A water-based boron nitride glass lubricant, its preparation method and application

Abstract

This invention discloses a water-based boron nitride glass lubricant, its preparation method, and its application. The water-based boron nitride glass lubricant comprises: 12-36 wt% of a lubricating agent, 1-3 wt% of a dispersant, 8-24 wt% of a binder, and 47-79 wt% of water. The lubricating agent comprises a first lubricating agent and a second lubricating agent. The first lubricating agent comprises boron nitride, and the second lubricating agent comprises at least one of silicon dioxide, graphite, and molybdenum disulfide. The dispersant comprises at least one of a silane coupling agent, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and sodium dodecyl sulfonate. The binder comprises at least one of a water-based polyamide-imide, an inorganic phosphate, and a silicate. The lubricant of this invention has good lubrication effect, excellent friction reduction and anti-wear properties, and can be used at temperatures above 1000°C, avoiding high-temperature oxidation of the workpiece.

Description

Technical Field

[0001] This invention relates to the field of lubricants, and more specifically, to a water-based boron nitride glass lubricant, its preparation method, and its application. Background Technology

[0002] Bonded solid lubricant coatings, also known as dry lubricant films, are generally defined as solid materials with inherent lubricating properties. They are a new type of lubrication technology that disperses solid lubricants in an organic or inorganic binder system and then forms a film on the surface of friction components using a coating process similar to paint, in order to reduce friction and wear. They have developed along with the development of high-tech industries such as aerospace.

[0003] Bonded solid lubricant coatings are not only economical and easy to operate, but also possess excellent anti-wear and friction-reducing properties, a low coefficient of friction, and a wide temperature range. They are commonly used to solve specific tribological problems, especially in applications where fluid lubricants are ineffective or cannot meet requirements. Since NASA developed the first molybdenum disulfide-containing organic bonded solid lubricant coating in 1946, research and application of this type of material have developed rapidly due to its unique properties. my country began research on bonded solid lubricant coatings in the 1960s, developing dozens of varieties of bonded solid lubricant coating materials. These materials have been widely used in aerospace and other military high-tech fields, as well as in civilian machinery industries. They have played a crucial role in solving lubrication and protection problems under a series of special working conditions and have been successfully applied in a range of special industrial and mining conditions such as high temperature, high load, high vacuum, and atomic oxygen. Compared with oil lubricants, bonded solid film lubricants have higher load-bearing capacity; some bonded solid lubricant films have ten times the load-bearing capacity of lubricating oils.

[0004] Extrusion forming is a metal shaping process with minimal or no cutting. During extrusion, the relative sliding between the billet and the extrusion cylinder generates significant friction, leading to uneven metal flow and large differences in microstructure between the surface and the center. It also increases extrusion energy consumption; typically, 30%–40% of the energy is consumed by friction on the inner surface of the extrusion cylinder. The intense frictional heating accelerates the wear of the extrusion die. Therefore, a suitable lubricating coating is necessary for its protection. In hot extrusion forming, the metal billet is heated above its recrystallization temperature, significantly reducing its deformation resistance. However, the high temperature also makes the billet surface prone to oxidation and decarburization defects, resulting in reduced dimensional accuracy and surface quality. Therefore, lubrication in hot extrusion forming mainly includes die lubrication and billet lubrication: the die polishes the surface of the extruded product, and excessive or inappropriate use of lubricant increases surface roughness; the high billet heating temperature makes lubrication difficult, typically requiring lubricants with high thermal stability and insulation properties.

[0005] In the presence of oxygen, graphite begins to oxidize to carbon dioxide (CO2) at temperatures below 400°C, leading to a significant decrease in the material's structural properties. Generally, graphite-based binder solid lubricants are used below 500°C or at room temperature. Above 500°C, lubrication is achieved through soft metal coating, while above 650°C, glass lubricants are required. Glass lubricants represent the most advanced high-temperature lubrication technology currently available; however, different glass lubricants have narrow operating temperature ranges, necessitating the formulation of different glass lubricants based on specific operating temperatures.

[0006] Therefore, there is an urgent need to develop a high-performance glass lubricant that can be used at high temperatures. Summary of the Invention

[0007] This invention is based on the inventor's discovery and understanding of the following facts and problems: glass lubricants are required for temperatures above 650°C. Glass lubricants are currently the most advanced high-temperature lubrication technology, but the operating temperature range of glass lubricants with different components is relatively narrow, and different glass lubricants need to be compounded according to the specific operating temperature.

