Cutting fluid for diamond wire saw cutting, preparation method and application thereof

Abstract

The present invention discloses a cutting fluid for diamond wire saw cutting, a preparation method thereof, and an application thereof, and belongs to the technical field of wire saw cutting. The cutting fluid for diamond wire saw cutting provided by the present invention comprises the following components: composite ceramic powder, a thickener, a surfactant, a pH stabilizer, a defoaming agent, and water; the composite ceramic powder comprises silicon carbide, boron carbide, and aluminum oxide; the average particle size of each component of the composite ceramic powder is independently 10 to 40 μm; the mass percentage of the composite ceramic powder in the cutting fluid is 10 to 40%. The present invention designs a formula of the cutting fluid and adds composite ceramic powder with a specific proportion and a specific particle size thereto, thereby achieving effective sharpening of the abrasive grains on the surface of the diamond wire saw, greatly improving the cutting efficiency and extending the service life of the wire saw; and the composite ceramic powder can also improve the surface quality of the sheet material obtained by cutting and reduce the warping of the sheet material.

Description

Technical Field

[0001] The present invention belongs to the technical field of wire saw cutting, and in particular relates to a cutting fluid for diamond wire saw cutting, a preparation method thereof, and an application thereof. Background Art

[0002] Diamond wire sawing involves attaching diamond abrasive to a metal wire using electroplating or resin bonding. Diamond wire sawing involves cutting workpieces using a diamond wire saw with a diameter of 100 to 500 μm. It boasts high cutting efficiency, minimal kerf loss, and environmental friendliness. It is currently widely used in the photovoltaic industry for cutting single crystal and polycrystalline silicon wafers, as well as in the semiconductor industry for sapphire and single crystal silicon carbide wafers. Therefore, using diamond wire saws to cut ceramic substrates for sheet production offers a viable alternative to tape-casting methods for sheet ceramic production. The diamond wire saw cutting process needs to meet the following requirements: (1) high workpiece surface quality and minimal subsurface damage to reduce subsequent grinding and polishing processes and improve production efficiency; (2) diamond wire saw abrasive particles only adhere to the core wire surface, which limits the regeneration of new cutting edges. As the cutting progresses, it continuously affects the wire saw cutting performance. Therefore, it is necessary to increase the service life of the diamond wire saw to reduce cutting costs and maintain high cutting efficiency; (3) For the cutting of large-sized and complex-shaped workpieces, chips may accumulate in the kerf, affecting the cutting performance. Therefore, it is necessary to use cutting fluid to clean and remove chips from the cutting area.

[0003] However, cutting fluids used in diamond wire sawing processes have traditionally been used for cutting hard and brittle materials such as single-crystal silicon, polycrystalline silicon, sapphire, and silicon carbide. These fluids have focused more on improving workpiece surface quality and reducing subsurface damage. Currently, there is limited research on cutting fluids specifically targeting silicon nitride ceramics, which possess relatively high toughness and strength. Silicon nitride ceramics have high fracture toughness and are a typical high-strength, high-toughness ceramic. Silicon nitride ceramics have a variety of excellent physical and thermodynamic properties, including a high dielectric constant, excellent thermal conductivity, good thermal stability, strong chemical stability, and a thermal expansion coefficient close to that of semiconductor components. Therefore, they have become a widely used electronic packaging substrate material. However, cutting fluids specifically designed for diamond wire sawing of silicon nitride ceramics are currently lacking.

[0004] The existing technology of cutting silicon nitride ceramics with diamond wire saw has the following disadvantages:

[0005] 1) The material removal rate during diamond wire saw cutting is low;

[0006] 2) The cutting force during the diamond wire saw cutting process is large, the abrasive wear on the wire saw is serious, and the service life of the wire saw is short;

[0007] 3) During the diamond wire saw cutting process, deep grooves parallel to the wire direction will be formed on the workpiece surface, resulting in a decrease in the surface quality of the workpiece. Summary of the Invention

[0008] In order to overcome the problems existing in the above-mentioned prior art, one of the objects of the present invention is to provide a cutting fluid for diamond wire saw cutting. By adding composite ceramic powder to the cutting fluid, the abrasive grains on the diamond wire saw can be effectively sharpened, the service life of the wire saw can be extended, and the cutting efficiency can be improved. At the same time, the relative rolling and scratching effect between the composite ceramic powder and the workpiece material can be used to further improve the surface quality of the workpiece.

[0009] A second object of the present invention is to provide a method for preparing the cutting fluid.

