A preparation method of a diamond wire saw

Abstract

The present invention relates to a preparation method of a diamond wire saw, which includes preparing carbon quantum dots, selecting a diamond wire saw substrate, pre-treating the diamond wire saw substrate, pre-plating, grit loading process, thickening process and cleaning and drying process; the electroplated layer of the diamond wire saw contains both diamond and carbon quantum dots; during cutting, both diamond and carbon quantum dots are worn simultaneously; during the cutting process, light with a wavelength of 260-500 nm is used for on-line real-time irradiation to cause the carbon quantum dots attached to the surface of the diamond wire saw to produce a fluorescence effect, and the wear condition of the diamond wire saw is judged on-line in real time according to the fluorescence distribution of the wire saw.

Description

Technical Field

[0001] The present invention belongs to the field of diamond wire saw preparation, and particularly relates to a method for preparing a diamond wire saw. Background Art

[0002] A diamond wire saw is a saw that uses high-hardness diamond as an abrasive. The wire diameter of the diamond wire saw is dozens of microns, and it can perform precision and narrow saw seam cutting on brittle materials (such as silicon ingots) to achieve shaping processing. It has the characteristics of small surface damage during processing, small flexural deformation, thin slices with good thickness consistency, and high cutting efficiency.

[0003] The manufacturing technology of diamond wire saws is becoming increasingly mature, but the detection technology is relatively backward; currently, there are three common detection methods for diamond wire saws. The first is the qualitative method, which mainly relies on a micrometer to measure the outer diameter, and observes the surface of the wire saw and the distribution of diamond abrasive grains on the wire saw by means of a stereomicroscope to evaluate the quality of the diamond wire saw; the second is the quantitative method, which uses relevant methods or equipment to measure and characterize the holding force of diamond abrasive grains. It is analyzed by measuring the flexural strength, tensile strength, etc. to evaluate the quality; the third is the finite element analysis method, which judges whether the diamond is in a critical shedding state to achieve the purpose of detecting the quality of the diamond wire saw.

[0004] The Chinese invention patent with the authorization announcement number CN106926375B discloses an on-line detection device for diamond wire saws. The detection method of this device belongs to the first qualitative method; the device includes that the back plate is vertically arranged on the rear side of the bottom plate, and the bottom plate is installed on the inner side wall of the wire release chamber of the diamond wire saw slicing machine through the back plate; the camera is installed on the front side of the bottom plate through the camera installation slide, an imaging cylinder is installed on the back plate, and the camera lens faces the imaging cylinder. The diamond wire saw passes horizontally between the camera lens and the imaging cylinder, and the position of the camera along the axial direction of the diamond wire saw is adjusted through the camera installation slide; the main light source is installed on the front side of the diamond wire saw on the bottom plate through a bracket, the back light source is installed on the rear side of the imaging cylinder on the bottom plate through the back light source installation slide, and the position of the back light source along the axial direction of the diamond wire saw is adjusted through the back light source installation slide; mainly by taking pictures of the wire saw by the camera to obtain an image, and judging the wear condition of the diamond wire saw according to the image. Directly photographing the surface of the diamond wire saw cannot accurately obtain the wear condition of the surface of the diamond wire saw; when the abrasive grains of the diamond wire saw are severely damaged, they cannot be replaced in time. Summary of the Invention

[0005] The present invention provides a method for preparing a diamond wire saw to achieve the purpose of simplifying the detection steps of the diamond wire saw and extending its service life; to achieve the above purpose, the technical solution adopted by the present invention is specifically as follows:

[0006] A method for preparing a diamond wire saw, the steps are specifically as follows:

[0007] (1) Preparation of carbon quantum dots: exfoliate carbon sources to obtain carbon quantum dots with a particle size less than 20 nm;

[0008] (2) Selection of the diamond wire saw substrate: select a steel wire with a carbon content of 0.6%-0.95%;

[0009] (3) Pretreatment of the diamond wire saw substrate: degrease, remove oil, and remove the surface oxide film and oxides from the diamond wire saw substrate;

