CN113430498B

CN113430498B - Preparation method of high-precision diamond polishing sheet

Info

Publication number: CN113430498B
Application number: CN202110699522.5A
Authority: CN
Inventors: 于盛旺; 吴艳霞; 黑鸿君; 高洁; 郑可; 马永; 周兵; 王永胜
Original assignee: Taiyuan University of Technology
Current assignee: Taiyuan University of Technology
Priority date: 2021-06-23
Filing date: 2021-06-23
Publication date: 2022-11-29
Anticipated expiration: 2041-06-23
Also published as: CN113430498A

Abstract

A preparation method of a high-precision diamond polishing sheet belongs to the technical field of machining tools and is realized by the following steps: firstly, an array patterning graph is formed by ablating a SiC matrix, then the surface of the matrix is cleaned by plasma, smooth sharp bulges are formed by etching, and finally the nano-diamond polishing coating is prepared by an MPCVD method, so that the nano-diamond coated pointed cone array high-precision diamond polishing sheet disclosed by the invention is formed. The method has the advantages of simple process, good controllability, high repetition rate and the like, and the diamond polishing sheet can meet the requirement of polishing precision of parts, improve the processing efficiency and prolong the service life of the polishing sheet in the field of polishing and processing of precise parts.

Description

Preparation method of high-precision diamond polishing sheet

Technical Field

The invention belongs to the technical field of machining cutters, and particularly relates to a preparation method of a high-precision diamond polishing sheet.

Background

The diamond polishing sheet can be used for grinding and polishing materials such as ceramics, hard alloy, glass and the like, is durable in use, has high polishing capacity, can not be deeply scratched, and has wide application range. However, the preparation of highly precise polishing pads, especially diamond pads with an array of sharp cones, has become an international challenge due to the high hardness and brittleness of the diamond itself. At present, the method is mainly realized internationally by embedding diamond particles on the surface of the hard alloy through micro-patterning and nickel electroplating to obtain a diamond array. However, because of the chemical inertness of the carbon atom structure in diamond, the diamond is difficult to process, and because the diamond is difficult to form a bond with hard alloy, the bonding force is poor, and the service life of the polishing sheet is limited. Therefore, two key problems need to be solved in manufacturing high-precision and long-life diamond polishing sheets: the first is substrate selection, and the second is patterning process.

The SiC substrate has good bonding performance with carbon atoms in diamond, has high thermal conductivity, low thermal expansion coefficient, high rigidity, good chemical corrosion resistance and thermal uniformity, and has important application prospect when used as a polishing sheet base material with small deformation. However, the SiC substrate has a problem that patterning processing is difficult, and the processing method of the SiC material at present mainly includes electrochemical corrosion, mechanical processing, ultrasonic processing, plasma dry etching (reactive ion etching, electron cyclotron resonance, inductively coupled plasma), and the like, but patterning processing still has problems of complex process, high cost, and the like. In addition, CF involved in plasma etching ₄ Or SF ₆ The gas has higher requirements on equipment and operation and is difficult to popularize.

Disclosure of Invention

The invention provides a preparation method of a high-precision diamond pointed cone array polishing sheet with ablation selectivity and anisotropy, simple structure, convenient operation and easy control.

A preparation method of a high-precision diamond polishing sheet is realized by the following steps:

A. preparing a patterned graph on the surface of the SiC matrix by using an ablation technology: placing a smooth and clean SiC substrate on a laser ablation base station, and obtaining a graphical matrix with different ablation patterns by setting ablation parameters;

B. cleaning the surface of the etched substrate by using a plasma chemical vapor deposition technology: placing the patterned SiC matrix in plasma chemical vapor deposition equipment, introducing oxygen and hydrogen into a vacuum chamber, and breaking down the gases into plasma under high pressure to clean and etch the surface of the matrix;

C. depositing the nano-diamond coating by using a plasma chemical vapor deposition technology: then introducing carbon-containing gas and hydrogen into the plasma chemical vapor deposition equipment, ionizing the gas under the action of microwaves to form carbon-containing plasma, and depositing the carbon-containing plasma on the surface of the substrate.

In step a, the ablation pattern may be any one of rectangular, circular, and polygonal.

In step B, the plasma activation process parameters range: the air pressure is 2000-8000 Pa, the microwave power is 1-3 kW, and the temperature is 600-1000 ℃.

In step C, the carbon-containing gas may be CH ₄ Or C ₂ H ₂ The air pressure of the cavity is 2000-8000 Pa, H ₂ And CH ₄ Or C ₂ H ₂ Gas volume flow ratio of 5:1 to 1:1, the microwave power is 2-60 kW, the temperature is 600-1000 ℃, and the thickness of the coating is 10-200 mu m.

The invention adopts the ablation method to etch the SiC matrix, and the etching device has the advantages of low price, convenient use, good controllability, good single-point repeatability, small error and the like, and can ablate various patterns with micro-nano scale. Meanwhile, the hydrogen-oxygen plasma is adopted, so that the surface can be cleaned and activated, and the SiC matrix can be etched in different degrees through parameter setting and atmosphere action to form pointed tapered patterns with different sizes. By combining the advantages of the two modes, a precisely etched pattern array can be formed on the surface of the SiC matrix, and meanwhile, the surface is activated by adopting oxyhydrogen plasma etching, so that the nucleation density and the growth speed of diamond can be improved, and the bonding strength between the diamond and the SiC matrix can be further improved. In addition, the nano-diamond polishing sheet obtained by MPCVD has high quality and good uniformity, and can be used in the field of grinding and polishing of materials such as ceramics, hard alloy, glass and the like.