[0010] A third object of the present invention is to provide an application of the above-mentioned cutting fluid in cutting silicon nitride ceramic materials.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is:

[0012] The first aspect of the present invention provides a cutting fluid for diamond wire saw cutting, comprising the following components: composite ceramic powder, a thickener, a surfactant, a pH stabilizer, a defoaming agent, and water; the composite ceramic powder comprises silicon carbide, boron carbide, and aluminum oxide; the average particle size of each component of the composite ceramic powder is independently 10 to 40 μm; and the mass percentage of the composite ceramic powder in the cutting fluid is 10 to 40%.

[0013] Preferably, the average particle size of each component of the composite ceramic powder is independently 12 to 30 μm; further preferably, the average particle size of each component of the composite ceramic powder is independently 13 to 25 μm; even further preferably, the average particle size of each component of the composite ceramic powder is independently 16 to 20 μm.

[0014] Preferably, the mass percentage of the composite ceramic powder in the cutting fluid is 12 to 38%; further preferably, the mass percentage of the composite ceramic powder in the cutting fluid is 14 to 34%; even further preferably, the mass percentage of the composite ceramic powder in the cutting fluid is 16 to 32%.

[0015] Preferably, in the composite ceramic powder, the mass ratio of silicon carbide, boron carbide and aluminum oxide is (0.1~5):(0.1~5):1; further preferably, in the composite ceramic powder, the mass ratio of silicon carbide, boron carbide and aluminum oxide is (0.2~4):(0.2~4):1; even further preferably, in the composite ceramic powder, the mass ratio of silicon carbide, boron carbide and aluminum oxide is (0.3~3):(0.3~3):1.

[0016] Preferably, the composite ceramic powder is prepared by mechanically mixing silicon carbide, boron carbide and aluminum oxide; further preferably, the mechanical mixing method is selected from tumble mixing, wherein the tumble mixing is performed in a tumble machine.

[0017] Preferably, the rolling speed of the tumble mixing is 40 to 100 rpm; further preferably, the rolling speed of the tumble mixing is 50 to 90 rpm; further preferably, the rolling speed of the tumble mixing is 60 to 80 rpm.

[0018] Preferably, the rolling time of the tumble mixing is 1 to 4 hours; further preferably, the rolling time of the tumble mixing is 1.2 to 3.5 hours; further preferably, the rolling time of the tumble mixing is 1.5 to 3 hours.

[0019] Preferably, in the cutting fluid, the thickener is selected from polyether polyols.

[0020] Preferably, the polyether polyol includes polyether diol, polyether triol or a combination thereof; further preferably, the polyether polyol is selected from polyether diol.

[0021] In a specific embodiment of the present invention, the polyether diol includes at least one of polyethylene glycol, polypropylene glycol, and polybutylene glycol; in a specific embodiment of the present invention, the polyether diol is selected from polyethylene glycol.

[0022] Preferably, the average molecular weight of the polyether polyol is 300-800; further preferably, the average molecular weight of the polyether polyol is 400-700; even more preferably, the average molecular weight of the polyether polyol is 400-600.

[0023] In a specific embodiment of the present invention, the average molecular weight of the polyether polyol is at least one of 300, 400 or 600; in a specific embodiment of the present invention, the polyether polyol is selected from polyethylene glycol, and the average molecular weight of the polyethylene glycol is at least one of 300, 400 or 600.

[0024] Preferably, in the cutting fluid, the surfactant includes a nonionic surfactant, an anionic surfactant or a combination thereof; further preferably, in the cutting fluid, the surfactant includes a nonionic surfactant and an anionic surfactant; further preferably, in the cutting fluid, the surfactant includes a nonionic surfactant and an anionic surfactant in a mass ratio of 1: (0.5 to 2); more preferably, in the cutting fluid, the surfactant includes a nonionic surfactant and an anionic surfactant in a mass ratio of 1: (0.8 to 1.5).

[0025] Preferably, the nonionic surfactant includes at least one of nonylcycloethanol polyoxyethylene ether, polyethylene glycol monooctylphenyl ether (OP-40) or nonylphenol polyoxyethylene ether; further preferably, the nonionic surfactant includes nonylcycloethanol polyoxyethylene ether, polyethylene glycol monooctylphenyl ether or a combination thereof; further preferably, the nonionic surfactant is selected from nonylcycloethanol polyoxyethylene ether.

[0026] Preferably, the anionic surfactant includes sodium dodecylbenzenesulfonate, polyacrylamide or a combination thereof; further preferably, the anionic surfactant is selected from sodium dodecylbenzenesulfonate.

