A method for preparing titanium-coated diamond
By uniformly coating the diamond surface with a titanium layer, the problem of insufficient bonding strength between diamond and copper is solved, achieving uniformity and integrity of titanium-coated diamond, making it suitable for mass production and improving the performance of composite materials.
Patent Information
- Application Number
- CN202610548310.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-23
- Publication Date
- 2026-07-07
AI Technical Summary
Insufficient interfacial bonding strength between diamond and copper, along with a large difference in their coefficients of thermal expansion, makes the composite material prone to porosity, microcracks, and residual thermal stress in the interfacial region, affecting the material's densification and thermal conductivity.
Titanium powder is uniformly attached to the surface of diamond using an organic carrier. After casting, drying, grinding, sieving, and heat treatment, a uniform titanium coating layer is formed, which solves the problem of interface bonding.
It achieves the integrity and uniformity of the coating layer on the surface of titanium-coated diamond particles, with controllable weight gain, suitable for mass production, promotes the formation of the interfacial reaction layer of composite materials, and improves the overall performance of the materials.
Smart Images
Figure CN122344724A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of diamond surface metallization technology, specifically relating to a method for preparing titanium-coated diamond. It uses an organic binder to help titanium powder adhere uniformly to the surface of diamond particles, and then obtains titanium-coated diamond with a titanium coating layer through subsequent heat treatment. Background Technology
[0002] Diamond, with its high thermal conductivity and low coefficient of thermal expansion, is an important reinforcing phase for constructing high thermal conductivity, low expansion electronic packaging materials. Composite materials prepared with diamond as the reinforcement and copper as the matrix have high application value in fields such as heat dissipation of high heat flux density devices, advanced packaging, and thermal management structures.
[0003] However, in practical applications, diamond and copper have poor natural wettability and insufficient interfacial bonding strength. Furthermore, their coefficients of thermal expansion differ significantly, easily inducing porosity, microcracks, and residual thermal stress in the interfacial region, thus weakening the densification and thermal conductivity of the composite material. Existing technologies often improve the interfacial state through surface metallization or the introduction of active elements, such as forming a carbide transition layer through high-temperature reactions. However, such processes often rely on high processing temperatures, which may not only cause graphitization or structural defects on the diamond surface but also lead to problems such as an excessively thick interfacial reaction layer and coarsening of the microstructure, thereby affecting the overall performance of the material.
[0004] On the other hand, while directly adding active components such as titanium, boron, and chromium to a copper matrix can improve wetting behavior to some extent, the diffusion and distribution of these elements within the matrix are difficult to control precisely, and residual active elements may also sacrifice the thermal conductivity of the copper matrix itself. Therefore, if a relatively uniform titanium source layer is pre-constructed on the diamond surface, and then controlled titanium carbide phase is formed at the interface through subsequent heat treatment, it is expected to provide a more easily scalable technical solution for the preparation of metal-based diamond composites, especially composite powders for additive manufacturing, while considering both interfacial bonding and process feasibility. Summary of the Invention
[0005] This invention aims to provide titanium-coated diamond and its preparation method. The method first uses an organic carrier containing solvent, binder, and dispersant to adhere titanium powder to the diamond surface. Then, through steps such as casting, drying, grinding, sieving, and heat treatment for curing, titanium-coated diamond particles with a relatively complete and uniformly distributed coating layer are obtained. This scheme has a clear process route, adjustable parameters, and is suitable for batch implementation.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] A method for preparing titanium-coated diamond includes the following steps:
[0008] S1. Preparation of organic system: The solvent and dispersant are put into a container and mixed evenly. The mixture is heated to 40~65℃ and stirred continuously. Then the organic binder is added until a homogeneous organic carrier is obtained.
[0009] S2. Preparation of coating slurry: First, diamond powder and titanium powder are premixed, and then the organic carrier is placed together in a high-speed mixer to mix and obtain titanium / diamond coating slurry;
[0010] S3. Film formation and pre-coating: The titanium / diamond coating slurry obtained in step S2 is spread on a glass plate through a wet film preparation device and dried in an oven to form a film; the obtained film is peeled off, ground and sieved to remove unattached titanium powder and free diamond to obtain pre-coated titanium-coated diamond.
[0011] S4. Heat treatment and curing: The pre-made titanium-coated diamond is placed in a tube furnace for sintering to obtain the finished titanium-coated diamond product.
