Titanium nitride-containing coating alloy and preparation method thereof

Abstract

The invention discloses a titanium nitride-containing coating alloy and a preparation method thereof, and belongs to the technical field of oxidation coatings, and the preparation method specifically comprises the following steps: removing impurities on the surface of an alloy workpiece; preparing a solution from sodium silicate, sodium phosphate, sodium aluminate, saccharin sodium salt, sodium fluoride, urea and rare earth salt, adding the titanium nitride particle solution, and uniformly mixing to prepare an electrolyte; the alloy workpiece is used as an anode, stainless steel is used as a cathode, micro-arc oxidation treatment is conducted, and specific parameters are as follows: the positive voltage is 400-600 V, the negative voltage is 30-80 V, the current density is 5-20 A / dm < 2 >, the pulse width is 10-30 microseconds, the frequency is 300-700 Hz, the oxidation time is 8-15 min, and the electrolyte temperature is 20-40 DEG C; and taking out the treated workpiece, cleaning, drying at low temperature, and carrying out hole sealing treatment. The oxidation coating has the advantages of being high in bonding strength with the alloy and excellent in coating performance, and the problems that an existing coating is prone to falling off and poor in performance can be effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oxidation coatings, and particularly relates to a titanium nitride-coated alloy and a preparation method thereof. Background Art

[0002] Aluminum alloy is an alloy formed with aluminum as the base material and adding a certain amount of other elements. It is one of the light metal materials. Aluminum alloy has the advantages of low density, high specific strength, easy processing and forming, strong recyclability, etc., and is widely used in fields such as aerospace, automobile manufacturing and mechanical engineering, especially in key parts such as aircraft fuselages, wing structures and lightweight body components. However, during the manufacturing and use process of aluminum alloy, surface defects such as uneven oxide layer, surface cracks, corrosion and mechanical damage are prone to occur, seriously affecting the use effect.

[0003] Titanium alloy is an alloy formed with titanium as the base material and adding a certain amount of other elements. It has the advantages of high strength, high temperature resistance, good biocompatibility, etc. Titanium alloy is widely used in the preparation of aircraft landing gears, engines, compressor casings and other various casings. Although titanium alloy has many advantages, it also has many defects, restricting its scope of use. During the use process of titanium alloy, phenomena such as adhesive wear and abrasive wear are prone to occur, seriously affecting its use effect.

[0004] Currently, in order to solve the problems existing in aluminum alloy and titanium alloy, most of them are to prepare a coating with better performance on the surface of the alloy to improve the performance defects of the alloy itself. However, most of the prepared coatings have problems such as easy cracking and easy peeling, affecting the service life. Summary of the Invention

[0005] In view of the above deficiencies in the prior art, the present invention provides a titanium nitride-coated alloy and a preparation method thereof. The oxidation coating has the advantages of high bonding strength with the alloy and excellent coating performance, and can effectively solve the problems of easy peeling and poor performance of some coatings.

[0006] To achieve the above object, the technical solution adopted by the present invention to solve its technical problems is:

[0007] A preparation method of a titanium nitride-coated alloy, comprising the following steps:

[0008] (1) Pretreat the alloy workpiece to remove impurities on the surface of the alloy workpiece;

[0009] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea and rare earth salt into water, dissolve to prepare a solution, add a titanium nitride particle solution thereto, and mix evenly to prepare an electrolyte;

[0010] (3) Use the alloy workpiece as the anode, stainless steel or graphite as the cathode. Place the electrolyte, anode, and cathode in an electrolytic cell and perform micro-arc oxidation treatment using a pulsed DC or AC power source. The specific parameters are as follows: forward voltage 400 - 600V, reverse voltage 30 - 80V, current density 5 - 20A / dm 2 , pulse width 10 - 30μs, frequency 300 - 700Hz, oxidation time 8 - 15min, electrolyte temperature 20 - 40°C;

[0011] (4) Take out the treated workpiece, wash it, dry it at low temperature, and then perform sealing treatment to obtain the product.