[0027] In a specific embodiment of the present invention, the surfactant is selected from nonylcycloethanol polyoxyethylene ether and sodium dodecylbenzenesulfonate in a mass ratio of 1: (0.5-2).

[0028] Preferably, in the cutting fluid, the pH stabilizer includes at least one of sodium bicarbonate, sodium carbonate, ammonium bicarbonate or ammonium carbonate; further preferably, in the cutting fluid, the pH stabilizer includes sodium bicarbonate, ammonium bicarbonate or a combination thereof; even further preferably, in the cutting fluid, the pH stabilizer is selected from sodium bicarbonate.

[0029] Preferably, in the cutting fluid, the defoaming agent is selected from an organosilane defoaming agent; further preferably, the organosilane defoaming agent is selected from dimethyl silicone oil.

[0030] Preferably, the mass fraction of composite ceramic powder in the cutting fluid is 10 to 40 parts; further preferably, the mass fraction of composite ceramic powder in the cutting fluid is 12 to 38 parts; further preferably, the mass fraction of composite ceramic powder in the cutting fluid is 14 to 34 parts; more preferably, the mass fraction of composite ceramic powder in the cutting fluid is 16 to 32 parts.

[0031] Preferably, the mass fraction of the thickener in the cutting fluid is 1 to 15 parts; further preferably, the mass fraction of the thickener in the cutting fluid is 2 to 14 parts; further preferably, the mass fraction of the thickener in the cutting fluid is 3 to 12 parts; more preferably, the mass fraction of the thickener in the cutting fluid is 5 to 10 parts.

[0032] Preferably, the mass fraction of the surfactant in the cutting fluid is 0.1 to 1 part; further preferably, the mass fraction of the surfactant in the cutting fluid is 0.2 to 0.9 part; further preferably, the mass fraction of the surfactant in the cutting fluid is 0.3 to 0.85 part; more preferably, the mass fraction of the surfactant in the cutting fluid is 0.4 to 0.8 part.

[0033] Preferably, the mass fraction of the pH stabilizer in the cutting fluid is 0.01 to 0.2 parts; further preferably, the mass fraction of the pH stabilizer in the cutting fluid is 0.02 to 0.15 parts; further preferably, the mass fraction of the pH stabilizer in the cutting fluid is 0.03 to 0.12 parts; more preferably, the mass fraction of the pH stabilizer in the cutting fluid is 0.05 to 0.1 parts.

[0034] Preferably, the mass fraction of the defoaming agent in the cutting fluid is 0.01 to 0.2 parts; further preferably, the mass fraction of the defoaming agent in the cutting fluid is 0.02 to 0.15 parts; further preferably, the mass fraction of the defoaming agent in the cutting fluid is 0.03 to 0.12 parts; more preferably, the mass fraction of the defoaming agent in the cutting fluid is 0.05 to 0.1 parts.

[0035] Preferably, the mass fraction of water in the cutting fluid is 40 to 90 parts; further preferably, the mass fraction of water in the cutting fluid is 45 to 86 parts; even more preferably, the mass fraction of water in the cutting fluid is 50 to 82 parts; more preferably, the mass fraction of water in the cutting fluid is 60 to 80 parts.

[0036] Preferably, the cutting fluid comprises the following components in the following mass ratios: 10 to 40 parts of composite ceramic powder, 1 to 15 parts of thickener, 0.1 to 1 part of surfactant, 0.01 to 0.2 parts of pH stabilizer, 0.01 to 0.2 parts of defoaming agent, and 40 to 90 parts of water.

[0037] Further preferably, the cutting fluid comprises the following components in the following mass ratios: 12 to 38 parts of composite ceramic powder, 2 to 14 parts of thickener, 0.2 to 0.9 parts of surfactant, 0.01 to 0.2 parts of pH stabilizer, 0.02 to 0.15 parts of defoaming agent, and 45 to 86 parts of water.

[0038] More preferably, the cutting fluid comprises the following components in the following mass ratios: 14 to 34 parts of composite ceramic powder, 3 to 12 parts of thickener, 0.3 to 0.85 parts of surfactant, 0.03 to 0.12 parts of pH stabilizer, 0.03 to 0.12 parts of defoaming agent, and 50 to 82 parts of water.

[0039] More preferably, the cutting fluid comprises the following components in the following mass ratios: 16 to 32 parts of composite ceramic powder, 5 to 10 parts of thickener, 0.4 to 0.8 parts of surfactant, 0.05 to 0.1 parts of pH stabilizer, 0.05 to 0.1 parts of defoaming agent, and 60 to 80 parts of water.

