Composite nano-lubricating additive, preparation method and application thereof

Abstract

The application discloses a composite nano-lubricating additive and a preparation method and application thereof. The lubricating additive is prepared by the following steps: dissolving 0.2-0.4 g of a rare earth samarium complex in a mixed solution of 20-30 mL of water and 30-35 mL of ethylene glycol, adding 110-230 g of modified black phosphorus quantum dots, stirring at 45-70 DEG C for 7-8 h, adjusting the pH to 6-7 by using a saturated sodium bicarbonate solution, and finally centrifugally cleaning and vacuum drying the precipitate. The application of the composite nano-lubricating additive is the application in the preparation of a titanium and titanium alloy wire cold drawing lubricant. The black phosphorus quantum dot composite nano-lubricating additive has the excellent characteristics of good wear resistance, good chemical stability, strong dispersing capacity and good adhesion, and can reduce the surface quality problem in the cold drawing process of titanium alloy wire, thereby providing a novel and efficient lubricating medium for the cold drawing lubrication of titanium alloy wire.

Description

Technical Field

[0001] This invention belongs to the field of lubricant technology, specifically relating to a black phosphorus quantum dot composite nano lubricant additive, its preparation method, and its application. Background Technology

[0002] Titanium and titanium alloys are widely used in fasteners and structural components in aerospace and other fields. Due to the high strength, heat resistance, and high deformation resistance of titanium and titanium alloy wires, they are prone to adhesion during drawing, making them difficult-to-machine materials. Furthermore, the frictional resistance generated at the drawing interface negatively impacts the surface quality of the finished product. Therefore, researching an efficient lubricating medium for the cold drawing process of titanium alloy wires is particularly important.

[0003] Rare earth complexes are complexes formed by rare earth elements and organic molecular ligands. They possess excellent synergistic properties, allowing for the controlled design of ligands to achieve superior performance for different purposes. Furthermore, they exhibit structural stability, enabling reliable and long-lasting lubrication. Additionally, rare earth complexes can be designed with different chemical structures to meet various lubrication requirements, making them suitable for a wide range of applications in friction lubrication. Quantum dots typically have particle sizes at the nanometer scale and possess tunable size and surface chemical properties.

[0004] The present invention aims to provide a black phosphorus quantum dot composite nano lubricant and its preparation method. Summary of the Invention

[0005] The first objective of this invention is to provide a black phosphorus quantum dot composite nano lubricant, and the second objective of this invention is to provide a method for preparing the lubricant and its application.

[0006] The first objective of this invention is achieved as follows: a black phosphorus quantum dot composite nano-lubricant additive is prepared by hybridization of rare earth samarium complex and modified black phosphorus quantum dots; the mass ratio of the rare earth samarium complex to the modified black phosphorus quantum dots is 0.2-0.4:110-23.

[0007] The preparation method of the rare earth samarium complex is carried out according to the following steps:

[0008] 1) Dissolve samarium oxide in hydrochloric acid to obtain samarium oxide hydrochloric acid solution, add samarium oxide hydrochloric acid solution to ethylene glycol, stir at 30-45℃ for 1.5-3h to obtain mixed solution A; wherein, the volume ratio of ethylene glycol to samarium oxide hydrochloric acid solution is 1-4:2-5, and the mass-volume ratio of samarium oxide to hydrochloric acid is 0.05-0.08:20-50g / mL;

[0009] 2) Add pyridine-2,6-dicarboxylic acid to ethylene glycol and stir at 45-50℃ for 2-4 hours. The volume-to-mass ratio of ethylene glycol solution to pyridine-2,6-dicarboxylic acid is 20-50:0.05-0.15 mL / g, to obtain mixed solution B;

[0010] 3) Slowly add mixed solution A to mixed solution B and mix. After adjusting the pH value to 6-7, add an aqueous solution of cinnamic acid in ethylene glycol. Stir and heat at 55-70℃ for 4-5 hours and adjust the pH value to 6.5-7. Then transfer to a reaction vessel and react at 100-120℃ for 12-15 hours. The obtained solid is washed by centrifugation with deionized water and anhydrous ethanol 3-4 times respectively. It is then vacuum dried at 55-60℃ for 16-18 hours to obtain a slightly yellow solid precipitate. Then, it is micro-ground to obtain rare earth samarium complex.