[0012] In the above solution, sodium silicate is added to the electrolyte. Its function is to provide a silicon source, participate in the formation of aluminum silicate, and significantly improve the hardness and wear resistance of the coating. At the same time, silicate has colloidal stability, which can improve the stability of suspended particles in the electrolyte; sodium phosphate is used to maintain the stability of the electrolyte. At the same time, phosphate ions react with aluminum ions to form aluminum phosphate, which is used to fill the pores of the coating and improve the density and corrosion resistance of the coating; aluminate is used to supplement the aluminum source and promote the formation of aluminum oxide; sodium fluoride is used to reduce the breakdown voltage, improve the discharge uniformity, and improve the coating uniformity; saccharin sodium is used as a surfactant, which can reduce the surface tension of the electrolyte, promote the discharge uniformity, reduce the generation of coating pores. At the same time, it adsorbs on the surface of the aluminum-based substrate, inhibits local corrosion, and improves the bonding strength of the coating; urea is used as a nitrogen source supply. In the plasma environment of micro-arc discharge, the nitrogen source combines with the carbon source to form carbon nitride or nitrogen-doped oxides deposited in the coating, thereby improving the hardness and wear resistance of the coating; rare earth salts can be used to refine the coating grains, reduce the porosity, improve the density of the coating, and enhance the high-temperature resistance and oxidation resistance of the coating; titanium carbide particles will also deposit during the micro-arc oxidation process to form a coating, further improving the wear resistance of the coating.

[0013] Furthermore, in step (1), the alloy workpiece is a 2024 aluminum alloy workpiece, an AlSiMg aluminum alloy workpiece, or a titanium alloy workpiece.

[0014] Furthermore, in step (2), the concentration of sodium silicate is 15 - 30g / L, the concentration of sodium phosphate is 5 - 15g / L, the concentration of aluminate is 5 - 20g / L, the concentration of saccharin sodium is 0.3 - 1g / L, the concentration of sodium fluoride is 2 - 8g / L, the concentration of urea is 3 - 8g / L, the concentration of rare earth salts is 1 - 5g / L, and the concentration of titanium nitride particles is 0.1 - 1.5g / L.

[0015] Further, in step (2), the concentration of sodium silicate is 15 - 25 g / L, the concentration of sodium phosphate is 8 - 10 g / L, the concentration of sodium aluminate is 14 - 16 g / L, the concentration of saccharin sodium is 0.4 - 0.6 g / L, the concentration of sodium fluoride is 4 - 6 g / L, the concentration of urea is 4 - 7 g / L, the concentration of rare earth salt is 2 - 4 g / L, and the concentration of titanium nitride particles is 0.2 - 1 g / L.

[0016] Further, the rare earth salt is Ce(NO3)3.

[0017] Further, the particle size of the titanium nitride particles is 8 - 20 nm.

[0018] Further, the specific parameters in step (3) are: the forward voltage is 500 - 600 V, the reverse voltage is 40 - 60 V, the current density is 10 - 20 A / dm 2 , the pulse width is 15 - 25 μs, the frequency is 400 - 600 Hz, the oxidation time is 10 - 13 min, and the electrolyte temperature is 25 - 30 °C.

[0019] Further, the drying temperature in step (4) is 40 - 60 °C.

[0020] A titanium nitride-coated alloy is prepared by the above method.

[0021] The beneficial effects produced by the present invention are as follows:

[0022] 1. The preparation method in the present invention is simple, the production cost is low, the surface coating of the obtained alloy is metallurgically bonded to the matrix alloy, the bonding is good, and it is not easy to fall off. It not only improves the surface hardness of the alloy, but also improves the structure. There are no obvious pores and through cracks in the coating. The coating improves the hardness and wear resistance of the alloy, effectively solving the problems of easy coating peeling and poor comprehensive performance in the prior art.