[0008] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a water-based boron nitride glass lubricant, its preparation method, and its application. The water-based boron nitride glass lubricant exhibits good lubrication performance, excellent friction-reducing and anti-wear properties, an operating temperature above 1000℃, room temperature curing, simple operation, simple post-coating treatment, environmental friendliness, and avoidance of high-temperature oxidation of workpieces.

[0009] This invention provides a water-based boron nitride glass lubricant, comprising: 12-36 wt% of a lubricant, 1-3 wt% of a dispersant, 8-24 wt% of a binder, and 47-79 wt% of water;

[0010] The lubricant comprises a first lubricant and a second lubricant, wherein the first lubricant comprises boron nitride and the second lubricant comprises at least one of silicon dioxide, graphite, and molybdenum disulfide.

[0011] The dispersant includes at least one of silane coupling agent, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and sodium dodecyl sulfonate;

[0012] The binder includes at least one of water-based polyamide-imide, inorganic phosphate, and silicate.

[0013] The advantages and technical effects of the water-based boron nitride glass lubricant of this invention are as follows: The main lubricant of the water-based boron nitride glass lubricant includes boron nitride, and also includes at least one of silicon dioxide, graphite, and molybdenum disulfide, which can significantly improve the lubrication effect. Simultaneously, by using a matching binder, the lubricant can firmly bond to the metal surface to be processed. The use of a water-based carrier liquid composed of water and a dispersant further improves the uniform dispersion and economic performance of the lubricant. It is harmless to the environment and personnel during use. The water-based boron nitride glass lubricant of this invention has good lubrication effect, excellent friction-reducing and anti-wear properties, an operating temperature above 1000℃, room temperature curing, simple operation, simple post-coating treatment, easy coating removal, environmental friendliness, and avoidance of high-temperature oxidation of the workpiece.

[0014] In some embodiments, the mass ratio of the first lubricant to the second lubricant in the lubricant is (4-16):(0-12);

[0015] And / or, the boron nitride has a layered structure;

[0016] And / or, the boron nitride has a particle size of 50–500 nm;

[0017] And / or, the boron nitride is hexagonal boron nitride;

[0018] And / or, the second lubricant has a micron-scale sheet-like structure;

[0019] And / or, the particle size of the second lubricant is 5 to 30 μm.

[0020] In some embodiments, the binder comprises water-based polyamide-imide, inorganic phosphate, and silicate, wherein the mass ratio of the water-based polyamide-imide, inorganic phosphate, and silicate is (0.5–1):(0.5–1):(1.5–2.5).

[0021] And / or, the silicate comprises potassium silicate and / or water glass;

[0022] And / or, the solid content of the water-based polyamide-imide is 26-30%;

[0023] And / or, the inorganic phosphate includes at least one of sodium phosphate, aluminum phosphate, and aluminum chromium phosphate.

[0024] In some embodiments, the mixture further comprises: 0.1 to 1 wt% of defoamer and 0.5 to 1 wt% of antioxidant.

[0025] In some embodiments, the defoamer includes at least one of C7-9 alcohol and polydimethylsiloxane;

[0026] And / or, the antioxidant includes at least one of 2,6-di-tert-butyl-p-cresol, phenolic ester-type ashless antioxidant, bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, and pentaerythritol ester.

[0027] This invention provides a method for preparing a water-based boron nitride glass lubricant, comprising the following steps:

[0028] (1) Mix the dispersant, binder and water to obtain the first mixture;

[0029] (2) The first mixture is mixed with the lubricant to obtain a water-based boron nitride glass lubricant.

[0030] In this embodiment of the invention, the main lubricant of the water-based boron nitride glass lubricant includes boron nitride, and also includes at least one of silicon dioxide, graphite, and molybdenum disulfide, which can significantly improve the lubrication effect of the lubricant. Simultaneously, by using a matching binder, the lubricant can firmly bond to the metal surface to be processed. The use of a water-based carrier fluid composed of water and a dispersant further improves the uniform dispersion and economic performance of the lubricant. It is harmless to the environment and personnel during use. The water-based boron nitride glass lubricant of this invention has good lubrication effect, excellent friction-reducing and anti-wear properties, an operating temperature above 1000℃, room temperature curing, simple operation, simple post-coating treatment, easy coating removal, environmental friendliness, and avoidance of high-temperature oxidation of the workpiece.

[0031] In some embodiments, step (1) further includes an antifoaming agent and an antioxidant, wherein the dispersant, binder, antifoaming agent, antioxidant and water are mixed to obtain a first mixture;

[0032] And / or, the first lubricant and the second lubricant are mixed to obtain the lubricant.

