Grinding fluid for machining high cobalt content cemented carbide and method for preparing the same

Abstract

The present application relates to the technical field of grinding aids, and discloses a grinding fluid for processing hard alloy with high cobalt content and a preparation method thereof, which comprises 10-15 parts of diglycol amine, 8-12 parts of organic acid rust inhibitor, 15-20 parts of high polymer polyether, 1.5-2.5 parts of cobalt inhibitor, 3-5 parts of non-ionic surfactant and 45-55 parts of deionized water, wherein the cobalt inhibitor is a composition of benzotriazole and borate ester with a mass ratio of 1:(3-5); the method comprises the following steps: adding deionized water into diglycol amine, organic acid rust inhibitor, high polymer polyether, benzotriazole, borate ester, non-ionic surfactant, defoaming agent and preservative to obtain a base fluid; cooling the base fluid to room temperature, adding microcapsule cobalt repair material under stirring, continuously stirring until the microcapsule cobalt repair material is uniformly dispersed in the base fluid; adding deionized water to the total mass, and finally filtering to obtain the grinding fluid. When the grinding fluid is used for grinding processing of hard alloy containing cobalt, the precipitation of cobalt element can be reduced, and the influence on the mechanical properties of the hard alloy containing cobalt can be avoided.

Description

Technical Field

[0001] This invention belongs to the field of grinding aids technology, and particularly relates to a grinding fluid for machining high cobalt content cemented carbide and its preparation method. Background Technology

[0002] With its superior hardness, high strength, and excellent high-temperature resistance, cemented carbide occupies an indispensable position in many key fields such as tool manufacturing and mold processing, becoming an important basic material driving the development of modern industry. Among the many types of cemented carbide, cobalt-containing cemented carbide (such as tungsten-cobalt alloys) stands out. The cobalt element acts as a binder, playing a decisive and crucial role in the mechanical properties of the material. It is like a "binder," tightly binding the hard phase together and giving cobalt-containing cemented carbide unique comprehensive properties.

[0003] However, a thorny problem urgently needs to be solved in the grinding process of cobalt-containing cemented carbide. When an unsuitable grinding fluid is used, cobalt is easily precipitated from the alloy. This phenomenon has many harmful effects: from the perspective of the material itself, the precipitation of cobalt causes the cemented carbide structure to become loose, and its originally excellent mechanical properties are greatly reduced. This seriously affects the sharpness and wear resistance of cutting tools, as well as the precision and service life of molds, thereby increasing production costs and the defect rate in the production process. From the perspective of the environment and human health, the precipitated cobalt may not only cause health problems such as skin allergies for operators, but also pollute the surrounding environment, which does not meet the increasingly stringent environmental protection requirements.

[0004] Currently, while some grinding fluids on the market possess certain cooling and lubrication properties, meeting the basic requirements of grinding to some extent, they fall short in addressing the critical issue of inhibiting cobalt precipitation, failing to effectively solve the core pain point in grinding cobalt-containing cemented carbides. More seriously, some grinding fluids contain harmful components such as sodium nitrite, which not only pose potential threats to human health but also cause long-term adverse environmental impacts, making it difficult to simultaneously meet the high standards of both environmental protection and processing quality. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a grinding fluid for machining high cobalt content cemented carbide and a method for preparing the same, which can reduce the precipitation of cobalt element during grinding of cobalt-containing cemented carbide and avoid affecting the mechanical properties of cobalt-containing cemented carbide.

[0006] The present invention solves the above-mentioned technical problems through the following technical means:

[0007] In a first aspect, the present invention discloses a grinding fluid for machining high cobalt content cemented carbide, comprising, by mass parts, 10-15 parts of diethylene glycolamine, 8-12 parts of organic acid rust inhibitor, 15-20 parts of high molecular weight polyether, 1.5-2.5 parts of cobalt inhibitor, 3-5 parts of nonionic surfactant, and 45-55 parts of deionized water, wherein the cobalt inhibitor is a composition of benzotriazole and borate ester, and the mass ratio of benzotriazole to borate ester is 1:(3-5).

