Additive Manufacturing Method of Modified Diamond-Reinforced Cordierite Ceramic Matrix Composite

Abstract

The present application discloses an additive manufacturing method for modified diamond-reinforced cordierite ceramic matrix composites. By utilizing the characteristic that cordierite has a low melting point and can be transformed into a liquid phase during the SLM printing process, the wettability between diamond particles and the cordierite ceramic matrix is improved through surface modification of the diamond particles, enabling the diamond particles and the cordierite ceramic matrix to form a tight metallurgical bond. At the same time, the phenomenon of thermal damage to diamond is avoided, the densification degree of the diamond-cordierite composite material is increased, and the mechanical properties of the SLM printed parts of the diamond-cordierite composite material are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing of cordierite ceramic matrix materials, and particularly to a selective laser melting (SLM) additive manufacturing method for modified diamond-reinforced cordierite ceramic matrix composites. Background Art

[0002] The content of the background art is used to understand the background conditions under which the technical solution of the present application is generated, and not all of it can be considered as the prior art.

[0003] Due to the high melting point and low laser absorption rate of conventional ceramic materials, it is very difficult for conventional ceramic materials to be printed and formed by SLM. The SLM printing technology is usually used for printing metal materials, and there are almost no reports on printing ceramic materials. Cordierite ceramic materials have the advantages of high porosity, low thermal expansion coefficient, good thermal stability, etc., and are usually prepared by photocuring additive manufacturing technology to produce cordierite ceramic material prints.

[0004] Diamond has excellent physical properties such as super hardness and wear resistance. By using diamond to reinforce cordierite ceramic matrix materials, the advantages of both can be combined. Cordierite has a relatively low melting point and is easy to transform into a liquid phase during the SLM printing process, making it possible to obtain high-density cordierite-based composite prints. However, during the SLM printing process, due to the difference in chemical properties between the two, the diamond particles and the cordierite matrix cannot be fully wetted. The presence of diamond particles hinders the fluidity of the molten pool and affects the forming quality of the print. At the same time, the input of laser energy is very likely to cause thermal damage to the diamond particles, resulting in the local graphitization of diamond particles, which will affect the mechanical properties of the printed formed parts. Summary of the Invention

[0005] In view of this, the present application provides an additive manufacturing method for modified diamond-reinforced cordierite ceramic matrix composites. By taking advantage of the low melting point of cordierite, which can transform into a liquid phase during the SLM printing process, and by surface-modifying the diamond particles to improve the wettability between the diamond particles and the cordierite ceramic matrix, the diamond particles and the cordierite ceramic matrix can form a tight metallurgical bond, while avoiding the occurrence of thermal damage to the diamond, improving the densification degree of the diamond-cordierite composite, and enhancing the mechanical properties of the SLM prints of the diamond-cordierite composite. The specific scheme adopted is as follows:

[0006] An additive manufacturing method for modified diamond-reinforced cordierite ceramic matrix composites, comprising the following steps:

[0007] Surface-modify diamond particles with a plating material to obtain modified diamond powder with a metal carbide plating layer formed on the surface;

[0008] Prepare a modified diamond-cordierite composite powder by using modified diamond powder and cordierite ceramic powder;

[0009] Perform SLM printing on the modified diamond-cordierite composite powder to obtain a dense cordierite composite printed part.

[0010] Preferably, in the raw materials of the modified diamond-cordierite composite powder: the volume ratio of the modified diamond powder to the cordierite ceramic powder is 1:99 to 49:51.

[0011] Preferably, the additive manufacturing method of the present application is also applicable to glass ceramics with a melting point not higher than 1000 °C, and the glass ceramics include SiO2-ZnO-B2O3-based glass, Na2O-Al2O3-B2O3-SiO2-based glass, and SiO2-Al2O3-TiO2-BaO-B2O3-based glass.

[0012] Preferably, the plating material includes at least one of Mo, Ti, W, Cr, and Si.

[0013] Preferably, the particle size range of the diamond particles is 5-70 μm; and / or the particle size of the plating material is 1-5 μm; and / or the particle size of the cordierite ceramic powder is 10-150 μm.

