A method for preparing an insulating hardened film layer on a titanium alloy surface and a titanium alloy

Abstract

The present invention provides a method for preparing an insulating hardened film layer on the surface of a titanium alloy and a titanium alloy. The preparation method includes the following steps: S1, pre-treating a titanium alloy sample to remove the oxide film on the surface of the titanium alloy; S2, oxidizing the titanium alloy sample at an oxidation temperature of 500-900°C and a holding time of 30 minutes to 5 hours; S3, placing the titanium alloy sample in a vacuum environment and introducing O2 for oxygenation at an oxygenation temperature of 400-900°C, a oxygenation time of 30 minutes to 10 hours, and an oxygen flow rate of 30-200 sccm. The method for preparing an insulating hardened film layer on the surface of a titanium alloy described in the present invention, first, greatly improves the hardness of the titanium alloy surface layer, and can achieve a hardness of the titanium alloy surface layer of HV1060 or above; second, the oxide layer generated on the titanium alloy surface can have a good insulating effect, with an insulation resistance of >200MΩ; and third, improves the wear resistance of the titanium alloy surface.

Description

Technical Field

[0001] The present invention relates to the field of metal surface treatment, and in particular to a method for preparing an insulating hardened film layer on the surface of a titanium alloy and the titanium alloy. Background Art

[0002] Titanium alloys have strong resistance to acid and alkali corrosion, low density and high specific strength. Their good corrosion resistance and excellent biocompatibility make them widely used in aerospace, navigation, biomedicine, chemical industry and bioengineering, especially in chloride atmospheres such as seawater and oceans.

[0003] Although titanium alloys have advantages such as corrosion resistance, which enable them to demonstrate good service performance in seawater pipelines, their low surface hardness and poor wear resistance, as well as their poor corrosion resistance in certain media, restrict their wider application. In engineering applications, titanium alloys suffer from severe adhesive wear due to their high and unstable coefficient of friction, and are prone to micro-wear and seizure, exhibiting poor wear resistance. Furthermore, the large potential difference between titanium alloys and associated non-titanium equipment can cause galvanic corrosion in non-titanium equipment in seawater environments. Therefore, the preparation of an insulating hardened film layer on the surface of titanium alloys has important application value.

[0004] Patent application number CN201110378673.7 in the prior art discloses a method for surface strengthening treatment of titanium alloy by oxygen permeation, wherein the titanium alloy material is placed in a treated medium, heated to 700-850°C in an ordinary air furnace under atmospheric atmosphere, and kept warm for 30-6000 minutes; an oxygen solid solution hardening layer is formed on the surface of the titanium alloy specimen by this method, and the depth of the oxygen solid solution hardening layer is 80-120 μm; the medium is ZrO2 powder. Although this patent improves the hardness of the titanium alloy surface to a certain extent, insulation cannot be achieved without the formation of a titanium oxide film layer on the surface.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing an insulating hardened film layer on the surface of a titanium alloy and a titanium alloy, so as to solve the problem that the treatment method of the oxygen-permeated surface of titanium alloy in the prior art cannot achieve insulation while improving the hardness of the titanium alloy surface.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A method for preparing an insulating hardened film layer on a titanium alloy surface, the method comprising the following steps:

[0009] S1. Pre-treating the titanium alloy sample to remove the oxide film on the titanium alloy surface;

[0010] S2. Oxidizing the titanium alloy sample at an oxidation temperature of 500-900°C for a holding time of 30 min-5 h;

[0011] S3. Place the titanium alloy sample in a vacuum environment and introduce O2 for oxygenation treatment. The oxygenation temperature is 400-900°C, the oxygenation time is 30 minutes to 10 hours, and the oxygen flow rate is 30-200 sccm.

[0012] The method for preparing the insulating hardened film layer on the surface of the titanium alloy described in the present invention, first, greatly improves the hardness of the titanium alloy surface layer, and can achieve a hardness of the titanium alloy surface layer of HV1060 or above; second, the oxide layer generated on the surface of the titanium alloy can have a good insulating effect, and the insulation resistance is greater than 200MΩ; third, the wear resistance of the titanium alloy surface layer is improved.

[0013] Furthermore, in step S2, the oxidation temperature is 600-900°C, and the holding time is 2-5 hours.

