High-wear-resistance graphene reinforced titanium alloy composite material as well as preparation method and application thereof

Abstract

The invention discloses a high-wear-resistance graphene reinforced titanium alloy composite material and a preparation method and application thereof. The invention belongs to the field of titanium-based composite materials. The invention aims to provide the titanium alloy composite material capable of effectively inhibiting a chemical reaction between graphene and a TC4 alloy matrix so as to remarkably improve the wear resistance of the composite material, and the preparation method and the application of the titanium alloy composite material. The method comprises the following steps: uniformly mixing TC4 powder, graphene powder and SiC nanoparticles in a three-dimensional mixer, carrying out cold pressing to form a green body, and carrying out vacuum arc melting in a water-cooled copper crucible. The graphene structure in the obtained composite material is complete and exists in TiC generated through in-situ chemical reaction with a matrix. The method is used in the fields of aerospace part manufacturing, automobile engine manufacturing and fastener manufacturing.

Description

Technical Field

[0001] The present invention belongs to the field of titanium matrix composites, and particularly relates to a high-wear-resistant graphene-reinforced titanium alloy composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Ti6Al4V (TC4) alloy is widely used in different fields due to its high specific strength, excellent corrosion resistance, and good biocompatibility. In the aerospace field, it is used to manufacture aircraft engine components, wing structural components, etc., which can reduce the weight of the aircraft and improve fuel efficiency; in the biomedical field, it is commonly used to make artificial joints, dental implants, etc., which can reduce the risk of human rejection. However, the TC4 alloy has poor wear resistance under sliding friction conditions. For example, in an automotive engine, the piston and the cylinder wall slide relative to each other frequently, and the TC4 alloy components are easily worn, resulting in a decline in engine performance, an increase in fuel consumption, and even failures, seriously affecting the service life and reliability of the equipment, and restricting its further application in fields with high wear resistance requirements.

[0003] To improve the wear resistance of the TC4 alloy, traditional methods such as heat treatment and alloy element modification are adopted. Although heat treatment can change the alloy microstructure and increase hardness, the improvement in wear resistance is limited, and excessive heat treatment will reduce the alloy toughness and increase the risk of brittle fracture. Alloy element modification is to add other elements such as Mo, Cr, etc. to the TC4 alloy, attempting to form new alloy phases to improve wear resistance. However, the improvement effect of these methods is limited, unable to meet the strict requirements of modern industry for high-performance materials, and will also increase the material cost and affect the processing performance. Introducing graphene as a reinforcing phase into the TC4 alloy to prepare titanium matrix composites is a current research hotspot. Graphene has excellent mechanical properties, excellent thermal conductivity, and unique self-lubricating properties, and is an ideal reinforcing phase for enhancing the wear resistance of materials. However, the high temperature during the material preparation process will cause a strong in-situ chemical reaction between graphene and the TC4 alloy matrix to generate TiC, destroying the graphene structure and making its self-lubricating effect unable to be effectively exerted, making it difficult to achieve the improvement of the wear resistance of the composite material, and restricting the practical application of graphene-reinforced titanium matrix composites in terms of wear resistance.

[0004] Currently, the preparation methods of titanium matrix composites mainly include powder metallurgy and vacuum arc melting. The powder metallurgy method mixes metal powders with a reinforcing phase and then compresses and sinters them to make composites. Although it can achieve uniform distribution of the reinforcing phase, it will introduce pores. These pores not only reduce the material density but also become stress concentration points, seriously affecting the mechanical properties and wear resistance of the material. The vacuum arc melting method uses the high temperature of the arc to melt the raw materials to prepare dense materials. However, the high temperature during the melting process will cause graphene to completely react with the matrix, destroying the graphene structure and making it unable to play the role of reinforcement and self-lubrication, affecting the comprehensive performance of the composite material. Summary of the Invention

[0005] The object of the present invention is to provide a titanium alloy composite material, a preparation method and an application thereof, which can effectively inhibit the chemical reaction between graphene and a TC4 alloy matrix, thereby significantly improving the wear resistance of the composite material.

