A method and device for preparing a friction spark discharge coating

Abstract

A preparation method and device based on friction spark discharge coating, the steps are as follows: the material required for preparing the coating is made into a spherical shape, and is placed in a container with a ceramic cone tube at the lower end and a metal tube at the upper end; then the ceramic cone tube is placed directly above the substrate on which the coating is required, and a reciprocating motion device is used to drive it to reciprocate on the surface of the substrate; finally, the substrate and the cone tube are respectively connected to the two poles of a pulse power supply, and protected by an inert gas. In this process, the high temperature generated by the discharge will cause the coating material ball to partially melt and adhere to the surface of the substrate, thereby realizing the preparation of the coating. The present invention can realize the preparation of the coating, and it uses the high temperature generated by the pulse discharge to melt the coating material and adhere to the surface of the substrate, which can form a metallurgical grade bond with high bonding strength; the prepared coating is uniform and efficient; it has a wide range of applicability, can complete the preparation of various metal coatings, and has the characteristics of simple operation and low cost.

Description

Technical Field

[0001] The invention relates to the technical field of coating preparation, and in particular to a method and device for preparing a coating based on friction spark discharge. Background Art

[0002] The technology of preparing coating by electric spark discharge is also called electric spark deposition technology. It is a method for repairing surface damage of metal materials, preparing coatings and strengthening them. This method has the advantages of simple equipment, convenient operation and wide application range. The prepared coating has strong bonding with the substrate, so it has good practical value and broad application prospects. However, the current electric spark deposition technology generally uses rod-shaped materials as electrodes, which is not easy to realize the automation of coating preparation. Therefore, manual operation is generally used for deposition, so the uniformity of the coating cannot be guaranteed, and the deposition efficiency cannot be improved.

[0003] Therefore, the present invention provides a method and device for preparing a friction spark discharge layer. The material required for preparing the coating is made into a spherical shape to obtain a coating material ball, and the ball is placed in a container with a ceramic cone tube at the lower end and a metal tube at the upper end; the cone tube containing the coating material ball is then placed directly above the substrate on which the coating is required, and a reciprocating motion device is used to drive the ball to reciprocate on the surface of the substrate; finally, the substrate and the cone tube are respectively connected to the two poles of a pulse power supply and protected by an inert gas. In this process, the high temperature generated by the discharge will cause the coating material ball to partially melt and adhere to the surface of the substrate, thereby realizing the preparation of the coating. The unstable contact between the coating material ball and the substrate surface is used to generate discharge, and then the coating material is melted on the substrate surface to form a coating. This process can obtain a uniform coating on the substrate surface with high efficiency. Summary of the invention

[0004] Technical problem to be solved: In view of the problems in the prior art that the electrospark deposition technology using rod-shaped electrodes cannot ensure the uniformity of the coating and cannot improve the deposition efficiency, the present invention proposes a preparation method and device based on friction spark discharge coating. The coating has high bonding strength, good uniformity and high preparation efficiency, can complete the preparation of various metal coatings, and has the characteristics of simple operation and low cost.

[0005] Technical solution: A method for preparing a friction spark discharge coating, the steps are as follows:

[0006] Step 1. The material required for preparing the coating is made into a ball to obtain a coating material ball, and the ball is placed in a container having a ceramic cone tube at the lower end and a metal tube at the upper end;

[0007] Step 2. Place the container containing the coating material ball just above the substrate on which the coating is to be prepared, and use a reciprocating motion device to drive it to reciprocate on the surface of the substrate;

[0008] Step 3. Connect the substrate and the container to the two poles of the pulse power supply respectively and use inert gas for protection;

[0009] Step 4. During the preparation process, the high temperature generated by the discharge will cause the coating material ball to partially melt and adhere to the surface of the substrate, thereby achieving the preparation of the coating.

[0010] Preferably, the coating material ball in step 1 is a conductive material, specifically a single metal ball or an alloy ball, with a diameter of 1 to 10 mm.

