High-temperature alloy cutting fluid and preparation method thereof

Abstract

The application relates to the technical field of cutting fluids, and discloses a high-temperature alloy cutting fluid and a preparation method thereof. The high-temperature alloy cutting fluid is composed of the following components: base oil, 30-50%; organic alkali, 5-10%; antirust agent, 5-10%; synthetic ester, 4-10%; extreme-pressure anti-wear agent, 15-20%; corrosion inhibitor, 0.5-1.5%; emulsifier, 7-15%; bactericide, 2-4%; defoaming agent, 0.05-0.1%; and water, the balance; and the extreme-pressure anti-wear agent is composed of chlorinated extreme-pressure anti-wear agent and sulfurized extreme-pressure anti-wear agent. The ester-based base oil, the organic alkali, the synthetic ester and the extreme-pressure anti-wear agent composed of the chlorinated extreme-pressure anti-wear agent and the sulfurized extreme-pressure anti-wear agent are combined to form a continuous high-strength lubricating film, and the organic acid antirust agent, the corrosion inhibitor and the bactericide and other additives are compounded, so that the rustproof corrosion resistance of the cutting fluid to workpieces and machine tools during machining and the long-term use safety and environmental protection performance are improved.

Description

Technical Field

[0001] This invention relates to the field of cutting fluid technology, and in particular to a high-temperature alloy cutting fluid and its preparation method. Background Technology

[0002] High-temperature alloys are materials with high strength, excellent oxidation and corrosion resistance, and the ability to operate for extended periods in high-temperature environments. They are primarily composed of elements such as nickel, cobalt, and iron. Common problems encountered during their machining include: 1. High-temperature alloys maintain high strength even at high temperatures, resulting in significant cutting forces and severe tool wear. Therefore, high-hardness and high-wear-resistance tool materials are required. 2. High-temperature alloys have poor thermal conductivity, making it difficult for heat to dissipate from the cutting area. This leads to a rapid temperature rise during machining, easily causing tool overheating and wear, and a decline in the surface finish. 3. High-temperature alloys readily react with reactive elements such as oxygen, nitrogen, and hydrogen in the air at high temperatures, forming a surface hardened layer. This increases machining difficulty and may cause tool chipping or failure.

[0003] Most commonly used high-temperature alloy cutting fluids are oil-based products. Oil-based cutting oils have poor flow properties, which are not conducive to removing heat from the cutting area during processing, easily leading to tool wear and a decline in the surface quality of the machined surface. Moreover, the viscosity of cutting oils is relatively high, leaving a lot of residue on the workpiece surface after processing and carrying away a large amount of it, which is not conducive to economic efficiency.

[0004] Water-based cutting fluids have good fluidity and require simpler cleaning conditions after processing, which is beneficial for energy conservation and environmental protection. However, there is currently little publicly available information on high-temperature alloy cutting fluids. The cutting fluids disclosed in the existing technology mainly use lubricants and organic alkalis as main additives in the base oil, supplemented by rust inhibitors, corrosion inhibitors and other secondary additives. The disadvantage is that the temperature and pressure in the cutting area are very high, and the heat is not easily dissipated, which will lead to the temperature rise during the processing, the friction coefficient between the tool and the workpiece will increase, and the tool will be prone to breakage and the surface roughness of the machined surface will increase.

[0005] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high-temperature alloy cutting fluid with excellent extreme pressure anti-wear properties, high lubricity, good cleaning performance, high emulsification degree, and strong diluent compatibility, as well as a method for its preparation.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A high-temperature alloy cutting fluid, by mass percentage, comprises the following components: base oil: 30%–50%, organic alkali: 5%–10%, rust inhibitor: 5%–10%, synthetic ester: 4%–10%, extreme pressure anti-wear agent: 15%–20%, corrosion inhibitor: 0.5%–1.5%, emulsifier: 7%–15%, bactericide: 2%–4%, defoamer: 0.05%–0.1%, and water: balance; wherein the extreme pressure anti-wear agent is composed of chlorinated extreme pressure anti-wear agent and sulfurized extreme pressure anti-wear agent.

[0009] The high-temperature alloy cutting fluid, wherein the chlorinated extreme pressure anti-wear agent is one or more of chlorinated fatty acid esters, chlorinated polyolefins, and chlorinated paraffin; and the sulfurized extreme pressure anti-wear agent is one or more of sulfurized isooctanoate, sulfurized cottonseed oil, sulfurized lard, sulfurized fatty acid esters, sulfurized olefins, and sulfurized olefin fatty acid esters.

[0010] In the high-temperature alloy cutting fluid, the ratio of the chloride extreme pressure anti-wear agent to the sulfurized extreme pressure anti-wear agent is 2:(3-4).

[0011] The high-temperature alloy cutting fluid, wherein the base oil has a viscosity of 6.5 to 12.5 cSt at 40°C.

[0012] The high-temperature alloy cutting fluid, wherein the base oil is one or more selected from the following: diester, trimethylolpropane, pentaerythritol diester, neopentyl glycol ester, isooctanoate, adipate, bis(2-ethylhexyl sebacate), sebacate, and 2-ethylhexyl oleate.

[0013] The high-temperature alloy cutting fluid, wherein the organic base is one or more selected from aminomethylpropanol, triisopropanolamine, diisopropanolamine, monoisopropanolamine, 1,1'-(methylimino)bis(2-propanol), N-methyldiethanolamine, N-butyldiethanolamine, 2-[2-(dimethylamino)ethoxy]ethanol, and N,N-dimethylethanolamine.

[0014] The high-temperature alloy cutting fluid, wherein the synthetic ester is a methyl-terminated polyethylene glycol-2-ethylhexyl trimerol, and the polyethylene glycol has a molecular weight of 350.

