Titanium material black surface and preparation method

Abstract

The present application relates to a kind of titanium material black surface and preparation method, comprising the following steps: pickling: the titanium or titanium alloy sample of surface cleaning is soaked in first solution for a period of time to carry out surface activation;First water washing: after pickling, titanium or titanium alloy sample is taken out to carry out water washing;Surface blackening: after water washing, titanium or titanium alloy sample is soaked in second solution for a period of time;Second water washing: after surface blackening, titanium or titanium alloy sample is washed again, then dry, the preparation of titanium material black surface can be completed, wherein, first solution is different from second solution.Compared with prior art, the present application has simple process, low cost and high efficiency, and has no special requirements for shape and surface roughness of titanium material, and any clean titanium material can be surface blackening treated by this method, especially suitable for surface blackening treatment of titanium material with complex shape.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material surface treatment, and particularly relates to a black surface of titanium material and a preparation method thereof. BACKGROUND

[0002] The black surface of titanium material has excellent optical absorption performance and has broad application prospects in the fields of aerospace and photocatalysis. The black surface of titanium material can reduce stray light of a remote sensing camera, thereby greatly improving imaging accuracy. At present, the main methods for preparing the black surface of titanium material are anodic oxidation method, micro-arc oxidation method and thermal oxidation method. The anodic oxidation method, the micro-arc oxidation method and the thermal oxidation method for preparing the black surface of titanium material need to load a high voltage, need to be heated, the electrolyte solution used is relatively complex, the equipment required is also relatively complex, and the cost is relatively high. For example, in the existing technology one, the anodic oxidation method is used to prepare the black surface of titanium material, and the electrolyte solution used is a mixed solution of potassium dichromate 20-60 parts, chromate 10-30 parts, sulfate 10-20 parts, sulfuric acid 10-50 parts, blackening agent 2-4 parts, phosphoric acid 25-40 parts, phosphate 20-40 parts, acetic acid 1-10 parts, ethylene glycol 10-20 parts, sodium gluconate 15-30 parts and distilled water 700-1000 parts by weight. The current density used for anodic oxidation is 2-9 A / dm 2 , the voltage is 15-150 V, the oxidation time is 30-60 min, and the solution temperature is 10-75℃. In the existing technology two, the black anodic oxidation process of titanium alloy, the electrolyte solution used is a mixed solution of potassium dichromate (K2Cr2O7) 20-60 parts, manganese sulfate (MnSO4) 10-20 parts, blackening agent 2-4 parts, ammonium sulfate ((NH4)2SO4) 25-55 parts and distilled water 1000 parts by weight. The current density used is 0.2 A / dm 2 , the temperature is 25℃, and the anodic oxidation time is 50 minutes. In the existing technology three, the electrochemical blackening method of titanium and titanium alloy, the electrolyte solution used is a mixed aqueous solution of manganese nitrate 10-30 g / L, potassium dichromate 20-30 g / L, ammonium sulfate 20-30 g / L and boric acid 10-20 g / L by volume concentration. The temperature of the electrolyte solution during the blackening process must be controlled at 10-40℃, and the direct current intensity must be controlled at 0.1-0.5 A / dm 2The above-mentioned technology uses complex solution and equipment, and the preparation process needs electricity and heating, and has high energy consumption. In the prior art, black titanium oxide film is prepared on the surface of titanium material by using atmospheric oxidation, anode oxidation and micro-arc oxidation respectively. The atmospheric oxidation is first heated in an atmospheric environment to generate a titanium oxide film with a thickness greater than 2 μm on the surface of titanium, and then a black titanium oxide film with a thickness of 0.5-10 μm is generated on the surface of titanium by keeping the vacuum degree less than 5 Pa at 300 ℃ for 50 min. The atmospheric oxidation method needs high temperature conditions, and has long preparation time, high energy consumption and low efficiency. The anode oxidation treatment is first carried out in a phosphoric acid solution to generate a titanium oxide film with a thickness greater than 0.01 μm, and then a black titanium oxide film with a thickness of 0.01-0.02 μm is generated on the surface of titanium by keeping the vacuum degree less than 5 Pa and passing in inert gas argon at 200 ℃ for 300 min. The anode oxidation method needs electricity and heating, has long preparation time, high energy consumption and low efficiency. The micro-arc oxidation is first prepared by using high voltage to generate a titanium oxide film with a thickness greater than 10 μm on the surface of titanium, and then a black titanium oxide film with a thickness greater than 3 μm is generated on the surface of titanium by keeping the vacuum degree less than 5*10 -2 Pa and keeping vacuum at 1000 ℃ for 1 min. The micro-arc oxidation method uses high voltage and high temperature, and has high energy consumption. SUMMARY