[0012] Further, in step S1, the weight ratio of solvent, organic binder, and dispersant is 80-98:1-5:1-5. The solvent is terpineol, the organic binder is polyacrylic acid and polyvinyl butyral or ethyl cellulose and polyvinyl butyral, and the dispersant is polyethylene glycol 300 or polyethylene glycol 4000. The weight ratio of polyacrylic acid or ethyl cellulose to polyvinyl butyral in the organic binder is 2:1.
[0013] Further, in step S2, the diamond powder has a particle size of 100-120 mesh, and the titanium powder has a particle size of 3-5 µm. The weight ratio of diamond powder, titanium powder, and organic carrier is 10-20:15-45:45-80. The stirring speed is 800-3000 r / min, and the stirring time is 3-6 min.
[0014] Furthermore, the film thickness in step S3 is 200~250µm. The drying temperature is 100~120℃, and the drying time is 2~4h.
[0015] Furthermore, the sintering temperature in step S4 is 600~800℃, and the sintering time is 1h.
[0016] The titanium-coated diamond particles prepared by the above method have a relatively complete surface coating layer and a relatively uniform distribution of titanium elements. Moreover, the preparation process is simple and easy to scale up for production.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] This invention does not employ the overall matrix alloying approach. Instead, it uses an organic carrier to pre-direct the titanium source onto the surface of diamond particles, which improves the uniformity of titanium distribution around the particles. After casting, drying, sieving, and heat treatment, a denser titanium layer can be obtained, with a weight gain controllable between 30% and 60%. This also facilitates the formation of a controlled interfacial reaction layer in subsequent composite material preparation. Furthermore, the equipment used in this method is simple, and it has good process repeatability and industrial application potential. Attached Figure Description
[0019] Figure 1 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 1 of the present invention.
[0020] Figure 2 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 2 of the present invention.
[0021] Figure 3 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 3 of the present invention.
[0022] Figure 4 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 4 of this invention.
[0023] Figure 5 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 5 of the present invention.
[0024] Figure 6 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 6 of the present invention.
[0025] Figure 7 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 7 of the present invention.
[0026] Figure 8 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 8 of the present invention.
[0027] Figure 9 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 9 of this invention.
[0028] Figure 10 This is a scanning electron microscope image of the titanium-coated diamond prepared in Example 10 of the present invention. Detailed Implementation
[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that the listed embodiments are only used to explain the technical solutions of the present invention and do not constitute a limitation on the scope of protection of the present invention; without departing from the concept of the present invention, those skilled in the art can make equivalent substitutions or combinations of related technical features.
[0030] Example 1
[0031] This embodiment provides a method for preparing titanium-coated diamond, as detailed below:
[0032] S1. Preparation of the Organic System: The organic carrier consists of a solvent, an organic binder, and a dispersant, with a weight ratio of 96.4:2.4:1.2. The solvent is terpineol; the organic binder is polyacrylic acid and polyvinyl butyral, with a weight ratio of 2:1; and the dispersant is polyethylene glycol 300. During preparation, the solvent and dispersant are weighed according to the ratio and added to a container for mixing. The mixture is stirred and heated in a 50°C water bath. Then, the organic binder is slowly added until a homogeneous and stable organic carrier is formed.
[0033] S2. Preparation of Coating Slurry: The titanium / diamond coating slurry consists of diamond powder, titanium powder, and the organic carrier obtained in step S1, with a weight ratio of 10:40:50. Specifically, the diamond powder and titanium powder are first mechanically premixed, then added together with the organic carrier into a high-speed mixer for mixing and dispersion. The mixture is first stirred at 800 rpm for 1 minute, then at 1800 rpm for 1 minute, and finally at 800 rpm for 1 minute, ultimately obtaining a relatively uniformly dispersed titanium / diamond coating slurry.
[0034] S3. Film Formation and Pre-coating: The titanium / diamond coating slurry obtained in step S2 is spread onto the surface of a glass plate using a wet film preparation device, with the film thickness controlled at 230µm. The glass plate is then placed in an oven and dried at 120℃ for 4 hours to solidify the slurry into a film. The dried film is peeled off the glass plate and ground using a mortar and pestle. Unattached titanium powder and free diamond are then removed by sieving to obtain pre-coated titanium-coated diamond.
