Zirconium carbide particles, zirconium carbide particle reinforced magnesium matrix composite and method for producing the same

Abstract

The application discloses zirconium carbide particles, a zirconium carbide particle reinforced magnesium-based composite material and a preparation method thereof, and belongs to the technical field of zirconium carbide particle preparation. The carbon source in CO2 and / or CO gas is solidified into nanoscale carbon powder through gas-liquid reaction with a magnesium melt, and through the addition of a magnesium-zirconium intermediate alloy, zirconium carbide particles are generated in situ in the magnesium melt, and the uniformly dispersed nanoscale carbon material in the melt promotes the uniform distribution of the zirconium carbide particles in the zirconium carbide particle reinforced magnesium-based composite material, thereby creating a carbon reaction raw material with high defect density and reactivity, significantly reducing the synthesis temperature of the zirconium carbide ceramic particles, and effectively avoiding the introduction of impurities, thereby significantly improving the mechanical properties and preparation efficiency of the magnesium-based composite material; the method provided by the application adopts a short process and a low-cost liquid metallurgy method, avoids the safety risk of directly adding powder, and realizes the synthesis of the zirconium carbide particles and the synergistic reinforcement of the magnesium matrix.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of zirconium carbide particle preparation, in particular to a zirconium carbide particle, a zirconium carbide particle reinforced magnesium-based composite material and a preparation method thereof. BACKGROUND

[0002] Zirconium carbide (ZrC) particles are often used to prepare wear-resistant coatings for protecting metal surfaces and improving their wear resistance and corrosion resistance due to their high hardness and good wear resistance. These coatings can be applied to cutting tools, molds, bearings and other industrial components. At the same time, zirconium carbide has a high melting point and excellent high-temperature mechanical properties, so nano-zirconium carbide particles can be used to prepare structural materials at high temperatures, such as engine components and thermal barrier coatings in the aerospace field. These application fields demonstrate the diversity and potential of zirconium carbide nanoparticles.

[0003] Currently, the synthesis methods of zirconium carbide particles mainly include the following:

[0004] (1) High-temperature carbon thermal reduction method, which is a traditional synthesis method by mixing zirconium oxide with carbon source (such as carbon black, graphite, etc.) and reacting at high temperature (usually above 2000℃). During the reaction, carbon reacts with zirconium oxide to form zirconium carbide. This method can be carried out in air or inert gas atmosphere.

[0005] (2) Chemical vapor deposition (CVD), CVD method is to use gas raw materials to carry out chemical reaction at high temperature to generate solid zirconium carbide. Zirconium halide and hydrocarbon gas are usually used as raw materials to deposit at a temperature range of 1000℃ to 1500℃.

[0006] (3) Self-propagating high-temperature synthesis (SHS), SHS method is to use the high temperature generated by exothermic reaction to synthesize materials. After the mixture of zirconium powder and carbon powder is ignited, the heat released by the reaction is enough to maintain the continuous reaction, and zirconium carbide is generated.

[0007] (4) Arc melting method, arc melting is a method of using the high temperature generated by electric arc to melt and synthesize materials. The mixture of zirconium and carbon is placed in the furnace and heated to melting state under the protection of inert gas, then cooled and solidified to obtain zirconium carbide.

[0008] Although the preparation of zirconium carbide particles has broad application prospects, in actual preparation, the synthesis of zirconium carbide usually requires high temperature conditions, which may cause difficulties in size control and morphology preservation of the particles. At high temperatures, zirconium carbide particles are prone to agglomeration and sintering, affecting the performance of the final product. In addition, the current synthesis method usually consumes a lot of energy and has low production efficiency, which leads to high production cost of zirconium carbide nanoparticles, limiting its large-scale commercial application. When selecting the most suitable method for large-scale production, factors to be considered include product quality requirements, production cost, energy consumption, environmental impact, and production scale.