[0003] In order to overcome the above-mentioned problems in the prior art, the present application provides a black surface of titanium material and a preparation method, which are used to solve the above-mentioned problems in the prior art.

[0004] A preparation method of a black surface of titanium material, comprising the following steps:

[0005] S1. Pickling: immersing a titanium or titanium alloy sample with clean surface in a first solution for a period of time to activate the surface;

[0006] S2. First water washing: taking out the titanium or titanium alloy sample after pickling to wash with water;

[0007] S3. Surface blackening: immersing the titanium or titanium alloy sample after water washing in a second solution for a period of time;

[0008] S4. Second water washing: washing the titanium or titanium alloy sample after surface blackening again, and then drying, so as to complete the preparation of the black surface of titanium material, wherein the first solution is different from the second solution.

[0009] According to any possible implementation manner of the above-mentioned aspect, a further implementation manner is provided, wherein the period of time in S1 is 5-10 min.

[0010] According to any possible implementation manner of the above-mentioned aspect, a further implementation manner is provided, wherein the period of time in S3 is 6-20 min.

[0011] According to the aspect and any possible implementation manner as described above, further provided is an implementation manner, wherein the first solution is a mixed solution of hydrofluoric acid HF and nitric acid HNO3.

[0012] According to the aspect and any possible implementation manner as described above, further provided is an implementation manner, wherein the concentration of the hydrofluoric acid HF is 0.5-1.2 mol / L; and the concentration of the nitric acid HNO3 is 0.5-1.0 mol / L.

[0013] According to the aspect and any possible implementation manner as described above, further provided is an implementation manner, wherein the second solution is a mixed solution of 0.5-1.0 mol / L ammonium fluoroborate NH4BF4 and 0.003-0.01 mol / L hydrofluoric acid HF aged for 24 h at room temperature.

[0014] According to the aspect and any possible implementation manner as described above, further provided is an implementation manner, wherein the second solution is a 0.5-1.0 mol / L ammonium fluoroborate NH4BF4 solution aged for 72-120 h at room temperature.

[0015] According to the aspect and any possible implementation manner as described above, further provided is an implementation manner, wherein the second solution is a 0.025-0.045 mol / L hydrofluoric acid HF solution.

[0016] According to the aspect and any possible implementation manner as described above, further provided is an implementation manner, wherein the steps S1 and S3 are performed in a plastic container.

[0017] According to the aspect and any possible implementation manner as described above, further provided is an implementation manner, wherein the drying process of the step S4 can adopt a normal-temperature fan drying or a normal-temperature environment air drying mode.

[0018] The application further provides a titanium material black surface obtained by the preparation method.

[0019] According to the aspect and any possible implementation manner as described above, further provided is an implementation manner, wherein the titanium material black surface has a reflectivity of visible light less than or equal to 8% and a reflectivity of near-infrared light less than 48%.

[0020] Advantages of the application

[0021] The preparation method of the black surface of the titanium material of the present application comprises the following steps: pickling: immersing the titanium or titanium alloy sample with clean surface in a first solution for a period of time to activate the surface; first water washing: taking out the titanium or titanium alloy sample after pickling to wash with water; surface blackening: immersing the titanium or titanium alloy sample washed with water in a second solution for a period of time; second water washing: washing again the titanium or titanium alloy sample after surface blackening, and then drying, so as to complete the preparation of the black surface of the titanium material, wherein the first solution is different from the second solution. The present application has the following advantages compared with the prior art:

[0022] 1. Compared with the prior art, the process of the present application is extremely simple, only two steps of chemical immersion and two steps of water washing are needed.

