Graphene reinforced titanium alloy composite material and preparation method thereof

Abstract

The present application relates to a kind of graphene reinforced titanium alloy composite material, it is in the β type titanium alloy powder mixing its mass 0.3~0.8wt% silver-coated graphene composite powder composition, wherein the silver-coated graphene composite powder is that graphene powder is treated after oil removal, cleavage, sensitization and activation, it is placed in the chemical plating solution containing silver ion, a layer of uniform dense metal silver layer is obtained on the surface of graphene powder to obtain silver-coated graphene powder.The graphene reinforced titanium alloy composite material of the present application is used to prepare β type titanium alloy parts using selective laser melting forming, can effectively enhance the strength, wear resistance and antibacterial properties of β type titanium alloy parts, suitable for preparing porous structure β type titanium alloy metal implant.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metal matrix composite modification, and relates to a graphene modified beta titanium alloy composite material that can be used for selective laser melting forming and a preparation method thereof. BACKGROUND

[0002] The selective laser melting (SLM) metal additive manufacturing technology can quickly and accurately customize a personalized metal implant according to different bone characteristics with a CT / MRI image of a patient's bone tissue as a design prototype, and overcomes the problem of low shape matching of a traditional metal implant to a patient, so the technology is widely concerned in the field of medical customized personalized implants.

[0003] The elastic modulus of beta titanium alloys such as Ti-13Nb-13Zr and Ti-24Nb-38Zr-2Mo is close to that of human bone, can effectively alleviate the stress shielding effect, and reduce the risk of loosening of the metal implant in the long-term use process, so the beta titanium alloys have a very broad application prospect in the field of bone implants. However, the lower elastic modulus of the beta titanium alloy is often accompanied by the decrease of the strength and wear resistance, which affects the service life of the metal implant. Therefore, the preparation of high-strength and wear-resistant beta titanium alloy by using the SLM technology has become a problem that researchers in various countries focus on.

[0004] Graphene (GNSs) has the advantages of high strength, high stiffness and high elasticity, and can be used as a reinforcing phase to improve the strength and wear resistance of the SLM formed beta titanium alloy composite material. However, there are the following problems in the direct mixing of graphene and beta titanium alloy and the SLM forming: 1) the strong van der Waals attraction between the graphene causes local aggregation, which causes defects in the beta titanium alloy; 2) the interfacial reaction between the graphene and the beta titanium alloy in the SLM forming process will destroy the nanostructure on the surface of the graphene, resulting in a significant reduction in the amount of graphene and affecting the strength and wear resistance of the beta titanium alloy.

[0005] Metallic silver, as a traditional biomaterial, has excellent ductility and good antibacterial effect. Coating the metallic silver on the surface of the graphene not only helps to eliminate the aggregation of the graphene, but also protects the graphene from being destroyed in the SLM forming process, so the metallic silver has potential application value in the field of SLM formed graphene reinforced beta titanium alloy composite materials.

[0006] CN 105562707A discloses a preparation method of a silver-graphene composite material. First, a graphene-silver ammonia suspension is prepared, and then a reducing solution is directly added to reduce silver ions to obtain the silver-graphene composite material. The method has the advantages of simple process steps and suitability for mass production, but has the disadvantages of being unable to accurately control the size of silver particles and uneven distribution of the metallic silver on the surface of the graphene, which affects the performance of the silver-graphene composite material. SUMMARY

[0007] The application aims to provide a graphene reinforced titanium alloy composite material and a preparation method thereof, which improves the mechanical properties and antibacterial properties of a β-type titanium alloy part after selective laser melting process forming by mixing silver-coated graphene composite powder in the β-type titanium alloy powder.

[0008] To achieve the above-mentioned application purposes, the graphene reinforced titanium alloy composite material provided by the application is composed of β-type titanium alloy powder mixed with 0.3-0.8wt% silver-coated graphene composite powder, wherein the silver-coated graphene composite powder is obtained by coating a uniform and dense silver layer on the surface of graphene powder after oil removal, cracking, sensitization and activation treatment of the graphene powder in a chemical plating solution containing silver ions.

[0009] Further, the β-type titanium alloy powder can be any one of Ti-13Nb-13Zr, Ti-24Nb-38Zr-2Mo, Ti-30Nb-28Zr-2Mo and the like.

[0010] Further, the average particle size of the β-type titanium alloy powder is preferably 45-55μm.

