LU501996B1 - Method for Preparing Cu@ZrC Core-shell Multiphase Granular Material by Electroless Plating - Google Patents

Abstract

The invention discloses a method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating, belonging to the technical field of powder metallurgy material manufacturing. The method comprise that following step: sequentially carrying out degreasing treatment, coarsening treatment, sensitization treatment, activation treatment and dispersion treatment on ZrC pow to obtain ZrC powder to be plated with copper; and then carrying out chemical copper plating treatment on the ZrC powder to be plated with copper to obtain the Cu@ZrC core-shell multiphase granular material. The method of the invention can effectively improve the binding property between the ZrC ceramic phase and the metal matrix, further can be used as a reinforcement to improve the mechanical properties of the metal matrix composite material, and provide a new choice of reinforcing phase particles for the preparation of the metal matrix composite material MMCs.

Description

DESCRIPTION LU501996 Method for Preparing Cu@ZrC Core-shell Multiphase Granular Material by Electroless Plating

TECHNICAL FIELD The invention belongs to the technical field of powder metallurgy material manufacturing, and particularly relates to a method for preparing Cu@ZrC core-shell multiphase granular materials by electroless plating.

BACKGROUND Metal matrix composites (MMCs) are composites made of metal and its alloy as matrix, and reinforced by one or more metals or nonmetals. MMCs has the characteristics of high strength and high elasticity, as well as excellent properties such as wear resistance and high temperature resistance. Metal matrix composites are mainly divided into particle reinforced metal matrix composites and fiber reinforced metal matrix composites. Compared with fiber reinforced metal matrix composites, particle reinforced metal matrix composites have more advantages in production technology and cost, and their properties are more uniform. Therefore, in the actual production process, reinforcing particles are often used to reinforce metal matrix composites. ZrC is a kind of excellent high-temperature structural ceramic material with high hardness, high strength, high wear resistance and high temperature resistance, so it is very suitable as the reinforcing phase particles of metal matrix composites. However, due to its small atomic diffusion coefficient, it is difficult to sinter, so its poor bonding with the base metal limits its application as reinforcement particles. Therefore, it is necessary to modify ZrC to improve the dispersity of ZrC particles and the combination with the metal matrix.

SUMMARY In order to solve the above problems in the prior art, the present invention aims to provide a method for preparing Cu@ZrC core-shell composite particle material by electroless plating. Cu@ZrC core-shell composite particle is obtained by uniformly plating copper on the surface of submicron ZrC powder by electroless plating, which effectively increases interfacial strength between ZrC ceramic phase and metal matrix.

To achieve the above purpose, the present invention provides the following technical scheme.

The first technical scheme of the present invention is a method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating, which comprises the following 501996 steps: degreasing, coarsening, sensitizing, activating and dispersing ZrC powder in sequence to obtain ZrC powder to be plated with copper, and then performing electroless copper plating on the ZrC powder to obtain the Cu@ZrC core-shell multiphase granular material.

Furthermore, the ZrC powder is submicron ZrC powder.

Further, the specific operation of the degreasing treatment includes soaking ZrC powder in NaOH solution, filtering, cleaning and drying.

Further, the concentration of the NaOH solution is 15vol.%.

Furthermore, the drying temperature in the degreasing treatment is 50°C and the time is 10h.

Further, the specific operation of the coarsening treatment is as follows: ultrasonically treating the degreased ZrC powder in HNO; solution, filtering, cleaning and drying, and the concentration of the HNO; solution is 40vol.%.

Further, the drying temperature in the coarsening treatment is 50°C and the time is 10h.

Further, the specific operation of the sensitization treatment is as follows: ultrasonically treating the coarsened ZrC powder in a sensitization solution, cleaning and filtering, and the sensitization solution is a mixed solution of SnCI2 and HCI.

Furthermore, the concentration of SnCl2 and HCl in the sensitization solution is 20g/L and 20g/L, respectively.

Further, the specific operation of the activation treatment is as follows: ultrasonically treating the sensitized ZrC powder in AgNOs solution, filtering, and cleaning to neutrality, and the concentration of AgNO; solution is 5g/L.