[0009] In practical applications, the common carbon source for synthesizing zirconium carbide ceramic particles is carbon black, graphite or other carbon-containing compounds. In order to reduce the cost, carbon dioxide (CO2) can be used as a carbon source to prepare zirconium carbide ceramic particles, thereby promoting its application in different fields. Since carbon dioxide is a weakly oxidizing carbon source, it often requires high temperatures (1000-2000℃) and specific chemical reaction conditions when preparing zirconium carbide. One possible method is to use chemical vapor deposition (CVD) technology to react carbon dioxide with zirconium metal or zirconium halide at high temperatures. In this process, zirconium metal or zirconium halide acts as a reducing agent to react with carbon dioxide to form zirconium carbide. Another method is to mix carbon dioxide with zirconium oxide through carbothermal reduction reaction and react at high temperatures.

[0010] In summary, using carbon dioxide (CO2) gas as a carbon source to prepare zirconium carbide ceramic particles has the advantage of low cost, but the current method still has technical deficiencies, the main challenge being that carbon dioxide gas has weak reducing properties, requiring high temperatures and long reaction times, and the preparation process is complex. SUMMARY

[0011] The purpose of the present application is to provide a kind of zirconium carbide particles, zirconium carbide particle reinforced magnesium matrix composite material and its preparation method, to solve the problems of high temperature, easy agglomeration and sintering, size control and morphology preservation difficulties, product performance instability, complex preparation process, low production efficiency and high production cost of the prior art zirconium carbide particle preparation.

[0012] To achieve the above-mentioned purpose, the present application provides a kind of zirconium carbide particle, the preparation method of zirconium carbide particle reinforced magnesium matrix composite material, steps are as follows:

[0013] S1, carbon source gas pretreatment, impurity removal treatment is carried out to carbon source gas with a purity of 99.9%;

[0014] S2, carbon solidification in carbon source gas, after pure magnesium is melted, the carbon source gas after impurity removal in step S1 is introduced under stirring to obtain a magnesium melt rich in carbon nanometer powder carbon source;

[0015] S3, synthesis of zirconium carbide ceramic particles and preparation of zirconium carbide particle reinforced magnesium matrix composite, adding magnesium-zirconium intermediate alloy into the magnesium melt prepared in step S2, and continuing to stir for 10 min;

[0016] S4, extraction of zirconium carbide particles, after the reaction is completed, the reaction medium is pressure cast into an ingot to obtain a zirconium carbide particle reinforced magnesium matrix composite, and the zirconium carbide particle reinforced magnesium matrix composite is purified to obtain high-purity zirconium carbide particles.

[0017] Preferably, the carbon source gas in step S1 is one or both of CO2 and CO.

[0018] Preferably, the impurity removal treatment of the carbon source gas in step S1 refers to removing alkaline impurities and moisture in the gas, and the method adopted is to make the gas pass through pure sulfuric acid and propylene glycol liquid gas washing bottles in sequence.

[0019] Preferably, the aeration speed of the carbon source gas in step S2 is 0.5-1.5 L / min, the aeration time is 20 min-2 h, and the carbon nanometer powder content is 1-5 wt%; the stirring state refers to a stirring rate of 1000-1800 r / min.

[0020] Preferably, the magnesium alloy in step S2 is any magnesium alloy containing elements that do not react with carbon elements, and the pure magnesium or magnesium alloy is melted at 720°C in a protective atmosphere, and is kept for 20 min after melting.

[0021] Preferably, the protective atmosphere refers to a volume ratio of CO2 to SF6 of 40:1.

[0022] Preferably, the magnesium-zirconium intermediate alloy in step S3 is Mg-30 wt.% Zr, and the addition amount of the magnesium-zirconium alloy is 1-5 wt% of the pure magnesium; the magnesium-zirconium intermediate alloy is preheated at 400°C for 30 min before being added.

[0023] Preferably, the method for purifying the zirconium carbide particle reinforced magnesium matrix composite in step S4 is to use 5-20% hydrochloric acid to erode the zirconium carbide particle reinforced magnesium matrix composite, then wash with distilled water, and then reduce pressure to filter to obtain high-purity zirconium carbide particles.

[0024] Zirconium carbide particles prepared by the method described above.

[0025] Zirconium carbide particle reinforced magnesium matrix composite prepared by the method described above.