[0011] The application adopts a chemical plating process to coat a dense silver layer on the surface of graphene powder to obtain silver-coated graphene composite powder, which is mixed in the β-type titanium alloy powder to form the graphene reinforced titanium alloy composite material, so that the silver-coated graphene composite powder is used to prepare a β-type titanium alloy part by selective laser melting forming, and the silver layer on the surface of the silver-coated graphene composite powder forms a defect-free metallurgical bond with the β-type titanium alloy powder in the high-temperature melting process, which not only effectively enhances the strength and wear resistance of the β-type titanium alloy part, but also improves the antibacterial properties of the β-type titanium alloy part as the silver is an antibacterial element.

[0012] Further, the application also provides a preparation method of the graphene reinforced titanium alloy composite material, which comprises the following steps:

[0013] 1) removing oil from graphene powder by an alkaline solution to obtain oil-removed graphene;

[0014] 2) cracking the oil-removed graphene in a potassium dichromate-concentrated sulfuric acid solution to obtain cracked graphene powder;

[0015] 3) sensitizing the cracked graphene powder in a stannous chloride sensitization solution to obtain sensitized graphene powder;

[0016] 4) activating the sensitized graphene powder in a palladium chloride activation solution to obtain activated graphene powder;

[0017] 5) The activated graphene powder is placed in a chemical silver plating solution containing silver ions with pH value of 8-9 for silver plating treatment to obtain silver-coated graphene composite powder with uniform plating;

[0018] 6) The silver-coated graphene composite powder is added into the beta titanium alloy powder at a blending amount of 0.3-0.8 wt% for mechanical blending to prepare graphene reinforced titanium alloy composite material.

[0019] Further, the graphene powder is preferably treated with a sodium hydroxide aqueous solution with a concentration of 5-7 mol / L for oil removal.

[0020] Further, the potassium dichromate-concentrated sulfuric acid solution used for the splitting treatment preferably contains 40-60 g / L of potassium dichromate.

[0021] The potassium dichromate-concentrated sulfuric acid solution has strong oxidizing property, can split the carbon-carbon bonds on the surface of the graphene, and is conducive to the attachment of active sites in the subsequent sensitization and activation process, thereby improving the quality of the silver coating.

[0022] Further, the stannous chloride sensitization solution preferably contains 15-25 g / L of stannous chloride, 100-300 mL / L of concentrated hydrochloric acid, and the rest of deionized water.

[0023] Further, the palladium chloride activation solution preferably contains 0.1-0.3 g / L of palladium chloride, 5-15 mL / L of concentrated hydrochloric acid, and the rest of deionized water.

[0024] The oil removal, splitting, sensitization and activation treatment time of the graphene powder in the present application are preferably 20-40 min, and stirring is assisted during the treatment.

[0025] The present application performs a series of pretreatments including oil removal, splitting, sensitization and activation on the graphene powder before the chemical silver plating treatment, and the palladium element micro-particles are attached to the surface of the graphene powder, so that the surface is easy to adsorb elemental silver, thereby improving the quality of the chemical plating layer.

[0026] In the preparation method, the activated graphene powder is preferably added to the chemical plating solution at a blending amount of 0.12-0.28 g / L for silver plating treatment.

[0027] Further, the chemical plating solution used in the present application is not particularly limited and can be various conventional chemical plating solutions containing silver ions suitable for chemical silver plating.

[0028] Further, the electroless plating solution preferably comprises silver nitrate 0.9-1.6 g / L, PVP 0.625-1.25 g / L, hydrazine hydrate 25-80 mL / L, tartaric acid 1-1.6 g / L, EDTA 1.25-2 g / L, and the rest is deionized water.

[0029] In the electroless plating solution, EDTA is used as a chelating agent to form a complex with silver ions, inhibit the rapid reaction of silver ions with hydrazine hydrate, and reduce the reaction speed, which is conducive to the formation of silver nanoparticles on the surface of graphene. Further, PVP is used as a dispersant, and the N and O atoms on PVP form coordinate bonds with the surface atoms of silver nanoparticles by providing lone pair electrons, which is conducive to the uniform distribution of silver nanoparticles on the surface of graphene.

[0030] Further, the pH value of the electroless plating solution is preferably adjusted to 8-9 using an ammonia solution.

[0031] Further, the activated graphene powder is preferably stirred in the electroless plating solution at 30-40℃ for not less than 1 h to obtain silver-coated graphene composite powder with uniform plating.

[0032] The silver-coated graphene composite powder obtained by the electroless plating process on the surface of graphene has a dense silver-coated layer and uniform layer thickness.

