Alloy material for folding device and preparation method thereof

Abstract

The invention discloses an alloy material for a folding device and a preparation method of the alloy material, and belongs to the technical field of alloy materials. The alloy material is prepared from the following components in percentage by weight: 3.3 to 4.6 percent of nano reinforcement, 4 to 5 percent of aluminum, 2.6 to 3.1 percent of carbon, 0.1 to 0.2 percent of tungsten, 0.09 to 0.12 percent of nickel, 0.22 to 0.26 percent of boron, 0.06 to 0.08 percent of neodymium, 0.02 to 0.03 percent of molybdenum and the balance of iron and inevitable impurities. According to the method, the strength and toughness of the material are improved by adjusting the components of the alloy material, meanwhile, the nano reinforcement is prepared, the alloy material is reinforced by synthesizing graphite phase carbon nitride, loading boron oxide and titanium oxide, the strength, toughness and wear resistance of the material are further improved, and the service life of the material is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloy materials, and specifically relates to an alloy material for a folding device and a preparation method thereof. Background Art

[0002] Traditional folding devices rely on complex locking components. For example, in folding bicycles, due to the insufficient strength and toughness of the folding device materials, problems such as fracture and inability to lock are likely to occur after long-term use, seriously affecting the use safety. Titanium alloys have the advantages of light weight and high strength, and have become the preferred materials for folding screen mobile phone hinges and aerospace folding components. At the same time, they show excellent anti-plastic deformation ability during repeated folding and have good fatigue resistance. However, due to their high price, it is difficult to be widely used in products with low added value. High-silicon aluminum alloys have good wear resistance and stiffness, but are prone to fracture during use. Although iron-based alloys have a low price, their various properties are seriously insufficient, being prone to wear, having low strength, and poor toughness. Currently, the commonly used methods to strengthen alloys include: using pinning particles, through in-situ synthesis, and using reinforcements.

[0003] The current existing technologies mainly have the following problems: The currently used iron-based alloy folding devices are prone to wear, have low strength, poor toughness, and have a poor service life. Summary of the Invention

[0004] In view of the above situation, in order to overcome the defects of the existing technologies, the present invention provides an alloy material for a folding device and a preparation method thereof. To solve the problems of easy wear, low strength, and poor toughness of the material, the present invention proposes to adjust the components of the alloy material to improve the strength and toughness of the material. At the same time, a nano-reinforcement is prepared. By synthesizing graphitic carbon nitride and loading boron oxide and titanium oxide to reinforce the alloy material, the strength, toughness, and wear resistance of the material are further improved, thereby improving the service life of the material.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: The present invention provides an alloy material for a folding device, and the alloy material for the folding device includes the following components in weight percentage: nano-reinforcement 3.3 - 4.6%, aluminum 4 - 5%, carbon 2.6 - 3.1%, tungsten 0.1 - 0.2%, nickel 0.09 - 0.12%, boron 0.22 - 0.26%, neodymium 0.06 - 0.08%, molybdenum 0.02 - 0.03%, and the balance is iron and inevitable impurities.

[0006] Preferably, the nano-reinforcement is prepared from the following components in parts by weight: 10 - 15 parts of urea, 2.6 - 2.8 parts of boric acid, and 2 - 3 parts of titanium chloride.

[0007] Preferably, the preparation method of the nano-reinforcement specifically includes the following steps:

[0008] S1. Add urea into a muffle furnace, raise the temperature, keep it warm for 2 h, then cool it down to room temperature, and grind it for 2 - 3 h to obtain graphitic carbon nitride.

[0009] S2. Add the graphitic carbon nitride obtained in S1 into a mixed solution of concentrated sulfuric acid and concentrated nitric acid, stir it in a water bath, filter, wash, and dry it to obtain oxidized graphitic carbon nitride.

[0010] S3. Disperse the oxidized graphitic carbon nitride obtained in S2 in deionized water, ultrasonically disperse it, add boric acid, add titanium chloride, stir it in a water bath, then transfer it to a crucible in a muffle furnace, calcine it at 200 °C for 0.5 h, then raise the temperature to 1100 °C and calcine it for 1 h, and finally cool it down to 800 °C and calcine it for 1 h to obtain a nano - reinforcement.

[0011] Calcining at 200 °C for 0.5 h dehydrates boric acid to obtain pyroboric acid.

[0012] Calcining at 1100 °C for 1 h completely dehydrates boric acid to form boron oxide.

