composite materials in the prior art, the coating powder is directly bonded to the surface of the ceramic particles by using an adhesive and then directly cast with the metal matrix. The problems of this method include: on the one hand, Simply mechanically bonded coating powder is in direct contact with the flowing high-temperature metal, causing the coating powder on the surface to be washed away; on the other hand, under long-term high-temperature conditions, the binder will evaporate quickly and even fall off from the surface of the ceramic particles as a whole Into the high-temperature molten metal, it will affect the integrity and uniformity of the cladding layer to varying degrees. The coating powder-metal coating-coated ceramic particles prepared through the steps S100-S102 can completely and uniformly coat the surface of the ceramic particles with the coating powder. After electroless plating, a layer of metal coating can be formed on the surface of the cladding layer, which avoids the direct contact between the cladding powder and the flowing high-temperature metal, and prevents the cladding powder from being washed away by the metal liquid. The metal layer formed after the cladding powder and electroless plating It can make the ceramic particles and the metal matrix better form a reactive interface during the composite process, and the bonding performance is better.

Further, the metal base may be titanium base, copper base, iron base or steel base, for example, the metal base may be HCCI high chromium cast iron. Of course, the metal base of the present invention is not limited thereto, for example, it may also be vanadium base, aluminum base and the like.

Further, the casting treatment may be performed in a pressureless infiltration manner.

In order to better understand the present invention, the content of the present invention will be further clarified below in conjunction with specific examples, but the content of the present invention is not limited to the following examples.

Example 1

Step 1. After mixing ZTA particles (ZTA _p ) with water glass binder, add Ti powder with a particle size of 4 μm, and mechanically stir to obtain ZTA particles coated with coated powder Ti, that is, ZTA _p -Ti.

In step 2, ZTA _p -Ti was mixed with PVA with a mass concentration of 3%, and dried at 60°C for 1 min to obtain ZTA _p coated with coated powder Ti and PVA, that is, ZTA _p -Ti/PVA.

Step 3, mix ZTA _p -Ti/PVA with Ni(Ac) ₂ activation solution and activate at 170°C for 25 minutes to obtain activated ceramic particles ZTA _p -Ti/PVA/Ni ²⁺ , where Ni(Ac) ₂ The activation solution is an activation solution with a mass concentration ratio of Ni(Ac) ₂ , NaH ₂ PO ₂ , C ₂ H ₆ O and H ₂ O in a ratio of 1:1:15:2.

Step 4, configure CuNi plating solution. The concentration of nickel sulfate (NiSO ₄ 6H ₂ O) in the CuNi plating solution is 30g/L, the concentration of copper sulfate (CuSO ₄ 5H ₂ O) can be 30g/L, and the concentration of sodium citrate (C ₆ H ₅ Na ₃ O ₇ •2H ₂ O) concentration can be 30g/L, sodium hypophosphite (NaH ₂ PO ₂ •H ₂ O) concentration can be 32g/L, boric acid (H ₃ BO ₃ ) concentration can be 15g/L and The concentration of choline chloride-ethylene glycol (ChCl-EG) may be 10 g/L.

Step 5, mix the activated ceramic particles ZTA _p -Ti/PVA/Ni ²⁺ with the CuNi plating solution, adjust the pH to 9.5, and perform electroless plating for 50 minutes at a rotation speed of 100 rpm and a temperature of 65°C to obtain CuNi coating ZTA _p -Ti/PVA, namely ZTA _p -Ti/PVA@CuNi.

Step 6, ZTA _p -Ti/PVA@CuNi and high chromium cast iron are subjected to pressureless impregnation treatment to obtain the composite material ZTA _p -Ti/PVA@CuNi/HCCI.

Comparative example 1

Step 100, after mixing ZTA particles (ZTA _p ) with water glass binder, adding Ti powder with a particle size of 4 μm, and mechanically stirring, to obtain ZTA particles coated with coated powder Ti, that is, ZTA _p -Ti.