[0014] This setting optimizes the process parameters in the preparation process of the insulating hardened film layer on the surface of the titanium alloy. On the one hand, it makes adequate preparations for improving the quality of oxygen permeation; on the other hand, it makes the insulating hardened film layer on the surface of the titanium alloy have insulating properties.

[0015] Furthermore, in step S3, the titanium alloy sample is placed in a vacuum environment and oxygen is introduced thereinto for oxygenation treatment. The oxygenation temperature is 500-600°C, the oxygenation time is 3-6 hours, and the oxygen flow rate is 100-200 sccm.

[0016] This setting optimizes the process parameters in the preparation process of the insulating hardened film layer on the surface of the titanium alloy, which is beneficial to improving the quality and density of oxygen permeation, thereby helping to improve the hardness of the insulating hardened film layer on the surface of the titanium alloy.

[0017] Furthermore, in step S2, the titanium alloy sample is placed in a muffle furnace for oxidation.

[0018] Furthermore, in step S3, the titanium alloy sample is placed in a vacuum tube furnace and oxygen is introduced into the furnace for oxygenation treatment.

[0019] Furthermore, step S1 includes the following steps:

[0020] S11. Place the titanium alloy sample in degreasing agent and pure water in turn, use ultrasonic cleaning, and wipe the surface with alcohol to ensure that the surface of the titanium alloy sample is dry and clean;

[0021] S12. Place the titanium alloy sample into an acidic mixed solution to remove the oxide film on the surface of the titanium alloy sample.

[0022] Although the oxide film generated by the initial passivation on the surface of the titanium alloy sample is relatively dense, it is very thin and uneven. The presence of the initial oxide film will also hinder the formation of surface titanium dioxide and the diffusion of oxygen during the heat treatment process. In step S1, the oxide film generated by the initial passivation on the surface of the titanium alloy sample is removed to avoid hindering the formation of surface titanium dioxide and the diffusion of oxygen during the heat treatment process.

[0023] Furthermore, the acidic mixed solution includes HF, CH3CH2OH and water, the ratio of HF, CH3CH2OH and water is: HF: CH3CH2OH: water = 1:1-10:1-10, and the pH of the acidic mixed solution is 2-5.

[0024] This setting optimizes the ratio of the acidic mixture, which facilitates the complete initial passivation of the oxide film formed on the surface of the titanium alloy sample without causing other effects on the titanium alloy surface.

[0025] Furthermore, in step S12, the titanium alloy sample is placed in the acidic mixed solution for a full reaction of 1 to 30 minutes.

[0026] This setting optimizes the ratio of the acidic mixture, which facilitates the complete initial passivation of the oxide film formed on the surface of the titanium alloy sample without causing other effects on the titanium alloy surface.

[0027] Furthermore, the ratio of HF, CH3CH2OH and water is: HF: CH3CH2OH: water = 1:1:1.

[0028] This setting optimizes the ratio of the acidic mixture, which facilitates the complete initial passivation of the oxide film formed on the surface of the titanium alloy sample without causing other effects on the titanium alloy surface.

[0029] In a second aspect of the present invention, a titanium alloy is provided, wherein the surface of the titanium alloy is an insulating hardened film layer, and the insulating hardened film layer on the surface of the titanium alloy is prepared using any one of the above-mentioned methods for preparing the insulating hardened film layer on the surface of the titanium alloy.

[0030] The present invention provides a method for preparing an insulating hardened film layer on the surface of a titanium alloy and a titanium alloy. Compared with the prior art, the method for preparing an insulating hardened film layer on the surface of a titanium alloy provided by the present invention has the following beneficial effects:

[0031] 1) The method for preparing an insulating hardened film layer on the surface of a titanium alloy and the titanium alloy described in the present invention greatly improve the hardness of the surface layer of the titanium alloy, and can achieve a hardness of the surface layer of the titanium alloy of above HV1060.

[0032] 2) The method for preparing an insulating hardened film layer on the surface of a titanium alloy and the titanium alloy described in the present invention can provide a good insulating effect with an insulation resistance greater than 200 MΩ.