[0040] The second aspect of the present invention provides a method for preparing the cutting fluid described in the first aspect of the present invention, comprising the following steps: mixing a thickener, a surfactant, a pH stabilizer, a defoaming agent and water, and then adding composite ceramic powder and mixing to obtain the cutting fluid.

[0041] Preferably, in the preparation method, the manner of mixing the thickener, surfactant, pH stabilizer, defoamer and water includes at least one of stirring, oscillation or ultrasonic dispersion; further preferably, in the preparation method, the manner of mixing the thickener, surfactant, pH stabilizer, defoamer and water is selected from ultrasonic dispersion.

[0042] Preferably, the power of the ultrasonic dispersion is 50 to 1200 W; further preferably, the power of the ultrasonic dispersion is 100 to 1000 W; even more preferably, the power of the ultrasonic dispersion is 300 to 500 W.

[0043] Preferably, the ultrasonic dispersion time is 1 to 60 min; further preferably, the ultrasonic dispersion time is 2 to 40 min; even further preferably, the ultrasonic dispersion time is 5 to 15 min.

[0044] Preferably, in the preparation method, the manner of adding the composite ceramic powder for mixing includes at least one of stirring, oscillation or ultrasonic dispersion; further preferably, in the preparation method, the manner of adding the composite ceramic powder for mixing is selected from stirring.

[0045] Preferably, the stirring speed is 300 to 1000 rpm; further preferably, the stirring speed is 400 to 800 rpm; further preferably, the stirring speed is 500 to 700 rpm.

[0046] Preferably, the stirring time is 10 to 60 minutes; more preferably, the stirring time is 20 to 50 minutes; even more preferably, the stirring time is 25 to 40 minutes.

[0047] A third aspect of the present invention provides a use of the cutting fluid described in the first aspect of the present invention in cutting silicon nitride ceramic materials with a diamond wire saw.

[0048] In some specific embodiments of the present invention, the silicon nitride ceramic material meets at least one of the following requirements:

[0049] 1) The room temperature flexural strength is above 800MPa;

[0050] 2) Fracture toughness is 4.5MPa·m 1 / 2 above.

[0051] In the room temperature bending strength, the room temperature is 20-30°C; in a specific embodiment of the present invention, the room temperature is 24-26°C.

[0052] In some other specific embodiments of the present invention, the silicon nitride ceramic material meets the following two requirements:

[0053] 1) The room temperature flexural strength is above 800MPa;

[0054] 2) Fracture toughness is 4.5MPa·m 1 / 2 above.

[0055] In a specific embodiment of the present invention, the silicon nitride ceramic material meets the following two requirements:

[0056] 1) Room temperature flexural strength is 800~1300MPa;

[0057] 2) Fracture toughness is 4.5~7MPa·m 1 / 2 .

[0058] Preferably, in the application, the flow rate of the cutting fluid during the cutting is 3 to 6 mL / min; further preferably, in the application, the flow rate of the cutting fluid during the cutting is 3.5 to 5.5 mL / min; further preferably, in the application, the flow rate of the cutting fluid during the cutting is 4 to 5 mL / min.

[0059] Preferably, in the application, the reciprocating speed of the diamond wire saw during cutting is 15 to 40 m / s; further preferably, in the application, the reciprocating speed of the diamond wire saw during cutting is 18 to 35 m / s; even further preferably, in the application, the reciprocating speed of the diamond wire saw during cutting is 20 to 30 m / s.

[0060] Preferably, in the application, the feed speed of the diamond wire saw during cutting is 0.05 to 0.2 mm / min; further preferably, in the application, the feed speed of the diamond wire saw during cutting is 0.06 to 0.18 mm / min; even further preferably, in the application, the feed speed of the diamond wire saw during cutting is 0.08 to 0.15 mm / min.

[0061] Preferably, in the application, the tensioning force of the diamond wire saw during cutting is 20 to 50 N; further preferably, in the application, the tensioning force of the diamond wire saw during cutting is 25 to 45 N; even further preferably, in the application, the tensioning force of the diamond wire saw during cutting is 30 to 40 N.

[0062] Preferably, in the application, the average particle size of the diamond abrasive grains on the diamond wire saw during cutting is 20 to 40 μm; further preferably, in the application, the average particle size of the diamond abrasive grains on the diamond wire saw during cutting is 22 to 35 μm; even further preferably, in the application, the average particle size of the diamond abrasive grains on the diamond wire saw during cutting is 25 to 30 μm.