[0011] The method for preparing the ethylene glycol aqueous solution of cinnamic acid is to add cinnamic acid to an ethylene glycol solution and mix well. The volume-to-mass ratio of the ethylene glycol aqueous solution to cinnamic acid is 30-60:0.1-0.3 mL / g, and the mass fraction of the ethylene glycol aqueous solution is 20%~25%.

[0012] The second objective of this invention is achieved as follows: the preparation method of the composite nano-lubricant additive is carried out according to the following steps: 0.2-0.4g of rare earth samarium complex is dissolved in a mixed solution of 20-30mL water and 30-35mL ethylene glycol, 110-230g of modified black phosphorus quantum dots are added, and the mixture is stirred at 45-70℃ for 7-8h. The pH is then adjusted to 6-7 using a saturated sodium bicarbonate solution. Finally, the precipitate is centrifuged, washed, and vacuum dried to obtain the composite nano-lubricant additive.

[0013] The application of the composite nano-lubricating additive in the preparation of lubricants for cold drawing of titanium and titanium alloy wires is specifically achieved by adding the lubricating additive to a base mineral oil and then dispersing it ultrasonically to obtain the lubricant for cold drawing of titanium alloy wires.

[0014] The black phosphorus quantum dot composite nano-lubricant additive prepared by the method of this invention is achieved through a combination of complex regulation and surface functionalization. It possesses the sustained lubrication effect achievable with rare earth complexes and the ball bearing effect of modified black phosphorus quantum dots, effectively solving the surface quality problem caused by insufficient lubrication during the cold drawing of titanium alloy wires. By introducing the first ligand, pyridine-2,6-dicarboxylic acid, and the second ligand, cinnamic acid, a stable complex of the rare earth element samarium is formed and hybridized with modified black phosphorus quantum dots, achieving excellent synergistic lubrication performance unattainable by basic mineral oils. Due to the unique electronic structure of rare earth complexes, they can lower the melting point of the contact interface. Similar to two-dimensional materials, the rare earth complex exhibits a hexagonal crystal structure, and the van der Waals forces between layers can significantly reduce friction and wear at the contact interface. The polyethylene glycol-modified black phosphorus quantum dots also possess excellent adsorption and stability. Furthermore, under certain mutual friction, shearing, and collision effects, the modified black phosphorus quantum dots and rare earth complexes achieve uniform mixing in localized areas, thereby improving the dispersion performance and load-bearing capacity of the lubricant. By preparing black phosphorus quantum dot composite nano-lubricant additives, a new and efficient lubricating medium can be provided for the cold drawing process of titanium alloy wires.

[0015] The black phosphorus quantum dot composite nano-lubricant provided by this invention possesses excellent characteristics such as good anti-wear properties, good chemical stability, strong dispersibility, and good adhesion, which can reduce surface quality problems in the cold drawing process of titanium alloy wires. It combines the long-lasting lubrication time of rare earth complexes and the excellent dispersibility of modified black phosphorus quantum dots with the high load-bearing capacity of the stable structure formed by the hybridization of the two, enabling it to achieve a highly efficient synergistic lubrication effect that is incomparable to basic mineral oils. Attached Figure Description

[0016] Figure 1 Friction curves of the lubricants prepared in Examples 1-4 and Comparative Example 1 of this invention;

[0017] Figure 2 The wear rate of the lubricants prepared in Examples 1-4 and Comparative Example 1 of this invention;

[0018] Figure 3 The zeta potential of the lubricating additives prepared in Examples 1-4 of this invention;

[0019] Figure 4 The contact angles of the lubricating additives prepared in Examples 1-4 and Comparative Example 1 of this invention;

[0020] Figure 5 The wear surface morphology of the titanium alloy lubricated with the lubricant prepared in Example 2 is shown in the figure, measured using a HYBRID L7 vacuum color confocal microscope. Detailed Implementation

[0021] The present invention will be further described below, but this is not intended to limit the invention in any way. Any modifications made based on the present invention are within the scope of protection of the present invention.