[0033] 3) The method for preparing an insulating hardened film layer on the surface of a titanium alloy and the titanium alloy described in the present invention improve the wear resistance of the surface of the titanium alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is an electron microscope scanning image of an oxide film layer on the surface of a titanium alloy according to Example 1 of the present invention;

[0035] Figure 2 This is an electron microscope scanning image of an insulating hardened film layer on the surface of a titanium alloy according to Example 1 of the present invention;

[0036] Figure 3 This is an electron microscope scanning image of an oxide film layer on the surface of a titanium alloy according to Example 2 of the present invention;

[0037] Figure 4 This is an electron microscope scanning image of an insulating hardened film layer on the surface of a titanium alloy according to Example 2 of the present invention;

[0038] Figure 5 This is an XRD test pattern of an insulating hardened film layer on a titanium alloy surface according to Example 1 of the present invention;

[0039] Figure 6 This is an XRD test pattern of an insulating hardened film layer on a titanium alloy surface according to Example 2 of the present invention;

[0040] Figure 7 This is an XRD test diagram of an insulating hardened film layer on a titanium alloy surface according to Comparative Example 1 of the present invention;

[0041] Figure 8 This is an XRD test diagram of an insulating hardened film layer on a titanium alloy surface as described in Comparative Example 2 of the present invention;

[0042] Figure 9 A three-dimensional topography of the front surface wear of a titanium alloy surface insulating hardened film layer prepared in Example 1, Comparative Example 1 and Comparative Example 2 of the present invention;

[0043] Figure 10 This is a three-dimensional morphology image of the surface wear after the insulating hardened film layer on the surface of a titanium alloy is prepared according to Example 1 of the present invention;

[0044] Figure 11 A three-dimensional topography of surface wear before preparing an insulating hardened film layer on a titanium alloy surface as described in Example 2 of the present invention;

[0045] Figure 12This is a three-dimensional morphology image of the surface wear of a titanium alloy after preparation of an insulating hardened film layer on the surface of the titanium alloy according to Example 2 of the present invention;

[0046] Figure 13 This is a three-dimensional morphology of the surface wear of a titanium alloy after preparation of an insulating hardened film layer on the surface of the titanium alloy described in Comparative Example 1 of the present invention;

[0047] Figure 14 This is a three-dimensional morphology image of the surface wear after the insulating hardened film layer on the surface of a titanium alloy is prepared as described in Comparative Example 2 of the present invention;

[0048] Figure 15 A two-dimensional contour map of the front surface wear is prepared for a titanium alloy surface insulating hardened film layer described in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention;

[0049] Figure 16 A two-dimensional contour diagram of surface wear after preparation of an insulating hardened film layer on the surface of a titanium alloy according to Example 1 of the present invention;

[0050] Figure 17 A two-dimensional contour map of the front surface wear of the insulating hardened film layer on the titanium alloy surface described in Example 2 of the present invention is prepared;

[0051] Figure 18 A two-dimensional contour diagram of surface wear after preparation of an insulating hardened film layer on the surface of a titanium alloy according to Example 2 of the present invention;

[0052] Figure 19 A two-dimensional contour diagram of surface wear after preparation of an insulating hardened film layer on the surface of a titanium alloy according to Comparative Example 1 of the present invention;

[0053] Figure 20 This is a two-dimensional contour diagram of the surface wear after the insulating hardened film layer on the surface of a titanium alloy described in Comparative Example 2 of the present invention is prepared. DETAILED DESCRIPTION

[0054] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The descriptions of "first", "second", etc. mentioned in the embodiments of the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0055] A method for preparing an insulating hardened film layer on a titanium alloy surface, the method comprising the following steps:

[0056] S1. Pre-treating the titanium alloy sample to remove the oxide film on the titanium alloy surface;

[0057] S2. Oxidizing the titanium alloy sample at an oxidation temperature of 500-900°C for a holding time of 30 min-5 h;

[0058] S3. Place the titanium alloy sample in a vacuum environment and introduce O2 for oxygenation treatment. The oxygenation temperature is 400-900°C, the oxygenation time is 30 minutes to 10 hours, and the oxygen flow rate is 30-200 sccm.