[0063] The beneficial effects of the present invention are as follows: the present invention designs a formula of the cutting fluid and adds a composite ceramic powder with a specific formula ratio and a specific particle size thereto, thereby achieving effective sharpening of the abrasive grains on the surface of the diamond wire saw, greatly improving the cutting efficiency, extending the service life of the wire saw, and reducing the cost of diamond wire saw cutting; and during the diamond wire saw cutting process, the composite ceramic powder rolls and scratches relative to the surface of the workpiece, which can remove grooves on the surface of the workpiece after the diamond wire saw cutting, thereby improving the surface quality of the cut sheet material and reducing the warping of the sheet material.

[0064] Specifically, compared with the prior art, the present invention has the following advantages:

[0065] 1) Existing cutting fluids used for diamond wire saws are primarily designed for cutting hard and brittle materials, while the cutting fluid provided by the present invention is specifically designed for cutting high-strength and high-toughness silicon nitride ceramics. The addition of a composite ceramic powder to the cutting fluid allows the composite ceramic powder to interact with the diamond abrasive grains electroplated on the diamond wire saw, sharpening the diamond abrasive grains. This allows for more efficient diamond wire saw cutting of silicon nitride ceramics, resulting in high material removal rates, high cutting efficiency, and a long wire saw life.

[0066] 2) The composite ceramic powder material (silicon carbide, boron carbide, and aluminum oxide) of the present invention has a specific formulation ratio and a specific particle size. The composite ceramic powder matches the particle size of the diamond abrasive grains on the diamond wire saw, which can improve the sharpness of the diamond abrasive grains electroplated on the surface of the diamond wire saw during the cutting process, significantly improving the efficiency and surface quality of the diamond wire saw in cutting silicon nitride ceramic materials.

[0067] 3) Driven by the diamond wire saw, or under the shear force and fluid dynamic pressure of the flowing cutting fluid, the composite ceramic powder in the cutting fluid will roll and scratch relative to the surface of the workpiece in the cutting area, thereby efficiently removing grooves that may exist on the surface of the workpiece after cutting with the diamond wire saw, improving the surface quality of the cut sheet material, and reducing the warping of the sheet material.

[0068] 4) The weight ratio of various additives in the cutting fluid is low, which reduces environmental pollution. Moreover, the cutting fluid can be recycled and reused multiple times after cutting, which reduces the cost of using and recycling the cutting fluid. The cutting fluid provided by the present invention has a wide range of applications in cutting silicon nitride ceramic materials with diamond wire saws. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 This is a microscopic morphology of the surface of the flaky silicon nitride ceramic obtained by cutting in Example 1.

[0070] Figure 2 This is a microscopic morphology of the surface of the sheet-like silicon nitride ceramic obtained by cutting in Example 2.

[0071] Figure 3 This is a microscopic morphology of the surface of the sheet-like silicon nitride ceramic obtained by cutting in Comparative Example 1.

[0072] Figure 4 This is a microscopic morphology of the surface of the sheet-like silicon nitride ceramic obtained by cutting in Comparative Example 2.

[0073] Figure 5 This is a microscopic morphology of the surface of the sheet-like silicon nitride ceramic obtained by cutting in comparative example 3.

[0074] Figure 6 This is a microscopic morphology of the surface of the sheet-like silicon nitride ceramic obtained by cutting in Comparative Example 4.

[0075] Figure 7 This is a microscopic morphology of the surface of the sheet-like silicon nitride ceramic obtained by cutting in comparative example 5. DETAILED DESCRIPTION

[0076] The content of the present invention is further described in detail below through specific examples. It should be understood that the following examples are only used to further illustrate the present invention and cannot be interpreted as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the principles set forth in the present invention all fall within the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples within a suitable range, and those skilled in the art can make selections within a suitable range through the description herein, and are not limited to the specific data exemplified below. The raw materials, reagents or devices used in the following examples and comparative examples, unless otherwise specified, can be obtained from conventional commercial sources, or can be obtained by existing known methods.

[0077] In the embodiments and comparative examples of the present invention, the fracture toughness of the silicon nitride ceramic material is 5.1 MPa·m 1 / 2 , the room temperature flexural strength is 1136.88MPa.