[0014] Preferably, the modified diamond powder is prepared by a molten salt process or vacuum micro evaporation plating.

[0015] More preferably, the process flow of the molten salt method includes the following steps:

[0016] Clean the surface of the diamond particles, mix the cleaned diamond particles with the plating material in a mass ratio of 9:1 to 6:4, and cover the diamond-plating material mixed powder with a chloride salt in a mass ratio of 9:1 to 7:3. Heat it to 800-1000 °C at a heating rate of 1-10 °C / min and keep it warm for 60-120 min. After cooling to room temperature, place it in boiling distilled water and ultrasonically clean it repeatedly to remove the molten salt. Dry the cleaned and filtered diamond particles at 50-80 °C for 3-8 h. After drying, the modified diamond powder coated with a metal carbide coating can be obtained.

[0017] Preferably, in the SLM printing process, the printing layer thickness range is 10-160 μm, the laser spot is 50-100 μm, the laser power is 10-1000 W, the scanning speed is 100-2000 mm / s, and the scanning spacing is 0.01-0.1 mm.

[0018] The beneficial effects of the present application:

[0019] Compared with the SLM printing process which is usually used to print metal composite materials, this application breakthroughly prints cordierite ceramic matrix materials through the SLM process. The strength and wear resistance of the ceramic materials are enhanced by modified diamond, and the obtained printed parts have high density.

[0020] By modifying the surface of diamond, the wettability between diamond particles and cordierite ceramic matrix during the SLM printing process can be significantly improved, enabling the diamond particles and cordierite ceramic matrix to form a tight metallurgical bond. At the same time, the phenomenon of thermal damage to diamond is avoided, the densification degree of the diamond-cordierite composite material is improved, and the mechanical properties of the SLM printed parts of the diamond-cordierite composite material are enhanced. Brief Description of the Drawings

[0021] Figure 1 It is the process flow chart of the present invention. Detailed Embodiments

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0023] An additive manufacturing method for modified diamond-reinforced cordierite ceramic matrix composite materials includes the following steps:

[0024] Surface modification of diamond particles is carried out using a plating material to obtain modified diamond powder with a metal carbide plating layer formed on the surface; the plating material includes at least one of Mo, Ti, W, Cr, and Si; the modified diamond powder is prepared by a molten salt process or vacuum micro-evaporation plating;

[0025] Prepare modified diamond-cordierite composite powder according to the volume ratio of modified diamond to cordierite ceramic powder being 1:99 to 49:51;

[0026] Perform SLM printing on the modified diamond-cordierite composite powder to obtain a dense cordierite composite printed part.

[0027] Among them, the molten salt process includes the following steps:

[0028] First, clean the surface of diamond particles, and then mechanically mix the cleaned diamond particles with the plating material at a mass ratio of 9:1 - 6:4. Place the mixed powder in an alumina crucible, weigh the chloride salt according to a mass ratio of 9:1 - 7:3 of the chloride salt and the above diamond-plating material mixture powder, and cover it on the diamond-plating material mixture powder. Place the crucible in a box furnace and heat it at a heating rate of 1 - 10 °C / min to 800 - 1000 °C and hold for 60 - 120 minutes. After cooling to room temperature with the furnace, place it in boiling distilled water and ultrasonically clean it repeatedly to remove the molten salt. Filter the cleaned diamond particles and dry them in a vacuum oven at 50 - 80 °C for 3 - 8 h. After drying, the modified diamond powder coated with metal can be obtained.

[0029] The methods for performance characterization of the printed parts are as follows:

[0030] Method for density test: Use the Archimedes drainage method to measure the density.

[0031] Method for hardness test: Adopt the Vickers hardness test method with a load of 1 kg and a holding time of 10 seconds.

[0032] Method for compressive strength test: Conduct the test according to GB / T 7314-2017 "Metallic materials - Compression testing at ambient temperature".

[0033] Method for thermal damage test: Use Raman spectroscopy to determine whether there are graphite characteristic peaks on the diamond surface.