[0033] This invention provides a water-based boron nitride glass lubricating coating, which is obtained by coating the water-based boron nitride glass lubricant described in this invention or the water-based boron nitride glass lubricant prepared by the preparation method described in this invention onto the surface of a substrate.

[0034] In this embodiment of the invention, the water-based boron nitride glass lubricating coating is prepared by applying a water-based boron nitride glass lubricant to the surface of a substrate. The water-based boron nitride glass lubricating coating possesses all the advantages of water-based boron nitride glass lubricants, which will not be elaborated further here. The water-based boron nitride glass lubricating coating exhibits excellent friction-reducing and anti-wear properties, an operating temperature above 1000℃, room temperature curing, simple post-coating treatment, environmental friendliness, and avoidance of high-temperature oxidation of the workpiece. During processing, the water-based boron nitride glass lubricating coating plays a role in reducing friction and preventing wear between relatively moving surfaces. Compared to traditional lubrication methods, the water-based boron nitride glass lubricating coating of this invention can achieve effective lubrication under high-temperature, high-load, and strong-oxidizing environmental conditions without causing pollution, making it particularly suitable for high-temperature extrusion lubrication of difficult-to-machine metals.

[0035] In some embodiments, the thickness of the water-based boron nitride glass lubricating coating is 20–50 μm;

[0036] And / or, the operating temperature of the water-based boron nitride glass lubricating coating is above 1000°C;

[0037] And / or, the substrate is a friction component, preferably, the substrate includes a die and / or blank in a metal extrusion forming process.

[0038] This invention provides an application of the water-based boron nitride glass lubricant described in this invention, or the water-based boron nitride glass lubricant prepared by the preparation method described in this invention, or the water-based boron nitride glass lubricating coating described in this invention, for use in metal extrusion forming processes. This invention possesses all the advantages of both water-based boron nitride glass lubricants and water-based boron nitride glass lubricating coatings, which will not be elaborated further here.

[0039] In some embodiments, the operating temperature is above 1000°C. Attached Figure Description

[0040] Figure 1 This is a thermogravimetric differential thermal analysis (TGA) diagram of the boron nitride powder in Example 1.

[0041] Figure 2 This is a thermogravimetric differential thermal imaging (TGA) diagram of the sample in Example 1.

[0042] Figure 3 This is the friction coefficient curve of the sample in Example 1 at 1000℃.

[0043] Figure 4 This is the friction coefficient curve of the sample in Comparative Example 1 at 1000℃. Detailed Implementation

[0044] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0045] An embodiment of the present invention provides a water-based boron nitride glass lubricant comprising: 12-36 wt% of a lubricant, 1-3 wt% of a dispersant, 8-24 wt% of a binder, and 47-79 wt% of water;

[0046] The lubricant comprises a first lubricant and a second lubricant, wherein the first lubricant comprises boron nitride, and the second lubricant comprises at least one of silicon dioxide, graphite, and molybdenum disulfide; optionally, the second lubricant comprises at least two of silicon dioxide, graphite, and molybdenum disulfide.

[0047] The dispersant includes at least one of silane coupling agent, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and sodium dodecyl sulfonate;

[0048] The binder includes at least one of water-based polyamide-imide, inorganic phosphate, and silicate.

[0049] The water-based boron nitride glass lubricant of this invention comprises boron nitride as the main lubricant, and at least one of silicon dioxide, graphite, and molybdenum disulfide. This significantly improves the lubrication effect. Furthermore, by using a matching binder, the lubricant can firmly bond to the metal surface to be processed. The use of a water-based carrier fluid composed of water and a dispersant further enhances the lubricant's uniform dispersion and economic performance. It is harmless to the environment and personnel during use. The water-based boron nitride glass lubricant of this invention exhibits excellent lubrication performance, superior friction-reducing and anti-wear properties, an operating temperature above 1000℃, room temperature curing, simple operation, simple post-coating treatment, easy coating removal, environmental friendliness, and avoidance of high-temperature oxidation of the workpiece.

[0050] In this embodiment of the invention, by using silica as the second lubricant, the lubrication effect during processing can be further enhanced. Using graphite and molybdenum disulfide as the second lubricant allows for synergistic lubrication with lamellar boron nitride, resulting in more stable lubrication and a longer service life. By using the binder, the coating formed on the workpiece surface can naturally cure at room temperature, and the adhesion and strength of the lubricant on the workpiece surface are significantly improved.