[0010] (4) Pre-plating: pre-plate a nickel film with a thickness of 1-3 μm on the surface of the diamond wire saw substrate by electroplating;

[0011] (5) Grit embedding process: add diamond powder with a particle size of 5 μm - 70 μm and the carbon quantum dots to the electroplating solution in step 4, set the diamond wire saw substrate pre-plated with a nickel film on one side as the cathode, and electroplate the diamond powder and carbon quantum dots on the surface of the diamond wire saw during electroplating;

[0012] (6) Thickening process: the electrode arrangement in the thickening process is the same as that in the grit embedding process, use the diamond wire saw substrate as the cathode, and install nickel anodes on both sides of the cathode. Control the thickness of the electroplated layer within 3 - 30 μm;

[0013] (7) Cleaning and drying process: wash the surface of the electroplated and thickened diamond wire saw with pure water and dry it.

[0014] The beneficial effects of the preparation method of the diamond wire saw of the present invention: Pretreat the surface of the diamond wire saw substrate to prevent the influence of oxide scales, grease, etc. on the surface adhesion ability of the diamond wire saw substrate; pre-plate a nickel layer to improve the bonding strength between the diamond wire saw substrate and the electroplated layer containing diamond powder and carbon quantum dots, reduce shedding, and extend the service life; control the electroplated layer within 3 - 30 μm to prevent the electroplated layer from being too thick and peeling off in chunks; if the electroplated layer is too thin, the service life will be reduced; wash and dry with pure water to effectively remove harmful hydrogen in the coating and reduce the hardness and brittleness of the coating. The electroplated layer of the diamond wire saw prepared by the present invention contains both diamond and carbon quantum dots; during cutting, both diamond and carbon quantum dots are worn; during cutting, light with a wavelength of 260 - 500 nm can be directly used for on-line real-time irradiation, so that the carbon quantum dots attached to the surface of the diamond wire saw produce a fluorescence effect and form a fluorescence image, and judge the wear condition of the on-line diamond wire saw in real time according to the fluorescence distribution of the wire saw; realize the real-time detection of the wear condition of the diamond wire saw during cutting, avoid the need to disassemble the diamond wire saw for detection, improve the detection efficiency, and reduce the detection cost.

[0015] Further improved, the preparation of carbon quantum dots in step 1 is specifically as follows: citric acid, cysteine, galactose, and succinic acid are used as carbon sources, and the carbon sources are stirred and dissolved in; the filtered solution is added to a reaction kettle and stirred for reaction; the temperature is controlled at 100 - 250 °C, the stirring speed is 5000 - 10000 rpm, and the reaction time is 5 - 35 h; the prepared carbon quantum dots.

[0016] Beneficial effects: Using citric acid, cysteine, galactose, and succinic acid as carbon sources, the raw materials of the carbon sources are extensive, which is convenient for reducing the cost of carbon source preparation; dissolving inorganic carbon in a solvent, reasonably controlling the temperature and stirring speed of the reaction kettle, thereby improving the yield of carbon quantum dots, and making the yield of carbon quantum dots above 36%.

[0017] Further improved, the degreasing and oil removal treatment of the diamond wire saw substrate in step 3 is specifically as follows: first, 95% sodium hydroxide and 10% surfactant are mixed evenly and diluted to a solution with a concentration of 20 g - 60 g / L; the surface of the diamond wire saw substrate is subjected to degreasing and oil removal treatment.

[0018] Beneficial effects: Adding a surfactant to sodium hydroxide to improve the activity of the surfactant and diluting it to a solution with a concentration of 20 g - 60 g / L; is conducive to removing the grease on the surface of the diamond wire saw substrate completely.

[0019] Further improved, the treatment of removing the surface oxide film and oxides of the diamond wire saw substrate in step 3 is specifically as follows: dilute sulfuric acid into a sulfuric acid solution with a volume concentration of 5% - 15%, and control the temperature of the sulfuric acid solution at 25 - 35 °C; perform surface oxide film and oxide treatment on the surface of the diamond wire saw substrate.