[0008] In this technical solution, deionized water serves as a carrier to ensure the diluent is colorless and transparent; diethylene glycol amine provides an alkaline environment and has weak cobalt complexation ability, thus inhibiting precipitation; organic acid rust inhibitors react with amines to form water-soluble soaps, providing excellent rust prevention; high molecular weight polyethers provide extreme pressure lubrication, are sulfur-free and chlorine-free, have good biodegradability, and meet environmental protection requirements; the composition of benzotriazole and borate esters in the cobalt inhibitor serves as the cobalt-inhibiting core, with benzotriazole forming a passivation film on the cobalt surface, and borate esters synergistically inhibiting cobalt precipitation and buffering pH; nonionic surfactants can improve the settling properties of grinding debris and prevent workpiece scratches.

[0009] Furthermore, it also includes 0.5-1.0 parts of microcapsule cobalt repair material, wherein the microcapsule cobalt repair material uses polyacrylic acid as the shell material and encapsulates nano-sized tetraethyl orthosilicate and auxiliary film-forming agent inside.

[0010] In this technical solution, the carboxyl groups abundant in the polyacrylic acid molecular chain exhibit extremely high selectivity and affinity for cobalt ions. When trace amounts of cobalt ions dissolve in the grinding fluid, they are rapidly captured and bonded to the microcapsule shell. pH-triggered release and in-situ reaction: Minor pH changes caused by localized high temperatures and friction in the grinding zone, or conformational changes in the shell triggered by the cobalt ion bonding itself, trigger the swelling or degradation of the microcapsule shell material, releasing the encapsulated nano-tetraethyl orthosilicate. The released tetraethyl orthosilicate hydrolyzes on the workpiece surface to generate active silanol groups (-SiOH). These silanol groups condense with the metallic hydroxyl groups (M-OH) on the workpiece surface and react with the captured cobalt ions, forming an inorganic-organic hybrid protective film with cobalt silicate as the main component near the in-situ dissolution of cobalt ions. This film is dense, hard, and firmly bonded to the substrate, achieving dynamic repair.

[0011] Furthermore, the preparation method of the microcapsule cobalt remediation material includes the following steps:

[0012] Oil phase preparation: Tetraethoxysilane (TEOS), hexadecyltrimethylammonium bromide (CTAB) and cyclohexane are added to a reaction vessel and stirred until completely dissolved to form a homogeneous and transparent oil phase solution; the first portion of deionized water is slowly added dropwise to the oil phase solution and stirring is continued for 20-40 minutes to obtain the oil phase solution;

[0013] Aqueous phase preparation: In a reaction vessel, acrylic acid and methylenebisacrylamide (MBA) are dissolved in a second portion of deionized water, the pH is adjusted to 4.0-5.0 with ammonia, and then ammonium persulfate (APS) is added and stirred until completely dissolved to obtain an aqueous phase solution;

[0014] Construction of the core-shell structure: The aqueous solution is slowly poured into the oil solution and emulsified for 3-7 minutes under high-speed stirring in an ice-water bath to form a stable water / oil emulsion; the emulsion is reacted at 65-75℃ under nitrogen protection for 5-7 hours; in this way, the acrylic acid in the aqueous phase polymerizes at the interface to form a cross-linked PAA network shell, while encapsulating the oil droplets containing TEOS, forming PAA / TEOS core-shell microcapsules.

[0015] Post-processing and activation: After the reaction was completed, the emulsion was cooled to room temperature, an equal volume of acetone was added to break the emulsion, the solid product was collected by centrifugation, and the microcapsule cobalt repair product was obtained after washing and drying.

[0016] Furthermore, the dried microcapsule cobalt repair material is heat-treated at 90-110℃ for 40-60 minutes. This setup in this technical solution causes slight pre-hydrolysis of the internal TEOS, improving its response sensitivity in the grinding fluid.

[0017] Further, by mass fractions, the tetraethoxysilane comprises 8-12 parts, hexadecyltrimethylammonium bromide comprises 0.4-0.6 parts, cyclohexane comprises 25-35 parts, the first part of deionized water comprises 2.5-2.5 parts; acrylic acid comprises 4-6 parts, methylenebisacrylamide comprises 0.2-0.3 parts, the second part of deionized water comprises 45-50 parts, and ammonium persulfate comprises 0.1-0.2 parts.

[0018] Furthermore, the rust inhibitor is a combination of sebacic acid and dodecanoic acid in a mass ratio of 1:(2-3).

[0019] Furthermore, the nonionic surfactant is a fatty alcohol polyoxyethylene ether.

[0020] Furthermore, it also includes 0.2-0.3 parts of defoamer and 0.2-0.3 parts of preservative, wherein the defoamer is polyether-modified silicone and the preservative is 1,2-benzisothiazolin-3-one.