[0035] S4. Heat treatment and curing: The above-mentioned pre-made titanium-coated diamond is placed in a tube furnace and sintered at 800°C for 1 hour to obtain the finished titanium-coated diamond product.
[0036] Figure 1 The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Example 1 of this invention. It can be seen that the titanium-coated diamond obtained through the above steps has a spherical overall morphology, good coating effect, no obvious detachment, and a weight gain of about 54.26% (as shown in Table 1).
[0037] Example 2
[0038] The difference between this embodiment and Embodiment 1 is as follows:
[0039] In step S1, the amount of organic binder is reduced, and the weight ratio of solvent, organic binder and dispersant is adjusted to 97:1.8:1.2.
[0040] Figure 2 The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Example 2 of this invention. It can be seen that compared with the titanium-coated diamond obtained in Example 1, some diamond surfaces are exposed, but the coating layer on most diamond surfaces is still relatively intact, with a weight gain of about 48.68% (as shown in Table 1).
[0041] Example 3
[0042] The difference between this embodiment and Embodiment 1 is as follows:
[0043] In step S1, the dispersant is changed from polyethylene glycol 300 to polyethylene glycol 4000.
[0044] Figure 3 The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Example 3 of this invention. It can be seen that the titanium-coated diamond obtained through the above steps has a lower surface coating coverage compared with the titanium-coated diamond obtained in Example 1. However, the titanium coating on most diamond surfaces is relatively intact, and the weight gain is about 38.54% (as shown in Table 1).
[0045] Example 4
[0046] The difference between this embodiment and Embodiment 1 is as follows:
[0047] In step S1, the dispersant is replaced with polyethylene glycol 4000, and the amount of organic binder is reduced. The weight ratio of solvent, organic binder and dispersant is adjusted to 97:1.8:1.2.
[0048] Figure 4 The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Example 4 of this invention. It can be seen that compared with the titanium-coated diamond obtained in Example 3, the surface coating coverage of the titanium-coated diamond obtained through the above steps is further reduced, but most of the diamond surface still has a titanium coating layer, with a weight gain of about 30.62% (as shown in Table 1).
[0049] Example 5
[0050] The difference between this embodiment and Embodiment 1 is as follows:
[0051] In step S1, the organic binder is replaced with a combination of ethyl cellulose and polyvinyl butyral.
[0052] Figure 5The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Example 5 of this invention. It can be seen that the titanium-coated diamond obtained through the above steps has a lower surface coating coverage compared with the titanium-coated diamond obtained in Example 1. However, the titanium coating on most diamond surfaces is relatively intact, and the weight gain is about 39.72% (as shown in Table 1).
[0053] Example 6
[0054] The difference between this embodiment and Embodiment 1 is as follows:
[0055] In step S1, the organic binder is changed to a combination of ethyl cellulose and polyvinyl butyral, and the amount of organic binder is reduced. The weight ratio of solvent, organic binder and dispersant is adjusted to 97:1.8:1.2.
[0056] Figure 6 The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Example 6 of this invention. It can be seen that compared with the titanium-coated diamond obtained in Example 5, the surface coating coverage of the titanium-coated diamond obtained through the above steps is further reduced, but the titanium coating on most diamond surfaces is relatively intact, with a weight gain of about 32.79% (as shown in Table 1).
[0057] Example 7
[0058] The difference between this embodiment and Embodiment 1 is as follows:
[0059] In step S4, the heat treatment temperature is adjusted to 700℃.
[0060] Figure 7 The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Comparative Example 1 of this invention. It can be seen that the titanium-coated diamond obtained through the above steps has a lower surface coating coverage compared with the titanium-coated diamond obtained in Example 1. However, the titanium coating on most diamond surfaces is relatively intact, and the coating peeling is not obvious. The weight gain is about 42.18% (as shown in Table 1).
[0061] Example 8
[0062] The difference between this embodiment and Embodiment 1 is as follows:
[0063] In step S1, the amount of organic binder is reduced, and the weight ratio of solvent, organic binder and dispersant is adjusted to 97:1.8:1.2. At the same time, the heat treatment temperature in step S4 is adjusted to 700℃.
[0064] Figure 8The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Example 8 of this invention. It can be seen that, compared with the titanium-coated diamond obtained in Example 2, some of the titanium coating on the surface of the diamond has fallen off, but the titanium coating on the surface of most diamonds is relatively intact, with a weight gain of about 36.83% (as shown in Table 1).