Drawings

FIG. 1 is a schematic view showing a process for producing a diamond polishing pad according to example 1.

FIG. 2 is a schematic view showing a process for producing a diamond polishing pad according to example 2.

Detailed Description

The present invention is further illustrated by, but is not limited to, the following examples.

Example 1:

1) Ablation of SiC substrates

Cleaning and drying the SiC substrate (the surface roughness is less than 0.01 mm) with a single-sided crystal face polished, setting laser ablation parameters and pattern types: frequency: 4 KHz, speed: 10. μ m/s, cylinder diameter: 200. μ m, height: 80. μ m, cylindrical single pattern and square array pattern, patterned array ablation of SiC was performed.

2) SiC substrate etching

Placing the ablation patterned SiC substrate in a plasma chemical vapor deposition apparatus with H ₂ And O ₂ As an etching gas, etching parameters were set: the air pressure is 3000 Pa, the microwave power is 1000W, and the temperature is 600 ℃.

3) Nanodiamond coating deposition

And after the etching is finished, depositing the nano diamond coating, wherein the deposition parameters are as follows: the air pressure of the cavity is 2000 Pa, H ₂ And CH ₄ Gas volume flow ratio of 5:1, the microwave power is 800 kW, the temperature is 600 ℃, and the coating thickness is 10 mu m. The preparation flow of the diamond polishing sheet is shown in FIG. 1.

Example 2:

1) Ablation of SiC substrates

Cleaning and drying the SiC substrate (the surface roughness is less than 0.01 mm) with a single-sided crystal face polished, setting laser ablation parameters and pattern types: frequency: 6 KHz, speed: 20. μ m/s, height: 100. μ m, individual patterns are squares of 100 μm diameter, the array is rectangular, and patterned ablation of SiC is essentially performed.

2) SiC substrate etching

Placing the ablation patterned SiC substrate in a plasma chemical vapor deposition apparatus with H ₂ And O ₂ As etching gas, etching parameters were set: the air pressure is 3000 Pa, the microwave power is 1000W, and the temperature is 600 ℃.

3) Nanodiamond coating deposition

And after the etching is finished, depositing the nano diamond coating, wherein the deposition parameters are as follows: the air pressure of the cavity is 2000 Pa, H ₂ And CH ₄ Gas volume flow ratio of 5:1, the microwave power is 800 kW, the temperature is 600 ℃, and the thickness of the coating is 10 mu m. The preparation flow of the diamond polishing sheet is shown in FIG. 1.

Example 3:

1) Ablation of SiC substrates

Cleaning and drying the SiC substrate (the surface roughness is less than 0.01 mm) with a single-sided crystal face polished, setting laser ablation parameters and pattern types: frequency: 8 KHz, speed: 40. μ m/s, height: 120. mu m, wherein the single pattern is a cuboid, the length is 70 mu m, the width is 50 mu m, the array pattern is a circle, and SiC is basically subjected to pattern array ablation.

2) SiC substrate etching

3) Nanodiamond coating deposition

And after the etching is finished, depositing the nano diamond coating, wherein the deposition parameters are as follows: the air pressure of the cavity is 2000 Pa, H ₂ And CH ₄ Gas volume flow ratio of 5:1, the microwave power is 800 kW, the temperature is 600 ℃, and the thickness of the coating is 10 mu m.

Claims

1. A preparation method of a high-precision diamond polishing sheet comprises the following steps:

A. pre-patterning: patterning the polished smooth and clean SiC matrix surface by using a laser ablation technology to obtain a patterned matrix with different columnar array patterns; the laser frequency is 4-20 KHz, the laser axial speed is 20-200 mu m/s, and the ablation thickness is 100-200 mu m;

B. plasma etching: placing the pre-patterned SiC matrix into a microwave plasma chemical vapor deposition device, introducing oxygen and hydrogen, starting the device, exciting to form oxygen and hydrogen composite plasma, cleaning the surface of the matrix by using the plasma, and simultaneously generating an etching effect to convert the columnar array into a pointed cone array; the technological parameters of plasma etching are as follows: the air pressure is 2-8 kPa, the microwave power is 1-3 kW, the matrix temperature is 600-1000 ℃, the hydrogen flow is 300-600 sccm, and the oxygen flow is 1-10% of the hydrogen flow;

C. preparing a nano diamond coating: and after the plasma cleaning step is completed, stopping introducing oxygen, introducing carbon-containing gas while adjusting the hydrogen flow, depositing a nano-diamond film on the surface of the patterned substrate, and finally preparing the nano-diamond coated pointed cone array high-precision diamond polishing sheet on the surface of the SiC substrate.

2. The method for producing a high-precision diamond polishing pad according to claim 1, wherein: in step A, the ablation pattern can be a rectangular array or a concentric circle array, wherein the pattern single figure is any one of a triangle, a circle or a polygon, and the like, and the interval between adjacent single figures is 50-200 μm.

3. The method for preparing a high precision diamond polishing pad according to claim 1, wherein: in step C, the carbon-containing gas is CH ₄ Or C ₂ H ₂ Wherein the air pressure of the cavity is 2000-8000 Pa, the hydrogen flow is 100-200 sccm ₄ Or C ₂ H ₂ And H ₂ Gas volume flow ratio of 1:1 to 1:5, the microwave power is 2-60 kW, the matrix temperature is 600-1000 ℃, the thickness of the prepared nano-diamond is 10-200 μm, and the particle size is 10-100 nm.