[0059] The present invention discloses a method for preparing an insulating hardened film layer on the surface of a titanium alloy, wherein steps S1 to S3 are interrelated and inseparable. Although the oxide film generated by the initial passivation on the surface of the titanium alloy sample is dense, it is very thin and uneven in thickness. The presence of the initial oxide film will also hinder the formation of titanium dioxide on the surface and the diffusion of oxygen during the heat treatment process. In step S1, the oxide film generated by the initial passivation on the surface of the titanium alloy sample is removed to avoid hindering the formation of titanium dioxide on the surface and the diffusion of oxygen during the heat treatment process. After the oxidation treatment in step S2, a dense and insulating oxide film with uniform thickness is formed on the surface of the titanium alloy sample. On the one hand, the in-situ generation of insulating TiO2 on the surface can effectively prevent the occurrence of galvanic corrosion of the titanium alloy and achieve a good insulating effect. On the other hand, the dense insulating oxide film can serve as an effective surface strengthening reinforcement, which is beneficial for oxygen atoms to penetrate into the interior of the titanium alloy matrix during oxygen permeation treatment, thereby improving the quality and density of oxygen permeation, thereby improving the hardness and wear resistance of the titanium alloy sample surface; after step S3, high-purity O2 is introduced into the vacuum environment for oxygen permeation, on the one hand, which can improve the surface activity of the titanium alloy, and is beneficial for the oxygen atoms of O2 to penetrate into the interior of the titanium alloy matrix during oxygen permeation treatment; on the other hand, it is beneficial for the oxygen atoms in the surface oxide film layer to effectively penetrate into the interior of the titanium alloy matrix through diffusion. Under the joint action of these two aspects, the density and quality of the oxygen permeation layer are effectively improved, so that the oxygen permeation layer forms an oversaturated solid solution layer in the α phase, effectively improving the surface hardness and wear resistance of the titanium alloy.

[0060] Specifically, in step S2, the oxidation temperature is 600-900°C, and the holding time is 2-5 hours.

[0061] This setting optimizes the process parameters in the preparation process of the insulating hardened film layer on the surface of the titanium alloy. On the one hand, it makes adequate preparations for improving the quality of oxygen permeation; on the other hand, it makes the insulating hardened film layer on the surface of the titanium alloy have insulating properties.

[0062] Specifically, in step S3, the titanium alloy sample is placed in a vacuum environment and oxygen is introduced thereinto for oxygenation treatment. The oxygenation temperature is 500-600° C., the oxygenation time is 3-6 hours, and the oxygen flow rate is 100-200 sccm.

[0063] This setting optimizes the process parameters in the preparation process of the insulating hardened film layer on the surface of the titanium alloy, which is beneficial to improving the quality and density of oxygen permeation, thereby helping to improve the hardness of the insulating hardened film layer on the surface of the titanium alloy.

[0064] Specifically, in step S2, the titanium alloy sample is placed in a muffle furnace for oxidation.

[0065] Specifically, in step S3, the titanium alloy sample is placed in a vacuum tube furnace and oxygen is introduced into the furnace for oxygen permeation treatment.

[0066] Specifically, step S1 includes the following steps:

[0067] S11. Place the titanium alloy sample in degreasing agent and pure water in turn, use ultrasonic cleaning, and wipe the surface with alcohol to ensure that the surface of the titanium alloy sample is dry and clean;

[0068] S12. Place the titanium alloy sample into an acidic mixed solution to remove the oxide film on the surface of the titanium alloy sample.

[0069] Specifically, the acidic mixed solution includes HF, CH3CH2OH and water, the ratio of HF, CH3CH2OH and water is: HF: CH3CH2OH: water = 1:1-10:1-10, and the pH of the acidic mixed solution is 2-5.

[0070] This setting optimizes the ratio of the acidic mixture, which facilitates the complete initial passivation of the oxide film formed on the surface of the titanium alloy sample without causing other effects on the titanium alloy surface.

[0071] More specifically, the ratio of HF, CH3CH2OH and water is: HF:CH3CH2OH:water=1:1:1.

[0072] This setting optimizes the ratio of the acidic mixture, which facilitates the complete initial passivation of the oxide film formed on the surface of the titanium alloy sample without causing other effects on the titanium alloy surface.

[0073] Specifically, in step S12, the titanium alloy sample is placed in the acidic mixed solution and fully reacted for 1 to 30 minutes.

[0074] This setting optimizes the reaction time of the titanium alloy sample in the acidic mixture, facilitates the complete initial passivation of the oxide film formed on the surface of the titanium alloy sample without causing other effects on the titanium alloy surface.

[0075] In a second aspect of the present invention, a titanium alloy is provided, wherein the surface of the titanium alloy is an insulating hardened film layer, and the insulating hardened film layer on the surface of the titanium alloy is prepared using any one of the above-mentioned methods for preparing the insulating hardened film layer on the surface of the titanium alloy.