[0023] 2. The coating prepared in the present invention has excellent corrosion resistance. The coating is a dense ceramicized oxide film, which can effectively isolate the penetration of corrosive media, significantly improving the corrosion resistance of the alloy in harsh environments; and the coating has extremely high hardness, which can significantly improve the wear resistance of the surface of the alloy, reduce surface damage caused by friction, scratching, etc., and extend the service life of the material; the coating has good insulation performance and thermal stability, and can be used in occasions where insulation protection is required; finally, the coating has high thermal stability and can maintain stability in high-temperature environments, suitable for high-temperature working conditions. Description of the Drawings

[0024] Figure 1 It is the microstructure diagram of the workpiece in Example 1;

[0025] Figure 2 It is the microstructure diagram of the workpiece in Example 3;

[0026] Figure 3 Microstructure diagram of the workpiece in Example 5;

[0027] Figure 4 Microstructure diagram of the workpiece in Comparative Example 1;

[0028] Figure 5 Microstructure diagram of the workpiece in Comparative Example 2;

[0029] Figure 6 Microstructure diagram of the workpiece in Comparative Example 3;

[0030] Figure 7 Microstructure diagram of the workpiece in Comparative Example 4. Detailed implementation manners

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0032] Therefore, the following detailed description of the provided embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0033] It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including an..." does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0034] The features and performance of the present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings.

[0035] Example 1

[0036] A titanium nitride-coated alloy, and its preparation method includes the following steps:

[0037] (1) Immerse the 2024 aluminum alloy workpiece in an alkaline cleaning solution to remove the oil, oxides, and other contaminants on the surface, then rinse it with water and dry it for later use;

[0038] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea, and rare earth salt to water, dissolve to obtain a solution, add a titanium nitride particle solution thereto, and mix well to obtain an electrolyte. In the electrolyte, the concentration of sodium silicate is 15 g / L, the concentration of sodium phosphate is 8 g / L, the concentration of sodium aluminate is 14 g / L, the sodium saccharin is 0.4 g / L, the concentration of sodium fluoride is 4 g / L, the urea is 4 g / L, the concentration of Ce(NO3)3 is 2 g / L, the concentration of titanium nitride particles is 0.2 g / L, and the particle size of the titanium nitride particles is 8 nm;

[0039] (3) Use the alloy workpiece as the anode and stainless steel as the cathode. Place the electrolyte, anode, and cathode in an electrolytic cell and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are: positive voltage 500 V, negative voltage 40 V, current density 10 A / dm 2 , pulse width 15 μs, frequency 400 Hz, electrolyte temperature 25 °C, oxidation time 13 min;

[0040] (4) Take out the treated workpiece, wash it, and then dry it at a low temperature of 40 °C, and then perform sealing treatment to obtain it.

[0041] Example 2

[0042] A titanium nitride-coated alloy, and its preparation method includes the following steps:

[0043] (1) Immerse the 2024 aluminum alloy workpiece in an alkaline cleaning solution to remove the oil, oxides, and other contaminants on the surface, then rinse it with water and dry it for later use;

[0044] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea, and rare earth salt to water, dissolve to obtain a solution, add a titanium nitride particle solution thereto, and mix well to obtain an electrolyte. In the electrolyte, the concentration of sodium silicate is 25 g / L, the concentration of sodium phosphate is 10 g / L, the concentration of sodium aluminate is 16 g / L, the sodium saccharin is 0.6 g / L, the concentration of sodium fluoride is 6 g / L, the urea is 7 g / L, the concentration of Ce(NO3)3 is 4 g / L, the concentration of titanium nitride particles is 1 g / L, and the particle size of the titanium nitride particles is 20 nm;

[0045] (3) Use the alloy workpiece as the anode and stainless steel as the cathode. Place the electrolyte, anode, and cathode in an electrolytic cell and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are: positive voltage 600 V, negative voltage 60 V, current density 20 A / dm 2, with a pulse width of 25 μs, a frequency of 600 Hz, an electrolyte temperature of 30 °C, and an oxidation time of 13 min;

[0046] (4) Take out the treated workpiece, wash it, dry it at a low temperature under the condition of 60 °C, and then perform sealing treatment to obtain it.