[0021] Secondly, the present invention also discloses a method for preparing the above-mentioned grinding fluid for machining high cobalt content cemented carbide, comprising the following steps:

[0022] In a container, deionized water is added according to the formula, followed by diethylene glycolamine, organic acid rust inhibitor, high molecular weight polyether, benzotriazole, borate ester, nonionic surfactant, defoamer and preservative to obtain the base solution.

[0023] Cool the base solution to room temperature, and slowly add the microcapsule cobalt repair agent while stirring, until the microcapsule cobalt repair agent is evenly dispersed in the base solution.

[0024] After stirring evenly, dilute to the total mass with deionized water, and finally filter to obtain the grinding fluid.

[0025] Furthermore, the stirring speed is 80-120 r / min, and the stirring time is 30-60 minutes.

[0026] In summary, this application has the following beneficial effects:

[0027] 1. This invention forms a chemical adsorption passivation film on the cobalt surface using benzotriazole (BTA) and provides pH buffering and auxiliary protection using borate esters, strongly inhibiting the dissolution of cobalt ions at the source, which constitutes the first basic line of defense. In addition, this invention also introduces cobalt ion responsive polymer microcapsules. The polyacrylic acid (PAA) shell can specifically capture trace amounts of dissolved cobalt ions. When triggered by local environmental changes (pH, temperature) in the grinding zone, the internally encapsulated nano-silica esters (TEOS hydrolysis products) are released in situ. The released active components can react with the captured cobalt ions and the workpiece surface to form a dense cobalt silicate hybrid protective film, realizing the dynamic repair and strengthening of corrosion points. Throughout the process, the BTA / boronic acid ester system and the microcapsule repair system do not work independently, but rather work synergistically to enhance each other. The BTA film provides initial protection and reduces the initial dissolution of cobalt; the microcapsules treat the cobalt ions that may be precipitated and transform harmful cobalt ions into a beneficial protective layer. This integrated technical approach can avoid affecting the mechanical properties of cobalt-containing cemented carbide during grinding.

[0028] 2. This invention utilizes the capture-repair function of microcapsules to reduce cobalt leaching to near zero over time, and even enhances the surface using the leached material, exceeding conventional expectations for grinding fluid functionality. Traditional additives are continuously consumed during the protective process, while the microcapsules of this invention, while being consumed, produce byproducts that slightly improve the surface hardness and wear resistance of the workpiece, achieving in-situ performance enhancement. Therefore, this invention achieves extreme cobalt suppression while being environmentally friendly as its formula is free of harmful substances such as sodium nitrite, sulfur, and chlorine; the high-molecular-weight polyether provides excellent lubrication; and the organic acid amine soap system ensures rust prevention. The product achieves a high level in both core cobalt suppression function and basic performance, meeting the multiple demands of efficient, environmentally friendly, and high-quality processing. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment describes a method for preparing microcapsule cobalt repair material, including the following steps:

[0032] 1. Oil phase preparation: In a dry reaction vessel, add tetraethoxysilane, hexadecyltrimethylammonium bromide, and cyclohexane according to the mass parts shown in Table 1, and stir until completely dissolved to form a homogeneous and transparent oil phase solution. Subsequently, slowly add the first portion of deionized water dropwise while stirring, and continue stirring for 20 minutes to obtain the final oil phase solution.

[0033] 2. Preparation of the aqueous phase: In another container, dissolve acrylic acid and methylenebisacrylamide in the second part of deionized water according to the mass ratios shown in Table 1. Adjust the pH of this mixture to 4.0 with ammonia. Then add ammonium persulfate and stir until completely dissolved to obtain the aqueous phase solution.

[0034] 3. Construction of the core-shell structure: Under ice-water bath conditions, the aqueous phase solution was slowly poured into the oil phase solution. Emulsification was performed using a high-speed homogenizer at 10,000 rpm for 3 minutes to form a stable water / oil (W / O) emulsion. The resulting emulsion was transferred to a three-necked flask and reacted at 65°C under nitrogen protection for 5 hours.

[0035] 4. Post-processing: After the reaction is complete, cool the emulsion to room temperature. Add an equal volume of acetone to break the emulsion. Centrifuge at 8000 rpm for 10 minutes and collect the solid product. Wash three times alternately with anhydrous ethanol and deionized water.