[0076] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0077] Example 1:

[0078] A method for preparing an insulating hardened film layer on a titanium alloy surface, the method comprising the following steps:

[0079] S1. Pre-treating the titanium alloy sample (α-Ti) to remove the oxide film on the surface of the titanium alloy;

[0080] S11 Place the titanium alloy sample in degreasing agent and pure water in turn, use ultrasonic cleaning, and wipe the surface with alcohol to ensure that the sample surface is dry and clean;

[0081] S12, then placing the titanium alloy sample in an acidic mixed solution and fully reacting for 10 minutes to remove the oxide film on the surface of the titanium alloy sample, wherein the acidic mixed solution includes HF, CH3CH2OH and water, and the ratio of HF, CH3CH2OH and water is 1:1:1;

[0082] S2. Place the titanium alloy sample in a muffle furnace for oxidation at a temperature of 600°C for 4 hours;

[0083] S3. Place the titanium alloy sample in a vacuum tube furnace and introduce high-purity O2 for oxygenation treatment. The oxygenation temperature is 500°C, the oxygenation time is 6 hours, and the oxygen flow rate is 200 sccm.

[0084] Example 2:

[0085] Different from Example 1, in this embodiment, in the method for preparing the insulating hardened film layer on the surface of the titanium alloy, the titanium alloy sample is ((α+β)-Ti).

[0086] In step S12, the titanium alloy sample is placed in the acidic mixed solution and fully reacted for 20 minutes.

[0087] In step S2, the oxidation temperature is 900°C and the holding time is 2h;

[0088] In step S3 , the oxygen permeation temperature is 600° C., the oxygen permeation time is 3 hours, and the oxygen flow rate is 100 sccm.

[0089] Comparative Example 1

[0090] Different from Example 1, in this comparative example, the method for preparing the insulating hardened film layer on the surface of the titanium alloy does not include step S1 of Example 1.

[0091] Comparative Example 2

[0092] Different from Example 1, in this comparative example, the method for preparing the insulating hardened film layer on the surface of the titanium alloy does not include step S2 of Example 1.

[0093] Comparative Example 3

[0094] The titanium alloy was subjected to oxygen permeation surface strengthening treatment according to the method of Example 1 in the background art CN201110378673.7.

[0095] Test Example 1: Morphology Characterization

[0096] The surface oxide film of the titanium alloy prepared in Example 1 and processed in step S1 and step S2 was characterized by scanning electron microscopy. The test results are as follows: Figure 1 shown.

[0097] The surface oxygen permeation layer of the titanium alloy prepared in Example 1 and processed by steps S1, S2 and S3 was characterized by scanning electron microscopy. The test results are as follows: Figure 2 shown.

[0098] The surface oxide film of the titanium alloy prepared in Example 2 and processed in step S1 and step S2 was characterized by scanning electron microscopy. The test results are as follows: Figure 3 shown.

[0099] The surface oxygen permeation layer of the titanium alloy prepared in Example 2 and processed by steps S1, S2 and S3 was characterized by scanning electron microscopy. The test results are as follows: Figure 4 shown.

[0100] like Figure 1 As shown, the thickness of the oxide film layer on the surface of the titanium alloy prepared in Example 1 after being processed in step S1 and step S2 is 4.46-5.07 μm.

[0101] like Figure 2 As shown, the thickness of the oxygen permeation layer on the surface of the titanium alloy prepared in Example 1 after being processed in steps S1, S2 and S3 is 55-58 μm.

[0102] like Figure 3 As shown, the thickness of the oxide film layer on the surface of the titanium alloy prepared in Example 2 after being processed in step S1 and step S2 is 14.28-15.88 μm.

[0103] like Figure 4As shown, the thickness of the oxygen permeation layer on the surface of the titanium alloy prepared in Example 2 after being processed in steps S1, S2 and S3 is 65 to 70 μm.

[0104] In summary, the thickness of the oxide film layer on the surface of the titanium alloy in Example 2 and the thickness of the oxygen-permeated layer on the surface of the titanium alloy are thicker than the thickness of the oxide film layer on the surface of the titanium alloy in Example 1. This is because the titanium alloy sample in Example 2 is different from the titanium alloy sample in Example 1. The titanium alloy sample in Example 1 is α-Ti, and the titanium alloy sample in Example 2 is (α+β)-Ti.