[0015] The high-temperature alloy cutting fluid, wherein the rust inhibitor is one or more of diisopropanolamide, a mixture of dicarboxylic acids, a mixture of polycarboxylic acids, fatty acid diethanolamine acyl, isopropanolamine borate ester, and disodium sebacic acid.

[0016] The high-temperature alloy cutting fluid, wherein the corrosion inhibitor is one or more selected from the following: tridecyl alcohol polyether-10-phosphate, isotrimethylene phosphate, aminotrimethylene phosphonic acid, 2-hydroxyethyl methacrylate phosphate, benzotriazole, and 1-hydroxyethyl-2-oleoimidazoline; and the emulsifier is one or more selected from the following: fatty alcohol polyoxyethylene ether carboxylic acid, polyethoxylated fatty alcohol, a mixture of C14-C15 monobranched primary alcohols, C12 Guerbert carboxylic acid, alkylated fatty alcohol, ricinoleic acid, and tall oil acid. One or more of the following: the bactericide is N,N-methylenebismorpholine, triazine, 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione, n-butyl-1,2-benzisothiazolin-3-one, 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, methylisothiazolinone, butyl iodopropynylcarbamate, sodium pyridinethione; the defoamer is a reaction product of three-dimensional siloxane and polyoxyethylene.

[0017] A method for preparing a high-temperature alloy cutting fluid includes the following steps:

[0018] S1. Add organic alkali and rust inhibitor to reactor A, and stir at 40-50℃ until the solution is clear and transparent;

[0019] S2. Add base oil, synthetic ester, extreme pressure anti-wear agent and corrosion inhibitor to reactor B, and stir at 40-50℃ until the solution is clear and transparent;

[0020] S3. Pour the solution from reactor A into reactor B, and stir at 40-50℃ for 1 hour before stopping heating;

[0021] S4. Add emulsifier to the solution in step S3 and stir until homogeneous;

[0022] S5. Add bactericide to the solution in step S4 and stir until homogeneous;

[0023] S6. Add defoamer to the solution in step S5 and stir evenly to obtain the high-temperature alloy cutting fluid.

[0024] Beneficial effects:

[0025] This invention provides a high-temperature alloy cutting fluid and its preparation method, which has the following advantages:

[0026] 1. Excellent extreme pressure anti-wear properties: The base oil, extreme pressure anti-wear agent, and synthetic ester in this invention play a complementary role in high-temperature alloy machining. The base oil acts as a carrier for the synthetic ester and extreme pressure anti-wear agent; the synthetic ester has high thermal stability and is not easily decomposed or oxidized under high-temperature conditions, ensuring long-term stability of lubrication and cooling effects; under high temperature and high pressure environments, the extreme pressure anti-wear agent reacts with the surface of high-temperature alloys using chloride compounds and sulfides under different cutting conditions, covering a wider temperature range and forming a more stable and widely covered protective chlorate and sulfate film. This film has good pressure resistance and temperature resistance, reducing direct contact between the workpiece and the tool, thereby effectively reducing wear and friction.

[0027] 2. Good fluidity: Water-based metalworking fluids have high specific heat capacity and good fluidity, which helps to continuously remove heat from the machining area during machining and reduce tool wear.

[0028] 3. Safe and environmentally friendly, free of harmful substances such as nitrites, phenols, and secondary amines, safe to store, non-irritating to the skin and respiratory tract during use, easily degradable, and environmentally friendly.

[0029] 4. It has good corrosion inhibition properties, does not corrode high-temperature alloys, aluminum alloy and copper alloy parts of machine tools, and can form an oil film to protect the high-temperature areas of the workpiece after processing from corrosion by oxygen, nitrogen and hydrogen in the environment.

[0030] 5. High stability; does not discolor or separate during long-term storage. Detailed Implementation

[0031] This invention provides a high-temperature alloy cutting fluid and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following embodiments are provided to further illustrate the invention in detail. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the scope of protection of the invention.

[0032] This invention provides a high-temperature alloy cutting fluid, which, by mass percentage, comprises the following components: base oil: 30%–50%, organic alkali: 5%–10%, rust inhibitor: 5%–10%, synthetic ester: 4%–10%, extreme pressure anti-wear agent: 15%–20%, corrosion inhibitor: 0.5%–1.5%, emulsifier: 7%–15%, bactericide: 2%–4%, defoamer: 0.05%–0.1%, and water: balance; wherein the extreme pressure anti-wear agent is composed of chlorinated extreme pressure anti-wear agent and sulfurized extreme pressure anti-wear agent.

[0033] Base oil:

[0034] Base oils form a protective film on metal surfaces, reducing direct contact between the tool and the workpiece, decreasing friction and wear, extending tool life, and improving machining quality. Their excellent thermal conductivity effectively dissipates heat, preventing thermal deformation and premature tool failure. Furthermore, base oils dissolve and disperse additives, enhancing cutting fluid performance, and reduce wear and defects caused by impurities by cleaning tool and workpiece surfaces.