[0051] In some embodiments, the water-based boron nitride glass lubricant comprises 12 to 36 wt% of a lubricant base, specifically, for example, 12 wt%, 18 wt%, 20 wt%, 24 wt%, 30 wt%, or 36 wt%.

[0052] In some embodiments, the water-based boron nitride glass lubricant includes 1 to 3 wt% of a dispersant, specifically, for example, 1 wt%, 2 wt%, or 3 wt%.

[0053] In some embodiments, the water-based boron nitride glass lubricant comprises 8 to 24 wt% binder, specifically, for example, 8 wt%, 12 wt%, or 24 wt%.

[0054] In some embodiments, the water-based boron nitride glass lubricant comprises 47 to 79 wt% water, specifically, for example, 47 wt%, 55 wt%, 66.4 wt%, or 79 wt%.

[0055] In some embodiments, the water-based boron nitride glass lubricant comprises 4 to 16 wt% of a first lubricant, specifically, for example, 4 wt%, 8 wt%, 12 wt%, and 16 wt%; and the water-based boron nitride glass lubricant comprises 0 to 12 wt% of a second lubricant, specifically, for example, 1 wt%, 4 wt%, 8 wt%, and 12 wt%.

[0056] In some embodiments, the mass ratio of the first lubricant to the second lubricant in the lubricant is (4-16):(0-12), specifically, for example, 4:1, 8:12, 12:8, 4:12, 16:12, preferably (4-16):(1-12), and more preferably (8-16):(4-12). In this embodiment of the invention, a further preferred mass ratio of the first lubricant to the second lubricant is beneficial for the coating to exhibit better tribological properties, such as a low coefficient of friction. When the proportion of the first lubricant is too low or 0, the lubrication performance of the coating deteriorates significantly or even fails; when the proportion of the first lubricant is too high, the viscosity of the coating is high and its fluidity is poor during high-temperature extrusion molding, leading to a reduction in tribological properties.

[0057] In some embodiments, the boron nitride has a layered structure; the particle size of the boron nitride is 50-500 nm, specifically, for example, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm.

[0058] In some embodiments, the boron nitride is hexagonal boron nitride. In these embodiments, hexagonal boron nitride (h-BN) as a solid lubricant exhibits low cost, excellent high-temperature lubrication performance, good chemical stability, heat resistance, and electrical insulation, making it suitable for use as a high-temperature lubricant.

[0059] In some embodiments, the second lubricant has a micron-scale sheet structure, i.e., silicon dioxide, graphite, or molybdenum disulfide has a micron-scale sheet structure; the particle size of the second lubricant is 5 to 30 μm.

[0060] In this embodiment of the invention, by using silica as the second lubricant, the lubrication effect during processing can be further enhanced. Micron-sized flake silica is preferably used, as silica possesses high-temperature resistance and oxidation resistance. Under hot extrusion conditions, the micron-sized flake silica can be dispersed within the three-dimensional network formed by the binder, collectively forming a dense protective layer. This allows the flake boron nitride to remain unoxidized in high-temperature atmospheric environments and maintain its two-dimensional layered structure, thereby leveraging its easy-sliding interlayer characteristics and ensuring the high-temperature lubrication performance of the coating. By using graphite and molybdenum disulfide as the second lubricant, a synergistic lubrication effect can be achieved with the flake boron nitride, resulting in more stable lubrication and a longer service life.

[0061] In some embodiments, the binder comprises water-based polyamide-imide, inorganic phosphate, and silicate, wherein the mass ratio of the water-based polyamide-imide, inorganic phosphate, and silicate is (0.5–1):(0.5–1):(1.5–2.5), preferably 1:1:2; and / or, the silicate comprises potassium silicate and / or water glass; the binder comprises water glass and potassium silicate, wherein the mass ratio of water glass to potassium silicate is 10:1; and / or, the solid content of the water-based polyamide-imide is 26–30%; and / or, the inorganic phosphate comprises at least one of sodium phosphate, aluminum phosphate, and aluminum chromium phosphate. In these embodiments, by optimizing the binder formulation, the coating formed on the workpiece surface can be naturally cured at room temperature, and the adhesion and strength of the lubricant on the workpiece surface are significantly improved. The combined use of organic and inorganic binders greatly broadens the operating temperature range of the coating.

