Diamond surface coating method and device

Abstract

The invention discloses a diamond surface coating method and device, and belongs to the technical field of material engineering. The method comprises the following steps: placing a container filled with experimental raw materials in a non-heating area at the head end of a quartz tube of a tubular furnace, and waiting for the tubular furnace to be heated; when the tubular furnace is heated to a temperature required by an experiment, a control device controls a traction device connected with a thermocouple to pull the material container to a heating area of the quartz tube according to real-time temperature information fed back by the thermocouple connected with the material container, and meanwhile, controls airflow of a rotor flow meter on an air pipe communicated with the quartz tube, so that raw materials in the material container react; after the reaction is completed, the thermocouple is pulled by a traction device to drive the material container to a non-heating area at the tail end of the quartz tube, meanwhile, the airflow of the rotor flow meter is closed, the diamond particles with the single crystal face uniform coating are obtained after the reaction is completed, and the cleaned coating diamond is obtained through cleaning. The raw materials react in a constant-temperature environment in the heating area, and it is ensured that all crystal faces of single diamond particles are heated consistently and plated uniformly.

Description

Technical Field

[0001] This invention belongs to the field of materials engineering, and in particular relates to a method and apparatus for coating a diamond surface. Background Technology

[0002] Tube furnaces, as commonly used heating devices in the materials science field, are widely applied in diamond surface coating experiments to heat the diamond and reactants during the reaction. However, if the diamond and the coating reactants are heated and cooled together with the tube furnace cavity, the diamond coating reaction will also occur during the heating and cooling of the tube furnace. However, due to the unstable temperature field during heating and cooling, the different crystal planes of the diamond particles, and the fact that this is not required by the experiment, uneven diamond coating is a common problem. Figure 5 The image shows a WC coating on a diamond surface obtained by a conventional heating and cooling reaction in a tube furnace. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method and apparatus for coating diamond surfaces. The aim is to ensure that the experimental raw materials reach the required temperature and a stable temperature field in a tube furnace before entering the furnace chamber for reaction, and to allow the airflow to be adjusted in real-time according to the experimental progress (airflow magnitude significantly affects the preparation of diamond coatings using the tube furnace salt bath method or CVD method). This solves the problem of uneven coatings leading to unsatisfactory results in diamond surface coating experiments using tube furnaces. The coating method of this invention can produce uniform coatings.

[0004] The objective of this invention is achieved through the following technical solution: This invention discloses a method for coating a diamond surface, comprising the following steps: (a) Place the container containing the experimental raw materials in the non-heated zone at the beginning of the quartz tube of the tube furnace and wait for the tube furnace to heat up. (b) When the tube furnace is heated to the required temperature for the experiment, the control device controls the traction device connected to the thermocouple to pull the container to the heating zone of the quartz tube based on the real-time temperature information fed back by the thermocouple connected to the container. At the same time, the control device controls the airflow of the rotor flowmeter on the gas pipe connected to the quartz tube so that the experimental raw materials in the container can react. (c) After the reaction is completed, the thermocouple is pulled by the traction device to the end of the quartz tube to the non-heated area. At the same time, the airflow of the rotor flow meter is turned off. The reaction ends and diamond particles with uniform coating on a single crystal face are obtained. The coated diamond is cleaned to obtain the cleaned coated diamond.

[0005] Furthermore, in steps (a)-(c), depending on the different diamond coatings, the quartz tube is filled with different inert gases or reactive gases, and the gas flow rate is controlled by the airflow velocity of the rotor flow meter installed on the gas tube through a control device.

[0006] Furthermore, the temperatures of both the first and last unheated areas are below 200°C.

[0007] Furthermore, the experimental raw materials contained in the container include diamond particles and coating materials.

[0008] Furthermore, the control device is a programmable logic controller or a microcontroller, and the control device is also connected to a touch screen for displaying real-time temperature and airflow parameters.

[0009] Furthermore, the traction device includes a traction wire and a traction machine. One end of the traction wire is connected to the traction wheel of the traction machine, and the other end is connected to a thermocouple. The traction machine is connected to a control device.