[0026] In order to reduce the synthesis temperature and reduce the preparation process, the present application uses carbon dioxide (CO2) and magnesium melt to react, converts the carbon in carbon dioxide into carbon nanosheet, and uses nanoscale carbon source powder to increase the reaction surface area with zirconium element. At the same time, the in-situ generated graphite nanosheet has high defect density and reactivity, thereby reducing the synthesis temperature of zirconium carbide (≤720℃) and accelerating the reaction speed. The zirconium carbide is prepared at low temperature by using carbon dioxide as the carbon source, and the zirconium carbide particle reinforced magnesium matrix composite material is formed. This will provide a new way for the resource utilization of carbon dioxide.

[0027] Therefore, the present application provides a preparation method of zirconium carbide particles and zirconium carbide particle reinforced magnesium matrix composite material, and the specific technical effects are as follows:

[0028] (1) The present application solidifies the carbon source in CO2 and / or CO gas into nanoscale carbon powder through gas-liquid reaction with magnesium melt, thereby creating carbon reaction raw materials with high defect density and reactivity, and significantly reducing the synthesis temperature of zirconium carbide ceramic particles;

[0029] (2) The added zirconium carbide particles may agglomerate or precipitate in the magnesium melt, resulting in uneven distribution, and further affecting the consistency of the microstructure and performance of the prepared material. The present application uses in-situ generated nanoscale carbon source, and generates zirconium carbide particles in-situ through the addition of magnesium-zirconium intermediate alloy, realizes the uniform dispersion of zirconium carbide particles at high temperature, and effectively avoids the introduction of impurities, thereby improving the mechanical properties and preparation efficiency of the magnesium matrix composite material;

[0030] (3) The uniformly dispersed nanoscale carbon material in the melt promotes the uniform distribution of zirconium carbide particles in the zirconium carbide particle reinforced magnesium matrix composite material;

[0031] (4) The method provided by the present application uses a short process and low-cost liquid metallurgy method, avoids the safety risk of direct powder addition, realizes the synthesis of zirconium carbide particles and the synergistic reinforcement of the magnesium matrix.

[0032] The technical solutions of the present application will be further described in detail below with the help of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0034] Figure 1is a flow chart of preparing zirconium carbide particles and zirconium carbide particle reinforced magnesium matrix composite provided by the present application;

[0035] Figure 2 is a photo of zirconium carbide particles (a), an SEM photo of zirconium carbide particle reinforced magnesium matrix composite ingot (b), and EDS spectrum analysis results of zirconium carbide particle reinforced magnesium matrix composite ingot ((c) and (d)) prepared by the embodiment of the present application;

[0036] Figure 3 is an EDS area scan chart of zirconium carbide particle reinforced magnesium matrix composite ingot prepared by the embodiment of the present application, wherein (a) is an SEM chart of ZrC / Mg composite material, and (b), (c) and (d) are magnesium element, zirconium element and carbon element respectively;

[0037] Figure 4 is the extrusion performance investigation results of pure magnesium and zirconium carbide particle reinforced magnesium matrix composite ingot prepared by the embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions of the present application are further described below by means of the accompanying drawings and examples.

[0039] In order to make the purpose, technical solutions and advantages of the present application more clear, thorough and complete, the technical solutions of the present application are clearly and completely described below by means of the accompanying drawings and examples. The following detailed description is the description of the examples, which aims to provide further detailed description of the present application. Unless otherwise specified, all technical terms used in the present application have the same meaning as generally understood by the general technical personnel in the field to which the present application belongs.

[0040] The instrument equipment and reagent materials used in the examples are obtained through commercial channels.

[0041] Example One

[0042] A kind of zirconium carbide particle, zirconium carbide particle reinforced magnesium matrix composite is prepared, and the preparation flow is as shown in Figure 1 The specific steps are as follows:

[0043] S1, carbon source gas pretreatment, 99.9% pure CO2 gas is sequentially passed through pure sulfuric acid and propylene glycol liquid gas washing bottle to remove basic impurities and moisture in the CO2 gas.