Further, the specific operation of the dispersion treatment 1s: dispersing the activated ZrC powder with dispersant to obtain ZrC powder to be plated with copper, wherein the dispersant 1s a mixed solution of sodium pyrophosphate and water glass, and the concentration of sodium pyrophosphate in the dispersant is 0.5wt.%.

Further, the specific operation of the dispersion treatment is as follows: the activated ZrC powder is added into the dispersant, and the ultrasonic dispersion treatment is carried out for

0.5h, and the power of the ultrasonic dispersion treatment is 40kHz.

Furthermore, the mass-volume ratio of activated ZrC powder to dispersant is 1g:10ml.

Further, the specific operation of the electroless copper plating treatment is as follows:

adding copper sulfate, complexing agent, buffer and catalyst into water in sequence to obtain a 59 1996 mixed solution, adjusting the pH value of the mixed solution to 11, and then adding ZrC powder to be plated with copper and reducing agent in sequence to obtain an electroless copper plating reaction system, wherein the electroless copper plating reaction system reacts at a temperature of 60°C, and after the reaction is finished, filtering, cleaning and drying are carried out to obtain the Cu@ZrC core-shell multiphase particles.

Furthermore, the complexing agent is trisodium citrate, the buffering agent is boric acid, the catalyst is nickel chloride hexahydrate, and the reducing agent is sodium hypophosphite, and the mass ratio of copper sulfate to ZrC powder to be plated with copper to sodium hypophosphite is 40: 20: 15; The pH value of the electroless copper plating reaction system is maintained at

10.5-11.5 in the whole reaction process.

Furthermore, the mass ratio of copper sulfate: trisodium citrate: boric acid: nickel chloride hexahydrate: ZrC powder to be plated with copper: sodium hypophosphite is 40: 258: 15: 23.8: 20: 15.

Further, the mass-volume ratio of copper sulfate to water is 40g: 300-700ml.

The reaction principle of electroless copper plating is: 2HP0, + Cu” + 20H —5Cu+2H,PO,” +H, The electroless copper plating reaction is intense, and the pH value of the solution gradually decreases and the hydroxide ions in the system gradually decrease during the reaction. As a result, the electroless copper plating reaction slows down or even cannot be carried out due to the lack of hydroxide ions. Therefore, it is necessary to continuously add sodium hydroxide solution to adjust the pH value to keep the pH value of the plating solution at about 11.

Further, the reaction time is 1-4h.

The second technical scheme of the present invention is a Cu@ZrC core-shell multiphase granular material prepared according to the above-mentioned chemical plating method for preparing Cu@ZrC core-shell multiphase granular material.

Furthermore, the core of the Cu@ZrC core-shell multiphase particle material is ZrC particles, and the shell is a Cu layer.

The third technical scheme of the invention is an application of the Cu@ZrC core-shell multiphase granular material prepared by the above electroless plating in metal matrix composite materials.

Furthermore, the Cu@ZrC core-shell multiphase granular material prepared by electroless, 1996 plating is used as the reinforcement of the metal matrix composite material, and the addition amount in the metal matrix composite material is 20vol.%, and the volume ratio of zirconium carbide to copper metal in the Cu@ZrC core-shell multiphase granular material is 1:2.

Compared with the prior art, the invention has the following beneficial effects: (1) according to the invention, Cu@ZrC core-shell multiphase particles are prepared by uniformly plating copper on the surface of zrc powder through degreasing treatment, coarsening treatment, sensitization treatment, activation treatment, dispersion treatment and electroless copper plating treatment; Oil removal and coarsening can remove impurities such as oil stain on the surface of ZrC powder, improve the specific surface area and roughness of ZrC powder, and thus improve the adhesion of copper plating layer on ZrC powder. Sensitization treatment, activation treatment and dispersion treatment can prevent ZrC powder from agglomeration and improve the uniformity and quality of copper plating layer. All the steps cooperated to prepare the Cu@ZrC core-shell composite particle reinforced material with high dispersibility and uniformity. The method of the invention can effectively improve the binding property between the ZrC ceramic phase and the metal matrix, further can be used as a reinforcement to improve the mechanical properties of the metal matrix composite material, and provide a new choice of reinforcing phase particles for the preparation of the metal matrix composite material MMCs.