[0033] In the above preparation method, the powders obtained after various treatments, including oil removal, cracking, sensitization, activation, and plating of a silver layer, need to be cleaned. Specifically, the powders are generally cleaned with deionized water for 2-3 times, then cleaned with anhydrous ethanol for 1-2 times, and dried, and each cleaning time should be not less than 5 min.

[0034] Further, the silver-coated graphene composite powder is preferably mixed into β-titanium alloy powder, and the mechanical mixing time is not less than 6 h.

[0035] The graphene-reinforced titanium alloy composite material prepared by the method is suitable for use in the preparation of graphene-reinforced β-titanium alloy parts by selective laser melting, and is particularly suitable for the preparation of β-titanium alloy metal implants with a porous structure.

[0036] The graphene-reinforced titanium alloy composite material prepared by the method is used to prepare β-titanium alloy parts by selective laser melting, and the silver layer on the surface of the composite powder forms a metallurgical bond with the β-titanium alloy at high temperature, so that the β-titanium alloy parts obtained have better strength, wear resistance, and antibacterial properties than silver-graphene-reinforced β-titanium alloy parts prepared by other methods. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is an XRD pattern of the silver-coated graphene powder and the graphene raw material powder prepared in Example 1.

[0038] Figure 2 is an SEM pattern of the silver-coated graphene powder and the graphene raw material powder prepared in Example 1.

[0039] Figure 3 is an energy spectrum pattern of the silver-coated graphene powder prepared in Example 1. Embodiment

[0040] The specific embodiments of the present application are described in further detail below in conjunction with the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present application, so that those skilled in the art can well understand and utilize the present application, and are not intended to limit the protection scope of the present application.

[0041] The production process, experimental method or detection method involved in the embodiments of the present application, if not specifically stated, are all conventional methods in the prior art, and the name and / or abbreviation thereof all belong to the conventional names in the art, which are very clear and explicit in the related application field. Those skilled in the art can understand the conventional process steps and apply the corresponding equipment according to the name, and implement it according to the conventional conditions or the conditions recommended by the manufacturer.

[0042] The various instruments, equipment, raw materials or reagents used in the embodiments of the present application do not have special restrictions on the source, and are all conventional products that can be purchased through normal commercial channels, or can be prepared according to the conventional methods well known to those skilled in the art.

[0043] In the following examples, the yield strength, elastic modulus and elongation of the β-type titanium alloy forming member were tested by using a universal mechanical testing machine, and the wear rate of the β-type titanium alloy forming member was tested by using a wear testing machine.

[0044] In the following examples, the antibacterial properties of different samples were determined according to the method specified in the standard SN / T 2399-2010 "Evaluation method for antibacterial metal materials".

[0045] 0.3 mL of test bacterial solution was added dropwise to the surface of each product in the embodiments of the present application, respectively. The cover film was covered on each product with sterilized tweezers, so that the bacterial solution uniformly contacted the product, and was placed in a sterilized culture dish in a 37℃ constant temperature incubator with humidity of more than 90% for 24h.

[0046] After culture, remove the specimens and add 15 mL of elution buffer to each specimen. Wash the specimens and covering film repeatedly, shake well, and then add 0.1 mL of elution buffer to the nutrient agar medium. Spread the solution evenly with a sterile triangular rake and incubate at 37℃ for 48 h. Then, count the viable bacteria according to GB / T 4789.2-2008. Make three parallel samples for each specimen and calculate the bactericidal rate of the specimens against common bacteria such as Escherichia coli and Staphylococcus aureus. Example

[0047] Example 1

[0048] Weigh 8g of sodium hydroxide and dissolve it in 40mL of deionized water. Add 0.5g of graphene powder and stir for 30min. Centrifuge and dry to obtain oil-free graphene.

[0049] Dissolve 0.2g of potassium dichromate in 1mL of deionized water, add 4mL of 98wt% concentrated sulfuric acid and stir until homogeneous, then add 0.5g of degreased graphene, stir for 30min, centrifuge and dry to obtain pyrolyzed graphene.

[0050] Dissolve 0.675g SnCl2·H2O in 40mL of deionized water, add 5mL of concentrated hydrochloric acid, stir magnetically until clear, then add 0.5g of pyrolyzed graphene, continue stirring for 30min, centrifuge and dry to obtain sensitized graphene.

[0051] Dissolve 0.005g PdCl2 in 45mL of deionized water, then add 0.45mL of concentrated hydrochloric acid and 0.5g of sensitized graphene. Stir for 30min, centrifuge, and dry to obtain activated graphene.