[0034] Example 1

[0035] An additive manufacturing method for a modified diamond-reinforced cordierite ceramic composite material, comprising the following steps:

[0036] S1. Perform surface modification on the diamond powder, use the surface molten salt method to coat molybdenum (Mo) metal on the diamond powder surface, and form a molybdenum carbide coating on the diamond surface. The average particle size of the diamond powder is 45 μm, and the particle size of the molybdenum metal powder is 1 - 5 μm; the mass ratio of the diamond particles to the molybdenum metal powder is 7:3.

[0037] S2. Use a planetary ball mill to dry-mix the modified diamond powder with the molybdenum carbide coating and the cordierite ceramic powder to prepare a diamond-cordierite composite powder. The particle size range of the cordierite ceramic powder is 15 - 53 μm, the volume ratio of the diamond powder to the cordierite ceramic powder is 5:95, the rotation speed of the ball mill is 350 rpm, and the mixing time is 180 min.

[0038] S3. Selectively laser melt and layer-print the above composite powder, where the laser power is 773 W, the scanning speed is 650 mm / s, the scanning spacing is 0.05 mm, and the powder layer thickness is 60 μm.

[0039] S4. Obtain a diamond-cordierite ceramic composite material printed part.

[0040] Example 2

[0041] An additive manufacturing method for a modified diamond-reinforced cordierite ceramic composite material, comprising the following steps:

[0042] S1. Perform surface modification on diamond powder. Use the surface molten salt method to coat molybdenum (Mo) metal on the surface of diamond powder, and form a molybdenum carbide coating on the diamond surface. The average particle size of the diamond powder is 50 μm, and the particle size of the molybdenum metal powder is 1 - 5 μm; the mass ratio of the diamond powder to the molybdenum metal powder is 7:3.

[0043] S2. Use a planetary ball mill to perform dry mixing of the modified diamond powder body with a molybdenum carbide coating and the cordierite ceramic powder body to prepare a diamond-cordierite composite powder body. The particle size range of the cordierite ceramic powder is 15 - 53 μm, the volume ratio of the diamond powder to the cordierite ceramic powder is 15:85, the rotation speed of the ball mill is 350 rpm, and the mixing time is 180 min.

[0044] S3. Perform selective laser melting (abbreviation: SLM) layer-by-layer printing on the above composite powder body, where the laser power is 805 W, the scanning speed is 600 mm / s, the scanning spacing is 0.05 mm, and the powder spreading layer thickness is 60 μm.

[0045] S4. Obtain a diamond-cordierite ceramic composite material printed part.

[0046] Example 3

[0047] An additive manufacturing method for a modified diamond-reinforced cordierite ceramic composite material, comprising the following steps:

[0048] S1. Perform surface modification on diamond powder. Use the surface molten salt method to coat molybdenum (Mo) metal on the surface of diamond powder, and form a molybdenum carbide coating on the diamond surface. The average particle size of the diamond powder is 45 μm, and the particle size of the molybdenum metal powder is 1 - 5 μm; the mass ratio of the diamond powder to the molybdenum metal powder is 7:3.

[0049] S2. Use a planetary ball mill to perform dry mixing of the modified diamond powder body with a molybdenum carbide coating and the cordierite ceramic powder body to prepare a diamond-cordierite composite powder body. The particle size range of the cordierite ceramic powder is 15 - 53 μm, the volume ratio of the diamond powder to the cordierite ceramic powder is 30:70, the rotation speed of the ball mill is 300 rpm, and the mixing time is 180 min.

[0050] S3. Selectively laser melt (abbreviation: SLM) the above composite material powder layer by layer, where the laser power is 860 W, the scanning speed is 600 mm / s, the scanning spacing is 0.05 mm, and the powder spreading layer thickness is 60 μm.

[0051] S4. Obtain a diamond-cordierite ceramic composite material printed part.