[0011] Preferably, in step 1, the inner diameter of the bottom of the ceramic cone tube is greater than or equal to twice the diameter of the coating material ball, the height of the ceramic cone tube is greater than or equal to the radius of the coating material ball, and the taper of the ceramic cone tube is 1:5~2:1.

[0012] Preferably, in step 1, the filling height of the coating material balls in the container is greater than the height of the ceramic cone tube.

[0013] Preferably, in step 1, the material of the ceramic cone tube is alumina or zirconia, and the material of the metal tube is the same as the required coating.

[0014] Preferably, in step 2, the distance between the bottom end of the ceramic cone tube and the substrate is less than or equal to the radius of the coating material ball.

[0015] Preferably, the reciprocating motion device in step 2 is a pneumatic system or a crank slider system, and the reciprocating motion speed is 0.5-50 m / min.

[0016] Preferably, in step three, the voltage of the pulse power supply is 20-200 V, the current is 10-1000 A, the pulse width is 10-1000 μs, and the duty cycle is 10:1-1:10.

[0017] Preferably, the inert gas in step three is nitrogen or argon, which is used to prevent oxidation during the coating preparation process.

[0018] Based on the above method, a device for preparing a friction spark discharge coating is provided, the device comprising a gas cylinder, a reciprocating motion device, a metal tube, a coating material ball, a ceramic cone tube, a substrate, a pulse power supply and a workbench, the gas outlet of the gas cylinder is connected to the gas inlet at the top end of the metal tube, the reciprocating motion device is connected to the outer wall of the metal tube for controlling the reciprocating motion of the metal tube, the large-diameter top end of the ceramic cone tube is connected to the bottom end of the metal tube, the coating material ball is arranged in the inner cavity connected to the metal tube and the ceramic cone tube, the substrate is arranged on the workbench, the lower diameter bottom end of the ceramic cone tube is arranged directly above the substrate, the positive pole of the pulse power supply is connected to the substrate, and the negative pole is connected to the metal tube.

[0019] Beneficial effects: (1) The present invention directly utilizes the high temperature energy generated by discharge to locally melt the coating material ball and adhere it to the surface of the substrate, thereby forming a metallurgical grade bond with high bonding strength;

[0020] (2) The present invention utilizes a reciprocating motion device to drive the container, so that the coating material ball rubs against the surface of the substrate, thereby obtaining a uniform coating;

[0021] (3) The coating material ball of the present invention can be prepared by powder metallurgy method and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the device for preparing the friction spark discharge coating according to the present invention.

[0023] The numbers in the figure represent the following: 1. gas cylinder; 2. reciprocating motion device; 3. metal tube; 4. coating material ball; 5. ceramic cone tube; 6. substrate; 7. pulse power supply; 8. workbench. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] A method for preparing a coating based on friction spark discharge, the steps are as follows:

[0027] Step 1. The material required for preparing the coating is made into a ball to obtain a coating material ball, and the ball is placed in a container having a ceramic cone tube at the lower end and a metal tube at the upper end;

[0028] Step 2. Place the container containing the coating material ball just above the substrate on which the coating is to be prepared, and use a reciprocating motion device to drive it to reciprocate on the surface of the substrate;

[0029] Step 3. Connect the substrate and the container to the two poles of the pulse power supply respectively and use inert gas for protection;

[0030] Step 4. During the preparation process, the high temperature generated by the discharge will cause the coating material ball to partially melt and adhere to the surface of the substrate, thereby achieving the preparation of the coating.

