Method for producing ceramic particle reinforced metal matrix composites

Abstract

The application relates to a preparation method of a ceramic particle reinforced metal matrix composite material and belongs to the technical field of new materials. A metal matrix is added into a high-temperature and high-pressure reaction container, the metal is made into a supercritical fluid through heating and pressurizing, and then ceramic particles are added into the metal supercritical fluid to prepare the metal matrix composite material. The metal matrix composite material prepared through the method can uniformly distribute the ceramic particles in the metal matrix, and effectively improves the comprehensive performance of the material.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology and relates to a method for preparing ceramic particle-reinforced metal matrix composite materials. Background Technology

[0002] In the preparation of metal matrix composites, many composite processes involve the interaction between a liquid metal matrix and a solid reinforcement to achieve composite. The wettability between the two is one of the key factors that enables composite, facilitates composite, and ensures good bonding after composite.

[0003] Wettability refers to the ability of a liquid to spread spontaneously on a solid surface. If the surface energy of the solid is greater than that of the liquid, the liquid will spread on the solid surface, meaning the liquid wets the solid. The degree of wetting can be expressed by the contact angle between the two.

[0004] Currently, in various ceramic nanoparticle dispersion-reinforced metal matrix composites used in engineering, the wetting angle between nanoparticles and molten metal is generally large. When the wetting angle is greater than 90°, the solid-gas interfacial energy is less than the solid-liquid interfacial energy, causing the surface tension of the solid to tend to drive the liquid away from the surface, making the solid adhere to the solid. As a result, nanoparticles tend to aggregate in the melt to reduce the surface free energy of the entire nanoparticle system. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for preparing ceramic particle reinforced metal matrix composite material, so that the ceramic particle reinforcing phase is stably and uniformly dispersed inside the metal matrix.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing ceramic particle-reinforced metal matrix composites involves adding ceramic particles into a metal matrix in a supercritical fluid state and dispersing the ceramic particles using the properties of supercritical fluid.

[0008] Optionally, the metal matrix can be brought into a supercritical fluid state by heating and pressurizing.

[0009] Optionally, the metal matrix is ​​one or more combinations of magnesium and its alloys.

[0010] Optionally, the ceramic particles are formed by one or more combinations of titanium carbide, titanium diboride, boron nitride, zirconium carbide, hafnium carbide, tantalum carbide, niobium carbide, silicon carbide, tungsten carbide, and tungsten boride.

[0011] Optionally, the heating temperature range is 2900K-3200K, and the pressurization pressure range is 130MPa-150MPa.

[0012] Optionally, a stirring rod can be used to assist in stirring during the dispersion of ceramic particles.

[0013] Optional, the stirring speed is 250-500 rpm.

[0014] Optionally, the stirring time is 10-30 minutes.

[0015] Optionally, after the ceramic particles are dispersed, the product is cooled. When the temperature drops to a certain temperature above the melting point of the metal matrix, the product is depressurized. After depressurization to atmospheric pressure, the product is cast.

[0016] Optionally, the product can be depressurized after the temperature drops to 373K-423K above the melting point of the metal matrix.

[0017] The beneficial effects of this invention are as follows:

[0018] When the temperature and pressure of a fluid are above its critical temperature and critical pressure, the fluid is in a supercritical state. At this state, the fluid exhibits physicochemical properties intermediate between those of a gas and a liquid, possessing solubility and heat transfer coefficients similar to liquids, and viscosity and diffusion coefficients similar to gases. The surface tension of supercritical metal fluids is almost zero. When a supercritical metal fluid comes into contact with ceramic particles, according to thermodynamic analysis based on wetting theory, to reduce the surface tension of the ceramic particles, the surface of the ceramic particles will adsorb as many molecules as possible per unit area, thus enhancing the wetting ability between the supercritical fluid and the ceramic particles. Simultaneously, because the temperature during the reaction process is higher than that during ordinary melting, the Brownian motion of the ceramic particles in the matrix is ​​more intense, resulting in a more uniform dispersion of the ceramic particles. The metal-based composite material prepared by this method allows ceramic particles to be uniformly distributed within the metal matrix, effectively improving the overall performance of the material.

[0019] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Detailed Implementation

[0020] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0021] The present invention achieves the above objective by means of the following technical solution: ceramic particles are uniformly mixed with a metal matrix treated with supercritical fluid technology to obtain the ceramic particle reinforced metal matrix composite material.