[0020] Beneficial effects: Using a sulfuric acid solution with a concentration of 5% - 15% and stably controlling the sulfuric acid solution at 25 - 35 °C to improve the activity of the sulfuric acid solution. During the surface treatment of the diamond substrate, while removing the surface oxide film and oxides completely, reducing the corrosion of the sulfuric acid solution on the surface of the diamond substrate.

[0021] Further improved, the pre - plating electroplating solution in step 4 includes nickel chloride with a concentration of 30 g / L, boric acid with a concentration of 30 g / L, and the rest is nickel sulfamate solution; the temperature of the electroplating solution is 35 - 60 °C, the pH value is 3.0 - 4.5, and the current density is 2 - 3 A / Dm 3 .

[0022] Beneficial effects: By reasonably designing the composition and concentration of the electroplating solution, as well as the temperature of the electroplating solution, it is conducive to the stable growth and thickness control of the nickel film on the diamond substrate surface; using boric acid to adjust the pH value of the electroplating solution, and taking advantage of the weak acidity of boric acid, is conducive to the stability of the pH value of the electroplating solution, improving the electroplating efficiency and quality. Description of the Drawings

[0023] Figure 1 is a partial cross-sectional view of a diamond wire saw prepared by using the preparation method of the diamond wire saw of the present invention;

[0024] Figure 2 is a fluorescence detection diagram of a diamond wire saw prepared by using the preparation method of the diamond wire saw of the present invention;

[0025] In the figure: 1 - diamond wire saw substrate; 2 - nickel film; 3 - diamond powder; 4 - carbon quantum dots. Specific embodiments

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific steps of the specific embodiment of the preparation method of the diamond wire saw of the present invention are as follows:

[0027] (1) Preparation of carbon quantum dots 4: Exfoliate carbon sources to obtain carbon quantum dots 4 with a particle size less than 20 nm. In this embodiment, the preparation of carbon quantum dots 4 is specifically as follows: Dissolve 1 g of citric acid and 1.5 g of thiourea in 20 mL of deionized water at room temperature; after stirring for 15 min until evenly dispersed and filtering, add it to the reaction kettle reaction system; control the temperature of the reaction kettle reaction system at 150 °C and the heating time at 15 h; centrifuge at 10,000 rpm for 30 min and wash three times with water to remove impurities, and obtain carbon quantum dots 4 after freeze-drying; screen out carbon quantum dots 4 with a particle size less than 20 nm. In other embodiments, inorganic carbon can be replaced by cysteine, galactose, and succinic acid instead of citric acid, and the carbon source is stirred and dissolved in a solvent; the filtered solution is added to the reaction kettle and stirred for reaction; the temperature is controlled at 100 °C and the heating time is 35 h; or the temperature is controlled at 250 °C and the heating time is 5 h; instead of controlling the temperature at 150 °C and the heating time at 15 h. Organic carbon can also be used instead of inorganic carbon as the carbon source.

[0028] (2) Selection of the diamond wire saw substrate 1: Select a steel wire with a carbon content of 0.6% - 0.95%. In this embodiment, the diamond wire saw substrate 1 is a piano wire with a diameter of 5 - 200 μm.

[0029] (3) Pretreatment of the diamond wire saw substrate 1: Perform degreasing, oil removal, and removal of surface oxide film and oxides on the diamond wire saw substrate 1.