Step 200, mixing ZTA _p -Ti with Ni(Ac) ₂ activation solution and activating at 170°C for 25 minutes to obtain activated ceramic particles ZTA _p -Ti/Ni ²⁺ , wherein the Ni(Ac) ₂ activation solution is An activation solution with a mass concentration ratio of Ni(Ac) ₂ , NaH ₂ PO ₂ , C ₂ H ₆ O and H ₂ O in a ratio of 1:1:15:2.

Step 300, configuring a CuNi plating solution. The concentration of nickel sulfate in CuNi plating solution is 30g/L, the concentration of copper sulfate (CuSO ₄ ·5H ₂ O) can be 30g/L, the concentration of sodium citrate (C ₆ H ₅ Na ₃ O ₇ ·2H ₂ O) It can be 30g/L, the concentration of sodium hypophosphite (NaH ₂ PO ₂ ·H ₂ O) can be 32g/L, the concentration of boric acid (H ₃ BO ₃ ) can be 15g/L and choline chloride-ethylene glycol The concentration of (ChCl-EG) can be 10g/L.

Step 400, mixing the activated ceramic particles ZTA _p -Ti/Ni ²⁺ with CuNi plating solution, adjusting the pH to 9.5, and electroless plating for 50 minutes at a rotation speed of 100 rpm and a temperature of 65°C to obtain a Ti-CuNi coating ZTA, that is, ZTA _p -Ti@CuNi.

In step 500, ZTA _p -Ti@CuNi and high chromium cast iron are subjected to pressureless impregnation to obtain composite material ZTA _p -Ti@CuNi/HCCI.

Compared with Example 1, the difference between Comparative Example 1 and Example 1 is that Step 2 of Example 1 is not carried out in Comparative Example 1, that is, ZTA _p -Ti is not mixed with PVA, and other steps are the same.

As shown in FIG. 1 , FIG. 1 shows a comparison of appearance morphology of ZTA _p -Ti/PVA in Example 1 before and after activation and ZTA _p -Ti in Comparative Example 1 before and after activation. The white one is the small crucible, and the green liquid in the picture (a ₁ and c ₁ ) is the activation solution. Picture (a) shows the original ceramic particles, which are off-white. After step 1 (or step 100), the ZTA particles coated with Ti powder are grayish black, as shown in figure (b). After step 2, after a layer of PVA is coated on the basis of ZTA _p -Ti particles, the ceramic is still gray-black, but the surface shows obvious luster, as shown in figure (c). When PVA is not coated, Ti powder will detach from the surface of ZTA ceramic particles, as shown in Figure (b1), and the activation solution turns black. However, for ZTA _p -Ti coated with PVA, the color of its activation solution is still light green, as shown in figure (c1), which is consistent with the color of (a1) when it is not coated with titanium, which proves that the PVA film is well protected. Ti powder coated with ZTA particles. After sintering at high temperature for 30 minutes, observe the color of ZTA ceramic particles after sintering. The original ZTA particles in Figure (a ₂ ) are gray, because Ni(Ac) ₂ in the activation solution is reduced by sodium hypophosphite, and Ni is activated. . In Figure (b ₂ ), the ZTA _p without PVA protection is black after sintering due to the mixing of Ti powder into the activation solution. In picture (c ₂ ), the color of ZTA _p -Ti coated PVA is the same as that of (a ₂ ) after activation, so it shows that PVA can protect ZTA _p -Ti at high temperature without affecting its activation , in order to carry out the next chemical plating process.