[0047] Example 3

[0048] A titanium nitride-coated alloy, and its preparation method includes the following steps:

[0049] (1) Immerse the AlSiMg aluminum alloy workpiece in an alkaline cleaning solution to remove the oil, oxides and other contaminants on the surface, then rinse it with water and dry it for standby;

[0050] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea and rare earth salt into water, dissolve to prepare a solution, add a titanium nitride particle solution to it, and mix well to obtain an electrolyte. In the electrolyte, the concentration of sodium silicate is 20 g / L, the concentration of sodium phosphate is 8 g / L, the concentration of sodium aluminate is 15 g / L, the concentration of sodium saccharin is 0.5 g / L, the concentration of sodium fluoride is 5 g / L, the concentration of urea is 5 g / L, the concentration of Ce(NO3)3 is 3 g / L, and the concentration of titanium nitride particles is 0.5 g / L. The particle size of the titanium nitride particles is 15 nm;

[0051] (3) Use the alloy workpiece as the anode and stainless steel as the cathode. Place the electrolyte, anode and cathode in an electrolytic cell, and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are: the forward voltage is 540 V, the reverse voltage is 50 V, and the current density is 15 A / dm 2 , with a pulse width of 20 μs, a frequency of 500 Hz, an oxidation time of 10 min, and an electrolyte temperature of 25 °C;

[0052] (4) Take out the treated workpiece, wash it, dry it at a low temperature under the condition of 50 °C, and then perform sealing treatment to obtain it.

[0053] Example 4

[0054] A titanium nitride-coated alloy, and its preparation method includes the following steps:

[0055] (1) Immerse the AlSiMg aluminum alloy workpiece in an alkaline cleaning solution to remove the oil, oxides and other contaminants on the surface, then rinse it with water and dry it for standby;

[0056] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea and rare earth salt into water, dissolve to prepare a solution, add a titanium nitride particle solution thereto, and mix well to prepare an electrolyte. In the electrolyte, the concentration of sodium silicate is 30 g / L, the concentration of sodium phosphate is 5 g / L, the concentration of sodium aluminate is 5 g / L, the concentration of sodium saccharin is 1 g / L, the concentration of sodium fluoride is 8 g / L, the concentration of urea is 8 g / L, the concentration of Ce(NO3)3 is 1 g / L, the concentration of titanium nitride particles is 0.1 g / L, and the particle size of the titanium nitride particles is 15 nm;

[0057] (3) Use the alloy workpiece as the anode and stainless steel as the cathode. Place the electrolyte, anode and cathode in an electrolytic cell, and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are: forward voltage 450 V, reverse voltage 30 V, current density 5 A / dm 2 , pulse width 10 μs, frequency 700 Hz, oxidation time 10 min, electrolyte temperature 25 °C;

[0058] (4) Take out the treated workpiece, wash it, and then dry it at a low temperature of 50 °C, and then perform sealing treatment to obtain the product.

[0059] Example 5

[0060] A titanium nitride-coated alloy, and its preparation method includes the following steps:

[0061] (1) Immerse the titanium alloy workpiece and aluminum alloy workpiece in an alkaline cleaning solution to remove oil stains, oxides and other contaminants on the surface, then rinse with water and dry for standby;

[0062] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea and rare earth salt into water, dissolve to prepare a solution, add a titanium nitride particle solution thereto, and mix well to prepare an electrolyte. In the electrolyte, the concentration of sodium silicate is 25 g / L, the concentration of sodium phosphate is 8 g / L, the concentration of sodium aluminate is 14 g / L, the concentration of sodium saccharin is 0.4 g / L, the concentration of sodium fluoride is 6 g / L, the concentration of urea is 7 g / L, the concentration of Ce(NO3)3 is 2 g / L, the concentration of titanium nitride particles is 0.2 g / L, and the particle size of the titanium nitride particles is 10 nm;

[0063] (3) Use the alloy workpiece as the anode and stainless steel as the cathode. Place the electrolyte, anode and cathode in an electrolytic cell, and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are: forward voltage 560 V, reverse voltage 55 V, current density 15 A / dm 2 , pulse width 20 μs, frequency 550 Hz, oxidation time 13 min, electrolyte temperature 30 °C;

[0064] (4) Take out the treated workpiece, wash it, and then dry it at a low temperature of 60 °C, and then perform sealing treatment to obtain the product.