[0035] The base oil has a viscosity of 6.5–12.5 cSt at 40°C. The viscosity of the base oil directly affects its lubrication performance. A base oil with a suitable viscosity can form a thicker oil film between the tool and workpiece surfaces. While the viscosity of base oils within the aforementioned range is relatively low, under machining pressure, they can still form a sufficiently thin and effective lubricating film on both the tool and workpiece surfaces. Compared to high-viscosity oils, this thin oil film better meets the high-precision requirements of machining. Furthermore, a suitable base oil viscosity ensures that heat is dissipated promptly during machining, preventing damage to the workpiece and tool due to overheating. Its good fluidity also effectively carries away grinding debris from the machining area, ensuring machining quality. However, if the base oil viscosity is too low, it may not provide sufficient force to completely remove grinding debris, especially for heavier or larger pieces. Conversely, a base oil with excessively high viscosity may make it difficult for grinding debris to suspend in the machining fluid, leading to easy deposition in the machining area. Moreover, the viscosity of the base oil affects the dissolution and dispersion of additives. Viscosities within the aforementioned range ensure that additives are uniformly dispersed in the base oil, allowing them to fully exert their effects. For example, additives such as extreme pressure anti-wear agents, emulsifiers, and rust inhibitors need to be evenly distributed in the base oil to fully exert their effects during processing. If the base oil viscosity is too high, the additives may be difficult to dissolve and disperse sufficiently, resulting in insufficient additive concentration in local areas and failing to achieve the expected protective effect; while if the viscosity is too low, the additives may be too dispersed and unable to exert sufficient effect in critical areas. Therefore, the optimal viscosity range is within the above-mentioned range, which ensures that the cutting fluid has sufficient oil film thickness while also taking into account good wettability, so as to fully exert effective lubrication overall.

[0036] Specifically, the base oil is one or more of the following: diester (viscosity 12.5 cSt at 40°C), trimethylolpropane ester, pentaerythritol diester, neopentyl glycol ester (viscosity 9.3 cSt at 40°C), isooctanoate (viscosity 7.9 cSt at 40°C), adipate (viscosity 10.8 cSt at 40°C), bis(2-ethylhexyl sebacate) (viscosity 12.4 cSt at 40°C), sebacate (viscosity 6.7 cSt at 40°C), and 2-ethylhexyl oleate (viscosity 9.6 cSt at 40°C). The above base oil is an ester-based base oil. The acyl group (C=O) and ether bond (-O-) in the ester molecule provide polar hydrophilic groups, which can form hydrogen bonds with water molecules, thus making it easier to form a stable emulsion in water. Moreover, these polar groups can adsorb onto the metal surface to form a dense adsorption film. This polar adsorption layer helps maintain the oil film between the friction surfaces, thereby reducing the coefficient of friction, reducing tool wear, and improving the surface quality of the workpiece.

[0037] Organic bases:

[0038] Organic bases play a crucial role in metalworking fluids. They can adjust the pH of the cutting fluid (typically 8-10), neutralizing acidic substances generated during machining, such as hydrogen ions produced by the reaction of metal and water during cutting. This maintains the alkaline environment of the fluid, inhibits microbial growth, extends service life, and reduces corrosion risk. Simultaneously, the polar groups in organic base molecules bind to active sites on the metal surface, forming a dense protective film that prevents moisture and oxygen from corroding the active metal. Organic bases with long-chain structures can adsorb onto the surfaces of tools and workpieces, forming a protective lubricating layer that isolates and reduces friction between them, improving machining efficiency and surface finish. In addition, organic bases can stabilize additives such as rust inhibitors, emulsifiers, and extreme pressure anti-wear agents. The emulsifying and dispersing effects of organic bases can help emulsifiers better stabilize the oil and water phases in cutting fluids, ensuring the stability of machining fluid performance and further enhancing the cooling and lubrication performance of machining fluids. They can also enhance the performance of extreme pressure anti-wear agents. Under extreme cutting pressure and temperature conditions, organic bases can promote the chemical reaction between extreme pressure anti-wear agents and metal surfaces, making the formed extreme pressure lubrication film more stable and effective.

[0039] Specifically, the organic base is one or more of aminomethylpropanol, triisopropanolamine, diisopropanolamine, monoisopropanolamine, 1,1'-(methylimino)bis(2-propanol), N-methyldiethanolamine, N-butyldiethanolamine, 2-[2-(dimethylamino)ethoxy]ethanol, and N,N-dimethylethanolamine. Organic amines can partially ionize in water to release hydroxide ions, thereby neutralizing the acidity of the cutting fluid. Organic amines can chelate with metal ions, thus adsorbing onto the metal surface to form a dense protective film. Because the molecular structure of organic amines contains both hydroxyl and amino groups, these polar groups can generate a strong adsorption effect with the metal surface, thus forming a lubricating film between the tool and the workpiece. The hydrophilic hydroxyl and hydrophobic amino groups in the organic amine can interact with the aqueous and oil phases respectively, reducing the surface tension at the oil-water interface and allowing oil droplets to be stably dispersed in water.

[0040] Synthetic esters:

[0041] Synthetic esters possess excellent lubricating properties, effectively reducing friction and wear between metal surfaces and extending the service life of equipment and tools. They maintain stable lubrication even under high temperature, high pressure, and high speed conditions, making them suitable for various metal processing techniques. Synthetic esters also form a protective film on metal surfaces, effectively preventing oxidation and corrosion, protecting metal surfaces from moisture and corrosive substances. Furthermore, synthetic esters exhibit high thermal stability, resisting decomposition or oxidation at high temperatures, ensuring long-term stability of lubrication and cooling effects, making them particularly outstanding during high-temperature processing.