[0031] A device for preparing a friction spark discharge coating based on the above method, see Figure 1The device includes a gas cylinder 1, a reciprocating motion device 2, a metal tube 3, a coating material ball 4, a ceramic cone tube 5, a substrate 6, a pulse power supply 7 and a workbench 8. The gas outlet of the gas cylinder 1 is connected to the gas inlet at the top of the metal tube 3, the reciprocating motion device 2 is connected to the outer wall of the metal tube 3 to control the reciprocating motion of the metal tube 3, the large-diameter top of the ceramic cone tube 5 is connected to the bottom of the metal tube 3, the coating material ball 4 is arranged in the inner cavity connected to the metal tube 3 and the ceramic cone tube 5, the substrate 6 is arranged on the workbench 8, the lower diameter bottom of the ceramic cone tube 5 is arranged directly above the substrate 6, the positive electrode of the pulse power supply 7 is connected to the substrate 6, and the negative electrode is connected to the metal tube 3.

[0032] Example 2

[0033] The same as Example 1, except that in the step 1, the coating material ball is a single metal ball or an alloy ball with a diameter of 1 to 10 mm, the inner diameter of the bottom of the ceramic cone tube is greater than or equal to twice the diameter of the coating material ball, the height of the ceramic cone tube is greater than or equal to the radius of the coating material ball, the taper of the ceramic cone tube is 1:5 to 2:1, the filling height of the coating material ball in the container is greater than the height of the ceramic cone tube, the ceramic cone tube is made of alumina or zirconia, and the material of the metal tube is the same as the required coating.

[0034] In the step 2, the distance between the bottom end of the ceramic cone tube and the substrate is less than or equal to the radius of the coating material ball, the reciprocating motion device is a pneumatic system or a crank slider system, and the reciprocating motion speed is 0.5-50 m / min.

[0035] In the step 3, the voltage of the pulse power supply is 20-200V, the current is 10-1000A, the pulse width is 10-1000μs, the duty cycle is 10:1-1:10, and the inert gas is nitrogen or argon.

[0036] Example 3

[0037] The same as Example 2, except that the material of the substrate 6 in this embodiment is 45 steel, with a size of 100 mm×10 mm×5 mm. The coating material ball 4 is a YG8 cemented carbide ball prepared by powder metallurgy, with a diameter of 5 mm; the lower end diameter of the ceramic cone tube 5 is 20 mm, the height is 5 mm, and the taper is 1:1; the metal tube 3 is a YG8 cemented carbide tube, the distance between the bottom end of the ceramic cone tube 5 and the substrate 6 is 1 mm, the reciprocating speed is 10 m / min, the pulse power supply voltage is 50 V, the peak current is 500 A, the pulse width is 100 μs, the duty cycle is 1:1, and the inert gas is nitrogen.

[0038] Before preparing the coating, the carbide ball was placed in the container with a filling height of 15 mm, the substrate 6 was connected to the positive electrode of the pulse power supply 7, the carbide tube was connected to the negative electrode, and the reciprocating speed was adjusted to 4 m / min. After starting the equipment for 5 minutes, the desired coating was obtained. After testing, the average thickness of the coating was 0.5 mm.

[0039] Comparative Example 1

[0040] Compared with Example 3, when other conditions remain unchanged, the ceramic conical tube is replaced with a ceramic cylindrical tube. After 1 minute of processing, due to the friction between the carbide ball and the ceramic, the bottom of the ceramic tube is worn, forming a local inverted cone structure. Therefore, during the movement of the container, the carbide ball often gets stuck, making it impossible to continue processing.

[0041] Comparative Example 2

[0042] Compared with Example 3, when other conditions remain unchanged, the ceramic cone tube is replaced with a metal cone tube. After 2 minutes of processing, the carbide ball will discharge with the metal cone tube, thereby aggravating the wear of the metal cone tube. At the same time, some alloy balls are firmly adhered to the surface of the cone tube, and then the container and the carbide ball are stuck, making it impossible to continue processing.