[0023] 2. Compared with the prior art, the cost of the present application is extremely low, only two kinds of solutions are needed, and the medicine prices for configuring the solutions are low, and no heating or voltage loading is needed in the preparation process, except for the possible energy consumption of the fan, there is no other energy consumption.

[0024] 3. Compared with the prior art, the efficiency of the present application is high, and the black surface of the titanium material can be successfully prepared in about 20-40 minutes.

[0025] 4. Compared with the prior art, the present application has no special requirements for the shape and surface roughness of the titanium material, and any clean titanium material can be treated by the surface blackening method, especially suitable for the surface blackening treatment of titanium materials with complex shape.

[0026] 5. Compared with the prior art, the present application has extremely low requirements for the preparation equipment, except for the possible fan, only a plastic container with appropriate size is needed. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram for testing the black surface by diffuse reflectance spectroscopy in Example 1 of the present application;

[0028] Figure 2 It is a schematic diagram for testing the black surface by diffuse reflectance spectroscopy in Example 2 of the present application;

[0029] Figure 3 It is a schematic diagram for testing the black surface by diffuse reflectance spectroscopy in Example 3 of the present application;

[0030] Figure 4 It is a schematic diagram for testing the black surface by diffuse reflectance spectroscopy in Example 4 of the present application;

[0031] Figure 5 It is a schematic diagram of the uniform and periodic nano-trapping light structure formed by the black surface of the present application;

[0032] Figure 6 The preparation method flow chart of the present application. DETAILED DESCRIPTION

[0033] In order to better understand the technical solutions of the present application, the present application includes but is not limited to the specific embodiments in the following detailed description, and similar technologies and methods should be considered as within the scope of the present application. In order to make the technical problems, technical solutions and advantages of the present application more clear, the following will be described in detail with reference to the drawings and specific embodiments.

[0034] It should be clear that the embodiments described in the present application are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0036] As Figure 6 shown, the present application provides a preparation method of black surface of titanium material, comprising the following steps:

[0037] S1. Acid pickling: immerse the surface cleaned titanium or titanium alloy sample in a first solution for a period of time to activate the surface;

[0038] S2. First water washing: take out the titanium or titanium alloy sample after acid pickling for water washing;

[0039] S3. Surface blackening: immerse the titanium or titanium alloy sample after water washing in a second solution for a period of time;

[0040] S4. Second water washing: water wash the titanium or titanium alloy sample after surface blackening again, and then dry, to complete the preparation of the black surface of titanium material, wherein the first solution and the second solution are different.

[0041] Specifically, the preparation method process of the present application is as follows:

[0042] S1, acid pickling: immerse the surface cleaned titanium or titanium alloy sample in a first solution for 5-10 min, and the effect of this step is to activate the surface of titanium and its alloy and remove the original oxide film on the surface;

[0043] S2, water washing: take out the sample after acid pickling for water washing, and the effect of this step is to remove the residual solution of step S1;

[0044] S3, surface blackening: the cleaned sample is immersed in the second solution for 6-20 min, and the effect of this step is to form a black surface of the titanium material;

[0045] S4, water washing: the blackened sample is washed with water and then dried, and the effect of this step is to remove the residual solution of step S3 and finally obtain a dry surface. The drying process is carried out by air drying at room temperature or natural drying at room temperature.

[0046] The first solution is a mixed solution of 0.78 mol / L hydrofluoric acid HF and 0.67 mol / L nitric acid HNO3, and the above concentration can well remove the oxide film on the surface of titanium and its alloy and complete the surface activation. The second solution has three options: the first is a mixed solution of 0.5-1.0 mol / L ammonium fluoroborate NH4BF4 and 0.003-0.01 mol / L hydrofluoric acid HF aged for 24 h at room temperature; the second is a 0.5-1.0 mol / L ammonium fluoroborate NH4BF4 solution aged for 72-120 h at room temperature; the third is a 0.025-0.045 mol / L hydrofluoric acid HF solution without aging; the above concentration of solution can form a uniform black surface on the surface of titanium and its alloy after 6-20 min of room temperature immersion. The steps S1 and S3 are carried out in a plastic container to avoid corrosion of the container by hydrofluoric acid.