[0042] Specifically, the synthetic ester includes methyl-terminated polyethylene glycol-2-ethylhexyl trimerol, 2-ethylhexyl ester of triacrylate, hexameric castor oil ester, isopropyl palmitate, and neopentyl glycol fatty acid ester. Preferably, the synthetic ester is methyl-terminated polyethylene glycol-2-ethylhexyl trimerol, and the molecular weight of the polyethylene glycol is 350. The methyl-terminated polyethylene glycol-2-ethylhexyl trimerol structure contains polyethylene glycol segments and polar functional groups, which can form a stronger adsorption layer with the metal surface. This polar characteristic improves the adhesion of the lubricant to the friction surface, reduces friction, and helps maintain the integrity of the lubricating film under high pressure conditions. Furthermore, the methyl-terminated polyethylene glycol-2-ethylhexyl trimerol has a relatively long and flexible molecule (its molecular structure contains a lipid-soluble 2-ethylhexyl moiety and a polyethylene glycol chain with a certain degree of flexibility), which can alter its chemical stability and solubility to some extent. This structure exhibits good shear stability under high loads and can maintain the continuity of the lubricating film under boundary lubrication conditions. In addition, the molecular weight of the polyethylene glycol moiety not only affects the water solubility, viscosity, and cutting fluid stability of the synthesized ester, but also affects the lubricating film formed between the tool and the workpiece, as well as its synergistic effect with emulsifiers.

[0043] Extreme pressure anti-wear agent:

[0044] During the machining of titanium alloys, extreme pressure anti-wear agents can react with the metal surface to form a stable protective layer on the high-temperature alloy surface, reducing direct contact and friction between the tool and the workpiece, thereby reducing the coefficient of friction.

[0045] Specifically, the chlorinated extreme pressure anti-wear agent is one or more of chlorinated fatty acid esters, chlorinated polyolefins, and chlorinated paraffin; the sulfurized extreme pressure anti-wear agent is one or more of sulfurized isooctanoate, sulfurized cottonseed oil, sulfurized lard, sulfurized fatty acid esters, sulfurized olefins, and sulfurized olefin fatty acid esters. During cutting, the chlorinated extreme pressure anti-wear agent reduces friction and wear by forming a chloride film on the metal surface with chlorine. At high temperatures, the chloride gradually decomposes, generating a thin metal chloride film. This metal chloride film protects the metal surface under high load conditions, preventing direct contact and thus reducing adhesive wear and abrasive wear. Chlorinated extreme pressure anti-wear agents are suitable for use at higher temperatures, but their effectiveness is affected by high-temperature oxidation. Therefore, they are generally suitable for use under cutting conditions with minimal temperature changes. In contrast, sulfurized anti-wear agents react chemically with the metal surface at high temperatures to form a sulfide film. This sulfide film has high shear strength and thermal stability, reducing wear under high load and high temperature conditions. The mechanism of action of sulfurized extreme pressure anti-wear agents is suitable for situations where the temperature rises sharply. During the cutting process, the decomposition temperature of sulfides is relatively high, which enables them to effectively protect the tool surface and reduce wear in the machining of high-temperature alloys.

[0046] The two types of films formed above exhibit different stabilities under varying temperatures and pressures. Therefore, their combined use can cover a wider temperature range, forming a more stable and broader protective film. This provides more comprehensive protection under instantaneous high pressure or shear force, achieving superior extreme pressure anti-wear performance. It is suitable for high-load, variable-temperature lubrication applications, preventing the failure of single additives due to overheating or shear. Specifically, after compounding, the chlorine-containing additive provides lubrication protection in the initial stage. As temperature and pressure continue to rise, the sulfur-based component begins to decompose, forming a sulfide film, thereby enhancing anti-wear performance. The sulfur and chlorine composite additive also exhibits good antioxidant effects. This synergistic antioxidant effect helps maintain the lubricating film on the metal surface in harsh environments, further enhancing anti-wear performance.

[0047] More specifically, the addition ratio of the chlorinated extreme pressure anti-wear agent to the sulfurized extreme pressure anti-wear agent is 2:(3-4). Since the protective film formed by the chlorinated extreme pressure anti-wear agent has low shear strength, while the protective film formed by the sulfurized extreme pressure anti-wear agent has high load-bearing capacity and anti-wear performance, a suitable ratio of the two is necessary for the protective film between the tool and the workpiece to better resist the high pressure and high temperature during the cutting process, reducing tool wear and workpiece surface damage. However, if the ratio is inappropriate, the protective film may lack sufficient strength or toughness, failing to effectively resist cutting forces. Furthermore, the chemical reactions of chlorine and sulfur on the metal surface compete with each other. If the proportion of the chlorinated extreme pressure anti-wear agent is too high, excessive chlorine will interfere with the process of the sulfurized anti-wear agent forming a sulfide protective film on the metal surface, or damage the already formed sulfide film, and vice versa. Thus, the advantages of both cannot be fully utilized.

[0048] Rust inhibitor:

[0049] The rust inhibitor described is an organic rust inhibitor. Organic rust inhibitors play a crucial protective role in metalworking fluids. They primarily work by reacting with the metal surface to form a dense organic passivation film, effectively blocking the penetration of oxygen, moisture, and other corrosive media, thus reducing the risk of metal oxidation and corrosion. Simultaneously, the weakly acidic nature of organic rust inhibitors helps stabilize the pH value of the working fluid, preventing corrosion problems caused by acid-base imbalance. In the working fluid, organic rust inhibitors can also work synergistically with other additives (such as extreme pressure anti-wear agents) to ensure the stability of cooling, lubrication, and cleaning functions. Compared to traditional inorganic rust inhibitors, organic rust inhibitors are more environmentally friendly and operator-friendly due to their low toxicity and absence of heavy metal components, making them an ideal choice for metalworking.