Fig. 2 shows the comparison of the microscopic morphology of the ZTAp _- Ti/PVA of Example 1 before and after activation and the _ZTAp -Ti of Comparative Example 1 before and after activation. After ZTA particles (figure a) coated with Ti powder, the Ti powder on the surface of ZTA _p -Ti particles is loose (figure b), after coating a layer of PVA on the basis of ZTA _p -Ti particles, Ti powder is coated Inside, the surface presents only a smooth layer of PVA film. CuNi alloy spherical particles and bare ZTA surface will be observed on the surface of ZTA _p -Ti@CuNi particles without PVA coating (as shown in Figure b ₁ ); while ZTA _p -Ti@CuNi particles obtained by plating after PVA coating The surface is evenly covered by spherical particles of CuNi alloy (see Figure c ₁ ). It can also be seen from the cross-section that the ZTA _p -Ti@CuNi particles obtained by plating after PVA coating, the Ti powder is completely and uniformly coated on the surface of the ZTA particles (as shown in Figure c ₂ ), without PVA coating After plating ZTA _p -Ti@CuNi particles, a large amount of Ti powder is lost (as shown in Figure b ₂ ).

Fig. 3 shows the surface distribution diagram of the ZTA _p -Ti/PVA@CuNi section elements prepared in Example 1. Figure (a) is the appearance of the ZTA _p -Ti/PVA@CuNi particles prepared in step 5. The surface of the ZTA _p -Ti particles coated with copper and nickel is smooth and has a red metallic luster. Figure b and the surface distribution of its elements can be seen that the mixture of Ti powder and water glass is uniformly coated on the surface of ZTA particles by CuNi coating.

Fig. 4 shows the surface distribution of elements at the ZTA _p -Ti@CuNi/HCCI interface prepared in Example 1. Figure (a) is the appearance of the ZTA _p -Ti@CuNi/HCCI composite material prepared in step 6, and the composite material has no hole defects. From Figure (b) and the surface distribution of elements, it can be seen that under the infiltration of high-temperature molten iron, the CuNi coating is melted and reacts with Ti powder, and forms a uniform and stable reactivity with elements in high-chromium cast iron interface.

Although the present invention has been described above in conjunction with the exemplary embodiments, it should be apparent to those skilled in the art that various modifications and changes may be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined in the claims. Change.

Claims (10)

1. A method for coating ceramic particles, comprising the following steps: mixing the ceramic particles with the binder, adding coating powder, and stirring to obtain ceramic particles coated with the coating powder; mixing the ceramic particles coated with the coating powder and polyvinyl alcohol, and drying to obtain the ceramic particles with the coating powder and polyvinyl alcohol attached to the surface; Activate the ceramic particles with coating powder and polyvinyl alcohol attached to the surface, and plate with a plating solution after activation to obtain ceramic particles coated with coating powder-metal coating. 2. The method for coating ceramic particles according to claim 1, characterized in that the drying temperature is 50°C-70°C. 3. The method for coating ceramic particles according to claim 1 or 2, characterized in that the coating powder is one or more of metal powder, ceramic powder, carbide powder and boride powder. 4. The method for coating ceramic particles according to claim 1 or 2, characterized in that the radial dimension of the coating powder is 0.1 μm-10 μm. 5. The method for coating ceramic particles according to claim 1 or 2, wherein the mass concentration of polyvinyl alcohol is 1.5% to 8.5%. 6. The method for coating ceramic particles according to claim 1 or 2, characterized in that the plating solution is one or a mixture of nickel-containing plating solution and copper-containing plating solution. 7. The method for coating ceramic particles according to claim 1 or 2, characterized in that, activating the ceramic particles with coating powder and polyvinyl alcohol on the surface includes attaching the ceramic particles with coating powder and polyvinyl alcohol to the surface. After the particles are mixed with the activation solution, they are activated at a temperature of 150°C to 200°C. 8. The method for coating ceramic particles according to claim 7, wherein the activation solution is Ni(Ac) ₂ activation solution, PbCl ₂ activation solution or AgNO ₃ activation solution. 9. A method for preparing a composite material, comprising the following steps: The method for coating ceramic particles described in any one of claims 1 to 8 is prepared to obtain coating powder-metal coating coated ceramic particles; The ceramic particles covered by the coating powder-metal coating and the metal matrix are cast to obtain a composite material. 10. The composite material preparation method according to claim 9, characterized in that the metal base is titanium base, copper base, iron base or steel base.

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