Preparation method of titanium alloy surface porous micro-nano structure

Abstract

The invention discloses a preparation method of a titanium alloy surface porous micro-nano structure, which comprises the following steps: cutting a titanium alloy into a required size, polishing with abrasive paper, and then carrying out two times of acid pickling and electrochemical treatment; and after electrochemical treatment, a titanium alloy sample is subjected to ultrasonic cleaning with distilled water and absolute ethyl alcohol for 10 min, after cleaning, the titanium alloy sample is dried for 20 min at the temperature of 80 DEG C in an electrothermal blowing constant-temperature drying box, and preparation is completed. A lock catch structure is formed by a hole structure on the surface of metal and a polymer column, high-strength combination of the metal and the polymer is achieved through the anchor bolt effect, the roughness and porosity of the prepared titanium alloy porous structure are remarkably improved, and the combination strength of the titanium alloy and plastic injection molding can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of nano-molding, and in particular to a method for preparing a porous micro-nano structure on the surface of a titanium alloy. Background Art

[0002] Titanium alloys are widely used in key parts of automobiles, such as braking systems, exhaust systems, chassis and suspension systems, due to their light weight, high strength, easy processing and corrosion resistance. In addition, titanium alloys are also used to manufacture lightweight parts, such as wheels, frames, doors and roofs, to improve vehicle fuel efficiency, reduce vehicle weight, enhance structural strength, and improve durability. Especially for the new energy vehicles that are being vigorously developed, it is required to reduce the body weight to improve the endurance of the vehicle while ensuring the strength of the body, which has a broad application prospect.

[0003] However, the density of titanium alloy is higher than that of aluminum alloy, which may increase the production cost and the weight of the car. 30% glass fiber reinforced polyphenylene sulfide (PPS) product filled with 30% glass fiber (hereinafter referred to as 30% glass fiber reinforced PPS) is a reinforced polymer composite material with high strength, high stiffness, good impact resistance, heat resistance, corrosion resistance, light weight, good dimensional stability, improved production performance and other advantages. It is widely used in automotive parts. Although 30% glass fiber reinforced PPS has good strength, its strength is still slightly worse than that of metal. By connecting TC4 titanium alloy with 30% glass fiber reinforced PPS, the requirements of light weight and high strength of the material can be met at the same time, and the defect that 30% glass fiber reinforced PPS may be damp when exposed to a humid environment for a long time, thereby reducing the performance of the material, can be avoided. Therefore, nano-molding technology is used to nano-treat the surface of the titanium alloy so that it has a special surface structure and properties. Then the plastic material is directly injection molded to make it closely bonded with the nano-treated titanium alloy surface.

[0004] However, as the market's performance requirements for titanium alloy-plastic composite materials increase, higher requirements are also placed on the bonding strength between titanium alloy and plastic. Among them, one of the key factors affecting the bonding strength of titanium alloy-plastic is the porous micro-nano structure on the surface of titanium alloy. By studying new treatment methods and optimizing the process, excellent titanium alloy surface morphology can be prepared to improve the bonding strength between titanium alloy and plastic. Summary of the invention

[0005] The purpose of the present invention is to solve the defects in the prior art and to propose a method for preparing a porous micro-nano structure on the surface of a titanium alloy.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing a porous micro-nano structure on the surface of a titanium alloy comprises the following steps:

[0008] The titanium alloy was cut into required sizes, polished with sandpaper, and then pickled twice and electrochemically treated;

[0009] After the electrochemical treatment, the titanium alloy sample was ultrasonically cleaned with distilled water and anhydrous ethanol for 10 minutes, respectively. After cleaning, it was dried at 80°C for 20 minutes in an electric blast constant temperature drying oven to complete the preparation.

[0010] Further, the first pickling step is:

[0011] First, the titanium alloy was pickled at room temperature for 6 minutes using a mixed solution of 2wt% HF and 20wt% HNO3 to remove the oxide layer and impurities on the surface of the titanium alloy. The pickling process was carried out in a fume hood.

[0012] The second pickling step is:

[0013] The titanium alloy was then placed in a 40wt% H2SO4 solution at a constant temperature of 50°C for secondary pickling for 15 minutes, and then taken out and ultrasonically cleaned in distilled water and anhydrous ethanol and dried. After drying, the surface morphology of the titanium alloy was photographed with a shape measurement laser microscope until it was observed that the surface of the titanium alloy was further corroded and the surface was uneven with small pits.