[0050] Specifically, the rust inhibitor is one or more of the following: diisopropanolamide, a mixture of dicarboxylic acids, a mixture of polycarboxylic acids, fatty acid diethanolamine acyl, isopropanolamine borate, and disodium sebacic acid. Diisopropanolamide has a certain polarity; its amide group can interact with active sites on the metal surface to form a protective film and also has good emulsifying properties. The carboxyl group (-COOH) in the dicarboxylic acid and polycarboxylic acid mixture can react chemically with metal ions to form metal carboxylates, which deposit on the metal surface to form a dense protective film. Fatty acid diethanolamine acyl molecules contain both fatty acid groups and ethanolamine groups. The fatty acid groups can adhere to the metal surface through physical and chemical adsorption, while the ethanolamine groups can enhance the molecule's solubility in water and react with some impurities on the metal surface. Isopropanolamine borate undergoes a hydrolysis reaction on metal surfaces, producing boric acid and isopropanolamine, which can react with the metal surface separately. Boric acid forms a borate protective film on the metal surface, while isopropanolamine adjusts the pH and assists in rust prevention. This dual-action protective film effectively prevents metal from rusting. Disodium sebacic acid ionizes in water to release sodium ions and sebate ions. The sebate ions can undergo an exchange reaction with cations on the metal surface, forming a protective film of sebate metal salt.

[0051] Corrosion inhibitor:

[0052] Corrosion inhibitors are a class of additives that prevent corrosive substances from penetrating by forming a protective layer on the metal surface. Their main function is to prevent corrosion of non-ferrous metals, enhance the stability of cutting fluids, and improve machining quality.

[0053] Specifically, the corrosion inhibitor is one or more of the following: tridecyl alcohol polyether-10-phosphate, isotrimethylene phosphate, aminotrimethylenephosphonic acid, 2-hydroxyethyl methacrylate phosphate, benzotriazole, and 1-hydroxyethyl-2-oleoimidazoline. Tridecyl alcohol polyether-10-phosphate contains a phosphate group, and the phosphorus and oxygen atoms in the phosphate group can combine with active sites on the metal surface to form a protective film. The polyether portion of its molecular structure is hydrophilic, giving it good emulsifying properties. Isotrimethylene phosphate undergoes hydrolysis on the metal surface, generating phosphate ions and a corresponding alcohol. The phosphate ions can combine with cations on the metal surface to form a metal phosphate salt protective film. Aminotrimethylenephosphonic acid is an organophosphate corrosion inhibitor. Its phosphate group (-PO3H2) can form a stable complex with metal ions, which adsorbs onto the metal surface to form a protective film. Simultaneously, its amino group can regulate the charge distribution and adsorption properties of the molecule, enhancing the stability and density of the protective film. The phosphate ester moiety in the 2-hydroxyethyl methacrylate phosphate ester molecule can chemically react with active sites on the metal surface to form a phosphate ester metal salt protective film; simultaneously, the acrylate moiety moiety in the molecule can form a polymer protective film through polymerization. The imidazoline ring structure and hydroxyl and oleyl groups in the 1-hydroxyethyl-2-oleoylimidazoline molecule can adsorb onto the metal surface.

[0054] Emulsifier:

[0055] The role of emulsifiers in cutting fluids is mainly reflected in promoting emulsification, enhancing lubrication, optimizing cooling effects, extending service life, and providing cleaning functions. First, emulsifiers reduce the interfacial tension between oil and water, promoting the mixing of the oil and water phases to form a stable emulsion, significantly improving the stability of the cutting fluid and preventing oil-water separation. Second, emulsifiers generate tiny oil droplets that are uniformly dispersed in the aqueous phase, enhancing lubrication performance, reducing friction between the tool and workpiece, and decreasing heat generation, thereby improving machining efficiency and surface quality. Furthermore, emulsifiers optimize the uniformity of oil-water mixing, improve heat conduction, effectively remove machining heat, and prevent workpiece deformation and tool damage. Simultaneously, they inhibit the decomposition and precipitation of the emulsion system, extending the service life of the cutting fluid and reducing replacement frequency and maintenance costs. Finally, emulsifiers help remove metal chips and impurities, maintaining the cleanliness of the machining area, further improving machining quality and tool life.

[0056] Specifically, the emulsifier is one or more of the following: fatty alcohol polyoxyethylene ether carboxylic acid, polyethoxylated fatty alcohol, a mixture of C14-C15 monobranched primary alcohols, C12 Guerbert carboxylic acid, alkylated fatty alcohol, castor oil acid, and tall oil acid. The fatty alcohol polyoxyethylene ether carboxylic acid molecule contains hydrophilic polyoxyethylene ether segments and hydrophobic fatty alcohol and carboxylic acid groups. In the cutting fluid, the hydrophilic portion attracts water, while the hydrophobic portion interacts with the oil phase. The molecular structure of polyethoxylated fatty alcohol consists of a fatty alcohol and a polyoxyethylene chain; the polyoxyethylene chain is hydrophilic, and the fatty alcohol portion is hydrophobic. The primary alcohol molecules in the C14-C15 monobranched primary alcohol mixture have a certain degree of hydrophobicity; their carbon chain portion can interact with the oil phase, while the hydroxyl portion has a certain degree of hydrophilicity. The carboxylic acid group in the C12 Guerbert carboxylic acid molecule has a certain degree of hydrophilicity, while the carbon chain portion is hydrophobic. In the molecular structure of alkylated fatty alcohols, the alkyl group is hydrophobic, while the fatty alcohol group is hydrophilic. Castor oil acid contains a carboxyl group and a long carbon chain; the carboxyl group is hydrophilic, and the long carbon chain is hydrophobic. Talloleic acid also contains a carboxyl group and a long carbon chain. Its emulsification mechanism is similar to that of castor oil acid; the hydrophilicity of the carboxyl group and the hydrophobicity of the long carbon chain cause them to align at the oil-water interface, reducing the surface tension at the oil-water interface and allowing the oil phase to emulsify in the aqueous phase.