[0022] The present invention is as follows:

[0023] (1) The selected metal matrix is ​​pure magnesium and its alloys; the selected ceramic reinforcing particles are one of titanium carbide, titanium diboride, boron nitride, zirconium carbide, hafnium carbide, tantalum carbide, niobium carbide, silicon carbide, tungsten carbide, and tungsten boride.

[0024] (2) The selected metal matrix is ​​added to the high temperature and high pressure reaction device. By heating and pressurizing, the temperature and pressure reach the critical temperature and critical pressure of the metal matrix, respectively, so that the metal matrix reaches the supercritical fluid state.

[0025] (3) Add ceramic particles into the reaction apparatus and use a stirring rod to assist stirring. The stirring speed is 250-500 rpm and the stirring time is 10-30 min.

[0026] (4) After stirring, the reaction apparatus is rapidly cooled down. Once the temperature drops to 373K-423K above the melting point of the metal matrix, the pressure is rapidly reduced. After the pressure drops to atmospheric pressure, casting is carried out to obtain an ingot.

[0027] Table 1 Mechanical properties of some reinforcements and contact angles with the magnesium matrix

[0028]

[0029] Example 1:

[0030] (1) Place the graphite crucible containing 100g of high-purity magnesium particles into the electric arc furnace and pressurize it to 143MPa using a pressurizing device.

[0031] (2) After the pressure in step (1) reaches 143MPa, turn on the electric arc furnace heating switch and heat up to 3000K to make the magnesium particles form a supercritical fluid.

[0032] (3) After the supercritical fluid is formed in step (2), 5 vol% titanium carbide ceramic particles are added to the crucible and stirred with a graphite stirring rod at a speed of 300 rpm for 20 min.

[0033] (4) After the stirring in step (3) is completed, stop heating and cool rapidly at a rate of 200 K / s. When the metal temperature drops to 1000 K, depressurize. After the pressure drops to atmospheric pressure, cast the ingot to obtain the ingot.

[0034] Example 2:

[0035] (1) Place the graphite crucible containing 200g of high-purity magnesium particles into the electric arc furnace and pressurize it to 140MPa using a pressurizing device.

[0036] (2) After the pressure in step (1) reaches 140MPa, turn on the electric arc furnace heating switch and raise the temperature to 3000K to make the magnesium particles form a supercritical fluid.

[0037] (3) After the supercritical fluid is formed in step (2), 3 vol% boron nitride ceramic particles are added to the crucible and stirred with a graphite stirring rod at a speed of 250 rpm for 25 min.

[0038] (4) After the stirring in step (3) is completed, stop heating and cool rapidly at a rate of 200 K / s. When the metal temperature drops to 1000 K, depressurize. After the pressure drops to atmospheric pressure, cast the ingot to obtain the ingot.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a ceramic particle-reinforced metal matrix composite material, characterized in that: Adding ceramic particles into a metal matrix in a supercritical fluid state, and dispersing the ceramic particles using the properties of supercritical fluid; specifically including: (1) The selected metal matrix is ​​one or more of pure magnesium and its alloys; the selected ceramic reinforcing particles are one or more of titanium carbide, titanium diboride, boron nitride, zirconium carbide, hafnium carbide, tantalum carbide, niobium carbide, silicon carbide, tungsten carbide, and tungsten boride. (2) The selected metal matrix is ​​added to the high temperature and high pressure reaction device. By heating and pressurizing, the temperature and pressure reach the critical temperature and critical pressure of the metal matrix respectively, so that the metal matrix reaches the supercritical fluid state. (3) Add ceramic particles to the reaction apparatus to disperse the ceramic particles, and use a stirring rod for auxiliary stirring; (4) After the ceramic particles are dispersed after stirring, the product is cooled down. After the temperature drops to a certain temperature above the melting point of the metal matrix, the pressure is reduced. After the pressure drops to normal, the product is cast to obtain an ingot.

2. The method for preparing ceramic particle-reinforced metal matrix composite material according to claim 1, characterized in that: The heating temperature range is 2900K-3200K, and the pressurization pressure range is 130MPa-150MPa.

3. The method for preparing ceramic particle-reinforced metal matrix composite material according to claim 1, characterized in that: The stirring speed is 250-500 rpm.

4. The method for preparing ceramic particle-reinforced metal matrix composite material according to claim 1, characterized in that: Stirring time is 10-30 minutes.

5. The method for preparing ceramic particle-reinforced metal matrix composite material according to claim 1, characterized in that: When the temperature drops to 373K-423K above the melting point of the metal matrix, the pressure of the product is reduced.

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