[0044] S2. Solidification of carbon in carbon source gas: 500g of pure magnesium with a purity of 99.9% was placed in a steel crucible and melted at 720℃ under a protective atmosphere with a volume ratio of CO2 to SF6 of 40:1. After holding for 20min, CO2 gas removed in step S1 was introduced at 720℃ and under stirring at 1200r / min. The CO2 gas introduction rate was 0.7L / min and the gas introduction time was 30min, so that the carbon nanoparticle content was 3wt.%, and a magnesium melt rich in carbon nanoparticle carbon source was obtained.

[0045] S3. Synthesis of zirconium carbide ceramic particles and preparation of zirconium carbide particle-reinforced magnesium matrix composite material: 400g of Mg-30wt.%Zr master alloy was added to the magnesium melt rich in carbon nanopowder carbon source prepared in step S2, and stirring was continued for 10min to obtain the zirconium carbide particle-reinforced magnesium matrix composite material melt.

[0046] S4. The molten zirconium carbide particle-reinforced magnesium matrix composite material is die-cast in a steel mold preheated at 450°C at a pressure of 160 MPa for 250 seconds. After cooling, a zirconium carbide particle-reinforced magnesium matrix composite material ingot is obtained.

[0047] S5. Extraction of zirconium carbide particles: Immerse the zirconium carbide particle-reinforced magnesium matrix composite ingot obtained in step S4 into a 10% hydrochloric acid solution. After soaking for 3 hours, wash with distilled water and filter under reduced pressure to obtain high-purity zirconium carbide particles.

[0048] Example 2

[0049] The specific steps for preparing a zirconium carbide particle and zirconium carbide particle-reinforced magnesium matrix composite material are as follows:

[0050] S1. Carbon source gas pretreatment: CO gas with a purity of 99.9% is passed sequentially through pure sulfuric acid and propylene glycol liquid washing bottles to remove alkaline impurities and moisture from the CO gas.

[0051] S2. Solidification of carbon in carbon source gas: 500g of pure magnesium with a purity of 99.9% was placed in a steel crucible and melted at 720℃ in a protective atmosphere with a volume ratio of CO2 to SF6 of 40:1. After holding for 20min, CO gas removed in step S1 was introduced at 720℃ and under stirring at 1000r / min. The CO gas introduction rate was 1.0L / min and the gas introduction time was 30min, so that the carbon nanoparticle content was 4wt.%, and a magnesium melt rich in carbon nanoparticle carbon source was obtained.

[0052] S3, synthesis of zirconium carbide ceramic particles and preparation of zirconium carbide particle reinforced magnesium matrix composite, adding 500g Mg-30wt.% Zr intermediate alloy to the magnesium melt prepared in step S2 with rich carbon nanometer powder carbon source, continuing stirring for 10min, to obtain zirconium carbide particle reinforced magnesium matrix composite melt.

[0053] S4, pressure casting the zirconium carbide particle reinforced magnesium matrix composite melt in a 450℃ preheated steel mold, with a pressure of 160MPa and a duration of 250s, to obtain a zirconium carbide particle reinforced magnesium matrix composite ingot after cooling.

[0054] S5, extraction of zirconium carbide particles, immersing the zirconium carbide particle reinforced magnesium matrix composite ingot obtained in step S4 in a 15% concentration hydrochloric acid solution for 3h, then washing with distilled water and filtering under reduced pressure to obtain high-purity zirconium carbide particles.

[0055] Test test

[0056] The photo of the zirconium carbide particles prepared in Example 1 is shown in Figure 2 (a).

[0057] The zirconium carbide particle reinforced magnesium matrix composite ingot obtained in step S4 of Example 1 was observed by scanning electron microscopy (SEM), and the results are shown in Figure 2 (b).

[0058] The zirconium carbide particle reinforced magnesium matrix composite ingot obtained in step S4 of Example 1 was analyzed by EDS energy spectrum, and the results are shown in Figure 2 (c) and (d).