[0057] bactericide:

[0058] The role of bactericides in cutting fluids is mainly reflected in the following aspects. First, they maintain the cleanliness and stability of the cutting fluid by interfering with the metabolism of microorganisms and inhibiting the reproduction of bacteria and fungi. Second, controlling microbial growth can reduce the spoilage and deterioration of the cutting fluid, significantly extending its service life and reducing replacement frequency and maintenance costs. Furthermore, bactericides maintain the physicochemical properties of the cutting fluid, ensuring its lubrication and cooling effects and preventing a decline in emulsification performance. Simultaneously, they also prevent the generation of odors and putrefactive substances, maintaining a hygienic working environment.

[0059] Specifically, the bactericide is one or more of N,N-methylenebismorpholine, triazine, 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione, n-butyl-1,2-benzisothiazolin-3-one, 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, methylisothiazolinone, butyl iodopropynylcarbamate, and sodium pyridinethione.

[0060] Defoamer:

[0061] Defoamers play a crucial role in cutting fluids, primarily by inhibiting foam formation. By reducing the surface tension of the liquid, defoamers can quickly eliminate foam in the cutting fluid, preventing foam accumulation. This property improves machining efficiency and reduces interference caused by foam.

[0062] Specifically, the defoamer is a reactant of three-dimensional siloxane and polyoxyethylene. The three-dimensional siloxane portion has low surface tension and can spread rapidly on the surface of the foam. When it comes into contact with the foam surface, it disrupts the elasticity and stability of the foam liquid film. Simultaneously, the polyoxyethylene portion can interact with the components in the foam system, further reducing the surface tension of the foam. This dual effect thins the foam liquid film, ultimately leading to foam rupture.

[0063] The above-mentioned high-temperature alloy cutting fluid uses organic alkali, synthetic ester and chlorinated and sulfidated extreme pressure anti-wear agent as the main additives, and is compounded with rust inhibitors, corrosion inhibitors and bactericides, so that the cutting fluid has excellent extreme pressure anti-wear, high lubrication, good cleaning performance, high degree of emulsification and strong compatibility with diluent.

[0064] This invention also provides a method for preparing a high-temperature alloy cutting fluid, comprising the following steps:

[0065] S1. Add organic alkali and rust inhibitor to reactor A, and stir at 40-50℃ until the solution is clear and transparent. At a temperature of 40-50℃, the thermal motion of molecules is relatively active, which helps the diffusion and contact of organic alkali and rust inhibitor molecules, and ensures that possible interactions between them (such as the formation of a protective film through chemical reactions and the pH regulation effect of organic alkali) can proceed stably, resulting in a preliminary stable and homogeneous mixture system.

[0066] S2. Add base oil, synthetic ester, extreme pressure anti-wear agent, and corrosion inhibitor to reactor B, and stir at 40-50℃ until the solution is clear and transparent. Base oil, as the main oil phase component, provides a medium for dissolving and dispersing other oil-soluble components; synthetic esters, due to their unique molecular structure, interact with the base oil and other components; extreme pressure anti-wear agent and corrosion inhibitor are also better dispersed in the oil phase at this temperature, and work synergistically with other components to achieve a clear and transparent homogeneous mixture.

[0067] S3. Pour the solution from reactor A into reactor B and stir at 40-50℃ for 1 hour, then stop heating. Pouring the solution from reactor A into reactor B and continuing to stir is to combine the two previously prepared mixed systems: one primarily composed of an aqueous phase (containing organic alkali and rust inhibitors), and the other primarily composed of an oil phase (containing base oil, synthetic esters, extreme pressure anti-wear agents, and corrosion inhibitors). Stirring further promotes the mixing and interaction between the oil and aqueous phases, gradually stabilizing and homogenizing the entire system.

[0068] S4. Add emulsifier to the solution in step S3 and stir for 30 minutes. The addition of emulsifier is used to reduce the surface tension of the oil-water interface, so that the oil phase can be more stably and uniformly dispersed in the aqueous phase, forming a stable emulsion structure.

[0069] S5. Add bactericide to the solution in step S4 and stir until the solution is clear and transparent.

[0070] S6. Add defoamer to the solution in step S5 and stir at low speed for 30 minutes to obtain the high-temperature alloy cutting fluid. The defoamer is added last to eliminate foam that may be generated during the stirring process in the previous steps and during the subsequent use of the cutting fluid.

[0071] To further illustrate the high-temperature alloy and its preparation method provided by the present invention, the following examples and comparative examples are provided.

[0072] The test objects of this invention are the stock solutions prepared in the examples and comparative examples, and the test objects are high-temperature alloy cutting fluids.

[0073] The testing method of this invention is as follows:

[0074] (1) pH value (GB / T 6144); defoaming property (GB / T 6144); corrosion test (cast iron, copper, LY12 aluminum) (GB / T 6144); rust prevention test (single sheet, stacked sheet) (GB / T 6144); saponification value (mgKOH / g) (GB / T 5530).

[0075] (2) The extreme pressure performance test method shall be in accordance with GB / 3142. Tester model: Xiamen Tianji MS-10A.

[0076] (3) Test method for tapping torque:

[0077] Extrusion speed 600 r / min, depth 8 mm, maximum torque 500 Ncm, cutting tool: TTT-M4F-T for Titan, test block: NiCr19NbMo TTT-testbar 2.4668 / M4F / hole diameter 3.7 mm / depth 12 mm.

[0078] Cutting speed: 600 r / min; depth: 8 mm; maximum torque: 500 Ncm; cutting tool: TTT-M4C-Ni; test block: NiCr19NbMo TTT-testbar 2.4668 / M4C(S) / hole diameter 3.3 mm / depth 12 mm; testing instrument model: TAPTTTSystem-G8.