[0062] In some embodiments, the product further comprises: 0.1–1 wt% of a defoamer and 0.5–1 wt% of an antioxidant; the defoamer includes C 7-9 At least one of alcohol and polydimethylsiloxane; the defoamer uses C 7-9 In alcohols, C 7-9 The amount of alcohol used is 0.1–1 wt%, specifically, for example, 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, and 1 wt%; when polydimethylsiloxane is used as the defoamer, the amount of polydimethylsiloxane used is 0.1–0.2 wt%; when C is used as the defoamer… 7-9 When alcohols and polydimethylsiloxanes are present, C 7-9 The preferred mass ratio of alcohol to polydimethylsiloxane is 4:1; the antioxidant includes at least one selected from 2,6-di-tert-butyl-p-cresol, phenolic ester-type ashless antioxidant, bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, and pentaerythritol ester. In this embodiment of the invention, the overall performance of the lubricant is further improved by preferably adding defoamers and antioxidants.

[0063] A method for preparing a water-based boron nitride glass lubricant according to an embodiment of the present invention includes the following steps:

[0064] (1) Mix the dispersant, binder and water to obtain the first mixture;

[0065] (2) The first mixture is mixed with the lubricant to obtain a water-based boron nitride glass lubricant.

[0066] In this embodiment of the invention, the main lubricant of the water-based boron nitride glass lubricant includes boron nitride, and also includes at least one of silicon dioxide, graphite, and molybdenum disulfide, which can significantly improve the lubrication effect of the lubricant. Simultaneously, by using a matching binder, the lubricant can firmly bond to the metal surface to be processed. The use of a water-based carrier fluid composed of water and a dispersant further improves the uniform dispersion and economic performance of the lubricant. It is harmless to the environment and personnel during use. The water-based boron nitride glass lubricant of this invention has good lubrication effect, excellent friction-reducing and anti-wear properties, an operating temperature above 1000℃, room temperature curing, simple operation, simple post-coating treatment, easy coating removal, environmental friendliness, and avoidance of high-temperature oxidation of the workpiece.

[0067] In some embodiments, mixing the first mixture with the lubricant is preferably done by adding the lubricant to the first mixture. In these embodiments, this further improves the performance of the prepared water-based boron nitride glass lubricant.

[0068] In some embodiments, step (1) further includes a defoamer and an antioxidant, wherein the dispersant, binder, defoamer, antioxidant and water are mixed to obtain a first mixture.

[0069] In some embodiments, the first lubricant and the second lubricant are mixed to obtain the lubricant; the mixing is performed by grinding.

[0070] This invention provides a water-based boron nitride glass lubricating coating, which is obtained by coating the water-based boron nitride glass lubricant described in this invention or the water-based boron nitride glass lubricant prepared by the preparation method described in this invention onto the surface of a substrate.

[0071] In this embodiment of the invention, the water-based boron nitride glass lubricating coating is prepared by applying a water-based boron nitride glass lubricant to the surface of a substrate. The water-based boron nitride glass lubricating coating possesses all the advantages of water-based boron nitride glass lubricants, which will not be elaborated further here. The water-based boron nitride glass lubricating coating exhibits excellent friction-reducing and anti-wear properties, an operating temperature above 1000℃, room temperature curing, simple post-coating treatment, environmental friendliness, and avoidance of high-temperature oxidation of the workpiece. During processing, the water-based boron nitride glass lubricating coating plays a role in reducing friction and preventing wear between relatively moving surfaces. Compared to traditional lubrication methods, the water-based boron nitride glass lubricating coating of this invention can achieve effective lubrication under high-temperature, high-load, and strong-oxidizing environmental conditions without causing pollution, making it particularly suitable for high-temperature extrusion lubrication of difficult-to-machine metals.

[0072] In some embodiments, the thickness of the water-based boron nitride glass lubricating coating is 20–50 μm.

[0073] In some embodiments, the operating temperature of the water-based boron nitride glass lubricating coating is above 1000°C.

[0074] In some embodiments, the substrate is a friction component; preferably, the substrate includes a die and / or blank in a metal extrusion forming process.

[0075] In some embodiments, coating includes at least one of spraying, dipping, or brushing.

[0076] In some embodiments, the preparation method of the water-based boron nitride glass lubricating coating includes: (1) cleaning the surface of the workpiece to be extruded, removing oil stains, and drying it for later use; (2) stirring or ultrasonically homogenizing the water-based boron nitride glass lubricant of the above embodiment; (3) coating the lubricant onto the surface of the workpiece to be processed and allowing it to dry naturally at room temperature. In the embodiments of the present invention, by using the above coating method to coat the water-based boron nitride glass lubricant of the present invention onto the surface of the workpiece to be processed, the lubricant can form a bonded solid lubricating film with a thickness of 20-50 μm on the surface of the workpiece, thereby further improving the lubrication effect during processing and preventing the workpiece from being oxidized under high temperature conditions. Moreover, after processing at 1000°C and above, the lubricant can be removed by shot blasting. The coating method proposed in this invention has the characteristics of simple operation, short processing time, good lubrication performance, and environmental friendliness.