(2) The excellent performance of MMCs depends mainly on the structure and performance of each component, but also on the characteristics of interface state to a great extent. In order to obtain metal matrix composites with excellent performance and meeting various requirements, a suitable interface is needed to make the reinforcement and matrix have good physical, chemical and mechanical compatibility. According to the invention, by coating copper on the surface of reinforced particles to modify them to prepare core-shell composite particles, the interfacial wettability and chemical compatibility between the ZrC ceramic particle reinforcement and the matrix can be improved, the uniform dispersion of particles in different phases can be realized, and the excellent characteristics of particles in different phases can be fully exerted.

(3) In the invention, the surface of ZrC ceramic particles is plated with copper by chemical plating. Compared with electroplating, electroless plating does not need an external power supply, and metal ions are reduced to metal by the reducing agent in the solution and deposited on the surface of the substrate to form a coating, which is convenient to operate, simple in process, uniform in coating, small in porosity and good in appearance. Compared with the =o 1996 conventional chemical plating process, the method of the invention avoids using highly toxic HF to corrode the components to be plated, and is safe and environment-friendly.

BRIEF DESCRIPTION OF THE FIGURES In order to more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without any creative effort.

Fig. 1 is the SEM image of ZrC powder without copper plating treatment; Fig. 2 is the SEM image of Cu@ZrC core-shell composite particles prepared in Example 1 after surface copper plating treatment; Fig. 3 is a schematic diagram of the microstructure of Cu@ZrC core-shell composite particles prepared in Example 1 after surface copper plating treatment.

DESCRIPTION OF THE INVENTION Now, various exemplary embodiments of the present invention will be described in detail. This detailed description should not be taken as a limitation of the present invention, but should be understood as a more detailed description of some aspects, characteristics and embodiments of the present invention.

It should be understood that the terms mentioned in the present invention are only used to describe specific embodiments, and are not used to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Every smaller range between any stated value or the intermediate value within the stated range and any other stated value or the intermediate value within the stated range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

Unless otherwise stated, all technical and scientific terms used herein have the same meanings commonly understood by those of ordinary skill in the field to which this invention relates. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification [¢1501996 incorporated by reference to disclose and describe the methods and/or materials related to the documents. In case of conflict with any incorporated documents, the contents of this specification shall prevail.

Without departing from the scope or spirit of the present invention, it is obvious to those skilled in the art that many modifications and changes can be made to the specific embodiments of the present specification. Other embodiments obtained from the description of the present invention will be obvious to the skilled person. The description and embodiment of that invention are only exemplary.

As used in this paper, the terms "include", "comprise", "have" and "contain" are all open terms, meaning including but not limited to.

Example 1 (1) Degreeasing treatment: 20g submicron ZrC powder (with particle size of 3-5um) is added into 100ml NaOH solution with concentration of 15vol.%, soaked for 1h to remove the oil stain on the powder surface, repeatedly filtered and cleaned with NaOH solution with concentration of 15vol.% for 3 times, then repeatedly filtered and cleaned with distilled water for 3 times, and then dried at 50°C for 10h in a vacuum drying oven.

(2) coarsening: ultrasonically treating the degreased ZrC powder in HNO; with a concentration of 40Vol.% for 2 hours (ultrasonic frequency of 40kHz), filtering after the powder settles, repeatedly washing with distilled water for 3 times, and then drying in a vacuum drying oven at 50°C for 10 hours for later use; The surface of coarsened ZrC powder is relatively rough.

(3) Sensitization treatment: put the coarsened ZrC powder into 100ml of mixed sensitization solution with the concentration of 20g/L SnCl2+20g/L HCI, and perform ultrasonic treatment for 1h (ultrasonic frequency is 40kHz). During the sensitization process, keep stirring with a glass rod to prevent the ZrC powder from depositing on the bottom of the beaker. After the sensitization treatment, filter and clean it with distilled water for three times. The particle morphology of sensitized ZrC powder is rougher than that of non-sensitized, and the particle size has no obvious change.

(4) Activation treatment: put the sensitized ZrC powder into 100ml AgNOs solution with the concentration of 5g/L for ultrasonic treatment for 30 min (the ultrasonic frequency is 40kHz),

wash it with distilled water until it is neutral, and then dry it in a vacuum drying oven at 50 s0 1996 for Sh; The morphology and structure of activated ZrC powder have no obvious change.