[0059] The zirconium carbide particle reinforced magnesium matrix composite ingot obtained in step S4 of Example 1 was analyzed by EDS surface scanning, and the results are shown in Figure 3

[0060] The zirconium carbide particle reinforced magnesium matrix composite ingot obtained in step S4 of Example 1 was subjected to low-speed (0.1-1mm / s) hot extrusion at 350℃, with an extrusion ratio of 20:1, to obtain a magnesium matrix composite with more uniform structure and better density. Compared with the performance of pure magnesium under the same extrusion conditions, the results are shown in Figure 4 The yield strength and elastic modulus of the zirconium carbide particle reinforced magnesium matrix composite prepared by the present application are significantly improved.

[0061] ​Therefore, the application solidifies the carbon source in the CO2 and or CO gas into nanoscale carbon powder through gas-liquid reaction with the magnesium melt, and generates zirconium carbide particles in situ in the magnesium melt by adding magnesium-zirconium intermediate alloy, while the uniformly dispersed nanocarbon material in the melt promotes the uniform distribution of the zirconium carbide particles in the zirconium carbide particle reinforced magnesium matrix composite, thereby creating a carbon reaction raw material with higher defect density and reaction activity, significantly reducing the synthesis temperature of the zirconium carbide ceramic particles, and effectively avoiding the introduction of impurities, thereby significantly improving the mechanical properties and preparation efficiency of the magnesium matrix composite; The method provided by the application adopts a short process and a low-cost liquid metallurgy method, avoids the safety risk of directly adding powder, and realizes the synthesis of zirconium carbide particles and the synergistic reinforcement of the magnesium matrix.

[0062] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the application and not to limit it, although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: it can still modify or equivalently replace the technical solutions of the application, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the application.

Claims

1. A method for producing zirconium carbide particles, characterized by, The steps are as follows: S1, carbon source gas pretreatment, impurity removal treatment is carried out on carbon source gas with a purity of 99.9%; S2, carbon solidification in carbon source gas, after the pure magnesium is melted, the carbon source gas after impurity removal in step S1 is introduced under stirring state, and the magnesium melt rich in carbon nanometer powder carbon source is obtained; S3, synthesis of zirconium carbide ceramic particles and preparation of zirconium carbide particle reinforced magnesium matrix composite, adding magnesium-zirconium intermediate alloy to the magnesium melt rich in carbon nanometer powder carbon source prepared in step S2, and continuing to stir for 10 min; S4, extraction of zirconium carbide particles, after the reaction is completed, the reaction medium is pressure cast into an ingot, and the zirconium carbide particle reinforced magnesium matrix composite is obtained, and the zirconium carbide particle reinforced magnesium matrix composite is purified, and high-purity zirconium carbide particles are obtained; The carbon source gas in step S1 is one or both of CO2 and CO; The method for purifying the zirconium carbide particle reinforced magnesium matrix composite in step S4 is to erode the zirconium carbide particle reinforced magnesium matrix composite with 5-20% hydrochloric acid, then wash with distilled water, and reduce pressure filtration to obtain high-purity zirconium carbide particles.

2. The method of claim 1, wherein: The impurity removal treatment of the carbon source gas in step S1 refers to removing alkaline impurities and moisture in the gas, and the method adopted is to make the gas pass through pure sulfuric acid and propylene glycol liquid gas washing bottles in turn.

3. The method of claim 1, wherein: The aeration speed of the carbon source gas in step S2 is 0.5-1.5 L / min, and the aeration time is 20 min-2 h, so that the content of carbon nanometer powder is 1-5 wt%; the stirring state refers to a stirring rate of 1000-1800 r / min.

4. The method of claim 1, wherein: The pure magnesium is melted at 720℃ in a protective atmosphere in step S2, and is kept for 20 min after melting.

5. The method of claim 4, wherein: The protective atmosphere refers to a volume ratio of CO2 to SF6 of 40:

1.

6. The method of claim 1, wherein: The magnesium-zirconium intermediate alloy in step S3 is Mg-30wt.%Zr, and the addition amount of the magnesium-zirconium alloy is 1-5 wt% of the pure magnesium; the magnesium-zirconium intermediate alloy is preheated at 400℃ for 30 min before adding the magnesium-zirconium intermediate alloy.

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