[0052] Add 0.15g AgNO3, 0.1g PVP, 0.16g tartaric acid and 0.2g EDTA to deionized water and stir to dissolve. Then add 6mL hydrazine hydrate and dilute to 160mL with deionized water to prepare a chemical plating solution.

[0053] Adjust the pH of the chemical plating solution to 8-9, add 0.12g of the above-mentioned activated graphene, place it in a 30℃ water bath, stir for 1 hour, let stand for 1 hour, centrifuge and dry to obtain silver-coated graphene composite powder.

[0054] from Figure 1 The X-ray diffraction patterns show that carbon was detected in both graphene and silver-coated graphene composite powders. Elemental silver was also detected in the silver-coated graphene composite powder, indicating that elemental silver was reduced on the graphene surface.

[0055] Figure 2The (a) and (b) in FIG. 1 are scanning electron microscope images of the graphene and silver-coated graphene composite powder, respectively. The (a) shows that the graphene structure is a sheet structure, and the carbon layer has a unique wrinkle structure of graphene; the (b) shows that the silver nanoparticles are uniformly and densely coated on the surface of the graphene particles, which will be conducive to forming a good interface between the silver-coated graphene composite powder and the beta titanium alloy in the selective laser melting forming process.

[0056] Further, according to the silver-coated graphene composite powder of the application, Figure 3 The energy spectrum of the silver-coated graphene composite powder of the application can further show that a large amount of metal silver is uniformly distributed on the surface of the graphene, which can effectively solve the graphene agglomeration problem of the composite powder in the mixing process, reduce the internal defects of the formed component, and improve the material performance.

[0057] Example 2

[0058] According to the doping amount of 0.3wt%, the silver-coated graphene composite powder prepared in Example 1 is doped into the Ti-13Nb-13Zr alloy powder, ball-milled and mixed for 6h to obtain the silver-coated graphene reinforced Ti-13Nb-13Zr composite powder.

[0059] The silver-coated graphene reinforced Ti-13Nb-13Zr alloy part is prepared on the TC4 substrate by the selective laser melting forming process using the EP-M150 type 3D printer of Yi Jia three-dimensional, setting the laser power to 320W, the scanning speed to 1000mm / s, the scanning interval to 0.12mm, and the powder laying thickness to 0.03mm, which is recorded as part 1.

[0060] As a control, the silver-graphene composite material prepared in CN 105562707A is also doped into the Ti-13Nb-13Zr alloy powder at a doping amount of 0.3wt%, ball-milled and mixed for 6h to obtain the silver-graphene reinforced Ti-13Nb-13Zr composite powder, and the same selective laser melting forming process is used to prepare the silver-graphene reinforced Ti-13Nb-13Zr alloy part on the TC4 substrate, which is recorded as part 2.

[0061] The mechanical properties and antibacterial properties of the above formed parts are tested respectively, and the test results are shown in Table 1.

[0062]

[0063] In Table 1, compared with the Ti-13Nb-13Zr alloy part doped with the silver-graphene composite material, the yield strength, ductility and antibacterial property of the Ti-13Nb-13Zr alloy part doped with the silver-coated graphene composite powder prepared by the application are significantly improved at the same doping amount, and the wear rate and elastic modulus are reduced, which is conducive to the application in the field of medical implants.

[0064] Example 3

[0065] 10 g of sodium hydroxide was weighed into 40 mL of deionized water, 0.5 g of graphene powder was added, stirred for 30 min, centrifuged, dried, and graphene without oil was obtained.

[0066] 0.25 g of potassium dichromate was dissolved in 1 mL of deionized water, 4 mL of concentrated sulfuric acid with a concentration of 98 wt% was added, stirred uniformly, 0.5 g of graphene without oil was added, stirred for 30 min, centrifuged, dried, and graphene was obtained.

[0067] 1 g of SnCl2·H2O was dissolved in 40 mL of deionized water, 10 mL of concentrated hydrochloric acid was added, and magnetic stirring was performed until it was clear, 0.5 g of graphene was added, and stirring was continued for 30 min, centrifuged, dried, and sensitized graphene was obtained.

[0068] 0.01 g of PdCl2 was dissolved in 45 mL of deionized water, 0.5 mL of concentrated hydrochloric acid was added, 0.5 g of sensitized graphene was added, stirred for 30 min, centrifuged, dried, and activated graphene was obtained.