[0105] The thickness of the oxide film on the surface of the titanium alloy sample in Comparative Example 1 is 3-4 μm, and the thickness of the oxygen-permeated layer on the titanium alloy sample in Comparative Example 1 is 20-30 μm. This is because Comparative Example 1 did not perform step S1 and did not remove the surface oxide layer, which was not conducive to the formation of the oxide film and the depth of oxygen diffusion.

[0106] No complete and continuous oxide film was detected on the titanium alloy sample of Comparative Example 2. The thickness of the oxygen-permeated layer of the titanium alloy sample of Comparative Example 2 was 0-10 μm. This is because Comparative Example 1 did not perform step S2. After removing the surface oxide layer, oxidation was directly performed in a vacuum environment, which was not conducive to the formation of dense titanium oxide on the titanium alloy surface and was also not conducive to the depth of oxygen diffusion.

[0107] The thickness of the oxygen permeation layer of the titanium alloy sample in Comparative Example 3 is 100 μm. This is because the preparation method of the titanium alloy surface insulating hardened film in Comparative Example 3 is completely different from that in the present application.

[0108] Test Example 2: X-ray diffraction test

[0109] The surface oxygen permeation layer of the titanium alloy prepared in Example 1 was subjected to XRD test, and the test results are as follows: Figure 5 shown.

[0110] The surface oxygen permeation layer of the titanium alloy prepared in Example 2 was subjected to XRD test, and the test results are as follows: Figure 6 shown.

[0111] The oxygen permeation layer on the titanium alloy surface prepared in Comparative Example 1 was subjected to XRD test, and the test results are as follows: Figure 7 shown.

[0112] The oxygen permeation layer on the titanium alloy surface prepared in Comparative Example 2 was subjected to XRD test, and the test results are as follows: Figure 8 shown.

[0113] like Figure 5 、 6As shown in Figure 7, after XRD testing, characteristic peaks belonging to rutile TiO2 and α-Ti appear in the XRD test diagram. Therefore, it can be determined that the main phases of the oxygen-permeated layer on the surface of the titanium alloy prepared in Example 1, Example 2, and Comparative Example 1 are rutile TiO2 and α-Ti.

[0114] like Figure 8 As shown, after XRD testing, characteristic peaks belonging to α-Ti appear in the XRD test graph, so it can be determined that the main phase of the oxygen-permeated layer on the surface of the titanium alloy prepared in Comparative Example 2 is α-Ti.

[0115] Test Example 3: Performance Test

[0116] The hardness test and insulation performance test were conducted on the titanium alloy surface insulation hardened film layers prepared in Examples 1 to 2 and Comparative Examples 1 to 3. The specific experimental results are shown in Table 1. The wear rate test of the titanium alloy surface insulation hardened film layers prepared in Examples 1 to 2 and Comparative Examples 1 to 2 before and after preparation was conducted. The specific experimental results are shown in Table 1. The three-dimensional morphology of the wear of the titanium alloy surface insulation hardened film layers prepared in Examples 1 to 2 and Comparative Examples 1 to 2 before and after preparation is shown in Table 1. Figures 9-14 As shown, the two-dimensional contour diagrams of the wear scars before and after the preparation of the insulating hardened film layer on the titanium alloy surface of Examples 1-2 and Comparative Examples 1-2 are shown. Figures 15-20 shown.

[0117] Table 1

[0118]

[0119] From Table 1, Figures 9-20 It can be seen that, first, the surface hardness of the titanium alloy in Examples 1 to 2 is very high, and the hardness of the titanium alloy surface can reach above HV1060; second, the oxide layer generated on the surface of the titanium alloy in Examples 1 to 2 can have a good insulation effect, and the insulation resistance is greater than 200MΩ; third, the oxide layer generated on the surface of the titanium alloy in Examples 1 to 2 improves the wear resistance of the surface of the titanium alloy, and the wear resistance of the oxide layer generated on the surface of the titanium alloy in Examples 1 to 2 is improved by 83.08%.

[0120] As can be seen from Table 1, the surface hardness of the titanium alloy in Comparative Example 1 is greatly reduced, and the wear resistance is also reduced. This is because the oxide film generated by the initial passivation on the surface of the titanium alloy sample is not removed, which is not conducive to the formation of a dense oxide film and oxygen diffusion during the oxidation treatment in step S2.