[0065] Example 9
[0066] The difference between this embodiment and Embodiment 1 is as follows:
[0067] In step S4, the heat treatment temperature is adjusted to 600℃.
[0068] Figure 9 The image shows a scanning electron microscope image of the titanium-coated diamond prepared in Example 9 of this invention. It can be seen that compared with the titanium-coated diamond obtained in Example 7, the surface coating coverage of the titanium-coated diamond obtained through the above steps is further reduced, but the titanium coating on most diamond surfaces is relatively intact, with a weight gain of about 35.63% (as shown in Table 1).
[0069] Example 10
[0070] The difference between this embodiment and Embodiment 1 is as follows:
[0071] In step S1, the amount of organic binder is reduced, and the weight ratio of solvent, organic binder and dispersant is adjusted to 97:1.8:1.2. At the same time, the heat treatment temperature in step S4 is adjusted to 600℃.
[0072] Figure 10 The image shown is a scanning electron microscope image of the titanium-coated diamond prepared in Example 10 of this invention. It can be seen that compared with the titanium-coated diamond obtained in Example 8, the titanium-coated diamond obtained through the above steps has a more severe degree of coating layer peeling off the diamond surface, with a weight increase of about 28.35% (as shown in Table 1).
[0073] Table 1 Weight gain of titanium-coated diamond prepared in different embodiments
[0074] Sample number Heat treatment temperature (°C) Weight gain (wt%) Example 1 800 54.26 Example 2 800 48.68 Example 3 800 38.54 Example 4 800 30.62 Example 5 800 39.72 Example 6 800 32.79 Example 7 700 42.18 Example 8 700 36.83 Example 9 600 35.63 Example 10 600 28.35
Claims
1. A method for preparing titanium-coated diamond, characterized in that, Includes the following steps: S1. Preparation of organic system: The solvent and dispersant are put into a container and mixed evenly. The mixture is heated to 40~65℃ and stirred continuously. Then the organic binder is added until a homogeneous organic carrier is obtained. S2. Preparation of coating slurry: First, diamond powder and titanium powder are premixed, and then the organic carrier is placed together in a high-speed mixer to mix and obtain titanium / diamond coating slurry; S3. Film formation and pre-coating: The titanium / diamond coating slurry obtained in step S2 is spread on a glass plate through a wet film preparation device and dried in an oven to form a film; the obtained film is peeled off, ground and sieved to remove unattached titanium powder and free diamond to obtain pre-coated titanium-coated diamond. S4. Heat treatment and curing: The pre-made titanium-coated diamond is placed in a tube furnace for sintering to obtain the finished titanium-coated diamond product.
2. The method for preparing titanium-coated diamond as described in claim 1, characterized in that, In step S1, the weight ratio of solvent, organic binder and dispersant is 80~98:1~5:1~5.
3. The method for preparing titanium-coated diamond as described in claim 1, characterized in that, The solvent in step S1 is terpineol, the organic binder is polyacrylic acid and polyvinyl butyral or ethyl cellulose and polyvinyl butyral, and the dispersant is polyethylene glycol 300 or polyethylene glycol 4000.
4. The method for preparing titanium-coated diamond as described in claim 3, characterized in that, The weight ratio of polyacrylic acid or ethyl cellulose to polyvinyl butyral in the organic binder is 2:
1.
5. The method for preparing titanium-coated diamond as described in claim 1, characterized in that, The diamond powder in step S2 has a particle size of 100-120 mesh, and the titanium powder has a particle size of 3-5µm.
6. The method for preparing titanium-coated diamond as described in claim 1, characterized in that, In step S2, the weight ratio of diamond powder, titanium powder and organic carrier is 10~20:15~45:45~80.
7. The method for preparing titanium-coated diamond as described in claim 1, characterized in that, In step S2, the stirring speed is 800~3000 r / min and the stirring time is 3~6 min.
8. The method for preparing titanium-coated diamond as described in claim 1, characterized in that, The film thickness in step S3 is 200~250µm.
9. The method for preparing titanium-coated diamond as described in claim 1, characterized in that, The drying temperature in step S3 is 100~120℃, and the drying time is 2~4h.
10. The method for preparing titanium-coated diamond as described in claim 1, characterized in that, The sintering temperature in step S4 is 600~800℃, and the sintering time is 1h.