[0052] Example 4

[0053] An additive manufacturing method for a modified diamond-reinforced cordierite ceramic composite material, comprising the following steps:

[0054] S1. Perform surface modification on diamond powder. Use the surface molten salt method to coat molybdenum (Mo) metal on the surface of diamond powder, forming a molybdenum carbide coating on the diamond surface. The average particle size of the diamond powder is 35 μm, and the particle size of the molybdenum metal powder is 1 - 5 μm; the mass ratio of the diamond powder to the molybdenum metal powder is 7:3.

[0055] S2. Use a planetary ball mill to perform dry mixing of the modified diamond powder with a molybdenum carbide coating and cordierite ceramic powder to prepare a diamond-cordierite composite material powder. The particle size range of the cordierite ceramic powder is 15 - 53 μm, the volume ratio of the diamond powder to the cordierite ceramic powder is 49:51, the rotation speed of the ball mill is 350 rpm, and the mixing time is 180 min.

[0056] S3. Selectively laser melt (abbreviation: SLM) the above composite material powder layer by layer, where the laser power is 892 W, the scanning speed is 500 mm / s, the scanning spacing is 0.05 mm, and the powder spreading layer thickness is 60 μm.

[0057] S4. Obtain a diamond-cordierite ceramic composite material printed part.

[0058] Example 5

[0059] An additive manufacturing method for a modified diamond-reinforced cordierite ceramic composite material, comprising the following steps:

[0060] S1. Perform surface modification on diamond powder. Use the surface molten salt method to coat molybdenum (Mo) metal on the surface of diamond powder, forming a molybdenum carbide coating on the diamond surface. The average particle size of the diamond powder is 20 μm, and the particle size of the molybdenum metal powder is 1 - 5 μm; the mass ratio of the diamond powder to the molybdenum metal powder is 7:3.

[0061] S2. Use a planetary ball mill to dry-mix the above-mentioned modified diamond powder with molybdenum carbide coating and cordierite ceramic powder to prepare diamond-cordierite composite powder. The particle size range of the cordierite ceramic powder is 15 - 53 μm, the volume ratio of the diamond powder to the cordierite ceramic powder is 20:80, the rotational speed of the ball mill is 350 rpm, and the mixing time is 180 min.

[0062] S3. Selective laser melting (abbreviation: SLM) layer-by-layer printing is performed on the above composite powder, where the laser power is 825 W, the scanning speed is 800 mm / s, the scanning spacing is 0.05 mm, and the powder spreading layer thickness is 60 μm.

[0063] S4. Obtain a diamond-cordierite ceramic composite printed part.

[0064] Comparative Example 1

[0065] This comparative example provides an additive manufacturing method for diamond-reinforced cordierite ceramic composites. The diamond powder added in this method is not surface-modified, and it includes the following steps:

[0066] S1. Use a planetary ball mill to dry-mix the above diamond powder and cordierite ceramic powder to prepare diamond-cordierite composite powder. The average particle size of the diamond powder is 45 μm, the particle size range of the cordierite ceramic powder is 15 - 53 μm, the volume ratio of the diamond powder to the cordierite ceramic powder is 5:95, the rotational speed of the ball mill is 350 rpm, and the mixing time is 180 min.

[0067] S2. Selective laser melting (abbreviation: SLM) layer-by-layer printing is performed on the above composite powder, where the laser power is 773 W, the scanning speed is 650 mm / s, the scanning spacing is 0.05 mm, and the powder spreading layer thickness is 60 μm.

[0068] S3. Obtain diamond-cordierite ceramic composite parts, and there are obvious ablation phenomena and tiny holes on the part surface.

[0069] Comparative Example 2

[0070] This comparative example provides an additive manufacturing method for diamond-reinforced cordierite ceramic composites. The diamond powder added in this method is not surface-modified, and it includes the following steps:

[0071] S1. Use a planetary ball mill to dry-mix the above diamond powder and cordierite ceramic powder to prepare diamond-cordierite composite powder. Among them, the average particle size of the diamond powder is 50 μm, the particle size range of the cordierite ceramic powder is 15 - 53 μm, the volume ratio of the diamond powder to the cordierite ceramic powder is 15:85, the rotational speed of the ball mill is 350 rpm, and the mixing time is 180 min.