[0013] Meanwhile, the following reactions occur during the calcination process:

[0014] TiCl 4 +O 2 →TiO 2 +Cl 2 ;

[0015] Calcining at 800 °C for 1 h removes trace water.

[0016] Preferably, in S1, the heating rate is 5 - 6 °C, and the heating temperature is 550 - 600 °C.

[0017] Preferably, in S2, the volume ratio of concentrated sulfuric acid to concentrated nitric acid is 1:2 - 3.

[0018] Preferably, in S2, when stirring in a water bath, the temperature is 20 - 25 °C, the speed is 60 - 100 rpm, and the time is 20 - 30 h.

[0019] Preferably, in S3, when stirring in a water bath, the temperature is 50 - 60 °C, the speed is 30 - 50 rpm, and the time is 10 - 12 h.

[0020] The present invention also provides a preparation method of an alloy material for a folding device, which specifically includes the following steps:

[0021] (1) Evacuate a vacuum arc furnace, close the molecular pump and the main pumping valve, and open the gas charging valve to fill argon into its furnace chamber until the vacuum degree reaches - 0.07 MPa.

[0022] (2) After uniformly mixing the raw materials by ball milling, add them into a vacuum arc furnace for arc melting. After melting repeatedly 4 times, take out the alloy ingot, put it into a water-cooled mold, evacuate and melt again. After melting is completed, let it cool naturally to obtain the alloy material for the folding device.

[0023] During the melting process, the following reaction occurs on the nano-reinforcement:

[0024] TiO 2 +B 2 O 3 +Al→TiB 2 +Al 2 O 3 .

[0025] Preferably, in step (1), the vacuum degree of evacuation is 3×10 -3 Pa to 4×10 -3 Pa.

[0026] Preferably, in step (2), the arc melting current is 5000 - 8000 A, the voltage is 30 - 40 V, and the protective gas is argon.

[0027] The beneficial effects achieved by the present invention are as follows: The present invention synthesizes graphitic carbon nitride from urea, loads boron oxide and titanium oxide to prepare nano-reinforcements. By reacting boron oxide and titanium oxide with aluminum during the melting process, titanium diboride and aluminum oxide are formed in the iron-based alloy, and the combination of carbon nitride and the matrix is enhanced, improving the strength, toughness and wear resistance of the material, thereby achieving an increase in the service life of the material; adjusting the components of the alloy material to improve the strength and toughness of the material, enhancing the wear resistance of the alloy and improving the toughness by adding tungsten, increasing the hardenability and improving the mechanical properties of the alloy by using boron, increasing the strength and wear resistance of the alloy by using nickel and neodymium, and improving the stability of the alloy by utilizing the solution strengthening effect of molybdenum on ferrite. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a result graph of the wear amount of the wear test for Examples 1 - 3 and Comparative Examples 1 - 3;

[0029] Figure 2 It is a result graph of the hardness of the hardness test for Examples 1 - 3 and Comparative Examples 1 - 3;

[0030] Figure 3 It is a result graph of the tensile strength for Examples 1 - 3 and Comparative Examples 1 - 3;

[0031] Figure 4 It is a result graph of the fracture elongation rate for Examples 1 - 3 and Comparative Examples 1 - 3.

[0032] The accompanying drawings are used to provide a further understanding of the present invention and form a part of the specification. They are used in conjunction with the embodiments of the present invention to explain the present invention, but do not constitute a limitation to the present invention. Detailed Embodiments

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0034] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the present invention. The preferred implementation methods and materials described herein are only for demonstration purposes and do not limit the content of this application.

[0035] The experimental methods in the following embodiments are all conventional methods unless otherwise specified; the test materials used in the following embodiments are all obtained from commercial channels unless otherwise specified.

[0036] Embodiment 1

[0037] An alloy material for a folding device is prepared from the following components by weight percentage: 3.3% of nano-reinforcement, 4% of aluminum, 2.6% of carbon, 0.1% of tungsten, 0.09% of nickel, 0.22% of boron, 0.06% of neodymium, 0.2% of molybdenum, and the balance is iron and inevitable impurities.

[0038] The nano-reinforcement is prepared from the following components by weight: 10 parts of urea, 2.6 parts of boric acid, and 2 parts of titanium chloride.