[0079] (4) Stability test method: The test object is sealed and left to stand at room temperature (25℃) for 12 hours and the state changes are observed; the test object is sealed and left to stand at low temperature (-13±2℃) for 24 hours and the changes are observed; the test object is sealed and left to stand at high temperature (70℃) for 5 hours and the changes are observed (GB / T 6144).

[0080] (5) Cleaning power test: First, weigh the NiCr19NbMo standard sample, then soak the NiCr19NbMo standard sample in the original cutting fluid, place it in a 40℃ oven to dry, then weigh it, soak the sample in 500mL tap water for 3 minutes, wash it 3 times, dry it and weigh it.

[0081] I. Examples of Extreme Pressure Anti-wear Agents

[0082] The preparation methods of the present invention were used to prepare Examples 1-1, 1-2, 1-3, Comparative Examples 1-1, 1-2, and 1-3 according to the components listed in Table 1.

[0083] Table 1. Component composition of Examples 1-1, 1-2, 1-3, Comparative Examples 1-1, 1-2, and 1-3

[0084]

[0085]

[0086] Table 2 Performance test results of Examples 1-1, 1-2, 1-3, Comparative Examples 1-1, 1-2, and 1-3

[0087]

[0088]

[0089] As can be seen from the table above, the extreme pressure anti-wear performance, lubrication performance, and coefficient of friction of Examples 1-1, 1-2, and 1-3 are all excellent, indicating that the combined use of sulfur-containing and chlorine-containing additives in the set proportions is better than using chlorinated extreme pressure anti-wear agents or sulfurized extreme pressure anti-wear agents alone in improving the lubrication performance of the cutting fluid. Among them, the lubrication performance of Comparative Example 1-2 is the second best, the lubrication performance of Comparative Example 1-3 is relatively poor, and the lubrication performance of Comparative Example 1-1 is the worst, indicating that the lubrication performance of using sulfurized extreme pressure anti-wear agents alone is better than that of using chlorinated extreme pressure anti-wear agents alone.

[0090] II. Examples of Synthetic Esters

[0091] The preparation methods of the present invention were used to prepare Examples 2, 2-1, 2-2 and 2-3 according to the components listed in Table 3.

[0092] Table 3. Component composition of Example 2, Comparative Example 2-1, Comparative Example 2-2, and Comparative Example 2-3

[0093]

[0094]

[0095] Table 4 Performance test results of Example 2, Comparative Example 2-1, Comparative Example 2-2 and Comparative Example 2-3

[0096]

[0097]

[0098] As can be seen from the table above, Example 2 exhibits the lowest tapping torque cutting and tapping torque extrusion, thus demonstrating the best lubrication performance and the lowest coefficient of friction. This is because the polarity of the methyl-terminated polyethylene glycol-2-ethylhexyl trimeryl structure is greater than that of the structures of 2-ethylhexyl trimeryl ester and isopropyl palmitate. The methyl-terminated polyethylene glycol-2-ethylhexyl trimeryl structure more readily forms a stronger adsorption layer on the metal surface, while 2-ethylhexyl trimeryl ester and isopropyl palmitate have lower polarity and are less likely to form a similar stable adsorption layer, resulting in poorer lubrication and anti-wear performance. Furthermore, the polyethylene glycol-2-ethylhexyl trimeryl molecular chain is longer and more flexible, while the molecular chains of isopropyl palmitate and neopentyl glycol fatty acid ester are shorter and more rigid, making it difficult to form an effective boundary lubrication film, leading to a decrease in lubrication performance under extreme pressure conditions.

[0099] III. Base Oil Examples

[0100] The preparation methods of the present invention were used to prepare Examples 3-1, 3-2, 3-3 and Comparative Example 3 according to the components listed in Table 5.

[0101] Table 5. Component composition of Examples 3-1, 3-2, 3-3 and Comparative Example 3

[0102]

[0103]

[0104] Table 6 Performance test results of Example 3, Comparative Example 3-1, Comparative Example 3-2 and Comparative Example 3-3

[0105]

[0106]

[0107] Ester compounds exhibit higher emulsification than naphthenic white oils (such as 4006# white oil) due to differences in their molecular structure and polarity. Ester compounds have higher polarity than naphthenic white oils. The acyl groups (C=O) and ether bonds (-O-) in the ester molecule provide hydrophilic groups, enabling them to form hydrogen bonds with water molecules, thus facilitating the formation of stable emulsions in water. Naphthenic white oils, primarily composed of saturated hydrocarbons, have lower polarity and lack the ability to interact with water molecules, making them more difficult to emulsify. Furthermore, esters offer superior lubrication compared to 4006# naphthenic white oil. This is because the higher polarity of ester compounds allows them to easily form a dense adsorption film on metal surfaces. This polar adsorption layer helps maintain the oil film between friction surfaces, reducing the coefficient of friction and minimizing wear. In contrast, naphthenic white oils are non-polar substances and cannot effectively adsorb onto metal surfaces, resulting in relatively poor lubrication.

[0108] The molecular structure of bis(2-ethylhexyl sebacate) contains two 2-ethylhexyl groups, giving the molecule good flexibility and significant steric hindrance, allowing it to adsorb more effectively onto the friction surface during lubrication. In contrast, ordinary sebacate esters have simpler structures and may lack the complex structure and significant steric hindrance of bis(2-ethylhexyl sebacate). During adsorption, the adsorption film formed on the metal surface is not as dense, resulting in less coverage of the friction surface compared to bis(2-ethylhexyl sebacate). Although pentaerythritol diester is also a diester, its molecular structure differs from that of bis(2-ethylhexyl sebacate). The center of the pentaerythritol diester molecule is a pentaerythritol structure, and its spatial structure and functional group distribution differ from the 2-ethylhexyl structure of bis(2-ethylhexyl sebacate). When adsorbed onto a metal surface, the pentaerythritol diester molecule cannot effectively utilize its molecular structure advantages to form a tight adsorption film as effectively as bis(2-ethylhexyl sebacate), thus its lubrication effect is relatively poor.