[0036] 5. Drying and Activation: The washed solid was dried in a vacuum drying oven at 40℃ for 10 hours. Subsequently, the dried product was reacted at 65℃ under nitrogen protection for 5 hours to obtain a white powdery microcapsule cobalt repair material. The dried microcapsule cobalt repair material was then heat-treated at 90℃ for 40 minutes.

[0037] Example 2

[0038] This embodiment describes a second method for preparing microcapsule cobalt repair materials, including the following steps:

[0039] 1. Oil phase preparation: In a dry reaction vessel, add tetraethoxysilane, hexadecyltrimethylammonium bromide, and cyclohexane according to the mass parts shown in Table 1, and stir until completely dissolved to form a homogeneous and transparent oil phase solution. Subsequently, slowly add the first portion of deionized water dropwise while stirring, and continue stirring for 30 minutes to obtain the final oil phase solution.

[0040] 2. Preparation of the aqueous phase: In another container, dissolve acrylic acid and methylenebisacrylamide in the second part of deionized water according to the mass ratios shown in Table 1. Adjust the pH of this mixture to 4.5 with ammonia. Then add ammonium persulfate and stir until completely dissolved to obtain the aqueous phase solution.

[0041] 3. Construction of the core-shell structure: Under ice-water bath conditions, the aqueous phase solution was slowly poured into the oil phase solution. Emulsification was performed using a high-speed homogenizer at 10,000 rpm for 5 minutes to form a stable water / oil (W / O) emulsion. The resulting emulsion was transferred to a three-necked flask and reacted at 70°C under nitrogen protection for 6 hours.

[0042] 4. Post-processing: After the reaction is complete, cool the emulsion to room temperature. Add an equal volume of acetone to break the emulsion. Centrifuge at 8000 rpm for 10 minutes and collect the solid product. Wash three times alternately with anhydrous ethanol and deionized water.

[0043] 5. Drying and Activation: The washed solid was dried in a vacuum drying oven at 45°C for 12 hours. Subsequently, the dried product was reacted at 70°C under nitrogen protection for 6 hours to obtain a white powdery microcapsule cobalt repair compound. The dried microcapsule cobalt repair compound was then heat-treated at 100°C for 50 minutes.

[0044] Example 3

[0045] This embodiment describes method three for preparing microcapsule cobalt repair materials, including the following steps:

[0046] 1. Oil phase preparation: In a dry reaction vessel, add tetraethoxysilane, hexadecyltrimethylammonium bromide, and cyclohexane according to the mass parts shown in Table 1, and stir until completely dissolved to form a homogeneous and transparent oil phase solution. Subsequently, slowly add the first portion of deionized water dropwise while stirring, and continue stirring for 40 minutes to obtain the final oil phase solution.

[0047] 2. Preparation of the aqueous phase: In another container, dissolve acrylic acid and methylenebisacrylamide in the second part of deionized water according to the mass ratios shown in Table 1. Adjust the pH of this mixture to 5.0 with ammonia. Then add ammonium persulfate and stir until completely dissolved to obtain the aqueous phase solution.

[0048] 3. Construction of the core-shell structure: Under ice-water bath conditions, the aqueous phase solution was slowly poured into the oil phase solution. Emulsification was performed using a high-speed homogenizer at 10,000 rpm for 7 minutes to form a stable water / oil (W / O) emulsion. The resulting emulsion was transferred to a three-necked flask and reacted at 75°C under nitrogen protection for 7 hours.

[0049] 4. Post-processing: After the reaction is complete, cool the emulsion to room temperature. Add an equal volume of acetone to break the emulsion. Centrifuge at 8000 rpm for 10 minutes and collect the solid product. Wash three times alternately with anhydrous ethanol and deionized water.

[0050] 5. Drying and Activation: The washed solid was dried in a vacuum drying oven at 50°C for 14 hours. Subsequently, the dried product was reacted at 75°C under nitrogen protection for 7 hours to obtain a white powdery microcapsule cobalt repair compound. The dried microcapsule cobalt repair compound was then heat-treated at 110°C for 60 minutes.