[0039] The preparation method of the nano-reinforcement specifically includes the following steps:

[0040] S1. Add urea to a muffle furnace, heat it to 550°C at a rate of 5°C / min, hold for 2 h, then cool to room temperature and grind for 2 h to obtain graphitic carbon nitride;

[0041] S2. Add the graphitic carbon nitride obtained in S1 to a mixed solution of concentrated sulfuric acid and concentrated nitric acid with a volume ratio of 1:2, stir at 60 rpm in a 20°C water bath for 20 h, filter, wash, and dry to obtain oxidized graphitic carbon nitride;

[0042] S3. Disperse the graphitic carbon nitride obtained in S2 in deionized water, ultrasonically disperse it, add boric acid, add titanium chloride, stir at 30 rpm in a water bath at 50 °C for 10 h, then transfer it to a crucible in a muffle furnace, calcine it at 200 °C for 0.5 h, then raise the temperature to 900 °C and calcine for 1 h, and finally cool down to 800 °C and calcine for 1 h to obtain the nano-reinforcement.

[0043] The present invention also provides a preparation method of an alloy material for a folding device, which specifically includes the following steps:

[0044] (1) Evacuate the vacuum arc furnace to a vacuum degree of 3×10 -3 Pa, close the molecular pump and the main pumping valve, open the gas charging valve to fill the furnace with argon until the vacuum degree is -0.07 MPa;

[0045] (2) After uniformly mixing the raw materials by ball milling, add them into the vacuum arc furnace, carry out arc melting with a current of 5000 A, a voltage of 30 V, and argon as the protective gas, take out the alloy ingot after repeatedly melting 4 times, put it into a water-cooled mold, evacuate and melt again, and naturally cool after the melting is completed to obtain the alloy material for the folding device.

[0046] Example 2

[0047] An alloy material for a folding device is prepared from the following components by weight percentage: 4.6% of nano-reinforcement, 5% of aluminum, 3.1% of carbon, 0.2% of tungsten, 0.12% of nickel, 0.26% of boron, 0.08% of neodymium, 0.3% of molybdenum, and the balance is iron and unavoidable impurities.

[0048] The nano-reinforcement is prepared from the following components by weight: 15 parts of urea, 2.8 parts of boric acid, and 3 parts of titanium chloride.

[0049] The preparation method of the nano-reinforcement specifically includes the following steps:

[0050] S1. Add urea into a muffle furnace, raise the temperature to 600 °C at a rate of 6 °C / min, keep it warm for 2 h, then cool it to room temperature, and grind it for 3 h to obtain graphitic carbon nitride;

[0051] S2. Add the graphitic carbon nitride obtained in S1 into a mixed solution of concentrated sulfuric acid and concentrated nitric acid with a volume ratio of 1:3, stir at 100 rpm in a water bath at 25 °C for 30 h, filter, wash, and dry to obtain oxidized graphitic carbon nitride;

[0052] S3. Disperse the graphitic carbon nitride obtained in S2 in deionized water, perform ultrasonic dispersion, add boric acid, add titanium chloride, stir at 50 rpm in a water bath at 60 °C for 12 h, then transfer it to a crucible in a muffle furnace, calcine at 200 °C for 0.5 h, then raise the temperature to 900 °C and calcine for 1 h, and finally cool down to 800 °C and calcine for 1 h to obtain the nano-reinforcement.

[0053] The present invention also provides a preparation method of an alloy material for a folding device, which specifically includes the following steps:

[0054] (1) Evacuate the vacuum arc furnace to a vacuum degree of 4×10 -3 Pa, close the molecular pump and the main pumping valve, open the inflation valve to fill the furnace with argon until the vacuum degree is -0.07 MPa;

[0055] (2) After uniformly mixing the raw materials by ball milling, add them into the vacuum arc furnace, perform arc melting with a current of 8000 A, a voltage of 40 V, and argon as the protective gas. After repeatedly melting 4 times, take out the alloy ingot, put it into a water-cooled mold, evacuate and melt again, and naturally cool after melting to obtain the alloy material for the folding device.

[0056] Example 3

[0057] An alloy material for a folding device is prepared from the following components by weight percentage: 3.9% nano-reinforcement, 4.5% aluminum, 2.9% carbon, 0.15% tungsten, 0.1% nickel, 0.24% boron, 0.07% neodymium, 0.25% molybdenum, and the balance is iron and unavoidable impurities.

[0058] The nano-reinforcement is prepared from the following components by weight: 12.5 parts of urea, 2.7 parts of boric acid, and 2.5 parts of titanium chloride.