[0043] Example 4

[0044] Same as Example 2, except that in this embodiment, the substrate 6 is made of stainless steel and has a size of 100 mm×100 mm×5 mm. The coating material ball 4 is a pure aluminum ball with a diameter of 3 mm; the lower end diameter of the ceramic cone tube 5 is 15 mm, the height is 5 mm, and the taper is 1:2; the metal tube 3 is an aluminum tube, the distance between the bottom end of the ceramic cone tube 5 and the substrate 6 is 1 mm, the reciprocating speed is 20 m / min, the pulse power supply voltage is 40 V, the peak current is 200 A, the pulse width is 100 μs, the duty cycle is 1:2, and the inert gas is nitrogen.

[0045] Before preparing the coating, the carbide ball was placed in the container with a filling height of 12 mm. The substrate 6 was connected to the positive electrode of the pulse power supply 7, and the carbide tube was connected to the negative electrode. The reciprocating speed was adjusted to 5 m / min. After starting the equipment for 3 minutes, the desired coating was obtained. After testing, the average thickness of the coating was 0.3 mm.

Claims

1. A method for preparing a friction spark discharge coating, characterized in that: Here are the steps: Step 1. The material required for preparing the coating is made into a ball to obtain a coating material ball, and the ball is placed in a container with a ceramic cone tube at the lower end and a metal tube at the upper end. The coating material ball is a single metal ball or an alloy ball with a diameter of 1 to 10 mm. The inner diameter of the bottom of the ceramic cone tube is greater than or equal to twice the diameter of the coating material ball. The height of the ceramic cone tube is greater than or equal to the radius of the coating material ball. The taper of the ceramic cone tube is 1:5 to 2:

1. The filling height of the coating material ball in the container is greater than the height of the ceramic cone tube. Step 2. Place the container containing the coating material ball just above the substrate on which the coating is to be prepared, and use a reciprocating motion device to drive it to reciprocate on the surface of the substrate; Step 3. Connect the substrate and the container to the two poles of the pulse power supply respectively and use inert gas for protection; Step 4. During the preparation process, the high temperature generated by the discharge will cause the coating material ball to partially melt and adhere to the surface of the substrate, thereby achieving the preparation of the coating.

2. The method for preparing a friction spark discharge coating according to claim 1, characterized in that: In the step 1, the material of the ceramic cone tube is alumina or zirconia, and the material of the metal tube is the same as the required coating.

3. The method for preparing a friction spark discharge coating according to claim 1, characterized in that: In the step 2, the distance between the bottom end of the ceramic cone tube and the substrate is less than or equal to the radius of the coating material ball.

4. The method for preparing a friction spark discharge coating according to claim 1, characterized in that: The reciprocating motion device in step 2 is a pneumatic system or a crank slider system, and the reciprocating motion speed is 0.5-50 m / min.

5. The method for preparing a friction spark discharge coating according to claim 1, characterized in that: In the step 3, the voltage of the pulse power supply is 20-200 V, the current is 10-1000 A, the pulse width is 10-1000 μs, and the duty cycle is 10:1-1:

10.

6. The method for preparing a friction spark discharge coating according to claim 1, characterized in that: In step 3, the inert gas is nitrogen or argon.

7. A device for preparing a friction spark discharge coating based on the method according to claim 1, characterized in that: The device comprises a gas cylinder (1), a reciprocating motion device (2), a metal tube (3), a coating material ball (4), a ceramic cone tube (5), a substrate (6), a pulse power supply (7) and a workbench (8); the gas outlet of the gas cylinder (1) is connected to the gas inlet at the top end of the metal tube (3); the reciprocating motion device (2) is connected to the outer wall of the metal tube (3) and is used to control the reciprocating motion of the metal tube (3); the large-diameter top end of the ceramic cone tube (5) is connected to the bottom end of the metal tube (3); the coating material ball (4) is arranged in the inner cavity connected to the metal tube (3) and the ceramic cone tube (5); the substrate (6) is arranged on the workbench (8); the lower diameter bottom end of the ceramic cone tube (5) is arranged directly above the substrate (6); the positive electrode of the pulse power supply (7) is connected to the substrate (6), and the negative electrode is connected to the metal tube (3).

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