[0022] This invention discloses a rare earth samarium complex for preparing a lubricating additive, wherein the preparation method of the rare earth samarium complex is carried out according to the following steps:

[0023] 1) Dissolve samarium oxide in hydrochloric acid to obtain samarium oxide hydrochloric acid solution, add samarium oxide hydrochloric acid solution to ethylene glycol, stir at 30-45℃ for 1.5-3h to obtain mixed solution A; wherein, the volume ratio of ethylene glycol to samarium oxide hydrochloric acid solution is 1-4:2-5, and the mass-volume ratio of samarium oxide to hydrochloric acid is 0.05-0.08:20-50g / mL;

[0024] 2) Add pyridine-2,6-dicarboxylic acid to ethylene glycol and stir at 45-50℃ for 2-4 hours. The volume-to-mass ratio of ethylene glycol solution to pyridine-2,6-dicarboxylic acid is 20-50:0.05-0.15 mL / g, to obtain mixed solution B;

[0025] 3) Slowly add mixed solution A to mixed solution B and mix. After adjusting the pH value to 6-7, add an aqueous solution of cinnamic acid in ethylene glycol. Stir and heat at 55-70℃ for 4-5 hours and adjust the pH value to 6.5-7. Then transfer to a reaction vessel and react at 100-120℃ for 12-15 hours. The obtained solid is washed by centrifugation with deionized water and anhydrous ethanol 3-4 times respectively. It is then vacuum dried at 55-60℃ for 16-18 hours to obtain a slightly yellow solid precipitate. Then, it is micro-ground to obtain rare earth samarium complex.

[0026] The method for preparing the ethylene glycol aqueous solution of cinnamic acid is to add cinnamic acid to an ethylene glycol solution and mix well. The volume-to-mass ratio of the ethylene glycol aqueous solution to cinnamic acid is 30-60:0.1-0.3 mL / g, and the mass fraction of the ethylene glycol aqueous solution is 20%~25%.

[0027] In step 1), the mass fraction of hydrochloric acid is 36%~38%.

[0028] In step 3), the centrifugation speed is 6000~8000 r / min and the centrifugation time is 20~30 min.

[0029] In step 3), the pH is adjusted using a saturated sodium bicarbonate solution.

[0030] The present invention also provides a composite nano-lubricant additive based on the rare earth samarium complex, which is prepared by hybridization of the rare earth samarium complex and modified black phosphorus quantum dots; the mass ratio of the rare earth samarium complex to the modified black phosphorus quantum dots is 0.2-0.4:110-230.

[0031] The modified black phosphorus quantum dots were prepared by high-energy ball milling of black phosphorus powder and polyethylene glycol powder, wherein the mass ratio of black phosphorus to polyethylene glycol was 3-4:12-16. The ball milling speed was 500-800 r / min, and the ball milling time was 200-350 h.

[0032] The preparation method of the composite nano-lubricant additive is carried out according to the following steps: 0.2-0.4g of rare earth samarium complex is dissolved in a mixed solution of 20-30mL water and 30-35mL ethylene glycol, 110-230g of modified black phosphorus quantum dots are added, and the mixture is stirred at 45-70℃ for 7-8h. The pH is then adjusted to 6-7 using a saturated sodium bicarbonate solution. Finally, the precipitate is centrifuged, washed, and vacuum dried to obtain the composite nano-lubricant additive.

[0033] The centrifugation speed is 9000~12000 r / min, the cleaning time is 30~40 min, the vacuum drying temperature is 80~90℃, and the drying time is 24~36 h.

[0034] The present invention also provides the application of the composite nano lubricant additive in the preparation of lubricant for cold drawing of titanium and titanium alloy wires. The specific method is to add the lubricant additive to a base mineral oil and disperse it by ultrasonication to obtain a lubricant for cold drawing of titanium alloy wires.

[0035] The base mineral oil is SN150.

[0036] The present invention further provides the application of the aforementioned titanium alloy wire cold drawing lubricant additive in the preparation of titanium and titanium alloy wire cold drawing lubricant. Specifically, the lubricant additive is added to SN150 mineral oil and ultrasonically dispersed to obtain titanium alloy wire cold drawing lubricant.

[0037] Example 1

[0038] (1) Add 0.05 g of samarium oxide to 20 mL of hydrochloric acid solution and wait for it to completely dissolve to obtain samarium oxide hydrochloric acid solution;

[0039] (2) Add 20 mL of samarium oxide hydrochloric acid solution to 10 mL of ethylene glycol, stir at a constant temperature of 30 °C for 1.5 h to obtain mixed solution A;

[0040] (3) Add 0.05 g of pyridine-2,6-dicarboxylic acid to 20 mL of ethylene glycol, stir at 45 °C for 2 h to obtain mixed solution B;