[0059] The preparation method of the nano-reinforcement specifically includes the following steps:

[0060] S1. Add urea to a muffle furnace, raise the temperature to 570 °C at a rate of 5.5 °C / min, keep it warm for 2 h, then cool it to room temperature, and grind for 2.5 h to obtain graphitic carbon nitride;

[0061] S2. Add the graphitic carbon nitride obtained in S1 to a mixed solution of concentrated sulfuric acid and concentrated nitric acid with a volume ratio of 1:2.5, stir at 80 rpm in a water bath at 22.5 °C for 25 h, filter, wash, and dry to obtain oxidized graphitic carbon nitride;

[0062] S3. Disperse the graphitic carbon nitride obtained in S2 in deionized water, perform ultrasonic dispersion, add boric acid, add titanium chloride, stir at 40 rpm in a water bath at 55 °C for 11 h, then transfer it to a crucible in a muffle furnace, calcine at 200 °C for 0.5 h, then raise the temperature to 900 °C and calcine for 1 h, and finally cool down to 800 °C and calcine for 1 h to obtain the nano-reinforcement.

[0063] The present invention also provides a preparation method of an alloy material for a folding device, which specifically includes the following steps:

[0064] (1) Evacuate the vacuum arc furnace to a vacuum degree of 3.5×10 -3 Pa, close the molecular pump and the main pumping valve, open the inflation valve to fill the furnace with argon until the vacuum degree is -0.07 MPa;

[0065] (2) After uniformly mixing the raw materials by ball milling, add them into the vacuum arc furnace, perform arc melting with a current of 6000 A, a voltage of 35 V, and argon as the protective gas, take out the alloy ingot after repeatedly melting 4 times, put it into a water-cooled mold, evacuate and melt again, and naturally cool after melting to obtain the alloy material for the folding device.

[0066] Comparative Example 1

[0067] This comparative example provides an alloy material, the difference from Example 1 is only that the component does not contain nano-reinforcement, and the other components and component contents are the same as those in Example 1.

[0068] Comparative Example 2

[0069] This comparative example provides an alloy material, the difference from Example 1 is only that the component does not contain graphitic carbon nitride, and the other components and component contents are the same as those in Example 1.

[0070] Comparative Example 2

[0071] This comparative example provides an alloy material, the difference from Example 1 is only that the component does not contain titanium chloride, and the other components and component contents are the same as those in Example 1.

[0072] Experimental Example

[0073] 1. Wear test

[0074] Respectively take the alloy materials obtained in Examples 1-3 and Comparative Examples 1-3 to prepare specimens with a size of Φ5.5 mm × 30 mm, perform wear tests on the specimens on an ML-100 pin-on-disc abrasive wear testing machine, and use an electronic balance to measure the mass before and after the wear test, and calculate the wear amount according to the following formula:

[0075] Wear amount = mass before experiment - mass after experiment.

[0076] Figure 1 It is a result graph of the wear amount in the wear tests of Examples 1 - 3 and Comparative Examples 1 - 3. As shown in the figure, the wear amounts of Examples 1 - 3 and Comparative Examples 1 - 3 are 6.1 mg, 6.5 mg, 6.9 mg, 11.3 mg, 9.2 mg, and 7.9 mg respectively. The wear amounts of Examples 1 - 3 are significantly lower than those of Comparative Examples 1 - 3, indicating that the use of nano - reinforcements, graphitic carbon nitride, and titanium chloride improves the wear resistance of the alloy material.

[0077] 2. Hardness Test

[0078] The materials obtained from Examples 1 - 3 and Comparative Examples 1 - 3 were made into test blocks of 10 mm×10 mm×10 mm. The surfaces of the specimens were polished clean with sandpaper, and the macro - hardness of the samples was measured using a KB3000BVRZ - SA universal hardness tester. Eight points were measured for each specimen, the experimental load was 50 g, the pressure - holding time was 15 s, and the average value was taken as the hardness of the specimen.

[0079] Figure 2 It is a result graph of the hardness in the hardness tests of Examples 1 - 3 and Comparative Examples 1 - 3. As shown in the figure, the hardnesses of Examples 1 - 3 and Comparative Examples 1 - 3 are 51.3 HRC, 50.1 HRC, 51.6 HRC, 42.3 HRC, 45.6 HRC, and 46.6 HRC respectively. The hardnesses of Examples 1 - 3 are significantly greater than those of Comparative Examples 1 - 3, indicating that the use of nano - reinforcements, graphitic carbon nitride, and titanium chloride improves the hardness of the alloy material.

[0080] 3. Tensile Test

[0081] Specimens were prepared from the alloy materials obtained from Examples 1 - 3 and Comparative Examples 1 - 3 respectively. The thickness of the specimens was 2 mm. A DDL300 type electronic universal testing machine was used for the tensile test, and the tensile speed was 0.6 mm / min to obtain the tensile strength and elongation at break.