[0010] The apparatus employing the method described in this invention includes a tubular furnace, a traction device, a gas pipe, a thermocouple, and a control device mounted thereon. A quartz tube is disposed within the chamber of the tubular furnace, with a gas pipe connected to the first end of the quartz tube and the traction device disposed at the second end of the quartz tube. The control device is connected to a rotor flowmeter mounted on the gas pipe, the traction device, and the thermocouple. One end of the thermocouple is connected to a container placed in the quartz tube, and the other end is connected to the traction device. The control device controls the airflow velocity of the rotor flowmeter on the gas pipe and the movement of the container pulled by the traction device during the reaction based on the temperature information fed back by the thermocouple in real time.

[0011] Furthermore, the traction device includes a traction wire and a traction machine. One end of the traction wire is connected to the traction wheel of the traction machine, and the other end is connected to a thermocouple. The traction machine is connected to a control device.

[0012] The beneficial effects of this invention are as follows: 1. The coating method of this invention uses a traction device to precisely move the container from the non-heated zone to the heated zone, allowing the experimental material to begin reacting instantly upon reaching the target temperature, thus avoiding the uneven temperature gradient problem caused by the heating process in traditional methods. The container maintains a constant temperature environment within the heated zone, ensuring that each crystal facet of a single diamond particle is heated uniformly, achieving a uniform coating on each crystal facet.

[0013] 2. This invention uses a real-time temperature feedback and control device linked by a thermocouple to achieve coordinated and precise control of temperature, traction, and airflow; it uses a rotor flow meter to precisely adjust the airflow according to process requirements, ensuring a stable reaction atmosphere and further improving the consistency of coating quality.

[0014] 3. In the initial stage of this invention, the container is placed in the first non-heated zone to avoid premature decomposition or deterioration of the experimental raw materials during the heating stage; after the reaction is completed, it is pulled to the last non-heated zone to achieve rapid cooling and isolation, and to prevent the defect of excessive coating caused by continuous high-temperature reaction.

[0015] 4. The entire process of this invention consists of heating and waiting, constant temperature reaction, and rapid cooling, forming a standardized closed-loop control. Each diamond particle undergoes the same temperature process and reaction time, resulting in good batch-to-batch repeatability and a high product qualification rate.

[0016] 5. This invention incorporates an external induction control device for the tube furnace. This device is connected to the sample inside the tube furnace via a high-temperature thermocouple. It senses the furnace temperature and transmits temperature changes to the controller in real time. The controller then adjusts the position of the experimental sample inside the tube furnace and the external gas flow rate according to the temperature changes. This automated control reduces manual intervention and operational errors, making it suitable for large-scale production applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process flow of the present invention.

[0018] Figure 2 This is a schematic diagram of the coating reaction in the heating zone according to the present invention.

[0019] Figure 3 This is a schematic diagram illustrating that no reaction occurs in the non-heated region at the end of the present invention.

[0020] Figure 4 This is a schematic diagram illustrating the effect of the WC coating on the diamond surface obtained using the present invention.

[0021] Figure 5 This is a schematic diagram of the WC coating effect on the diamond surface obtained by the existing heating and cooling reaction in a tube furnace.

[0022] In the figure: 1-Rotameter, 2-Quartz tube, 3-Filler, 4-Thermocouple, 5-Tube furnace cavity, 6-Thermocouple temperature measuring point, 7-Control device, 8-Traction device; 9-Experimental raw material; 10-Diamond particles; 11. First end non-heated zone, 12. Heated zone, 13. Last end non-heated zone. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Example: Figures 1-4As shown, the device for diamond surface coating of the present invention includes a tubular furnace, a traction device 8, a gas pipe, a thermocouple 4, and a control device 7. A quartz tube 2 is installed inside the tubular furnace cavity 5. A gas pipe is connected to the first end of the quartz tube 2, and the traction device 8 is installed at the end of the quartz tube 2. The control device 7 is connected to a rotor flow meter 1, the traction device 8, and the thermocouple 4 installed on the gas pipe. One end of the thermocouple 4 is connected to a container 3 placed on the quartz tube 2, and the other end is connected to the traction device 8. The control device 7 controls the airflow velocity of the rotor flow meter 1 on the gas pipe and the movement of the container 3 pulled by the traction device 8 during the reaction based on the temperature information fed back by the thermocouple 4 in real time.