[0077] This invention provides an application of the water-based boron nitride glass lubricant described in this invention, or the water-based boron nitride glass lubricant prepared by the preparation method described in this invention, or the water-based boron nitride glass lubricating coating described in this invention, for use in metal extrusion forming processes. This invention possesses all the advantages of both water-based boron nitride glass lubricants and water-based boron nitride glass lubricating coatings, which will not be elaborated further here.

[0078] In some embodiments, the operating temperature is above 1000°C.

[0079] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0080] Example 1

[0081] 1. Preparation of water-based boron nitride glass lubricant:

[0082] Raw material composition: 8 wt% boron nitride; 12 wt% silica; 12 wt% silicate binder (water glass:potassium water glass = 10:1); 1 wt% hexadecyltrimethylammonium chloride; 0.1 wt% polydimethylsiloxane; 0.5 wt% 2,6-di-tert-butyl-p-cresol; 66.4 wt% tap water. The boron nitride particle size is ~300 nm, and the silica particle size is 5–10 μm.

[0083] 2. Preparation of water-based boron nitride glass lubricating coating:

[0084] (1) Mix the boron nitride and silicon dioxide in the above weight ratio and grind them to obtain the lubricant.

[0085] (2) Mix the binder, dispersant, defoamer and antioxidant components in the above mass ratio with tap water and stir evenly to obtain a mixed aqueous solution.

[0086] (3) Add the lubricant to the mixed aqueous solution and stir to obtain water-based boron nitride glass lubricant.

[0087] The water-based boron nitride glass lubricant prepared above is sprayed onto the surface of the metal workpiece using a spray gun under compressed air (oil-free) (the surface should be cleaned and free of oil and other surface treatments). The sprayed workpiece is left to cure naturally at room temperature for 5-8 hours.

[0088] 3. Performance testing of water-based boron nitride glass lubricating coating

[0089] This invention uses an RTEC-MFT5000 friction and wear testing machine to test the lubrication performance of a lubricating coating. The specific experimental conditions are as follows:

[0090] Friction pair: Titanium alloy / Si3N4 ball

[0091] Load: 100N

[0092] Rotational speed: 90 mm / s

[0093] Temperature: 1000℃

[0094] Experiment time: 300s

[0095] Note: After the temperature reaches 1000℃, maintain the temperature for 30 minutes before starting the test.

[0096] 4. Test Results

[0097] Under normal conditions, boron nitride has poor stability in an oxygen atmosphere and can be used at temperatures below 1000℃. For example... Figure 1 As shown, the boron nitride used in Example 1 begins to undergo a significant oxidation reaction at 880°C. However, the water-based boron nitride glass lubricant coating formed by the present invention only undergoes a relatively significant oxidation reaction at 1280°C, and only a minor oxidation reaction occurs at around 900°C. This is presumably due to the oxidation of boron nitride on the coating surface. Figure 2 As shown. Therefore, this coating can maintain the layered structure of the lubricant boron nitride in a temperature range below 1280°C, achieving lubrication for extrusion processes at temperatures of 1000°C and above.

[0098] The friction coefficient curve of the sample in Example 1 at 1000℃ is shown below. Figure 3 As shown, the lubricating coating of Example 1, after running and stabilizing within the test time, has a coefficient of friction of ~0.11, which fully meets the lubrication requirements of the extrusion process.

[0099] Example 2

[0100] A water-based boron nitride glass lubricant was prepared using essentially the same method as in Example 1, and the resulting lubricant was used to form a lubricating coating for performance testing. The difference lies in...

[0101] The raw material composition of water-based boron nitride glass lubricant is as follows: 12 wt% boron nitride; 8 wt% silica; 12 wt% silicate binder (water glass: potassium water glass = 10:1); 1 wt% hexadecyltrimethylammonium chloride; 0.1 wt% polydimethylsiloxane; 0.5 wt% 2,6-di-tert-butyl-p-cresol; and 66.4 wt% tap water. The boron nitride has a particle size of ~300 nm, and the silica has an average particle size of 5–10 μm.

[0102] The performance test temperature was 1000℃. The test results showed that, within the test time, the coefficient of friction of the coating stabilized at ~0.15 after running-in, indicating that the lubricating coating could fully meet the lubrication requirements of the extrusion process.