[0109] In summary, (1) in view of the problems existing in the high-temperature alloy cutting fluid described in the prior art, the present invention uses ester-based base oil, organic alkali, synthetic ester and extreme pressure anti-wear agent composed of chlorinated extreme pressure anti-wear agent and sulfurized extreme pressure anti-wear agent to form a continuous high-strength lubricating film, and compounded with additives such as organic acid rust inhibitor, corrosion inhibitor and bactericide, thereby improving the rust prevention and corrosion inhibition of the cutting fluid on the workpiece and machine tool during processing and the safety and environmental protection of long-term use.

[0110] (2) To test the surface roughness of the workpiece after cutting, a simulated cutting test was designed. The SRV multi-functional friction and wear tester was used to test the lubricity and friction coefficient during on-site cutting using quantitative and timed methods.

[0111] (3) To assess the cleaning performance after cutting, a test method for simulating post-processing cleaning is designed (refer to GB / T35759) to quantitatively and periodically measure the surface cleanliness of the workpiece after water washing.

[0112] It is understood that those skilled in the art can make equivalent substitutions or changes to the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A high-temperature alloy cutting fluid, characterized by, By percentage, it is composed of the following components: base oil: 30%~50%, organic base: 5%~10%, anti-rust agent: 5%~10%, synthetic ester: 4%~10%, extreme pressure anti-wear agent: 15%~20%, corrosion inhibitor: 0.5%~1.5%, emulsifier: 7%~15%, bactericide: 2%~4%, defoaming agent: 0.05%~0.1%, water: the balance; The extreme pressure anti-wear agent is composed of chlorinated extreme pressure anti-wear agent and sulfurized extreme pressure anti-wear agent; The viscosity of the base oil at 40 DEG C is 6.5~12.5 cSt; The base oil is one or more of dibasic acid ester, trimethylolpropane ester, pentaerythritol double ester, neopentyl glycol ester, isooctanoic acid ester, adipic acid ester, bis (sebacic acid-2-ethylhexyl ester), sebacic acid ester, oleic acid-2-ethylhexyl ester; The synthetic ester is methyl-terminated polyethylene glycol-2-ethylhexyl trimer ester, and the molecular weight of polyethylene glycol is 350.

2. The high-temperature alloy cutting fluid of claim 1, wherein, The chlorinated extreme pressure anti-wear agent is one or more of chlorinated fatty acid ester, chlorinated polyolefin, chlorinated paraffin; The sulfurized extreme pressure anti-wear agent is one or more of sulfurized isooctanoic acid ester, sulfurized cottonseed oil, sulfurized lard oil, sulfurized fatty acid ester, sulfurized olefin, sulfurized olefin fatty acid ester.

3. The high-temperature alloy cutting fluid of claim 2, wherein, The addition ratio of the chlorinated extreme pressure anti-wear agent and the sulfurized extreme pressure anti-wear agent is 2: (3-4).

4. The high-temperature alloy cutting fluid of claim 1, wherein, The organic base is one or more of aminomethylpropanol, triisopropanolamine, diisopropanolamine, monoisopropanolamine, 1,1'-(methylimino) bis (2-propanol), N-methyl diethanolamine, N-butyl diethanolamine, 2-[2-(dimethylamino) ethoxy] ethanol, N, N-dimethyl ethanolamine.

5. The high-temperature alloy cutting fluid of claim 1, wherein, The anti-rust agent is one or more of diisopropanol amide, dicarboxylic acid mixture, polycarboxylic acid mixture, fatty acid diethanolamine acyl, isopropanolamine borate, sebacic acid disodium salt.

6. The high-temperature alloy cutting fluid of claim 1, wherein, The corrosion inhibitor is one or more of tridecyl alcohol polyether-10-phosphate, isopropyl phosphoric acid ester, amino tri (methylene) phosphonic acid, 2-hydroxyethyl methacrylate phosphate ester, benzotriazole, 1-hydroxyethyl-2-oil imidazoline; The emulsifier is one or more of fatty alcohol polyoxyethylene ether carboxylic acid, polyethoxylated fatty alcohol, C14-C15 single branched primary alcohol mixture, C12 gilbert carboxylic acid, alkylated fatty alcohol, ricinoleic acid, tall oil acid; The bactericide is one or more of N, N-methylene bis morpholine, s-triazine, 1,3-bis (hydroxymethyl) -5,5-dimethyl imidazolidine-2,4-dione, n-butyl-1, 2-benzisothiazolin-3-one, 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, methyl isothiazolinone, iodine propargyl butyl carbamate, pyrithione sodium; The defoaming agent is a three-dimensional siloxane and polyoxyalkylene reactant.

7. A method of preparing a high-temperature alloy cutting fluid, characterized by, It includes the following steps: S1, add organic base and anti-rust agent in A reaction kettle, stir at 40-50 DEG C until the solution is clear and transparent; S2, add base oil, synthetic ester, extreme pressure anti-wear agent and corrosion inhibitor in B reaction kettle, stir at 40-50 DEG C until the solution is clear and transparent; S3, pour the solution in the A reactor into the B reactor, stop heating after stirring for 1 hour at 40-50℃; S4, add emulsifier to the solution in step S3, and stir until uniform; S5, add bactericide to the solution in step S4, and stir until uniform; S6, add defoaming agent to the solution in step S5, and stir until uniform to obtain the high-temperature alloy cutting fluid according to any one of claims 1-6.

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