[0047] The preparation method of the present application adopts a two-step chemical immersion method, and is based on the principle of nano-trap light structure and titanium dioxide light-absorbing semiconductor to prepare a black surface of titanium material. First, the surface-cleaned titanium or titanium alloy sample is immersed in a mixed solution of 0.5-1.2 mol / L hydrofluoric acid HF and 0.5-1.0 mol / L nitric acid HNO3 for 5-10 min to remove the original oxide film on the surface and complete the surface activation. After activation, the titanium or titanium alloy sample is immersed in a mixed solution of 0.5-1.0 mol / L ammonium fluoroborate NH4BF4 and 0.003-0.01 mol / L hydrofluoric acid HF aged for 24 h at room temperature or a 0.5-1.0 mol / L ammonium fluoroborate NH4BF4 solution aged for 72-120 h at room temperature or a 0.025-0.045 mol / L hydrofluoric acid HF solution for 6-20 min. Due to the etching effect of low-solubility hydrofluoric acid, a uniform and periodic nano-trap light structure is formed on the surface of titanium (see Figure 5 ), and a very thin Ti 3+ self-doped titanium dioxide passivation film, nano-trap light structure and Ti 3+ self-doped titanium dioxide passivation film contribute to the excellent light absorption performance of the black surface.

[0048] Reaction etching and passivation principle:

[0049] (BF4)- + H2O → [(BF3)(OH)] -1 + HF

[0050] TiO2 + 6HF → H2TiF6 + 2H2O

[0051] Ti + 6HF → H2TiF6 + 2H2↑

[0052] 2Ti + 6HF → 2TiF3 + 3H2↑

[0053] H2TiF6 + 4H2O → Ti(OH)4 + 6HF

[0054] TiF3 + 3H2O → Ti(OH)3 + 3HF

[0055] Ti(OH)4 → TiO2↓ + 2H2O

[0056] 2Ti(OH)3 → Ti2O3↓ + 3H2O

[0057] In addition, the application further provides a black surface of a titanium material, which is obtained by the preparation method.

[0058] The application will be further described in combination with examples.

[0059] Example 1

[0060] A preparation technology of a black surface of a titanium material, comprising the following steps:

[0061] S1, pickling: immersing a sample made of industrial pure titanium TA1 in a mixed solution of 0.78 mol / L hydrofluoric acid HF and 0.67 mol / L nitric acid HNO3 for 10 min;

[0062] S2, water washing: taking out the sample after pickling and removing residual solution by water washing;

[0063] S3, surface blackening: immersing the sample after water washing in a mixed solution of 0.715 mol / L ammonium fluoroborate NH4BF4 and 0.004 mol / L hydrofluoric acid HF aged at room temperature for 24 h for 6 min;

[0064] S4, water washing: water washing the sample after blackening, and then drying by air blowing at room temperature or air drying at room temperature to obtain the black surface of the titanium material.

[0065] The diffuse reflectance spectrum test of the black surface is shown in Figure 1The black surface has excellent light absorption performance, and the reflectivity of visible light is controlled below 8%, and the reflectivity of near-infrared light is controlled below 47.1%.

[0066] Example 2

[0067] A titanium material black surface preparation technology comprises the following steps:

[0068] S1, pickling: immerse the sample made of industrial pure titanium TA1 in a mixed solution of 0.78 mol / L hydrofluoric acid HF and 0.67 mol / L nitric acid HNO3 for 8 min;

[0069] S2, water washing: take out the sample after pickling, and remove the residual solution by water washing;

[0070] S3, surface blackening: immerse the sample after water washing in a mixed solution of 0.715 mol / L ammonium fluoroborate NH4BF4 and 0.004 mol / L hydrofluoric acid HF aged at room temperature for 24 h for 10 min;

[0071] S4, water washing: the sample after blackening is washed with water, and then dried by air blowing at room temperature or air drying at room temperature to obtain a titanium material black surface.