[0030] The degreasing and oil removal treatment of the diamond wire saw substrate 1 in Step 3 is specifically as follows: First, mix 95% sodium hydroxide and 10% surfactant evenly, and dilute it into a solution with a concentration of 20g - 60g / L; perform degreasing and oil removal treatment on the surface of the diamond wire saw substrate 1. Add the surfactant to sodium hydroxide to improve the activity of the surfactant and dilute it into a 20g - 60g / L solution; it is beneficial to remove the grease on the surface of the diamond wire saw substrate 1 completely. In this embodiment, 95% sodium hydroxide and 10% surfactant are mixed evenly and diluted into a solution with a concentration of 40g / L. In other embodiments, 95% sodium hydroxide and 5% surfactant, the concentration of the diluted solution is 60g / L; or 80% sodium hydroxide and 20% surfactant, the concentration of the diluted solution is 20g / L; thus replacing the mixture of 95% sodium hydroxide and 10% surfactant and diluting it into a solution with a concentration of 40g / L.

[0031] The treatment of removing the surface oxide film and oxides of the diamond wire saw substrate 1 in Step 3 is specifically as follows: Dilute sulfuric acid into a sulfuric acid solution with a volume concentration of 5% - 15%, and control the temperature of the sulfuric acid solution at 25 - 35°C; perform surface oxide film and oxide treatment on the surface of the diamond wire saw substrate 1. Improve the activity of the sulfuric acid solution. During the surface treatment of the diamond wire saw substrate 1, while removing all the oxide film and oxides on the surface, reduce the corrosion of the sulfuric acid solution to the surface of the diamond wire saw substrate 1. In this embodiment, sulfuric acid is diluted into a sulfuric acid solution with a volume concentration of 10%, and the temperature of the sulfuric acid solution is controlled at 30°C. In other embodiments, sulfuric acid is diluted into a volume concentration of 15% and the temperature is 25°C; or the concentration is 5% and the temperature is 35°C, thus replacing the concentration of 10% and the temperature of 30°C.

[0032] (4) Pre - plating: Use electroplating to pre - plate a nickel film 2 on the surface of the diamond wire saw substrate 1, and the thickness of the nickel film 2 is 1 - 3μm (1μm). In this embodiment, the thickness of the nickel film 2 is preferably controlled at about 1.5μm.

[0033] The electroplating solution for pre - plating in Step 4 includes nickel chloride with a concentration of 30g / L, boric acid with a concentration of 30g / L, and the rest is nickel sulfamate solution; the temperature of the electroplating solution is 35 - 60°C, the pH value is 3.0 - 4.5, and the current density is 2 - 3A / Dm 3 ; By reasonably designing the composition and concentration of the electroplating solution, as well as the temperature of the electroplating solution, it is beneficial to the stable growth and thickness control of the nickel film 2 on the surface of the diamond wire saw substrate 1; use boric acid to adjust the pH value of the electroplating solution. Utilizing the weak acidity of boric acid is beneficial to the stability of the pH value of the electroplating solution and improves the electroplating efficiency and quality. In this embodiment, the temperature of the electroplating solution is 50°C, the pH value is 4, and the current density is 2.5A / Dm 3 .

[0034] (5) Upper sanding process: Diamond powder 3 with a particle size of 5μm - 70μm and carbon quantum dots 4 are added to the electroplating solution in step 4 and stirred evenly, so that the diamond particles and carbon quantum dots 4 are evenly distributed in the electroplating solution. The plating solution containing diamond micropowder and carbon quantum dots 4 is pumped to the working tank by a lift pump to form a stable liquid level. Nickel anodes are installed on both sides of the baseline advancing in the working tank. The diamond wire saw substrate 1 pre-coated with a layer of nickel film 2 is set as the cathode, and during electroplating, diamond powder 3 and carbon quantum dots 4 are electroplated on the surface of the diamond wire saw.

[0035] (6) Thickening process: The electrode arrangement in the thickening process is the same as that in the upper sanding process. The diamond wire saw substrate 1 is used as the cathode, and nickel anodes are installed on both sides of the cathode. The thickness of the electroplated layer is controlled within 3 - 30μm; by thickening the plating on the surface of the baseline, the diamond micropowder will be firmly fixed on the baseline, and carbon quantum dots 4 also exist on the diamond micropowder; according to different diamond particle sizes, the thickness of the nickel plating layer is 3 - 30μm. In this embodiment, the thickness of the electroplated layer is controlled at 18μm.