[0065] Example 6

[0066] A titanium nitride-coated alloy, and its preparation method comprises the following steps:

[0067] (1) Immerse the titanium alloy workpiece and the aluminum alloy workpiece in an alkaline cleaning solution to remove the oil stains, oxides and other contaminants on the surface, then rinse with water and dry for standby;

[0068] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea and rare earth salts into water, dissolve to prepare a solution, add a titanium nitride particle solution thereto, and mix well to prepare an electrolyte. In the electrolyte, the concentration of sodium silicate is 30 g / L, the concentration of sodium phosphate is 15 g / L, the concentration of sodium aluminate is 20 g / L, the concentration of sodium saccharin is 0.3 g / L, the concentration of sodium fluoride is 2 g / L, the concentration of urea is 3 g / L, the concentration of Ce(NO3)3 is 5 g / L, and the concentration of titanium nitride particles is 1.5 g / L. The particle size of the titanium nitride particles is 10 nm;

[0069] (3) Use the alloy workpiece as the anode and stainless steel as the cathode. Place the electrolyte, anode and cathode in an electrolytic cell, and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are: positive voltage 600 V, negative voltage 80 V, current density 20 A / dm 2 , pulse width 30 μs, frequency 600 Hz, oxidation time 13 min, electrolyte temperature 30 °C;

[0070] (4) Take out the treated workpiece, wash it and then dry it at a low temperature of 60 °C, and then perform sealing treatment to obtain it.

[0071] Comparative Example 1

[0072] A titanium nitride-coated alloy, and its preparation method comprises the following steps:

[0073] (1) Immerse the 2024 aluminum alloy workpiece in an alkaline cleaning solution to remove the oil stains, oxides and other contaminants on the surface, then rinse with water and dry for standby;

[0074] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride and rare earth salts into water, dissolve to prepare a solution, and mix well to prepare an electrolyte. In the electrolyte, the concentration of sodium silicate is 15 g / L, the concentration of sodium phosphate is 8 g / L, the concentration of sodium aluminate is 14 g / L, the concentration of sodium saccharin is 0.4 g / L, the concentration of sodium fluoride is 4 g / L, and the concentration of Ce(NO3)3 is 2 g / L;

[0075] (3) Using the alloy workpiece as the anode and stainless steel as the cathode, place the electrolyte, anode, and cathode in an electrolytic cell, and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are as follows: positive voltage 500V, negative voltage 40V, current density 10A / dm 2 , pulse width 15μs, frequency 400Hz, electrolyte temperature 25°C, oxidation time 13min;

[0076] (4) Take out the treated workpiece, wash it, and then dry it at a low temperature of 40°C, and then perform sealing treatment to obtain it.

[0077] Comparative Example 2

[0078] A titanium nitride-coated alloy, and its preparation method includes the following steps:

[0079] (1) Immerse the AlSiMg aluminum alloy workpiece in an alkaline cleaning solution to remove oil, oxides, and other contaminants on the surface, then rinse it with water and dry it for standby;

[0080] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium fluoride, and urea to water, dissolve to prepare a solution, add a titanium nitride particle solution to it, and mix well to obtain an electrolyte. In the electrolyte, the concentration of sodium silicate is 20g / L, the concentration of sodium phosphate is 8g / L, the concentration of sodium aluminate is 15g / L, the concentration of sodium fluoride is 5g / L, urea is 5g / L, the concentration of titanium nitride particles is 0.5g / L, and the particle size of titanium nitride particles is 15nm;

[0081] (3) Using the alloy workpiece as the anode and stainless steel as the cathode, place the electrolyte, anode, and cathode in an electrolytic cell, and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are as follows: positive voltage 540V, negative voltage 50V, current density 15A / dm 2 , pulse width 20μs, frequency 500Hz, oxidation time 10min, electrolyte temperature 25°C;

[0082] (4) Take out the treated workpiece, wash it, and then dry it at a low temperature of 50°C, and then perform sealing treatment to obtain it.