[0121] The titanium alloy surface layer of Comparative Example 2 is not insulated, and its hardness and wear resistance are greatly reduced. This is because oxygenation is directly performed in a vacuum environment after removing the oxide film formed by initial passivation on the surface of the titanium alloy sample, which is not conducive to the formation of dense titanium oxide on the titanium alloy surface.

[0122] The titanium alloy surface layer in Comparative Example 3 is not insulated and has a reduced hardness. This is because Comparative Example 3 did not perform step S1 of the present application to remove the oxide film formed by the initial passivation on the surface of the titanium alloy sample, nor did it perform step S2 of the oxidation treatment. Furthermore, during step S3 of the oxygenation, the oxygenation was not performed under vacuum, and the oxygenation method was also different.

[0123] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A method for preparing an insulating hardened film layer on the surface of a titanium alloy, characterized in that: The method for preparing the insulating hardened film layer on the titanium alloy surface comprises the following steps: S1. Pre-treating the titanium alloy sample to remove the oxide film on the titanium alloy surface; S2. Oxidation treatment of the titanium alloy sample at an oxidation temperature of 500-900°C and a holding time of 30 min-5 h; S3. Place the titanium alloy sample in a vacuum environment and introduce O2 for oxygenation treatment. The oxygenation temperature is 400-900°C, the oxygenation time is 30 minutes to 10 hours, and the oxygen flow rate is 30-200 sccm. Step S1 includes the following steps: S11. Place the titanium alloy sample in degreasing agent and pure water in turn, use ultrasonic cleaning, and wipe the surface with alcohol to ensure that the surface of the titanium alloy sample is dry and clean; S12, placing the titanium alloy sample into an acidic mixed solution to remove an oxide film on the surface of the titanium alloy sample; The acidic mixed solution includes HF, CH3CH2OH and water, the ratio of HF, CH3CH2OH and water is: HF: CH3CH2OH: water = 1:1-10:1-10, and the pH of the acidic mixed solution is 2-5; In step S12, the titanium alloy sample is placed in the acidic mixed solution and fully reacted for 1 to 30 minutes; The hardness of the titanium alloy surface reaches HV1060 or above; The insulation resistance of the oxide layer formed on the surface of titanium alloy is greater than 200MΩ; Titanium alloy When the surface oxide film thickness is 4.46~5.07um, the depth of the oxygen permeation layer is 55~58um, and the main phases of the oxygen permeation layer on the surface of titanium alloy are rutile TiO2 and ; Titanium alloy When the thickness of the surface oxide film is 14.28~15.88um, the depth of the oxygen permeation layer is 65~70um; the main phases of the oxygen permeation layer on the surface of titanium alloy are rutile TiO2 and .

2. The method for preparing an insulating hardened film layer on a titanium alloy surface according to claim 1, characterized in that: In step S2, the oxidation temperature is 600-900°C, and the holding time is 2-5 hours.

3. The method for preparing an insulating hardened film layer on a titanium alloy surface according to claim 1, characterized in that: In step S3, the titanium alloy sample is placed in a vacuum environment and oxygen is introduced into the sample for oxygenation treatment. The oxygenation temperature is 500-600°C, the oxygenation time is 3-6 hours, and the oxygen flow rate is 100-200 sccm.

4. The method for preparing an insulating hardened film layer on a titanium alloy surface according to claim 1 or 2, characterized in that: In step S2, the titanium alloy sample is placed in a muffle furnace for oxidation.

5. The method for preparing an insulating hardened film layer on a titanium alloy surface according to claim 1 or 3, characterized in that: In step S3, the titanium alloy sample is placed in a vacuum tube furnace and oxygen is introduced into the furnace for oxygen permeation treatment.

6. The method for preparing an insulating hardened film layer on a titanium alloy surface according to claim 1, characterized in that: The ratio of HF, CH3CH2OH and water is: HF: CH3CH2OH: water = 1:1:

1.

7. A titanium alloy, wherein the surface of the titanium alloy is an insulating hardened film layer, and the insulating hardened film layer on the surface of the titanium alloy is prepared using the method for preparing an insulating hardened film layer on the surface of a titanium alloy according to any one of claims 1 to 6.

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