[0006] One of the objects of the present invention is to provide a method for preparing a high wear-resistant graphene-reinforced titanium alloy composite material, and the method is carried out according to the following steps:

[0007] Put TC4 powder, graphene powder and SiC nanoparticles into a three-dimensional mixer and mix evenly, then first cold press into a blank, and then put it into a water-cooled copper crucible for vacuum arc melting.

[0008] Further defined, the graphene is few-layer graphene, the mass of the graphene powder is 0.3-0.5% of the sum of the masses of the TC4 powder and the graphene powder, and the mass of the SiC nanoparticles is 25-35% of the graphene powder.

[0009] Further defined, the particle size of the TC4 powder is 100-300 μm, the particle size of the SiC nanoparticles is 30-50 nm, and the particle size of the graphene powder is 5-10 μm.

[0010] Further defined, the rotation speed of the mixer is 100-200 r / min, and the mixing time is 0.5-1.5 h.

[0011] Further defined, the cold pressing pressure is 30-50 MPa, and the time is 10-30 s.

[0012] Further defined, the water temperature of the water-cooled copper crucible is 15-25 °C.

[0013] Further defined, the current of the vacuum arc melting is 100-300 A, and the time is 30-120 s.

[0014] Further defined, after melting, the ingot is taken out after cooling in the water-cooled copper crucible for 20-40 min.

[0015] Another object of the present invention is to provide a high wear-resistant graphene-reinforced titanium alloy composite material prepared by the above method.

[0016] Another object of the present invention is to provide an application of the high wear-resistant graphene-reinforced titanium alloy composite material prepared by the above method in the manufacture of aerospace components, the manufacture of automotive engines, and the manufacture of fasteners.

[0017] The remarkable effects of the present invention compared with the prior art:

[0018] (1) The method of the present invention combines powder metallurgy and vacuum arc melting. By utilizing the pre-uniformity characteristic of powder metallurgy, the raw materials are fully mixed and pressed into compacts before melting, reducing the melting reaction time and the risk of damage to the graphene structure at high temperatures. By taking advantage of the good densification of the materials prepared by vacuum arc melting, voids that may appear in the materials are eliminated, and the wear resistance is improved.

[0019] (2) The present invention further weakens the in-situ chemical reaction degree between graphene and the TC4 alloy matrix by precisely controlling the current and time of vacuum arc melting; meanwhile, the in-situ chemical reaction between graphene and the TC4 alloy matrix is inhibited by introducing SiC nanoparticles. During melting, the SiC nanoparticles react with the matrix first. The solid solution of Si and the formation of TiC with the matrix change the subsequent reaction form between graphene and the matrix, protecting the integrity of the graphene structure. At the same time, the diffusion of C in graphene and the in-situ reaction at the matrix interface form a small amount of TiC nano-transition layer, which, as a transition layer connecting graphene and the matrix, effectively enhances the interfacial bonding strength between graphene and the matrix, having a positive impact on the wear resistance of the composite material. Description of the Drawings

[0020] Figure 1 XRD patterns of the composite materials obtained in Example 1 of the present invention and Comparative Examples 1-2;

[0021] Figure 2 Raman spectra of the composite materials obtained in Example 1 of the present invention and Comparative Examples 1-2;

[0022] Figure 3 SEM-EDS images of the composite material obtained in Example 1 of the present invention;

[0023] Figure 4 TEM images of the composite material obtained in Example 1 of the present invention in different modes;

[0024] Figure 5 SEM images of the composite material obtained in Comparative Example 1;

[0025] Figure 6 TEM-EDS images of the composite material obtained in Comparative Example 1;

[0026] Figure 7 SEM images of the composite material obtained in Comparative Example 2;

[0027] Figure 8 TEM-EDS images of the composite material obtained in Comparative Example 2;

[0028] Figure 9 Mechanical property test results of the composite materials obtained in Example 1 of the present invention and Comparative Examples 1-2. Detailed Embodiments

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified. The materials, reagents, methods and instruments used, unless otherwise specified, are all conventional materials, reagents, methods and instruments in this field, and those skilled in the art can obtain them through commercial channels.

[0031] The terms "comprising", "including", "having", "containing" or any other variation thereof used in the following embodiments are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or device containing the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article or device.

[0032] As used herein, "one embodiment" or "an embodiment" means a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that exclude each other from other embodiments.