[0051] Table 1. Raw materials and proportions used in Examples 1-3

[0052]

[0053] Example 4

[0054] This embodiment is a method for preparing a grinding fluid for machining high cobalt content cemented carbide, including the following steps:

[0055] 1. Preparation of the base solution: In a reaction vessel, add 45 kg of deionized water. At room temperature, add 10 kg of diethylene glycolamine sequentially and stir to dissolve. Then add 8 kg of rust inhibitor and stir to dissolve. Subsequently, add 15 kg of high molecular weight polyether, 1.5 kg of cobalt inhibitor, and 3 kg of fatty alcohol polyoxyethylene ether, and stir until benzotriazole is completely dissolved and the system is homogeneous and transparent. Finally, add 0.2 kg of polyether-modified silicone and 0.2 kg of 1,2-benzisothiazolin-3-one, and stir for 10 minutes to obtain the base solution. In this embodiment, the rust inhibitor is a composition of sebacic acid and dodecanoic acid in a mass ratio of 1:2, and the cobalt inhibitor is a composition of benzotriazole and borate ester in a mass ratio of 1:3.

[0056] 2. Adding microcapsules: Cool the base solution to room temperature (below 25°C). Slowly add 0.5 kg of the microcapsule powder prepared in Example 1 while stirring at a low speed of 80 r / min for 30 minutes.

[0057] 3. Volume Adjustment and Discharge: After the microcapsules are evenly dispersed, rinse the container wall with a small amount of deionized water and combine the solutions. Adjust the volume to the total mass. Filter to obtain the grinding fluid concentrate.

[0058] 4. Preparation of working solution: Dilute the concentrate with deionized water at a ratio of 1:19 (volume ratio) to obtain a 5% working solution.

[0059] Example 5

[0060] 1. Preparation of the base solution: Add 50 kg of deionized water to a reaction vessel. At room temperature, add 12.5 kg of diethylene glycolamine sequentially and stir to dissolve. Then add 10 kg of rust inhibitor and stir to dissolve. Subsequently, add 17.5 kg of high molecular weight polyether, 2 kg of cobalt inhibitor, and 4 kg of fatty alcohol polyoxyethylene ether, and stir until benzotriazole is completely dissolved and the system is homogeneous and transparent. Finally, add 0.25 kg of polyether-modified silicone and 0.25 kg of 1,2-benzisothiazolin-3-one, and stir for 10 minutes to obtain the base solution. In this embodiment, the rust inhibitor is a composition of sebacic acid and dodecanoic acid in a mass ratio of 1:2.5, and the cobalt inhibitor is a composition of benzotriazole and borate ester in a mass ratio of 1:4.

[0061] 2. Adding microcapsules: Cool the base solution to room temperature (below 25°C). Slowly add 0.75 kg of the microcapsule powder prepared in Example 1 while stirring at a low speed of 100 r / min for 45 minutes.

[0062] 3. Volume Adjustment and Discharge: After the microcapsules are evenly dispersed, rinse the container wall with a small amount of deionized water and combine the solutions. Adjust the volume to the total mass. Filter to obtain the grinding fluid concentrate.

[0063] 4. Preparation of working solution: Dilute the concentrate with deionized water at a ratio of 1:19 (volume ratio) to obtain a 5% working solution.

[0064] Example 6

[0065] 1. Preparation of the base solution: In a reaction vessel, add 55 kg of deionized water. At room temperature, add 15 kg of diethylene glycolamine sequentially and stir to dissolve. Then add 12 kg of rust inhibitor and stir to dissolve. Subsequently, add 20 kg of high molecular weight polyether, 2.5 kg of cobalt inhibitor, and 5 kg of fatty alcohol polyoxyethylene ether, and stir until benzotriazole is completely dissolved and the system is homogeneous and transparent. Finally, add 0.3 kg of polyether-modified silicone and 0.3 kg of 1,2-benzisothiazolin-3-one, and stir for 10 minutes to obtain the base solution. In this embodiment, the rust inhibitor is a composition of sebacic acid and dodecanoic acid in a mass ratio of 1:3, and the cobalt inhibitor is a composition of benzotriazole and borate ester in a mass ratio of 1:5.

[0066] 2. Adding microcapsules: Cool the base solution to room temperature (below 25°C). Slowly add 1.0 kg of the microcapsule powder prepared in Example 1 while stirring at a low speed of 120 r / min for 60 minutes.

[0067] 3. Volume Adjustment and Discharge: After the microcapsules are evenly dispersed, rinse the container wall with a small amount of deionized water and combine the solutions. Adjust the volume to the total mass. Filter to obtain the grinding fluid concentrate.

[0068] 4. Preparation of working solution: Dilute the concentrate with deionized water at a ratio of 1:19 (volume ratio) to obtain a 5% working solution.