[0014] Further, the electrochemical treatment steps are:

[0015] A three-electrode system was used for measurement, with the pickled titanium alloy as the working electrode, the platinum sheet as the counter electrode, and the saturated calomel electrode as the reference electrode. The electrodes were placed in an electrolyte containing 10wt% H2SO4, 5wt% HCl, and 0.04g / mL NaCl, and reacted at a constant voltage of 10V and a constant temperature of 50°C for 20min. The reaction was carried out in a fume hood.

[0016] Furthermore, the roughness of the titanium alloy surface microstructure is 5.32 μm, the porosity is 45.18%, and the obtained pore diameter is about 500 nm to 5000 nm, with small pores being the majority.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] By utilizing the pore structure on the metal surface and the polymer columns to form a "locking" structure, a high-strength bond between metal and polymer is achieved through the "anchor effect". The roughness and porosity of the prepared titanium alloy porous structure are significantly improved, which can improve the bonding strength between titanium alloy and plastic injection molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0020] Figure 1 : (1a, 1b, 1c, 1d, 1e) are macroscopic images of the surface treatment of titanium alloy in an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a scanning electron microscope showing that the porous surface of the titanium alloy in an embodiment of the present invention is a nanostructure;

[0022] Figure 3 It is a 3D schematic diagram of the shape measurement of the titanium alloy microstructure in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] like Figure 1 As shown in the macroscopic diagram of titanium alloy surface treatment, Figure 1 a is a blank sample, Figure 1 b is a schematic diagram of mechanical grinding treatment. Figure 1 c is a schematic diagram of the process after pickling with hydrofluoric acid and nitric acid. Figure 1 d is the schematic diagram after sulfuric acid pickling. Figure 1 e is a schematic diagram after electrochemical treatment.

[0025] Reference Figure 1-3 , a method for preparing a porous micro-nano structure on the surface of a titanium alloy, comprising the following steps:

[0026] The titanium alloy was cut into required sizes, polished with sandpaper, and then pickled twice and electrochemically treated;

[0027] After the electrochemical treatment, the titanium alloy sample was ultrasonically cleaned with distilled water and anhydrous ethanol for 10 minutes, respectively. After cleaning, it was dried at 80°C for 20 minutes in an electric blast constant temperature drying oven to complete the preparation.

[0028] Embodiment 1

[0029] Based on the above scheme, the first pickling step is:

[0030] First, the titanium alloy was pickled at room temperature for 6 minutes using a mixed solution of 2wt% HF and 20wt% HNO3 to remove the oxide layer and impurities on the surface of the titanium alloy. The pickling process was carried out in a fume hood.

[0031] The second pickling step is:

[0032] The titanium alloy was then placed in a 40wt% H2SO4 solution at a constant temperature of 50°C for secondary pickling for 15 minutes, and then taken out and ultrasonically cleaned in distilled water and anhydrous ethanol and dried. After drying, the surface morphology of the titanium alloy was photographed with a shape measurement laser microscope until it was observed that the surface of the titanium alloy was further corroded and the surface was uneven with small pits.

[0033] Preferably, the electrochemical treatment steps are:

[0034] A three-electrode system was used for measurement, with Ti-6Al-4V titanium alloy as the working electrode (WE), a platinum sheet as the counter electrode (AE), and a saturated calomel electrode as the reference electrode (RE). The electrodes were placed in an electrolyte containing 10wt% H2SO4, 5wt% HCl, and 0.04g / mL NaCl, and reacted at a constant voltage of 10V and a constant temperature of 50°C for 20min. The reaction was carried out in a fume hood.

[0035] As a preferred embodiment of the present application, the roughness of the titanium alloy surface microstructure is 5.32 μm, the porosity is 45.18%, and the obtained pore size is about 500 nm to 5000 nm, with small pores being the majority.

[0036] Embodiment 2

[0037] A method for preparing a porous micro-nano structure on the surface of a titanium alloy, using Ti-6Al-4V titanium alloy, firstly grinding step by step with 400#, 800#, 1000#, and 1200# sandpapers respectively, and grinding the titanium alloy on the sandpaper along the same vertical direction each time a type of sandpaper is used for grinding until the direction of the frosted grain on the surface of the titanium alloy is consistent. When grinding with a different type of sandpaper, the titanium plate is rotated 90°C according to the direction of the previous grinding and then ground again, and the operation is the same as above, until the direction of the surface grain is vertically consistent and uniform. Finally, the surface is polished to be bright grayish white, the grain direction is consistent, and there are a few scratches. After grinding, it is thoroughly ultrasonically cleaned with distilled water and anhydrous ethanol for 10 minutes to remove surface dust and stains, and then dried in an oven at 80°C for 5 minutes.