[0025] The traction device 8 includes a traction wire and a traction motor. One end of the traction wire is connected to the traction wheel of the traction machine, and the other end is connected to the thermocouple 4. The signal input terminal of the traction machine is connected to the control device 7, which controls the traction machine to drive the rotation of the traction wheel. The position of the experimental sample inside the tubular furnace cavity 5 is changed by changing the position of the thermocouple 4. In this example, the traction machine is a small 12V miniature electric winch, which consists of a miniature motor and a winch. The miniature motor serves as the traction machine, and the winch serves as the traction wheel.

[0026] The material container 3 has an existing structure, which can be a trough structure or a box structure. The traction wire is a tungsten wire, and the material container 3 is connected to the traction wheel of the traction machine through the folded tungsten wire.

[0027] The tubular furnace adopts an existing structure, with a heating wire inside the furnace cavity 5 to heat the entire cavity. The thermocouple's temperature measuring point 6 is located in the middle of the quartz tube 2 within the furnace cavity 5 for real-time temperature measurement. The control device 7 uses a programmable logic controller (PLC) or a microcontroller; in this example, it uses an existing microcontroller (Arduino) to receive temperature data from the thermocouple 4. When the required experimental temperature is reached within the furnace cavity 5, a touchscreen display can be connected to it to show real-time temperature and airflow parameters. The control device 7 activates the traction mechanism 8, driving the traction wheel to rotate. The microcontroller connects to the electric regulating valve of the rotor flowmeter 1 to adjust the gas flow rate to the required experimental flow. The control device 7 achieves automated traction and flow rate coordination control under high-temperature conditions.

[0028] In this example, thermocouple 4 is a type K thermocouple, which is connected to the microcontroller (existing) of control device 7, and the collected temperature is input into the microcontroller; the temperature measurement range of the thermocouple is 0-1350℃.

[0029] The method for coating a diamond surface according to the present invention, taking the coating of a WC layer as an example, includes the following steps: (a) Place the container 3 containing the experimental raw material 9 in the non-heating zone 11 at the beginning of the quartz tube 2 of the tube furnace and wait for the tube furnace to heat up. (b) When the tube furnace is heated to the required temperature for the experiment, the control device 7 controls the traction device 8 connected to the thermocouple 4 to pull the container 3 to the heating zone 12 of the quartz tube 2 based on the real-time temperature information fed back by the thermocouple 4 connected to the container 3. At the same time, it controls the airflow of the rotor flowmeter 1 on the gas pipe connected to the quartz tube 2 so that the experimental raw material 9 in the container 3 can react. (c) After the reaction is completed, the thermocouple 4 is pulled by the traction device 8 to the non-heated area 13 at the end of the quartz tube 2, and the airflow of the rotor flow meter 1 is turned off. The reaction ends and diamond particles 10 with uniform coating on a single crystal face are obtained. The coated diamond is cleaned to obtain the cleaned coated diamond.

[0030] In steps (a)-(c), depending on the different diamond coatings, the quartz tube 2 is filled with different inert gases or reactive gases, and the gas flow rate is controlled by the airflow velocity of the rotor flowmeter 1 installed on the gas tube by the control device 7.

[0031] The temperatures of the first unheated zone 11 and the last unheated zone 13 are both below 200°C.

[0032] The reaction time of the container 3 in the heating zone 12 of the quartz tube 2 in step (2) is determined according to different coating requirements; in this example, it is 5 minutes.

[0033] The coating method of this invention uses a traction device 8 to precisely move the container 3 from the non-heated zone 11 to the heated zone 12, ensuring that the experimental material 9 begins to react instantly upon reaching the target temperature. This avoids the problem of uneven temperature gradients caused by the heating process in traditional methods. The container 3 maintains a constant temperature environment within the heated zone 12, ensuring that each crystal facet of the individual diamond particle 10 is heated uniformly, achieving a uniform coating on each crystal facet. Figure 4 As shown.