[0033] In the present invention, the endpoints and any values of the disclosed ranges are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0034] In the following embodiments, the purity of TC4 powder is not less than 99.99%, and the particle size is 100 - 300 μm; the purity of SiC nanoparticles is not less than 99.99%, and the particle size is 30 - 50 nm; the graphene is few-layer graphene, the purity is not less than 99.99%, and the particle size is 5 - 10 μm.

[0035] Example 1

[0036] (1) Weigh the weight using an electronic balance, and mix TC4 powder, graphene powder and SiC nanoparticles in a mass ratio of 99.6:0.4:0.12 for 1 h at a rotation speed of 150 r / min using a three-dimensional mixer to obtain a mixed powder;

[0037] (2) Use a tablet press to press the mixed powder into a green body under a pressure of 40 MPa for 20 s.

[0038] (3) Place the green body into a water-cooled copper crucible until it is flush with the crucible. The crucible has a diameter of 60 mm and a height of 20 mm, and the water temperature is 20 °C.

[0039] (4) Close the furnace door of the vacuum arc melting system and evacuate to a vacuum of 5 ± 0.5 × 10 -3 Pa. Then introduce argon and melt for 30 s at a current of 300 A.

[0040] (5) After melting, cool in the water-cooled copper crucible for 30 min and then take out the ingot.

[0041] As Figure 1 shown, the X-ray diffraction results show that: there are α-Ti phase and trace amounts of TiC phase in the composite material, indicating that graphene has undergone a small degree of in-situ chemical reaction with the matrix to generate TiC.

[0042] As Figure 2 shown, the Raman spectroscopy detection results show that: the intensity ratio (I D / I G ) of the D peak and G peak of graphene is low, and graphene has almost no defects.

[0043] As Figures 3-4 shown, the scanning electron microscopy and transmission electron microscopy test results show that: in the composite material, graphene exists in the in-situ generated TiC, its structure is relatively complete, the layered structure characteristics are obvious, and it forms a "sandwich" structure with TiC.

[0044] As Figure 9 shown, the mechanical property test shows that: the tensile strength is 925.74 MPa, the tensile modulus is 1559.34 MPa, and the tensile strength and tensile modulus are significantly improved compared with the pure TC4 alloy, increasing by 11.74% and 29.35% respectively.

[0045] The pin-on-disc friction and wear test shows that: with a Cr12MoV steel as the friction disc, under the conditions of a load of 50 N, a rotational speed of 200 r / min, and a friction diameter of 24 mm, the wear amount of the composite material is 324.3 × 10 -15 m 3 / N·m, and the wear rate is reduced by more than 25.29% compared with the pure TC4 alloy, and is reduced by more than 23.17% compared with the composite material without adding SiC nanoparticles processed under the same current and time.

[0046] Comparative Example 1

[0047] The main difference between this comparative example and Example 1 is that SiC is not introduced. The specific operation is as follows:

[0048] (1) Weigh the weight using an electronic balance, and mix the TC4 powder and graphene powder in a mass ratio of 99.6:0.4 for 1 h by a three-dimensional mixer at a rotation speed of 150 r / min;

[0049] (2) Press the mixed powder into a green body by a tablet press under a pressure of 40 MPa for 20 s;

[0050] (3) Place the green body into a water-cooled copper crucible until it is flush with the crucible. The diameter of the crucible is 60 mm, the height is 20 mm, and the water temperature is 20 °C;

[0051] (4) Close the furnace door of the vacuum arc melting system, evacuate to a vacuum degree of 5 ± 0.5×10 -3 Pa, and then introduce argon gas and melt for 30 s at a current of 300 A;

[0052] (5) After melting, cool in the water-cooled copper crucible for 30 min and then take out the ingot.

[0053] As Figure 1 shown, the X-ray diffraction results found that: there are α-Ti phase and a certain amount of TiC phase in the composite material, indicating that a certain degree of in-situ chemical reaction has occurred between graphene and the matrix to generate TiC.

[0054] As Figure 2 shown, the Raman spectroscopy detection results found that: the intensity ratio (I D / I G ) of the D peak and G peak of graphene is relatively high, and the degree of graphene defects is relatively large.