[0069] 0.2 g of AgNO3, 0.15 g of PVP, 0.2 g of tartaric acid, and 0.25 g of EDTA were added to deionized water and stirred to dissolve, 9 mL of hydrazine hydrate was added, and deionized water was added to 160 mL to prepare a chemical plating solution.

[0070] The pH value of the chemical plating solution was adjusted to 8-9, 0.2 g of the above activated graphene was added, placed in a 30°C water bath, stirred for 1 h, and allowed to stand for 1 h, centrifuged, and dried to obtain silver-coated graphene composite powder.

[0071] Example 4

[0072] The silver-coated graphene composite powder prepared in Example 3 was mixed into Ti-24Nb-38Zr-2Mo alloy powder at a doping amount of 0.5 wt%, and ball milling was performed for 6 h to obtain silver-coated graphene reinforced Ti-24Nb-38Zr-2Mo composite powder.

[0073] A 3D printer of EP-M150 type from Easy Additive was used, the laser power was set to 320 W, the scanning speed was 1000 mm / s, the scanning interval was 0.12 mm, the powder laying thickness was 0.03 mm, and a silver-coated graphene reinforced Ti-24Nb-38Zr-2Mo alloy part was prepared on a TC4 substrate by a selective laser melting forming process, which is referred to as part 3.

[0074] As a control, the silver-graphene composite material prepared in CN 105562707A was also doped into the Ti-24Nb-38Zr-2Mo alloy powder at a doping amount of 0.5wt%, ball-milled and mixed for 6h to obtain a silver-graphene reinforced Ti-24Nb-38Zr-2Mo composite powder, and a silver-graphene reinforced Ti-24Nb-38Zr-2Mo alloy part was prepared on a TC4 substrate by using the same selective laser melting forming process, which is denoted as part 4.

[0075] The mechanical properties and antibacterial properties of the above formed parts were tested respectively, and the test results are shown in Table 2.

[0076]

[0077] As can be seen from Table 2, compared with the Ti-24Nb-38Zr-2Mo alloy part doped with the silver-graphene composite material, the yield strength, ductility and antibacterial properties of the Ti-24Nb-38Zr-2Mo alloy part doped with the silver-coated graphene composite powder are significantly improved, and the wear rate and elastic modulus are reduced at the same doping amount.

[0078] Example 5

[0079] 12g of sodium hydroxide was weighed into 40mL of deionized water, 0.5g of graphene powder was added, stirred for 30min, centrifuged and dried to obtain oil-removed graphene.

[0080] 0.3g of potassium dichromate was dissolved in 1mL of deionized water, 4mL of concentrated sulfuric acid with a concentration of 98wt% was added and stirred uniformly, and then 0.5g of oil-removed graphene was added, stirred for 30min, centrifuged and dried to obtain cracked graphene.

[0081] 1.375g of SnCl2·H2O was dissolved in 40mL of deionized water, 15mL of concentrated hydrochloric acid was added, and magnetic stirring was performed until it was clear, then 0.5g of cracked graphene was added, and stirring was continued for 30min, and then centrifugation and drying were performed to obtain sensitized graphene.

[0082] 0.015g of PdCl2 was dissolved in 45mL of deionized water, 0.55mL of concentrated hydrochloric acid was added, 0.5g of sensitized graphene was added, stirring was performed for 30min, and then centrifugation and drying were performed to obtain activated graphene.

[0083] 0.25g of AgNO3, 0.2g of PVP, 0.25g of tartaric acid and 0.3g of EDTA were added to deionized water and stirred to dissolve, 12mL of hydrazine hydrate was added, and deionized water was added to a constant volume of 160mL to prepare a chemical plating solution.

[0084] The pH value of the electroless plating solution is adjusted to 8-9, 0.25 g of the activated graphene is added, and the mixture is placed in a 40℃ water bath for stirring for 1 h, standing for 1 h, centrifugation, and drying to obtain the silver-coated graphene composite powder.

[0085] Example 6

[0086] The silver-coated graphene composite powder prepared in Example 5 is mixed into Ti-30Nb-28Zr-2Mo alloy powder at a doping amount of 0.8 wt%, and ball milling is performed for 6 h to obtain silver-coated graphene reinforced Ti-30Nb-28Zr-2Mo composite powder.

[0087] The silver-coated graphene reinforced Ti-30Nb-28Zr-2Mo alloy part is prepared on a TC4 substrate by using an EP-M150 3D printer of Easy Additive, setting the laser power to 320 W, the scanning speed to 1000 mm / s, the scanning interval to 0.12 mm, the powder laying thickness to 0.03 mm, and the selective laser melting forming process, and is denoted as Part 5.