[0041] (4) Add 0.5 mL of mixed solution A slowly to mixed solution B each time, and adjust the pH to 6 with saturated sodium bicarbonate solution to obtain mixed solution C;

[0042] (5) Add 0.1 g of cinnamic acid to 30 mL of ethylene glycol solution, and then add 1 mL dropwise to the mixed solution C. After mixing evenly, stir and heat at 55 °C for 4 h. Adjust the pH to 6.5 with saturated sodium bicarbonate solution, and react in a high-pressure reactor at 100 °C for 12 h. Wash the obtained product three times each with deionized water and anhydrous ethanol at 6000 r / min, centrifuging for 20 min each time. Dry the solid under vacuum at 55 °C for 16 h to obtain a slightly yellow solid precipitate. Finally, grind it for 20 min to obtain the rare earth samarium complex.

[0043] (6) 100g of black phosphorus powder and 400g of polyethylene glycol powder were ball-milled in a high-energy ball mill at a speed of 500r / min for 350h;

[0044] (7) 110g of modified black phosphorus quantum dots were added to 50mL of a mixed solution of rare earth samarium complex in water and ethylene glycol. The mixture was stirred at 45℃ for 7h. The pH was then adjusted to 6 with a saturated sodium bicarbonate solution. The mixture was then washed three times each with deionized water and anhydrous ethanol at a speed of 9000r / min for 30min each time. Finally, the solid obtained was vacuum dried at 80℃ for 24h to obtain a black phosphorus quantum dot composite nano lubricant.

[0045] (8) Add black phosphorus quantum dot composite nano lubricant additive to SN150 mineral oil at a concentration of 10 mg / L and ultrasonically disperse for 40 min to obtain lubricant.

[0046] Example 2

[0047] (1) Add 0.06 g of samarium oxide to 30 mL of hydrochloric acid solution and wait for it to completely dissolve to obtain samarium oxide hydrochloric acid solution;

[0048] (2) Add 30 mL of samarium oxide hydrochloric acid solution to 20 mL of ethylene glycol, stir at 35 °C for 2 h to obtain mixed solution A;

[0049] (3) Add 0.1 g of pyridine-2,6-dicarboxylic acid to 30 mL of ethylene glycol, stir at a constant temperature of 46 °C for 3 h to obtain mixed solution B;

[0050] (4) Add 0.6 mL of mixed solution A slowly to mixed solution B each time, and adjust the pH to 6.2 with saturated sodium bicarbonate solution to obtain mixed solution C;

[0051] (5) Add 0.2 g of cinnamic acid to 40 mL of ethylene glycol solution, and then add 1.1 mL dropwise to the mixed solution C. After mixing evenly, stir and heat at 58 °C for 4.5 h. Adjust the pH to 6.6 with saturated sodium bicarbonate solution, and react in a high-pressure reactor at 102 °C for 13 h. The obtained product is washed three times each with deionized water and anhydrous ethanol at 7000 r / min for 23 min each time. The solid is vacuum dried at 55 °C for 16.5 h to obtain a slightly yellow solid precipitate. Finally, micro-grind for 20 min to obtain the rare earth samarium complex;

[0052] (6) 110g of black phosphorus powder and 440g of polyethylene glycol powder were ball-milled in a high-energy ball mill at a speed of 650r / min for 300h;

[0053] (7) 140g of modified black phosphorus quantum dots were added to 53mL of a mixed solution of rare earth samarium complex in water and ethylene glycol. The mixture was stirred at 46℃ for 7.2h. The pH was then adjusted to 6.2 with a saturated sodium bicarbonate solution. The mixture was then washed three times each with deionized water and anhydrous ethanol at a speed of 10000r / min for 32min each time. Finally, the solid was vacuum dried at 82℃ for 28h to obtain a black phosphorus quantum dot composite nano lubricant.

[0054] (8) Add black phosphorus quantum dot composite nano lubricant additive to SN150 mineral oil at a concentration of 20 mg / L and ultrasonically disperse for 42 min to obtain lubricant.