(5) Dispersion treatment: the mixed solution of sodium pyrophosphate and water glass (the concentration of sodium pyrophosphate is 0.5wt.%) is used as dispersant to disperse the submicron ZrC powder, and the mass-volume ratio of activated ZrC powder to dispersant is 1g:10ml; ; The activated ZrC powder was added into dispersant, and then dispersed by ultrasonic for 0.5h (ultrasonic frequency was 40kHz). The dispersed ZrC powder was well dispersed, and there was no obvious agglomeration among particles.

(6) Electroless copper plating: Weigh 40g of copper sulfate into a beaker with a volume of IL, add 500ml of distilled water, and then mechanically stir and dissolve it in a constant-temperature water bath at 60°C. Add 258g citric acid trisodium as complexing agent into copper sulfate solution, then add 15g boric acid as buffering agent and 23.8g nickel chloride hexahydrate (NiCl,*6H,0) as catalyst in turn. After the above reagents are completely dissolved, add sodium hydroxide to adjust the pH value to 11. After the adjustment, add 20g of ZrC powder after dispersion treatment, and finally add 15g sodium hypophosphite as reducing agent to obtain the electroless copper plating reaction system. The reaction temperature of electroless copper plating system is 60°C and the reaction time is 3 hours. The electroless copper plating reaction is intense, and the pH value of the solution gradually decreases during the intense reaction. In the process, sodium hydroxide solution is continuously added to adjust the pH value, so that the pH value of the plating solution is kept at about 11 (10.5-11.5). When the reaction is finished, turn off the stirrer and the water bath pot, wash the copper-plated ZrC powder with distilled water for 6 times, and dry it in a blast drying oven at 80°C for 5 hours to obtain the Cu@ZrC core-shell multiphase granular material.

Take ZrC powder raw materials which have not been subjected to surface copper plating treatment (neither degreasing treatment, coarsening treatment, sensitization treatment, activation treatment, dispersion treatment, that is, without any treatment) and Cu@ZrC core-shell multiphase granular materials prepared in Example 1 after surface copper plating treatment for electron microscope scanning. Fig. 1 is the SEM image of ZrC powder without surface copper plating, and Fig. 2 is the SEM image of Cu@ZrC core-shell composite particles prepared in Example 1 after surface copper plating. From Fig. 1 and Fig. 2, it can be seen that ZrC powder still has good dispersibility after copper plating with the addition of dispersant, without obvious agglomeration, while ZrC powder without surface copper plating has obvious agglomeration and, 501996 uneven dispersion.

The microstructure diagram of the Cu@ZrC core-shell composite particle material prepared in Example 1 after the surface copper plating treatment is shown in Fig. 3. It can be seen from Fig. 3 that the Cu@ZrC core-shell composite particle prepared in Example 1 has a core-shell structure, and a uniform copper layer is formed on the surface of ZrC particles.

Comparative example 1 As in Example 1, the difference is that the activated Cu@ZrC powder is directly used for electroless copper plating without dispersion treatment.

Comparative example 2 As in Example 1, the difference is that without activation treatment, the sensitized Cu@ZrC powder is directly subjected to dispersion treatment and electroless copper plating treatment after drying.

Effect verification The Cu@ZrC core-shell multiphase granular materials prepared in Example 1 and Comparative Examples 1-2 of the present invention and ZrC powder raw materials without surface copper plating treatment (without degreasing treatment, coarsening treatment, sensitization treatment, activation treatment and dispersion treatment, that is, without any treatment) were used as reinforcements to prepare titanium matrix composites, and the addition amount of reinforcements was 20vol.% of that of metal matrix composites. The specific preparation method is as follows: Firstly, according to the formula, Ti powder, 6Al-4V alloy powder, ZrC powder or Cu@ZrC core-shell multiphase particles without surface copper plating are mixed by ball milling in a certain proportion, and the ball milling is carried out at 80r/min for 20min. After ball milling, the mixed powder is put into a mold, pressed into a cylindrical blank by 300MPa cold isostatic pressing, and the blank is put into a vacuum resistance furnace for vacuum sintering, the vacuum degree is above 5x10 Pa, the temperature is increased to 1500°C at a speed of 20°C/min, and the heat preservation is carried out for 3 hours, so that the powder metallurgy titanium matrix composite block is prepared.