[0055] As Figures 5-6 shown, the scanning electron microscopy and transmission electron microscopy tests found that: in the composite material, only a small amount of graphene can be observed in TiC.

[0056] As Figure 9 shown, the mechanical property tests found that: the tensile strength is 853.23 MPa, the tensile modulus is 1308.66 MPa, and the tensile strength and tensile modulus are slightly increased compared with the pure TC4 alloy, from 828 MPa to 853 MPa;

[0057] The pin-on-disk friction and wear test found that: the wear volume of the composite material is 422.1×10 -15 m 3 / N·m, and the wear rate is only reduced by about 3% compared with the pure TC4 alloy.

[0058] Comparative Example 2

[0059] The main difference between this comparative example and Example 2 lies in the current magnitude and melting time. The specific operations are as follows:

[0060] (1) Weigh the weight using an electronic balance, and mix TC4 powder and graphene powder in a mass ratio of 99.6:0.4 for 1 h at a rotation speed of 150 r / min by a three-dimensional mixer;

[0061] (2) Use a tablet press to press the mixed powder into a green body under a pressure of 40 MPa for 20 s;

[0062] (3) Place the green body into a water-cooled copper crucible until it is flush with the crucible. The diameter of the crucible is 60 mm, the height is 20 mm, and the water temperature is 20 °C;

[0063] (4) Close the furnace door of the vacuum arc melting system, evacuate to a vacuum degree of 5 ± 0.5 × 10 -3 Pa, then introduce argon and melt for 15 s at a current of 400 A;

[0064] (5) After melting, cool in the water-cooled copper crucible for 30 min and then take out the ingot.

[0065] As Figure 1 shown, the X-ray diffraction results show that: there are α-Ti phase and a large amount of TiC phase in the composite material, indicating that a violent in-situ chemical reaction has occurred between graphene and the matrix to generate TiC;

[0066] As Figure 2 shown, the Raman spectroscopy detection results show that: the D peak and G peak of graphene are not found, and graphene has completely reacted to form TiC.

[0067] As Figures 7-8 shown, the scanning electron microscope and transmission electron microscope test results show that: in the composite material, graphene only has TiC formed by in-situ reaction.

[0068] As Figure 9 shown, the mechanical property test shows that: the tensile strength is 828.49 MPa and the tensile modulus is 1205.51 MPa.

[0069] The pin-on-disc friction and wear test shows that: the wear amount of the composite material is 434.1 × 10 -15 m 3 / N·m.

[0070] As mentioned above, only the preferred specific embodiments of the present invention are described. These specific embodiments are all different implementation manners based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for preparing a highly wear-resistant graphene-reinforced titanium alloy composite material, characterized in that: The method: TC4 powder, graphene powder and SiC nanoparticles are placed in a three-dimensional mixer and mixed evenly, then cold-pressed into a green body and then placed in a water-cooled copper crucible for vacuum arc melting.

2. The method according to claim 1, characterized in that The graphene is a few-layer graphene, the mass of the graphene powder is 0.3-0.5% of the sum of the mass of the TC4 powder and the graphene powder, and the mass of the SiC nanoparticles is 25-35% of the graphene powder.

3. The method according to claim 1, characterized in that The particle size of TC4 powder is 100-300μm, the particle size of SiC nanoparticles is 30-50nm, and the particle size of graphene powder is 5-10μm.

4. The method according to claim 1, characterized in that: The mixer speed is 100-200r / min and the mixing time is 0.5-1.5h.

5. The method according to claim 1, characterized in that The cold pressing pressure is 30-50MPa and the time is 10-30s.

6. The method according to claim 1, characterized in that The water temperature of the water-cooled copper crucible is 15-25℃.

7. The method according to claim 1, characterized in that The current of vacuum arc melting is 100-300A and the time is 30-120s.

8. The method according to claim 1, characterized in that After smelting, cool the ingot in a water-cooled copper crucible for 20-40 minutes and then take it out.

9. A highly wear-resistant graphene reinforced titanium alloy composite material prepared by the method according to any one of claims 1 to 8.

10. Application of the highly wear-resistant graphene-reinforced titanium alloy composite material prepared by the method according to any one of claims 1 to 8 in the manufacture of aerospace parts, automobile engines, and fasteners.

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