[0036] (7) Cleaning and drying process: The surface of the electroplated and thickened diamond wire saw is washed with pure water and dried; this is repeated multiple times. Through the drying process, harmful hydrogen in the plating layer can be effectively removed, reducing the hardness and brittleness of the plating layer.

[0037] When the diamond wire saw prepared by the preparation method of the diamond wire saw of the present invention is used to cut single crystal SiC, the feed rate is 0.5mm / min; every 10 minutes of cutting, when the diamond wire saw cuts under dark conditions, light with a wavelength of 260 - 320nm is used for real-time irradiation, so that the carbon quantum dots 4 attached to the surface of the diamond wire saw generate a fluorescence effect and form a fluorescence image, as Figure 2 shown. The real-time wear condition during the cutting of the diamond is judged and detected according to the fluorescence image. It is avoided that the diamond wire saw needs to be disassembled for detection, improving the detection efficiency and reducing the detection cost.

[0038] In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0039] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a diamond wire saw, characterized in that, The steps are as follows: (1) Prepare carbon quantum dots: Exfoliate carbon sources to obtain carbon quantum dots with a particle size less than 20 nm; (2) Select a diamond wire saw substrate: Select a steel wire with a carbon content of 0.6% - 0.95%; (3) Pretreatment of the diamond wire saw substrate: Degrease, defat, and remove the surface oxide film and oxides from the diamond wire saw substrate; (4) Pre - plating: Pre - plate a nickel film with a thickness of 1 - 3 μm on the surface of the diamond wire saw substrate by electroplating; (5) Graining process: Add diamond powder with a particle size of 5 μm - 70 μm and the carbon quantum dots into the electroplating solution in step 4. Set the diamond wire saw substrate pre - plated with a nickel film on one side as the cathode, and electroplate the diamond powder and carbon quantum dots onto the surface of the diamond wire saw during electroplating; (6) Thickening process: The electrode arrangement in the thickening process is the same as that in the graining process. The diamond wire saw substrate is used as the cathode, and nickel anodes are installed on both sides of the cathode. The thickness of the electroplated layer is controlled at 3 - 30 μm; (7) Cleaning and drying process: Wash the surface of the electroplated and thickened diamond wire saw with pure water and then dry it.

2. The manufacturing method of the diamond wire saw according to claim 1, characterized in that, Specifically, in step 1, the preparation of carbon quantum dots is as follows: Use citric acid, cysteine, galactose, and succinic acid as carbon sources, stir and dissolve the carbon sources in a solvent; add the filtered solution into a reaction kettle and stir - react; control the temperature at 100 - 250 °C, the stirring speed at 5000 - 10000 rpm, and the reaction time at 5 - 35 h; prepare the carbon quantum dots.

3. The method for preparing a diamond wire saw according to claim 1 or 2, characterized in that, Specifically, in step 3, for the degreasing and defatting treatment of the diamond wire saw substrate: First, mix 95% sodium hydroxide and 10% surfactant evenly, and dilute it to a solution with a concentration of 20 g - 60 g / L; perform degreasing and defatting treatment on the surface of the diamond wire saw substrate.

4. The method for preparing a diamond wire saw according to claim 3, characterized in that, Specifically, in step 3, for the treatment of removing the surface oxide film and oxides from the diamond wire saw substrate: Dilute sulfuric acid into a sulfuric acid solution with a volume concentration of 5% - 15%, and control the temperature of the sulfuric acid solution at 25 - 35 °C; perform treatment on the surface oxide film and oxides of the diamond wire saw substrate.

5. The manufacturing method of the diamond wire saw according to claim 1, characterized in that, The electroplating solution pre-plated in the step 4 includes nickel chloride with a concentration of 30 g / L, boric acid with a concentration of 30 g / L, and the rest is nickel sulfamate solution; the temperature of the electroplating solution is 35-60 °C, the pH value is 3.0-4.5, and the current density is 2-3 A / Dm 3 .

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