[0072] S2. Selective laser melting (abbreviation: SLM) layer-by-layer printing is performed on the above composite powder. Among them, the laser power is 805 W, the scanning speed is 600 mm / s, the scanning spacing is 0.05 mm, and the powder spreading layer thickness is 60 μm.

[0073] S3. Obtain diamond-cordierite ceramic composite parts, and there are obvious ablation phenomena and micro-holes on the surface of the parts.

[0074] Example 6

[0075] On the basis of Example 3, when the plating materials are replaced with Ti, W, Cr, and Si respectively, the relative density of the printed parts is between 92% and 95%, the printed parts have no thermal damage, the hardness is between 1240 and 1450 HV, and the compressive strength is between 1100 and 1300 Mpa.

[0076] Experimental result test

[0077] The relative density, thermal damage, hardness, and compressive strength of the SLM formed parts prepared in Examples 1 - 5 and Comparative Examples 1 - 2 of the present invention were tested, and the test results are shown in Table 1.

[0078] Table 1 Performance comparison of SLM formed parts prepared in Examples 1 - 5 and Comparative Examples 1 - 2

[0079]

[0080]

[0081] It can be seen from the test results of the above examples and comparative examples that the surface-modified diamond proposed by the present invention has better thermal stability, avoids thermal damage during the SLM printing process, and the surface-modified diamond proposed by the present invention has better bonding performance with the cordierite matrix, and the relative density of the printed parts is higher.

Claims

1. Additive manufacturing method for modified diamond-reinforced cordierite ceramic matrix composite, comprising the following steps: Surface-modify diamond particles with a plating material to obtain modified diamond powder with a carbide plating layer formed on the surface; Prepare modified diamond-cordierite composite powder through the modified diamond powder and cordierite ceramic powder; Perform SLM printing on the modified diamond-cordierite composite powder to obtain a dense cordierite composite printed part; The plating material includes at least one of Mo, Ti, W, Cr, and Si.

2. The additive manufacturing method of the modified diamond-reinforced cordierite ceramic matrix composite according to claim 1, characterized in that: In the raw materials of the modified diamond-cordierite composite powder: the volume ratio of the modified diamond powder to the cordierite ceramic powder is 1:99 to 49:

51.

3. The additive manufacturing method of the modified diamond-reinforced cordierite ceramic matrix composite according to claim 1, wherein: The particle size range of the diamond particles is 5 to 70 μm; and / or the particle size of the plating material is 1 to 5 μm; and / or the particle size of the cordierite ceramic powder is 10 to 150 μm.

4. The additive manufacturing method of the modified diamond-reinforced cordierite ceramic matrix composite according to claim 1, wherein: The modified diamond powder is prepared by a molten salt process or vacuum micro evaporation plating.

5. The additive manufacturing method of the modified diamond-reinforced cordierite ceramic matrix composite according to claim 4, characterized in that: The process flow of the molten salt method includes the following steps: Clean the surface of the diamond particles, mix the cleaned diamond particles with the plating material at a mass ratio of 9:1 to 6:4, and cover the diamond-plating material mixed powder with a chloride salt at a mass ratio of 9:1 to 7:

3. Heat it to 800 to 1000 °C at a heating rate of 1 to 10 °C / min and hold for 60 to 120 min. After cooling to room temperature, place it in boiling distilled water and ultrasonically clean it repeatedly to remove the molten salt. Dry the filtered diamond particles at 50 to 80 °C for 3 to 8 h. After drying, modified diamond powder plated with a carbide plating layer can be obtained.

6. The additive manufacturing method of the modified diamond-reinforced cordierite ceramic matrix composite according to claim 1, characterized in that: In the SLM printing process, the printing layer thickness range is 10 - 160 μm, the laser spot is 50 - 100 μm, the laser power is 10 - 1000 W, the scanning speed is 100 - 2000 mm / s, and the scanning pitch is 0.01 - 0.1 mm.

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