[0072] The diffuse reflectance spectrum test of the black surface is shown in Figure 2 The black surface has excellent light absorption performance, and the reflectivity of visible light is controlled below 7.8%, and the reflectivity of near-infrared light is controlled below 35.3%.

[0073] Example 3

[0074] A titanium material black surface preparation technology comprises the following steps:

[0075] S1, pickling: immerse the sample made of industrial pure titanium TA1 in a mixed solution of 0.78 mol / L hydrofluoric acid HF and 0.67 mol / L nitric acid HNO3 for 10 min;

[0076] S2, water washing: take out the sample after pickling, and remove the residual solution by water washing;

[0077] S3, surface blackening: immerse the sample after water washing in a 0.715 mol / L ammonium fluoroborate NH4BF4 solution aged at room temperature for 115 h for 10 min;

[0078] S4, water washing: the sample after blackening is washed with water, and then dried by air blowing at room temperature or air drying at room temperature to obtain a titanium material black surface.

[0079] The diffuse reflectance spectrum test of the black surface is shown in Figure 3The black surface has excellent light absorption performance, and the reflectivity of visible light is controlled below 5%, and the reflectivity of near-infrared light is controlled below 24%.

[0080] Example 4

[0081] A titanium material black surface preparation technology comprises the following steps:

[0082] S1, pickling: immerging a sample made of industrial pure titanium TA1 in a mixed solution of 0.78 mol / L hydrofluoric acid HF and 0.67 mol / L nitric acid HNO3 for 10 min;

[0083] S2, water washing: taking out the sample after pickling and water washing to remove residual solution;

[0084] S3, surface blackening: immersing the sample after water washing in a 0.032 mol / L hydrofluoric acid HF solution for 10 min;

[0085] S4, water washing: water washing the sample after blackening, and then air drying at normal temperature or airing at normal temperature to obtain a titanium material black surface.

[0086] The diffuse reflectance spectrum test of the black surface is shown in Figure 4 The black surface has excellent light absorption performance, and the reflectivity of visible light is controlled below 6.5%, and the reflectivity of near-infrared light is controlled below 25%.

[0087] The above description shows and describes several preferred embodiments of the present application, but as previously described, it should be understood that the present application is not limited to the forms disclosed herein, should not be considered as excluding other embodiments, and can be used in various other combinations, modifications and environments, and can be modified within the scope of the application described herein, by the above teaching or related technical or knowledge. The modifications and changes made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the appended claims of the present application.

Claims

1. A method for preparing a black surface of a titanium material, characterized in that: The steps include: S1. Pickling: The surface of the clean titanium or titanium alloy sample is immersed in a first solution for a period of time for surface activation, the first solution is a mixed solution of 0.5 to 1.2 mol / L hydrofluoric acid HF and 0.5 to 1.0 mol / L nitric acid HNO3; S2. First washing: The titanium or titanium alloy sample after pickling is removed and washed; S3. Surface blackening: The washed titanium or titanium alloy sample was immersed in a second solution for a period of time. The second solution had three options: a mixed solution of 0.5-1.0 mol / L ammonium fluoroborate NH4BF4 and 0.003-0.01 mol / L hydrofluoric acid HF aged at room temperature for 24 h; a 0.5-1.0 mol / L ammonium fluoroborate NH4BF4 solution aged at room temperature for 72-120 h; and a 0.025-0.045 mol / L hydrofluoric acid HF solution. S4. Second water washing: The titanium or titanium alloy sample with the blackened surface is washed again with water and then dried to complete the preparation of the black surface of the titanium material.

2. The method for preparing a black surface of titanium material according to claim 1, characterized in that: The period of time in S1 is 5 to 10 minutes.

3. The method for preparing a black surface of titanium material according to claim 1, characterized in that: The period of time in S3 is 6 to 20 minutes.

4. A black surface of titanium material, characterized in that: The black surface of the titanium material is obtained by the preparation method according to any one of claims 1 to 3.

5. The black surface of titanium material according to claim 4, characterized in that: The reflectivity of the black surface of the titanium material to visible light is less than or equal to 8%, and the reflectivity to near-infrared light is less than 48%.

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