[0078] Example 1

[0079] A cutting fluid for diamond wire saw cutting, comprising the following components in percentage by mass:

[0080] 16wt.% composite ceramic powder (composed of silicon carbide, boron carbide and alumina ceramic powders in a mass ratio of 1:1:1, with a powder particle size of 18μm), 5wt.% thickener polyethylene glycol (Macklin 3837273, Mn400), 0.25wt.% nonionic surfactant nonylcycloethanol polyoxyethylene ether (Macklin 18637), 0.25wt.% anionic surfactant sodium dodecylbenzenesulfonate (Macklin 88092), 0.05wt.% pH stabilizer sodium bicarbonate (Macklin 82474) and 0.05wt.% defoaming agent dimethyl silicone oil (Macklin 81930), and the balance is deionized water.

[0081] The composite ceramic powder is prepared by a method comprising the following steps: placing silicon carbide, boron carbide and aluminum oxide ceramic powders (all with a powder particle size of 18 μm) in a mass ratio of 1:1:1 into a can body, and rolling mixing the powders on a rolling can machine at a rolling speed of 70 rpm for 2 hours to obtain a composite ceramic powder in which all components are evenly mixed.

[0082] This example also provides a method for preparing the cutting fluid, comprising the following steps:

[0083] A thickener, nonionic surfactant, anionic surfactant, pH stabilizer, defoamer, and deionized water were added to a beaker according to the mass fraction of the cutting fluid components. Ultrasonic dispersion was performed at 400 W for 10 minutes. The composite ceramic powder was then added to the beaker and stirred at 600 rpm for 30 minutes to prepare the cutting fluid.

[0084] The obtained cutting fluid is used to cut silicon nitride ceramics. The specific process is as follows:

[0085] A silicon nitride ceramic block with a length of 90 mm, a width of 90 mm and a thickness of 25 mm is bonded and fixed on the workpiece platform of the multi-wire saw cutting machine. The multi-wire saw wire mesh is parallel to the workpiece 90*25 mm. 2 The roller slot pitch was set to 0.8 mm, and the final product was 25 pieces per cut. An electroplated diamond wire saw with a wire diameter of 0.3 mm and an average diamond abrasive grit diameter of 28 μm was used. The multi-wire saw cutting parameters were set as follows: a reciprocating speed of 25 m / s, a feed rate of 0.1 mm / min, and a wire tension of 35 N. The single-wire cutting fluid flow rate was 4.5 ml / min.

[0086] The material removal rate of cutting silicon nitride ceramics for 30 minutes using the method of Example 1 is 78.75 mm 3 / min, the material removal rate of cutting for 150min is 69mm 3 / min; the average kerf width is 390μm; the average surface roughness of the silicon nitride ceramic sheet is 0.32μm, the average warpage is 0.05%, and the cutting yield is 89%. The surface micromorphology of the silicon nitride ceramic sheet obtained by cutting in Example 1 is as follows Figure 1 shown.

[0087] Example 2

[0088] A cutting fluid for diamond wire saw cutting, comprising the following components in percentage by mass:

[0089] 32 wt.% composite ceramic powder (composed of silicon carbide, boron carbide and aluminum oxide ceramic powders in a mass ratio of 1:1:1, with a powder particle size of 18 μm, prepared as in Example 1), 5 wt.% thickener polyethylene glycol (Macklin 3837273, Mn400), 0.25 wt.% nonionic surfactant nonylcycloethanol polyoxyethylene ether (Macklin 18637), 0.25 wt.% anionic surfactant sodium dodecylbenzenesulfonate (Macklin 88092), 0.05 wt.% pH stabilizer sodium bicarbonate (Macklin 82474) and 0.05 wt.% defoamer dimethyl silicone oil (Macklin 81930), with the balance being deionized water.

[0090] This example also provides a method for preparing the cutting fluid, comprising the following steps:

[0091] A thickener, nonionic surfactant, anionic surfactant, pH stabilizer, defoamer, and deionized water were added to a beaker according to the mass fraction of the cutting fluid components. Ultrasonic dispersion was performed at 400 W for 10 minutes. The composite ceramic powder was then added to the beaker and stirred at 600 rpm for 30 minutes to prepare the cutting fluid.

[0092] The obtained cutting fluid is used to cut silicon nitride ceramics. The specific process is as follows:

[0093] A silicon nitride ceramic block with a length of 90 mm, a width of 90 mm and a thickness of 25 mm is bonded and fixed on the workpiece platform of the multi-wire saw cutting machine. The multi-wire saw wire mesh is parallel to the workpiece 90*25 mm. 2 The roller slot pitch was set to 0.8 mm, and the final product was 25 pieces per cut. An electroplated diamond wire saw with a wire diameter of 0.3 mm and an average diamond abrasive grit diameter of 28 μm was used. The multi-wire saw cutting parameters were set as follows: a reciprocating speed of 25 m / s, a feed rate of 0.1 mm / min, and a wire tension of 35 N. The single-wire cutting fluid flow rate was 4.5 ml / min.