[0069] Example 7

[0070] This example is a long-term performance verification example.

[0071] The formulation and preparation are the same as in Example 5.

[0072] Special tests: In addition to routine tests, dynamic monitoring of cobalt precipitation for up to 90 days and analysis of the surface morphology and composition of the workpiece after grinding were added to verify the active repair and performance enhancement effects of the present invention.

[0073] Comparative Example 1

[0074] The only difference between this embodiment and embodiment 5 is that this embodiment uses a base solution that does not contain microcapsules or cobalt inhibitors.

[0075] Comparative Example 2

[0076] The only difference between this embodiment and Example 5 is that this embodiment does not contain microcapsules and only contains benzotriazole, a cobalt inhibitor.

[0077] Comparative Example 3

[0078] The only difference between this embodiment and Example 5 is that this embodiment does not contain microcapsules and only contains borate esters in the cobalt inhibitor.

[0079] Comparative Example 4

[0080] The only difference between this embodiment and Example 5 is that this embodiment does not contain microcapsules, but contains benzotriazole and borate esters as cobalt inhibitors.

[0081] Comparative Example 5

[0082] The only difference between this embodiment and embodiment 5 is that this embodiment contains only microcapsules and no cobalt inhibitor.

[0083] The grinding fluids prepared in Examples 4-6 and Comparative Examples 1-7 were diluted to a concentration of 5% and tested. The test methods and key technical evaluation indicators are shown in Table 2 below:

[0084] Table 2. Performance Index Results of Each Embodiment

[0085]

[0086] Based on the experimental data in the table above, it can be seen that:

[0087] 1. Comparison of Comparative Example 4 with Comparative Examples 2 & 3 shows that the cobalt precipitation of Comparative Example 4 (BTA + borate ester) (0.8 ppm) is significantly lower than the simple summation of Comparative Example 2 (3.5 ppm) and Comparative Example 3 (2.8 ppm), proving that the two have a synergistic cobalt suppression effect and constitute a reliable first line of defense.

[0088] 2. A comparison between Example 5 and Comparative Example 4 shows that, based on the same BTA + borate ester, the addition of microcapsules in Example 5 further reduces the amount of cobalt leaching (<0.5 ppm), and dynamic data from Example 7 shows that its content approaches 0 over time. This completely surpasses the static effect of the traditional inhibition concept, achieving dynamic repair and self-purification, and reaching unexpected technical effects.

[0089] 3. In Comparative Example 5, relying solely on microcapsules, although there were signs of repair in the later stages (the amount of precipitation decreased slightly), the initial defense and the final effect were not as good as the complete system, which proved the necessity and superiority of the synergistic effect of the dual mechanism of "passive inhibition" and "active repair".

[0090] 4. The cobalt precipitation in Examples 5 and 7 is consistently <1 ppm, reaching an industry-leading level.

[0091] 5. The lubrication performance (P value, PD value) of Examples 5-7 is better than that of Comparative Example 4, and there is a further increasing trend with the addition of microcapsules and the extension of time (Example 7). This suggests that the repair products of the microcapsules may improve the state of the friction interface and achieve the gain effect of strengthening the workpiece surface during processing.

[0092] 6. All embodiments of the present invention fully meet or exceed the assessment indicators in terms of rust prevention, environmental protection (free from sodium nitrite, etc.), and appearance, proving that the present invention can solve the core objective of cobalt suppression without sacrificing any basic performance, and achieve a significant improvement in comprehensive performance.

[0093] In summary, the comparison of the above embodiments and test data demonstrates that this invention, through the combination of a dual mechanism of "benzotriazole / boronate synergistic passivation" and "intelligent response repair of microencapsulated cobalt repair material," not only achieves highly efficient suppression of cobalt precipitation in high-cobalt-content cemented carbide (<0.5 ppm), but also produces unexpected technical effects such as self-enhancing cobalt suppression over time and simultaneous improvement in lubrication performance. Furthermore, while achieving ultimate cobalt suppression, the formulation of this invention is free of harmful substances such as sodium nitrite, sulfur, and chlorine, making it environmentally friendly; the high-molecular-weight polyether provides excellent lubrication; and the organic acid amine soap system ensures rust prevention. The product achieves a high level in both core cobalt suppression function and basic performance, meeting the multiple requirements of efficient, environmentally friendly, and high-quality processing.

[0094] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.