[0055] Example 3

[0056] (1) Add 0.07 g of samarium oxide to 40 mL of hydrochloric acid solution and wait for it to completely dissolve to obtain samarium oxide hydrochloric acid solution;

[0057] (2) Add 40 mL of samarium oxide hydrochloric acid solution to 30 mL of ethylene glycol, stir at a constant temperature of 38 °C for 2.5 h to obtain mixed solution A;

[0058] (3) Add 0.12 g of pyridine-2,6-dicarboxylic acid to 40 mL of ethylene glycol, stir at a constant temperature of 48 °C for 3.5 h to obtain mixed solution B;

[0059] (4) Add 0.7 mL of mixed solution A slowly to mixed solution B each time, and adjust the pH to 6.5 with saturated sodium bicarbonate solution to obtain mixed solution C;

[0060] (5) Add 0.25 g of cinnamic acid to 50 mL of ethylene glycol solution, and then add 1.3 mL dropwise to the resulting mixed solution C. After mixing evenly, stir and heat at 65 °C for 4.8 h. Adjust the pH to 6.8 with saturated sodium bicarbonate solution and react in a high-pressure reactor at 110 °C for 14 h. Wash the obtained product three times each with deionized water and anhydrous ethanol at 7500 r / min, centrifuging for 28 min each time. Dry the solid under vacuum at 58 °C for 17 h to obtain a slightly yellow solid precipitate. Finally, grind it micro-grind for 28 min to obtain the rare earth samarium complex.

[0061] (6) 115g of black phosphorus powder and 460g of polyethylene glycol powder were ball-milled in a high-energy ball mill at a speed of 750r / min for 200h;

[0062] (7) 220g of modified black phosphorus quantum dots were added to 58mL of a mixed solution of rare earth samarium complex in water and ethylene glycol. The mixture was stirred at 50℃ for 7.5h. The pH was then adjusted to 6.5 with a saturated sodium bicarbonate solution. The mixture was then washed three times each with deionized water and anhydrous ethanol at a speed of 11000r / min for 36min each time. Finally, the solid obtained was vacuum dried at 85℃ for 30h to obtain a black phosphorus quantum dot composite nano lubricant.

[0063] (8) Add black phosphorus quantum dot composite nano lubricant additive to SN150 mineral oil at a concentration of 30 mg / L and ultrasonically disperse for 50 min to obtain lubricant.

[0064] Example 4

[0065] (1) Add 0.08 g of samarium oxide to 50 mL of hydrochloric acid solution and wait for the samarium oxide hydrochloric acid solution to completely dissolve;

[0066] (2) Add 50 mL of samarium oxide hydrochloric acid solution to 40 mL of ethylene glycol, stir at a constant temperature of 45 °C for 3 h to obtain mixed solution A;

[0067] (3) Add 0.15 g of pyridine-2,6-dicarboxylic acid to 50 mL of ethylene glycol, stir at 50 °C for 4 h to obtain mixed solution B;

[0068] (4) Add 1 mL of mixed solution A slowly to mixed solution B each time, and adjust the pH to 7 with saturated sodium bicarbonate solution to obtain mixed solution C;

[0069] (5) Add 0.3 g of cinnamic acid to 60 mL of ethylene glycol solution, and then add 1.5 mL dropwise to the mixed solution C. After mixing evenly, stir and heat at 70 °C for 5 h. Adjust the pH to 7 with saturated sodium bicarbonate solution, and react in a high-pressure reactor at 120 °C for 15 h. Wash the obtained product three times each with deionized water and anhydrous ethanol at 8000 r / min, centrifuging for 30 min each time. Dry the solid under vacuum at 60 °C for 18 h to obtain a slightly yellow solid precipitate. Finally, grind it by micro-grinding for 30 min to obtain the rare earth samarium complex.

[0070] (6) 120g of black phosphorus powder and 480g of polyethylene glycol powder were ball-milled in a high-energy ball mill at a speed of 800r / min for 350h;

[0071] (7) 230g of modified black phosphorus quantum dots were added to a 65mL mixture of water and ethylene glycol of rare earth samarium complex. The mixture was stirred at 70℃ for 8h. The pH was then adjusted to 7 with a saturated sodium bicarbonate solution. The mixture was then washed three times each with deionized water and anhydrous ethanol at a speed of 1200r / min. Finally, the solid was vacuum dried at 90℃ for 36h to obtain a black phosphorus quantum dot composite nano lubricant.

[0072] (8) Add black phosphorus quantum dot composite nano lubricant additive to SN150 mineral oil at a concentration of 40 mg / L and ultrasonically disperse for 55 min to obtain lubricant.