Titanium matrix composites prepared by using Cu@ZrC core-shell composite particles prepared in Example 1 and Comparative Examples 1-2 as reinforcements were used as corresponding Examples 1 and Comparative Examples 1-2; The titanium matrix composite 591996 prepared by using ZrC powder without surface copper plating as reinforcement was used as control group 1; The titanium alloy material without reinforcement was used as the blank control group 2 (the preparation method of titanium alloy is the same as that of titanium matrix composite material, but without reinforcement). The following performance tests were carried out on the above titanium matrix composites and titanium alloy materials.

(1) Mechanical performance test Take the titanium-based composite materials of Example 1, Comparative Examples 1-2, Control Group 1 and the titanium alloy materials of blank control group 2, measure the density of sintered materials according to the method specified in GB/T 10421-2002 (Determination of the density of sintered metal friction materials), test the tensile strength performance according to the room temperature tensile test method of GB/T228-2002 metal materials, and perform the Rockwell hardness test with a digital Rockwell hardness meter. The test results are shown in Table 1.

Table 1 Density/% Rockwell Tensile strength hardness /MPa como | ws | en | wm The above are only preferred embodiments of the present invention, and it is not intended to limit the present invention. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims (10)

CLAIMS LU501996

1. A method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating, which is characterized by comprising the following steps: degreasing, coarsening, sensitizing, activating and dispersing ZrC powder in sequence to obtain ZrC powder to be plated with copper, and then performing electroless copper plating on the ZrC powder to obtain the Cu@ZrC core-shell multiphase granular material.

2. The method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating according to claim 1, which is characterized in that the specific operation of the degreasing treatment includes soaking ZrC powder in NaOH solution, filtering, cleaning and drying; the specific operation of the coarsening treatment includes ultrasonic treatment of the degreased ZrC powder in HNO; solution, filtering, cleaning and drying, and the concentration of the HNO; solution is 40vol %.

3. The method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating according to claim 1, which is characterized in that the specific operation of the sensitization treatment includes ultrasonic treatment, cleaning and filtering of coarsened ZrC powder in sensitization solution; and the sensitizing solution is a mixed solution of SnCI2 and HCI.

4. The method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating according to claim 3, which is characterized in that the concentration of SnCl2 and HCI in the sensitization solution 1s 20g/L and 20g/L respectively.

5. The method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating according to claim 1, which is characterized in that the specific operation of the activation treatment is as follows: ultrasonically treating the sensitized ZrC powder in AgNO3 solution, filtering, and cleaning to neutrality, and the concentration of AgNO; solution is 5g/L.

6. The method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating according to claim 1, which is characterized in that the specific operation of the dispersion treatment is: dispersing the activated ZrC powder with a dispersant to obtain ZrC powder to be plated with copper, wherein the dispersant is a mixed solution of sodium pyrophosphate and water glass, and the concentration of sodium pyrophosphate in the dispersant is 0.5wt.%.

7. The method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating according to claim 1, which is characterized in that the specific operation of the so 1996 electroless copper plating treatment is as follows:adding copper sulfate, complexing agent, buffer and catalyst into water to obtain a mixed solution, adjusting the pH value of the mixed solution to 11, and then adding ZrC powder to be plated with copper and reducing agent to obtain an electroless copper plating reaction system, wherein the electroless copper plating reaction system reacts at a temperature of 60°C, and after the reaction is finished, filtering, cleaning and drying are carried out to obtain the Cu@ZrC core-shell multiphase granular material.

8. The method for preparing Cu@ZrC core-shell multiphase granular material by electroless plating according to claim 1, which is characterized in that the complexing agent is trisodium citrate, the buffering agent is boric acid, the catalyst is nickel chloride hexahydrate, and the reducing agent is sodium hypophosphite, and the mass ratio of copper sulfate to ZrC powder to be plated with copper to sodium hypophosphite is 40: 20: 15; during the whole reaction process, the pH value of the electroless copper plating reaction system was maintained at 10.5-11.5.

9. A Cu@ZrC core-shell multiphase granular material prepared according to the chemical plating method for preparing Cu@ZrC core-shell multiphase granular material in any one of claims 1-8.

10. An application of the Cu@ZrC core-shell multiphase granular material prepared by the electroless plating in metal matrix composite materials in claim 9.