[0083] Comparative Example 3

[0084] A titanium nitride-coated alloy, and its preparation method includes the following steps:

[0085] (1) Immerse the titanium alloy workpiece and aluminum alloy workpiece in an alkaline cleaning solution to remove oil, oxides, and other contaminants on the surface, then rinse it with water and dry it for standby;

[0086] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea and rare earth salt into water, dissolve to prepare a solution, add a titanium nitride particle solution thereto, and mix well to obtain an electrolyte. In the electrolyte, the concentration of sodium silicate is 10 g / L, the concentration of sodium phosphate is 5 g / L, the concentration of sodium aluminate is 14 g / L, the concentration of sodium saccharin is 0.4 g / L, the concentration of sodium fluoride is 6 g / L, the concentration of urea is 10 g / L, the concentration of Ce(NO3)3 is 2 g / L, the concentration of titanium nitride particles is 0.2 g / L, and the particle size of the titanium nitride particles is 10 nm;

[0087] (3) Use the alloy workpiece as the anode and stainless steel as the cathode. Place the electrolyte, anode and cathode in an electrolytic cell, and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are: positive voltage 560 V, negative voltage 55 V, current density 15 A / dm 2 , pulse width 20 μs, frequency 550 Hz, oxidation time 13 min, electrolyte temperature 30 °C;

[0088] (4) Take out the treated workpiece, wash it, and then dry it at a low temperature of 60 °C, and then perform sealing treatment to obtain.

[0089] Comparative Example 4

[0090] A titanium nitride-coated alloy, and its preparation method includes the following steps:

[0091] (1) Immerse the AlSiMg aluminum alloy workpiece in an alkaline cleaning solution to remove oil, oxides and other contaminants on the surface, then rinse it with water and dry it for standby;

[0092] (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea and rare earth salt into water, dissolve to prepare a solution, add a titanium nitride particle solution thereto, and mix well to obtain an electrolyte. In the electrolyte, the concentration of sodium silicate is 20 g / L, the concentration of sodium phosphate is 8 g / L, the concentration of sodium aluminate is 15 g / L, the concentration of sodium saccharin is 0.5 g / L, the concentration of sodium fluoride is 5 g / L, the concentration of urea is 5 g / L, the concentration of Ce(NO3)3 is 3 g / L, the concentration of titanium nitride particles is 0.5 g / L, and the particle size of the titanium nitride particles is 15 nm;

[0093] (3) Use the alloy workpiece as the anode and stainless steel as the cathode. Place the electrolyte, anode and cathode in an electrolytic cell, and perform micro-arc oxidation treatment with pulsed direct current. The specific parameters are: positive voltage 700 V, negative voltage 70 V, current density 15 A / dm 2 , pulse width 20 μs, frequency 500 Hz, oxidation time 20 min, electrolyte temperature 25 °C;

[0094] (4) Take out the processed workpiece, wash it, and then dry it at a low temperature of 50 °C, and then perform sealing treatment to obtain it.

[0095] Test Example

[0096] Taking the workpieces in Examples 1, 3, and 5 and the workpieces in Comparative Examples 1-4 as examples, observe the coating situation on the surface of the workpieces. The specific results are shown in the appendix Figures 1-7 .

[0097] Figure 1 It is the microstructural diagram of the workpiece in Example 1. It can be seen that the coating on the surface of the workpiece is dense, there are no obvious longitudinal cracks, and there are fewer defects such as voids and cracks at the coating joint.

[0098] Figure 2 It is the microstructural diagram of the workpiece in Example 3. It can be seen that the surface coating is relatively dense, there are no longitudinal cracks perpendicular to the coating, there is no overburning or coating collapse and deformation, and there are fewer defects such as voids and cracks at the coating joint.

[0099] Figure 3 It is the microstructural diagram of the workpiece in Example 5. It can be seen that the coating is well combined with the substrate, there are no obvious longitudinal cracks in the coating, there is no overburning or coating collapse and deformation, and there are a certain number of holes, which can be filled by sealing.

[0100] Figure 4 It is the microstructural diagram of the workpiece in Comparative Example 1. It can be seen that there are a large number of pores between the coating and the substrate, and there are many longitudinal cracks on the surface of the coating, and the cracks are relatively deep, so it cannot protect the substrate.