[0082] Figure 3 It is a result graph of the tensile strength of Examples 1 - 3 and Comparative Examples 1 - 3. As shown in the figure, the tensile strengths of Examples 1 - 3 and Comparative Examples 1 - 3 are 876 MPa, 873 MPa, 881 MPa, 693 MPa, 732 MPa, and 755 MPa respectively. The tensile strengths of Examples 1 - 3 are significantly stronger than those of Comparative Examples 1 - 3, indicating that the use of nano - reinforcements, graphitic carbon nitride, and titanium chloride improves the tensile strength of the alloy material.

[0083] Figure 4Results graph of the elongation at break of Examples 1-3 and Comparative Examples 1-3. As shown in the figure, the elongations at break of Examples 1-3 and Comparative Examples 1-3 are 22.6%, 21.3%, 21.9%, 10.4%, 12.1%, and 13.5% respectively. The significantly higher elongations at break of Examples 1-3 than those of Comparative Examples 1-3 indicate that the use of nano-reinforcements, graphitic carbon nitride, and titanium chloride improves the elongation at break of the alloy material.

[0084] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention.

[0085] The present invention and its embodiments have been described above. Such description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual application is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design, without creative efforts, ways and embodiments similar to the technical solution without departing from the purpose of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. An alloy material for a folding device, characterized in that: The invention comprises the following ingredients in weight percentage: 3.3-4.6% of nano-reinforcement, 4-5% of aluminum, 2.6-3.1% of carbon, 0.1-0.2% of tungsten, 0.09-0.12% of nickel, 0.22-0.26% of boron, 0.06-0.08% of neodymium, 0.02-0.03% of molybdenum, and the balance is iron and inevitable impurities; the nano-reinforcement is prepared from the following components in weight parts: 10-15 parts of urea, 2.6-2.8 parts of boric acid, and 2-3 parts of titanium chloride.

2. A method for preparing an alloy material for a folding device according to claim 1, characterized in that: The specific steps include: (1) Evacuate the vacuum arc furnace, close the molecular pump and the main pumping valve, and open the gas filling valve to fill the furnace with argon until the vacuum degree is -0.07MPa; (2) The raw materials are mixed evenly by ball milling and then added into a vacuum arc furnace for arc melting. After repeated melting for 4 times, the alloy ingot is taken out and placed into a water-cooled mold for vacuuming and melting again. After melting is completed, the mold is naturally cooled to obtain an alloy material for the folding device.

3. The method for preparing the alloy material for the folding device according to claim 2, characterized in that: The method for preparing the nano-enhancement body specifically comprises the following steps: S1. Add urea into a muffle furnace, raise the temperature, keep it warm for 2 hours, then cool it down to room temperature, and grind it for 2-3 hours to obtain graphite phase carbon nitride; S2, adding the graphite phase carbon nitride obtained in S1 to a mixture of concentrated sulfuric acid and concentrated nitric acid, stirring in a water bath, filtering, washing and drying to obtain oxidized graphite phase carbon nitride; S3. Disperse the graphite oxide phase carbon nitride obtained in S2 in deionized water, ultrasonically disperse, add boric acid, add titanium chloride, stir in a water bath, and then transfer to a crucible in a muffle furnace, calcine at 200°C for 0.5h, then heat to 1100°C for 1h, and finally cool to 800°C for 1h to obtain a nano-reinforcement.

4. The method for preparing the alloy material for the folding device according to claim 3, characterized in that: In S1, the heating rate is 5-6°C and the heating temperature is 550-600°C.

5. The method for preparing the alloy material for the folding device according to claim 4, characterized in that: In S2, the volume ratio of concentrated sulfuric acid to concentrated nitric acid is 1:2-3.

6. The method for preparing the alloy material for the folding device according to claim 5, characterized in that: In S2, stir in a water bath at a temperature of 20-25°C, a speed of 60-100 rpm, and a time of 20-30 h.

7. The method for preparing the alloy material for the folding device according to claim 6, characterized in that: In S3, stir in a water bath at a temperature of 50-60°C, a speed of 30-50 rpm, and a time of 10-12 h.

8. The method for preparing the alloy material for the folding device according to claim 7, characterized in that: In step (1), the vacuum degree of the vacuum pump is 3-4×10 -3 Pa.

9. The method for preparing the alloy material for a folding device according to claim 8, characterized in that: In step (2), the arc melting current is 5000-8000A, the voltage is 30-40V, and the shielding gas is argon.

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