[0103] Example 3

[0104] A water-based boron nitride glass lubricant was prepared using essentially the same method as in Example 1, and the resulting lubricant was used to form a lubricating coating for performance testing. The difference lies in...

[0105] The raw material composition of water-based boron nitride glass lubricant is as follows: 16 wt% boron nitride; 4 wt% silica; 12 wt% silicate binder (water glass: potassium water glass = 10:1); 1 wt% hexadecyltrimethylammonium chloride; 0.1 wt% polydimethylsiloxane; 0.5 wt% 2,6-di-tert-butyl-p-cresol; and 66.4 wt% tap water. The boron nitride has a particle size of ~300 nm, and the silica has an average particle size of 5–10 μm.

[0106] The performance test temperature was 1000℃. The test results showed that, within the test time, the coefficient of friction of the coating stabilized at ~0.14 after running-in, indicating that the lubricating coating could fully meet the lubrication requirements of the extrusion process.

[0107] Example 4

[0108] A water-based boron nitride glass lubricant was prepared using essentially the same method as in Example 1, and the resulting lubricant was used to form a lubricating coating for performance testing. The difference lies in...

[0109] The raw material composition of water-based boron nitride glass lubricant is as follows: 8 wt% boron nitride; 12 wt% graphite; 12 wt% silicate binder (water glass: potassium water glass = 10:1); 1 wt% hexadecyltrimethylammonium chloride; 0.1 wt% polydimethylsiloxane; 0.5 wt% 2,6-di-tert-butyl-p-cresol; and 66.4 wt% tap water. The boron nitride has a particle size of ~300 nm, and the graphite has an average particle size of 10-20 μm.

[0110] The performance test temperature was 1000℃. The test results showed that, within the test time, the coefficient of friction of the coating stabilized at ~0.10 after running-in, indicating that the lubricating coating could fully meet the lubrication requirements of the extrusion process.

[0111] Example 5

[0112] A water-based boron nitride glass lubricant was prepared using essentially the same method as in Example 1, and the resulting lubricant was used to form a lubricating coating for performance testing. The difference lies in...

[0113] The raw material composition of water-based boron nitride glass lubricant is as follows: 8 wt% boron nitride; 12 wt% molybdenum disulfide; 12 wt% silicate binder (water glass: potassium water glass = 10:1); 1 wt% hexadecyltrimethylammonium chloride; 0.1 wt% polydimethylsiloxane; 0.5 wt% 2,6-di-tert-butyl-p-cresol; and 66.4 wt% tap water. The boron nitride has a particle size of ~300 nm, and the molybdenum disulfide has an average particle size of 10-20 μm.

[0114] The performance test temperature was 1000℃. The test results showed that, within the test time, the coefficient of friction of the coating stabilized at ~0.09 after running-in, indicating that the lubricating coating could fully meet the lubrication requirements of the extrusion process.

[0115] Comparative Example 1

[0116] A water-based boron nitride glass lubricant was prepared using essentially the same method as in Example 1, and the resulting lubricant was used to form a lubricating coating for performance testing. The difference lies in...

[0117] Lubricant raw material composition: 12 wt% boron nitride; 12 wt% silicate binder (water glass: potassium water glass = 10:1); 1 wt% hexadecyltrimethylammonium chloride; 0.1 wt% polydimethylsiloxane; 0.5 wt% 2,6-di-tert-butyl-p-cresol; 74.4 wt% tap water. The boron nitride particle size is ~300 nm.

[0118] The performance test temperature was 1000℃. Test results showed that, within the test time, the coating's coefficient of friction stabilized at approximately 0.18 after running-in. Figure 4 As shown, compared to Example 1, the absence of the second lubricant leads to severe oxidation of the first lubricant, resulting in a high viscosity of the product under high temperature conditions. This leads to significant accumulation on the surface of the upper friction pair, which in turn significantly degrades the lubrication performance of the lubricating coating.

[0119] Comparative Example 2

[0120] A water-based boron nitride glass lubricant was prepared using essentially the same method as in Example 1, and the resulting lubricant was used to form a lubricating coating for performance testing. The difference lies in...

[0121] Raw material composition: 4 wt% boron nitride; 12 wt% silicate binder (water glass: potassium water glass = 10:1); 1 wt% hexadecyltrimethylammonium chloride; 0.1 wt% polydimethylsiloxane; 0.5 wt% 2,6-di-tert-butyl-p-cresol; 82.4 wt% tap water. The boron nitride particle size is ~300 nm.