[0038] The titanium alloy sample after mechanical grinding was pickled to remove surface impurities and activate the surface. First, pickle in a mixed solution of 2wt% HF and 20wt% HNO3 for 6 minutes to remove impurities and oxide layer on the surface of the titanium alloy. During the pickling process, make sure to carry out in a fume hood. After pickling, ultrasonically clean with distilled water and anhydrous ethanol for 10 minutes. Then, a secondary pickling is performed to activate the surface of the titanium alloy. The titanium alloy is placed in a 40wt% H2SO4 solution at a constant temperature of 50°C for pickling for 15 minutes and stirred with a magnetic stirrer. After pickling, ultrasonically clean with distilled water and anhydrous ethanol for 10 minutes, and then dry in an oven at 80°C for 5 minutes.

[0039] After pickling, the electrochemical corrosion experiment of titanium alloy was carried out by CorrTest electrochemical workstation. The three-electrode system was used for measurement, with Ti-6Al-4V titanium alloy as the working electrode (WE), platinum sheet as the counter electrode (AE), and saturated calomel electrode as the reference electrode (RE). The electrodes were placed in the electrolyte and the titanium alloy was electrochemically treated at a constant voltage of 10V. After the electrochemical treatment, it was ultrasonically rinsed with distilled water and anhydrous ethanol for 10 minutes respectively, then dried in an oven at 80°C for 20 minutes, and sealed in a vacuum bag for storage. In the electrochemical experiment, the electrolyte was a mixed solution of 10wt% H2SO4, 5wt% HCl, and 0.04g / mL NaCl, the electrolysis time was 20 minutes, and the electrolysis temperature was 50°C.

[0040] The treated titanium alloy samples were photographed using an ultra-high resolution field emission scanning electron microscope, and the porosity of the treated titanium alloy surface micromorphology was calculated using Image-Pro Plus 6.0 software, and the surface roughness of the sample was measured using a shape measurement laser microscope VK-X110. The surface roughness of the titanium alloy was 5.47μm, the porosity of the micro-nanostructure was 45.18%, and the pore size was about 0.5μm to 5μm, with most of the pores being small.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a porous micro-nano structure on the surface of a titanium alloy, characterized in that: The following steps are involved: The titanium alloy was cut into required sizes, polished with sandpaper, and then pickled twice and electrochemically treated; After the electrochemical treatment, the titanium alloy sample was ultrasonically cleaned with distilled water and anhydrous ethanol for 10 minutes, respectively. After cleaning, it was dried at 80°C for 20 minutes in an electric blast constant temperature drying oven to complete the preparation.

2. The method for preparing a porous micro-nano structure on the surface of a titanium alloy according to claim 1, characterized in that: The first pickling step is: First, the titanium alloy was pickled at room temperature for 6 minutes using a mixed solution of 2wt% HF and 20wt% HNO3 to remove the oxide layer and impurities on the surface of the titanium alloy. The pickling process was carried out in a fume hood. The second pickling step is: The titanium alloy was then placed in a 40wt% H2SO4 solution for secondary pickling at a constant temperature of 50°C for 15 minutes. After being taken out, it was placed in distilled water and anhydrous ethanol for ultrasonic cleaning and drying. After drying, the surface morphology of the titanium alloy was photographed with a shape measurement laser microscope until it was observed that the surface of the titanium alloy was further corroded and the surface was uneven with small pits.

3. The method for preparing a porous micro-nano structure on the surface of a titanium alloy according to claim 2, characterized in that: The electrochemical treatment steps are: A three-electrode system was used for measurement, with the pickled titanium alloy as the working electrode, the platinum sheet as the counter electrode, and the saturated calomel electrode as the reference electrode. The electrodes were placed in an electrolyte containing 10wt% H2SO4, 5wt% HCl, and 0.04g / mL NaCl, and reacted at a constant voltage of 10V and a constant temperature of 50°C for 20min. The reaction was carried out in a fume hood.

4. The method for preparing a porous micro-nano structure on the surface of a titanium alloy according to claim 3, characterized in that: The roughness of the titanium alloy surface microstructure is 5.32 μm, the porosity is 45.18%, and the obtained pore size is about 500 nm to 5000 nm, with small pores being the majority.

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