[0094] The material removal rate of cutting silicon nitride ceramics by the method of Example 2 for 30 minutes is 82.5 mm 3 / min, the material removal rate of cutting for 150min is 77.25mm 3 / min; the average kerf width is 392μm; the average surface roughness of the sheet silicon nitride ceramic is 0.30μm, the average warpage is 0.043%, and the cutting yield is 93%. The surface micromorphology of the sheet silicon nitride ceramic obtained by cutting in Example 2 is as follows Figure 2 shown.

[0095] Comparative Example 1

[0096] In this example, deionized water is used as the cutting fluid.

[0097] The cutting fluid is used to cut silicon nitride ceramics, and the specific process is the same as that in Example 1.

[0098] The material removal rate of cutting silicon nitride ceramics for 30 minutes by the method of Comparative Example 1 is 72.75 mm 3 / min, the material removal rate of cutting for 150min is 51mm 3 / min; the average kerf width is 398μm; the average surface roughness of the silicon nitride ceramic sheet is 0.41μm, the average warpage is 0.74%, and the cutting yield is 68%. Figure 3 shown.

[0099] Comparative Example 2

[0100] No cutting fluid was used in this case.

[0101] In this example, no cutting fluid is used in the process of cutting silicon nitride ceramics, and dry cutting is performed. The specific process is the same as that of Example 1.

[0102] The material removal rate of cutting silicon nitride ceramics for 30 minutes by the method of Comparative Example 2 is 75.75 mm 3 / min, the material removal rate of cutting for 150min is 65.25mm 3 / min; the average kerf width is 408μm; the average surface roughness of the sheet silicon nitride ceramic is 0.56μm, the average warpage is 1.1%, and the cutting yield is 43%. Figure 4 shown.

[0103] Comparative Example 3

[0104] In this example, extreme pressure coolant (DK-760C5, Kozer Lubricant Co., Ltd.) was used as the cutting fluid.

[0105] The cutting fluid is used to cut silicon nitride ceramics, and the specific process is the same as that in Example 1.

[0106] The material removal rate of cutting silicon nitride ceramics for 30 minutes by the method of Comparative Example 3 is 77.25 mm 3 / min, the material removal rate of cutting for 150min is 60mm 3 / min; the average kerf width is 396μm; the average surface roughness of the silicon nitride ceramic sheet is 0.26μm, the average warpage is 0.23%, and the cutting yield is 79%. Figure 5 shown.

[0107] Comparative Example 4

[0108] The cutting fluid of this example differs from that of Example 1 in that the composition of the composite ceramic powder is different: the composite ceramic powder of this example only includes silicon carbide ceramic powder, and the powder particle size is 18 μm.

[0109] The cutting fluid is used to cut silicon nitride ceramics, and the specific process is the same as that in Example 1.

[0110] The material removal rate of cutting silicon nitride ceramics for 30 minutes by the method of Comparative Example 4 is 76.8 mm 3 / min, the material removal rate of cutting for 150min is 67mm 3 / min; the average kerf width is 398μm; the average surface roughness of the sheet silicon nitride ceramic is 0.37μm, the average warpage is 0.11%, and the cutting yield is 82%. Figure 6 shown.

[0111] Comparative Example 5

[0112] The cutting fluid of this example differs from that of Example 1 in that the particle size of the composite ceramic powder is different. In the composite ceramic powder of this example, the particle size of silicon carbide, boron carbide, and aluminum oxide is all 50 μm.

[0113] The cutting fluid is used to cut silicon nitride ceramics, and the specific process is the same as that in Example 1.

[0114] The material removal rate of cutting silicon nitride ceramics for 30 minutes by the method of comparative example 5 is 76 mm 3 / min, the material removal rate of cutting for 150min is 62mm 3 / min; the average kerf width is 404μm; the average surface roughness of the sheet silicon nitride ceramic is 0.5μm, the average warpage is 0.56%, and the cutting yield is 70%. Figure 7 shown.