[0122] The performance test temperature was 1000℃. The test results showed that the coefficient of friction of the coating stabilized at ~0.16 after running and stabilizing within the test time. The content of the first lubricant in Comparative Example 2 was lower than that in Comparative Example 1, and the oxidation products at high temperature were also reduced compared with Comparative Example 1, which alleviated the enrichment of the coating on the upper friction pair surface. Therefore, the friction performance was improved compared with Comparative Example 1, but the lubrication performance of the lubricating coating was significantly worse than that in Example 1.

[0123] Comparative Example 3

[0124] A water-based boron nitride glass lubricant was prepared using essentially the same method as in Example 1, and the resulting lubricant was used to form a lubricating coating for performance testing. The difference lies in...

[0125] Raw material composition: 8 wt% boron nitride; 18 wt% silica; 12 wt% silicate binder (water glass:potassium silicate = 10:1); 1 wt% hexadecyltrimethylammonium chloride; 0.1 wt% polydimethylsiloxane; 0.5 wt% 2,6-di-tert-butyl-p-cresol; 60.4 wt% tap water. The boron nitride has a particle size of ~300 nm, and the silica has a particle size of 5–10 μm.

[0126] The performance test temperature was 1000℃. The test results showed that the coefficient of friction of the coating stabilized at ~0.25 after running and stabilizing within the test time. Compared with Example 1, the lubrication performance of the second lubricating agent, silica, was worse than that of the first lubricating agent, boron nitride. Its high content caused the lubrication performance of the lubricating coating to deteriorate significantly.

[0127] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0128] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A water-based boron nitride glass lubricant, characterized in that, include: 20-36 wt% of lubricant, 1-3 wt% of dispersant, 8-24 wt% of binder and 47-66.4 wt% of water; The lubricant is composed of a first lubricant and a second lubricant, wherein the first lubricant is boron nitride and the second lubricant is at least one of graphite and molybdenum disulfide; the mass ratio of the first lubricant to the second lubricant is (8~16):(4~12); the boron nitride has a layered structure; and the second lubricant has a micron-scale sheet-like structure. The dispersant includes at least one of silane coupling agent, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and sodium dodecyl sulfonate; The adhesive is a silicate; The boron nitride has a particle size of 50~500 nm; The particle size of the second lubricant is 10~20 μm.

2. The water-based boron nitride glass lubricant according to claim 1, characterized in that, The boron nitride is hexagonal boron nitride.

3. The water-based boron nitride glass lubricant according to claim 1, characterized in that, The silicate includes water glass.

4. The water-based boron nitride glass lubricant according to claim 1, characterized in that, Further includes: 0.1~1 wt% of defoamer and 0.5~1 wt% of antioxidant.

5. The water-based boron nitride glass lubricant according to claim 4, characterized in that, The defoamer includes at least one of C7-9 alcohol and polydimethylsiloxane; And / or, the antioxidant includes at least one of 2,6-di-tert-butyl-p-cresol, phenolic ester-type ashless antioxidant, bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, and pentaerythritol ester.

6. A method for preparing a water-based boron nitride glass lubricant according to any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Mix the dispersant, binder and water to obtain the first mixture; (2) The first mixture is mixed with the lubricant to obtain a water-based boron nitride glass lubricant.

7. The method for preparing the water-based boron nitride glass lubricant according to claim 6, characterized in that, Step (1) further includes defoamer and antioxidant. Dispersant, binder, defoamer, antioxidant and water are mixed to obtain a first mixture; And / or, the first lubricant and the second lubricant are mixed to obtain the lubricant.

8. A water-based boron nitride glass lubricating coating, characterized in that, A water-based boron nitride glass lubricant coating is obtained by coating the substrate surface with the water-based boron nitride glass lubricant prepared by any one of claims 1 to 5 or by any one of claims 6 to 7.

9. The water-based boron nitride glass lubricating coating according to claim 8, characterized in that, The thickness of the water-based boron nitride glass lubricating coating is 20~50 μm; And / or, the operating temperature of the water-based boron nitride glass lubricating coating is above 1000 ℃; And / or, the substrate is a friction component.

10. The water-based boron nitride glass lubricating coating according to claim 9, characterized in that, The substrate includes dies and / or blanks used in metal extrusion forming processes.

11. The application of a water-based boron nitride glass lubricant according to any one of claims 1 to 5, or a water-based boron nitride glass lubricant prepared by the preparation method according to any one of claims 6 to 7, or a water-based boron nitride glass lubricating coating according to any one of claims 8 to 10, characterized in that, Used in metal extrusion forming processes.

12. The application according to claim 11, characterized in that, The operating temperature is above 1000 ℃.

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