[0101] Figure 5 It is the microstructural diagram of the workpiece in Comparative Example 2. It can be seen that there are many longitudinal cracks on the surface of the coating, the longitudinal cracks are relatively deep and extend to the substrate, so it cannot play a protective role.

[0102] Figure 6 It is the microstructural diagram of the workpiece in Comparative Example 3. It can be seen that the surface of the coating is uneven, there are a large number of relatively large pore structures in the coating, and there are voids between the coating and the substrate, so it cannot play a protective role.

[0103] Figure 7 It is the microstructural diagram of the workpiece in Comparative Example 4. It can be seen that there are cracks in many places in the coating, the cracks mostly extend to the substrate, and there is a large area of collapse, and the combination with the substrate is not tight, and there are more microscopic gaps at the combination part.

Claims

1. A preparation method of a titanium nitride coating alloy, characterized in that, It includes the following steps: (1) Pretreat the alloy workpiece to remove the impurities on the surface of the alloy workpiece; (2) Add sodium silicate, sodium phosphate, sodium aluminate, sodium saccharin, sodium fluoride, urea and rare earth salt into water, dissolve to prepare a solution, add a titanium nitride particle solution thereto, and mix well to prepare an electrolyte; (3) Take the alloy workpiece as the anode, stainless steel or graphite as the cathode, place the electrolyte, anode and cathode in an electrolytic cell, and carry out micro-arc oxidation treatment using a pulsed DC or AC power supply. The specific parameters are: positive voltage 400 - 600V, negative voltage 30 - 80V, current density 5 - 20A / dm 2 , pulse width 10 - 30μs, frequency 300 - 700Hz, oxidation time 8 - 15min, electrolyte temperature 20 - 40°C; (4) Take out the treated workpiece, wash it, dry it at a low temperature, and then perform a sealing treatment to obtain it.

2. The preparation method of the titanium nitride-coated alloy according to claim 1, characterized in that, In step (1), the alloy workpiece is a 2024 aluminum alloy workpiece, an AlSiMg aluminum alloy workpiece or a titanium alloy workpiece.

3. The method for preparing an alloy containing a titanium nitride coating according to claim 2, wherein, In step (2), the concentration of sodium silicate is 15 - 30 g / L, the concentration of sodium phosphate is 5 - 15 g / L, the concentration of sodium aluminate is 5 - 20 g / L, the concentration of sodium saccharin is 0.3 - 1 g / L, the concentration of sodium fluoride is 2 - 8 g / L, the concentration of urea is 3 - 8 g / L, the concentration of rare earth salt is 1 - 5 g / L, and the concentration of titanium nitride particles is 0.1 - 1.5 g / L.

4. The method for preparing an alloy containing a titanium nitride coating according to claim 3, characterized in that, In step (2), the concentration of sodium silicate is 15 - 25 g / L, the concentration of sodium phosphate is 8 - 10 g / L, the concentration of sodium aluminate is 14 - 16 g / L, the concentration of sodium saccharin is 0.4 - 0.6 g / L, the concentration of sodium fluoride is 4 - 6 g / L, the concentration of urea is 4 - 7 g / L, the concentration of rare earth salt is 2 - 4 g / L, and the concentration of titanium nitride particles is 0.2 - 1 g / L.

5. The preparation method of the alloy containing a titanium nitride coating according to claim 1, characterized in that, The rare earth salt is Ce(NO3)3.

6. The preparation method of the alloy containing a titanium nitride coating according to claim 1, characterized in that, The particle size of the titanium nitride particles is 8 - 20 nm.

7. The preparation method of the alloy containing a titanium nitride coating according to claim 1, characterized in that, The specific parameters in step (3) are: forward voltage 500 - 600V, reverse voltage 40 - 60V, current density 10 - 20A / dm 2 , pulse width 15 - 25μs, frequency 400 - 600Hz, oxidation time 10 - 13min, electrolyte temperature 25 - 30°C.

8. The preparation method of the alloy containing a titanium nitride coating according to claim 1, characterized in that, In step (4), the drying temperature is 40 - 60 °C.

9. A titanium nitride-coated alloy, characterized in that, It is obtained by using the method described in any one of claims 1 - 8.

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