[0115] From the above, it can be seen that the present invention designs the formula of the cutting fluid and adds composite ceramic powder thereto to achieve effective sharpening of the abrasive grains on the surface of the diamond wire saw, greatly improving the cutting efficiency, extending the service life of the wire saw, and reducing the cutting cost of the diamond wire saw cutting silicon nitride ceramics; and during the diamond wire saw cutting process, the composite ceramic powder rolls and scratches relative to the workpiece surface, which can remove the grooves on the workpiece surface after the diamond wire saw cuts the silicon nitride ceramics, thereby improving the surface quality of the cut sheet silicon nitride ceramics and reducing the warping of the sheet silicon nitride ceramics.

[0116] While existing cutting fluids for diamond wire saws are primarily designed for cutting hard and brittle materials, the cutting fluid provided by this invention is specifically designed for the high-strength and high-toughness silicon nitride ceramic material. The addition of composite ceramic powder to the cutting fluid allows the interaction of the composite ceramic powder with the diamond abrasive grains electroplated on the diamond wire saw, sharpening the diamond abrasive grains. This allows the diamond wire saw to more efficiently cut high-strength and high-toughness materials, resulting in high material removal rates, high cutting efficiency, and a long wire saw life.

[0117] The composite ceramic powder material (silicon carbide, boron carbide and aluminum oxide) of the present invention has a specific formula ratio and a specific particle size. The composite ceramic powder matches the particle size of the diamond abrasive grains on the diamond wire saw, which can improve the sharpness of the diamond abrasive grains electroplated on the surface of the diamond wire saw during the cutting process, and significantly improve the efficiency and surface quality of the diamond wire saw in cutting silicon nitride ceramics.

[0118] Driven by the diamond wire saw, or under the action of the shear force and fluid dynamic pressure of the flowing cutting fluid, the composite ceramic powder in the cutting fluid will roll and scratch relative to the surface of the workpiece in the cutting area, thereby efficiently removing grooves that may exist on the workpiece surface after the diamond wire saw cuts the silicon nitride ceramic, improving the surface quality of the cut silicon nitride sheet ceramic, and reducing the warping of the silicon nitride sheet ceramic.

[0119] The cutting fluid contains a relatively low percentage of additives, which reduces environmental pollution. Furthermore, the cutting fluid can be recycled and reused multiple times after cutting, reducing both the cost of using and recycling the cutting fluid. The cutting fluid provided by the present invention has a wide range of applications in cutting silicon nitride ceramic materials with diamond wire saws.

Claims

1. A cutting fluid for diamond wire saw cutting, characterized in that: The invention comprises the following components in parts by mass: 10 to 40 parts of composite ceramic powder, 1 to 15 parts of thickener, 0.1 to 1 part of surfactant, 0.01 to 0.2 parts of pH stabilizer, 0.01 to 0.2 parts of defoaming agent, and 40 to 100 parts of water; the composite ceramic powder comprises silicon carbide, boron carbide and aluminum oxide; the average particle size of each component of the composite ceramic powder is independently 10 to 40 μm; the mass percentage of the composite ceramic powder in the cutting fluid is 10 to 40%; the mass ratio of the silicon carbide, boron carbide and aluminum oxide is (0.1 to 5): (0.1 to 5): 1; the thickener is selected from polyether polyol; and the average molecular weight of the polyether polyol is 300 to 800.

2. The cutting fluid according to claim 1, characterized in that: The surfactant includes a nonionic surfactant, an anionic surfactant or a combination thereof; The nonionic surfactant includes at least one of nonyl cycloethanol polyoxyethylene ether, polyethylene glycol monooctylphenyl ether or nonylphenol polyoxyethylene ether; The anionic surfactant includes sodium dodecylbenzenesulfonate, polyacrylamide or a combination thereof.

3. The cutting fluid according to claim 1, characterized in that: The pH stabilizer includes at least one of sodium bicarbonate, sodium carbonate, ammonium bicarbonate or ammonium carbonate; And / or, the defoaming agent is selected from organosilane defoaming agents.

4. The method for preparing the cutting fluid according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: mixing a thickener, a surfactant, a pH stabilizer, a defoamer and water, and then adding composite ceramic powder and mixing to obtain the cutting fluid.

5. Use of the cutting fluid according to any one of claims 1 to 3 in cutting silicon nitride ceramic materials with a diamond wire saw.

6. The application according to claim 5, characterized in that: The silicon nitride ceramic material meets at least one of the following requirements: 1) The room temperature flexural strength is above 800MPa; 2) Fracture toughness is 4.5MPa·m 1 / 2 above.

7. The use according to claim 5, characterized in that The flow rate of the cutting fluid during the cutting is 3 to 6 mL / min.

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