[0088] As a control, the silver-graphene composite material prepared in CN 105562707A is mixed into Ti-30Nb-28Zr-2Mo alloy powder at a doping amount of 0.8 wt%, and ball milling is performed for 6 h to obtain silver-graphene reinforced Ti-30Nb-28Zr-2Mo composite powder, and the silver-graphene reinforced Ti-30Nb-28Zr-2Mo alloy part is prepared on a TC4 substrate by using the same selective laser melting forming process, and is denoted as Part 6.

[0089] The mechanical properties and antibacterial properties of the above formed parts are tested respectively, and the test results are shown in Table 3.

[0090]

[0091] As can also be seen from Table 3, compared with the Ti-30Nb-28Zr-2Mo alloy part doped with the silver-graphene composite material, the yield strength, ductility and antibacterial property of the Ti-30Nb-28Zr-2Mo alloy part doped with the silver-coated graphene composite powder prepared in the application are all significantly improved, and the wear rate and elastic modulus are reduced.

[0092] The above examples of the application do not describe all the details, nor limit the application to the above described examples. Various changes, modifications, replacements and variations made to these examples by those of ordinary skill in the art without departing from the principles and purposes of the application shall be included in the protection scope of the application.

Claims

1. A graphene reinforced titanium alloy composite material, which is composed of a β-type titanium alloy powder as a base, and 0.3-0.8 wt% of a silver-coated graphene composite powder mixed therein, wherein, The beta titanium alloy powder is any one of Ti-13Nb-13Zr, Ti-24Nb-38Zr-2Mo, Ti-30Nb-28Zr-2Mo, the silver-coated graphene composite powder is obtained by coating a uniform and dense silver layer on the surface of graphene powder after oil removal, cracking, sensitization and activation treatment of the graphene powder, and then placing the graphene powder in a chemical plating solution containing silver ions; the specific preparation method comprises the following steps: 1) performing oil removal treatment on the graphene powder with an alkali solution to obtain oil-removed graphene; 2) placing the oil-removed graphene in a potassium dichromate-concentrated sulfuric acid solution for cracking treatment to obtain cracked graphene powder; 3) performing sensitization treatment on the cracked graphene powder in a stannous chloride sensitization solution to obtain sensitized graphene powder; 4) performing activation treatment on the sensitized graphene powder in a palladium chloride activation solution to obtain activated graphene powder; 5) placing the activated graphene powder in a chemical plating solution containing silver ions with a pH value of 8-9 for silver plating treatment to obtain silver-coated graphene composite powder with uniform plating; 6) adding the silver-coated graphene composite powder into the beta titanium alloy powder at a mixing amount of 0.3-0.8 wt% for mechanical mixing to prepare graphene-reinforced titanium alloy composite material.

2. The graphene-reinforced titanium alloy composite of claim 1, wherein The average particle size of the beta titanium alloy powder is 45-55 μm.

3. The graphene-reinforced titanium alloy composite of claim 1, wherein The alkali solution is a sodium hydroxide aqueous solution with a concentration of 5-7 mol / L; the potassium dichromate-concentrated sulfuric acid solution contains 40-60 g / L of potassium dichromate; the stannous chloride sensitization solution contains 15-25 g / L of stannous chloride and 100-300 mL / L of concentrated hydrochloric acid; and the palladium chloride activation solution contains 0.1-0.3 g / L of palladium chloride and 5-15 mL / L of concentrated hydrochloric acid.

4. The graphene-reinforced titanium alloy composite of claim 1, wherein The activated graphene powder is added into the chemical plating solution at a mixing amount of 0.12-0.28 g / L for silver plating treatment.

5. The graphene-reinforced titanium alloy composite of claim 1, wherein The chemical plating solution comprises silver nitrate 0.9-1.6 g / L, PVP 0.625-1.25 g / L, hydrazine hydrate 25-80 mL / L, tartaric acid 1-1.6 g / L, EDTA 1.25-2 g / L, and the rest is deionized water.

6. The graphene-reinforced titanium alloy composite of claim 1, wherein The activated graphene powder is stirred in the chemical plating solution at 30-40 °C for not less than 1 h.

7. The graphene-reinforced titanium alloy composite of claim 1, wherein The silver-coated graphene composite powder is mechanically mixed with the beta titanium alloy powder for not less than 6 h.

8. Application of the graphene-reinforced titanium alloy composite material of claim 1 in the preparation of graphene-reinforced beta titanium alloy parts by selective laser melting.

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