Claims

1. A grinding fluid for machining high-cobalt-content cemented carbide, characterized in that, The composition, by weight, includes 10-15 parts of diethylene glycolamine, 8-12 parts of organic acid rust inhibitor, 15-20 parts of high molecular weight polyether, 1.5-2.5 parts of cobalt inhibitor, 3-5 parts of nonionic surfactant, and 45-55 parts of deionized water. The cobalt inhibitor is a composition of benzotriazole and borate ester, wherein the mass ratio of benzotriazole to borate ester is 1:(3-5).

2. The grinding fluid for machining high-cobalt-content cemented carbide according to claim 1, characterized in that, It also includes 0.5-1.0 parts of microcapsule cobalt repair material, wherein the microcapsule cobalt repair material uses polyacrylic acid as the shell material and encapsulates nano-sized tetraethyl orthosilicate and auxiliary film-forming agent inside.

3. The grinding fluid for machining high-cobalt-content cemented carbide according to claim 2, characterized in that, The preparation method of the microcapsule cobalt remediation material includes the following steps: Oil phase preparation: Tetraethoxysilane, hexadecyltrimethylammonium bromide and cyclohexane are added to a reaction vessel and stirred until completely dissolved to form an oil phase solution; the first portion of deionized water is slowly added dropwise to the oil phase solution and stirring is continued for 20-40 minutes to obtain the oil phase solution; Aqueous phase preparation: In a reaction vessel, acrylic acid and methylenebisacrylamide are dissolved in a second portion of deionized water, the pH is adjusted to 4.0-5.0, ammonium persulfate is added, and the mixture is stirred until completely dissolved to obtain an aqueous solution; Constructing a core-shell structure: Slowly pour the aqueous solution into the oil solution, emulsify under high-speed stirring in an ice-water bath for 3-7 minutes to form a stable water / oil emulsion; react the emulsion at 65-75℃ under nitrogen protection for 5-7 hours. Post-processing and activation: After the reaction was completed, the emulsion was cooled to room temperature, an equal volume of acetone was added to break the emulsion, the solid product was collected by centrifugation, and the microcapsule cobalt repair product was obtained after washing and drying.

4. The grinding fluid for machining high-cobalt-content cemented carbide according to claim 3, characterized in that, The dried microcapsule cobalt repair material was heat-treated at 90-110℃ for 40-60 minutes.

5. The grinding fluid for machining high-cobalt-content cemented carbide according to claim 1, characterized in that, By mass fractions, the tetraethoxysilane comprises 8-12 parts, hexadecyltrimethylammonium bromide comprises 0.4-0.6 parts, cyclohexane comprises 25-35 parts, the first part is deionized water comprises 2.5-2.5 parts; acrylic acid comprises 4-6 parts, methylenebisacrylamide comprises 0.2-0.3 parts, the second part is deionized water comprises 45-50 parts, and ammonium persulfate comprises 0.1-0.2 parts.

6. The grinding fluid for machining high-cobalt-content cemented carbide according to claim 1, characterized in that, The rust inhibitor is a combination of sebacic acid and dodecanoic acid in a mass ratio of 1:(2-3).

7. A grinding fluid for machining high-cobalt-content cemented carbide according to any one of claims 1-6, characterized in that, The nonionic surfactant is a fatty alcohol polyoxyethylene ether.

8. A grinding fluid for machining high-cobalt-content cemented carbide according to any one of claims 1-6, characterized in that, It also includes 0.2-0.3 parts of defoamer and 0.2-0.3 parts of preservative, wherein the defoamer is polyether-modified silicone and the preservative is 1,2-benzisothiazolin-3-one.

9. A method for preparing a grinding fluid for machining high-cobalt-content cemented carbide, for preparing the grinding fluid of claim 8, characterized in that, Includes the following steps: In a container, deionized water is added according to the formula, followed by diethylene glycolamine, organic acid rust inhibitor, high molecular weight polyether, benzotriazole, borate ester, nonionic surfactant, defoamer and preservative to obtain the base solution. Cool the base solution to room temperature, and slowly add the microcapsule cobalt repair agent while stirring, until the microcapsule cobalt repair agent is evenly dispersed in the base solution. After stirring evenly, dilute to the total mass with deionized water, and finally filter to obtain the grinding fluid.

10. A method for preparing a grinding fluid for machining high-cobalt-content cemented carbide according to claim 9, characterized in that, The stirring speed is 80-120 r / min, and the stirring time is 30-60 minutes.

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