[0034] In addition to WC coatings, this invention can be widely applied to diamond surface coating materials obtained by heating in a tube furnace, such as diamond surface metal W coatings, WC coatings, Ti coatings, Mo2C coatings, and TiC coatings.

[0035] In the case of diamond coating using the molten salt method, the quartz tube 2 is filled with an inert gas; in the case of diamond coating using the CVD method, the quartz tube 2 is filled with a gas that participates in the reaction. The experimental raw material 9 contained in the container 3 includes diamond particles 10 and coating materials. The coating materials and inert gases or gases that participate in the reaction in both methods are shown in Table 1 below: Table 1:

[0036] The parts not described in detail in this application are all existing conventional technologies and will not be elaborated here.

[0037] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. A method for coating a diamond surface, characterized in that: Includes the following steps: (a) Place the container (3) containing the experimental raw material (9) in the non-heating zone (11) at the beginning of the quartz tube (2) of the tube furnace and wait for the tube furnace to heat up; (b) When the tubular furnace is heated to the required temperature for the experiment, the control device (7) controls the traction device (8) connected to the thermocouple (4) to pull the container (3) to the heating zone (12) of the quartz tube (2) according to the real-time temperature information fed back by the thermocouple (4) connected to the container (3), and at the same time controls the airflow of the rotor flowmeter (1) on the gas pipe connected to the quartz tube (2) so that the experimental raw material (9) in the container (3) reacts. (c) After the reaction is completed, the thermocouple (4) is pulled by the traction device (8) to drive the container (3) to the end of the non-heated area (13) of the quartz tube (2), and the airflow of the rotor flow meter (1) is turned off. The reaction ends and diamond particles (10) with uniform coating on a single crystal face are obtained. The coated diamond is cleaned to obtain the cleaned coated diamond.

2. The method according to claim 1, characterized in that: During steps (a)-(c), different gases are filled into the quartz tube (2) according to different diamond coatings, and the gas flow rate is controlled by the airflow velocity of the rotor flowmeter (1) set on the gas tube by the control device (7).

3. The method according to claim 1, characterized in that: The temperatures of the unheated area at the beginning (11) and the unheated area at the end (13) are both below 200°C.

4. The method according to claim 1, characterized in that: The experimental raw materials (9) contained in the container (3) include diamond particles (10) and coating materials.

5. The method according to claim 1, characterized in that: The control device (7) is a programmable logic controller or a microcontroller, and the control device (7) is also connected to a touch screen for displaying real-time temperature and airflow parameters.

6. The method according to claim 1, characterized in that: The traction device (8) includes a traction wire and a traction machine. One end of the traction wire is connected to the traction wheel of the traction machine, and the other end is connected to the thermocouple (4). The traction machine is connected to the control device (7).

7. An apparatus employing the method as described in any one of claims 1-6, characterized in that: The device includes a tubular furnace, a traction device (8) installed on it, a gas pipe, a thermocouple (4) and a control device (7). A quartz tube (2) is installed inside the tubular furnace cavity (5). A gas pipe is connected to the first end of the quartz tube (2). The traction device (8) is installed at the end of the quartz tube (2). The control device (7) is connected to the rotor flow meter (1), the traction device (8) and the thermocouple (4) installed on the gas pipe respectively. One end of the thermocouple (4) is connected to the container (3) placed on the quartz tube (2), and the other end is connected to the traction device (8). The control device (7) controls the airflow velocity of the rotor flow meter (1) on the gas pipe and the movement of the container (3) pulled by the traction device (8) during the reaction based on the temperature information fed back by the thermocouple (4) in real time.

8. The apparatus according to claim 7, characterized in that: The traction device (8) includes a traction wire and a traction machine. One end of the traction wire is connected to the traction wheel of the traction machine, and the other end is connected to the thermocouple (4). The traction machine is connected to the control device (7).

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