[0073] Detection Example 1

[0074] The tribological properties of the lubricants prepared in Examples 1-4 were studied using a UMT-5 tribological apparatus. A ball-disc contact mode was used to simulate the friction and wear during the drawing process of titanium alloy wire. The load was 10 N, the rotation speed was 100 r / min, the upper friction pair consisted of a GCr15 ball, the lower friction pair consisted of a titanium alloy TC4 plate, and the rotation radius was 3.5 mm. Before the friction test, the surfaces of the friction pairs were repeatedly cleaned with anhydrous ethanol and petroleum ether and then dried. During the test, 200 μL of the lubricant or base mineral oil prepared in Examples 1-4 (Comparative Example 1) was introduced into the contact interface. The test time was 1800 s, and the friction coefficient was recorded as long as the curve on the test platform did not shift backward.

[0075] Comparative Example 2

[0076] 0.5 mg of the rare earth samarium complex prepared in Example 1 was added to 50 mL of base mineral oil, and its tribological properties were studied using a UMT-5 tribological apparatus. The friction and wear during the drawing process of titanium alloy wire was simulated using a ball-disc contact mode. The load was 10 N, the rotation speed was 100 r / min, the upper friction pair consisted of a GCr15 ball, the lower friction pair consisted of a titanium alloy TC4 plate, and the rotation radius was 3.5 mm. Before the friction test, the surfaces of the friction pairs were repeatedly cleaned with anhydrous ethanol and petroleum ether and then dried. 200 μL of lubricant was introduced at the contact interface during the test. The test time was 1800 s. The friction coefficient was recorded after the curve on the test platform did not shift backward, and the average friction coefficient was obtained.

[0077] Comparative Example 3

[0078] (1) Add 90g of black phosphorus and 360g of polyethylene glycol into a high-energy ball mill jar. Ball mill at 500r / min for 200h to obtain modified black phosphorus quantum dots.

[0079] (2) 0.5 mg of modified black phosphorus quantum dots prepared in step (1) were added to 50 mL of base mineral oil, and their tribological properties were studied using a UMT-5 tribometer. The friction and wear of titanium alloy wire during drawing was simulated using a ball-disc contact mode. The load was 10 N, the rotation speed was 100 r / min, the upper friction pair was a GCr15 ball, the lower friction pair was a titanium alloy TC4 plate, and the rotation radius was 3.5 mm. Before the friction test, the surfaces of the friction pairs were repeatedly cleaned with anhydrous ethanol and petroleum ether and then dried. 200 μL of lubricant was introduced into the contact interface during the test. The test time was 1800 s. The curve on the test platform did not shift backward. The friction coefficient was recorded, and the average friction coefficient was obtained. Result analysis:

[0080] Table 1. Average coefficient of friction and diameter of upper frictional wear scar for the lubricants in Examples 1-4 and Comparative Examples 1-3

[0081]

[0082] From Table 1 and Figure 1 It can be seen that the average coefficient of friction and wear scar diameter of the lubricants prepared in Examples 1-4 are smaller than those in Comparative Examples 1-3. The coefficient of friction of the lubricants prepared in this invention is much lower than that of pure mineral oil. Among them, the average coefficient of friction of the lubricant prepared in Example 2 reached 0.19356, which is 49.727% lower than the average coefficient of friction of pure mineral oil (0.38502). The wear rate also showed the same trend as the coefficient of friction, decreasing from Comparative Example 1 to Example 2, and decreasing to 18.68709 (×10). -6 mm 3 / N·m)( Figure 2 ).

[0083] Detection Example 2

[0084] The zeta potentials of the lubricating additives prepared in Examples 1-4 were measured using a Malvern Zetasizer Nano ZS90 instrument. The samples were dispersed in a solvent, maintaining appropriate pH and ionic strength, and then injected into the sample cell of the Zetasizer Nano ZS90 using a pipette tip. After measurement, the Zetasizer software on the instrument's display screen provided detailed zeta potential data for the samples.

[0085] Result: As Figure 3 As shown, the absolute value of the Zeta potential of the lubricating additive prepared in Example 2 is 29.9 mV, and its dispersion stability is better than that of Examples 1, 3 and 4. Therefore, the lubricating additive prepared in Example 2 is the best lubricating additive.

[0086] Detection Example 3

[0087] The contact angles of the lubricants prepared in Examples 1-4 were measured using a self-assembled contact angle measuring instrument. The method was as follows: at room temperature, 1 μL of the lubricant prepared in Examples 1-4 and Comparative Example 1 was added to a titanium alloy TC4 plate using a microsyringe. The device connected to the instrument automatically captured and photographed the image. The contact angle of the lubricant was obtained by taking the average value of multiple measurements using Digimizer software.

[0088] Result: From Figure 4 As can be seen from the above, the contact angles of the lubricants prepared by the present invention are all smaller than those of Comparative Example 1, indicating that the lubricants prepared by the present invention have good wettability on the titanium alloy surface.

Claims

1. A rare earth samarium complex for preparing lubricating additives, characterized in that, The preparation method of the rare earth samarium complex is carried out according to the following steps: 1) Dissolve samarium oxide in hydrochloric acid to obtain samarium oxide hydrochloric acid solution. Add samarium oxide hydrochloric acid solution to ethylene glycol and stir at 30-45℃ for 1.5-3 hours to obtain mixed solution A; wherein, the volume ratio of ethylene glycol to samarium oxide hydrochloric acid solution is 1-4:2-5, the mass-volume ratio of samarium oxide to hydrochloric acid is 0.05-0.08:20-50 g / mL, and the mass fraction of hydrochloric acid is 36%-38%; 2) Add pyridine-2,6-dicarboxylic acid to ethylene glycol and stir at 45~50℃ for 2~4h. The volume-to-mass ratio of ethylene glycol solution to pyridine-2,6-dicarboxylic acid is 20~50:0.05~0.15mL / g to obtain mixed solution B; 3) Slowly add mixed solution A to mixed solution B and mix. After adjusting the pH value to 6-7, add an aqueous solution of cinnamic acid in ethylene glycol. Stir and heat at 55-70℃ for 4-5 hours and adjust the pH value to 6.5-7. Then transfer to a reaction vessel and react at 100-120℃ for 12-15 hours. The obtained solid is washed by centrifugation with deionized water and anhydrous ethanol 3-4 times respectively. It is then vacuum dried at 55-60℃ for 16-18 hours to obtain a slightly yellow solid precipitate. Then, it is micro-ground to obtain rare earth samarium complex. The method for preparing the ethylene glycol aqueous solution of cinnamic acid is to add cinnamic acid to an ethylene glycol solution and mix well. The volume-to-mass ratio of the ethylene glycol aqueous solution to cinnamic acid is 30~60:0.1~0.3mL / g, and the mass fraction of the ethylene glycol aqueous solution is 20%~25%.

2. The rare earth samarium complex according to claim 1, characterized in that, In step 3), the centrifugation speed is 6000~8000 r / min and the centrifugation time is 20~30 min.

3. The rare earth samarium complex according to claim 1, characterized in that, In step 3), the pH is adjusted using a saturated sodium bicarbonate solution.

4. A composite nano-lubricant additive based on rare earth samarium complexes, characterized in that, The composite nano-lubricant additive is prepared by hybridization of the rare earth samarium complex described in claim 1 and modified black phosphorus quantum dots, wherein the mass ratio of the rare earth samarium complex to the modified black phosphorus quantum dots is 0.2~0.4:110~230; the modified black phosphorus quantum dots are prepared by high-energy ball milling of black phosphorus powder and polyethylene glycol powder, wherein the mass ratio of black phosphorus to polyethylene glycol is 3~4:12~16, the ball milling speed is 500~800 r / min, and the ball milling time is 20 minutes. The preparation method of the composite nano-lubricant additive is carried out according to the following steps: 0.2~0.4g of rare earth samarium complex is dissolved in a mixed solution of 20~30mL water and 30~35mL ethylene glycol, 110~230g of modified black phosphorus quantum dots are added, and the mixture is stirred at 45~70℃ for 7~8h. The pH is adjusted to 6~7 using a saturated sodium bicarbonate solution. Finally, the precipitate is centrifuged, washed, and vacuum dried to obtain the composite nano-lubricant additive.

5. The composite nano-lubricant additive according to claim 4, characterized in that, The centrifugation speed in the preparation method is 9000~12000 r / min, the washing time is 30~40 min, the vacuum drying temperature is 80~90℃, and the drying time is 24~36 h.

6. The application of the composite nano-lubricant additive of claim 4 in the preparation of lubricant for cold drawing of titanium and titanium alloy wires, characterized in that, The composite nano-lubricant additive is added to a base mineral oil and ultrasonically dispersed to obtain a lubricant for cold drawing of titanium alloy wire.

7. The application according to claim 6, characterized in that, The base mineral oil is SN150.

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