阅读说明：本技术 一种能够提高钛合金抗高温氧化性能的TiAl涂层及其制备方法 (TiAl coating capable of improving high-temperature oxidation resistance of titanium alloy and preparation method thereof ) 是由 欧阳佩旋 张淑婷 孙伟 杨谨赫 董志超 李航 吴艳 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种能够提高钛合金抗高温氧化性能的TiAl涂层及其制备方法,所述TiAl涂层中包括α-AlF-(3)纳米颗粒,α-AlF-(3)纳米颗粒含量为TiAl涂层的5～30vol.％。所述TiAl涂层的制备方法为以TiAl合金靶材和α-AlF-(3)靶材为原料,在基材表面进行磁控溅射沉积制备涂层；所述磁控溅射为双靶共溅射,溅射时的基材温度为150℃,其中TiAl合金靶材采用直流溅射,功率为0.5～2kW,α-AlF-(3)靶材采用射频溅射,功率为0.07～0.2kW。双靶共溅射得到涂层后再将所得涂层在600～800℃的温度下热处理5～20h,得到最终的涂层。(The invention discloses a TiAl coating capable of improving high-temperature oxidation resistance of titanium alloy and a preparation method thereof, wherein the TiAl coating comprises alpha-AlF 3 Nanoparticles, alpha-AlF 3 The content of the nano particles is 5-30 vol.% of TiAl coating. The preparation method of the TiAl coating comprises the steps of using a TiAl alloy target material and alpha-AlF 3 The target material is used as a raw material, and magnetron sputtering deposition is carried out on the surface of the substrate to prepare a coating; the magnetron sputtering is double-target co-sputtering, the substrate temperature during sputtering is 150 ℃, wherein the TiAl alloy target material adopts direct-current sputtering, the power is 0.5-2 kW, and the alpha-AlF 3 The target material is subjected to radio frequency sputtering, and the power is 0.07-0.2 kW. After the coating is obtained by double-target co-sputteringAnd carrying out heat treatment on the obtained coating at the temperature of 600-800 ℃ for 5-20 h to obtain the final coating.)

1. A TiAl coating capable of improving high-temperature oxidation resistance of a titanium alloy is characterized in that the coating comprises alpha-AlF₃Nanoparticles, alpha-AlF₃The content of the nano particles is 5-30 vol.% of TiAl coating.

2. The TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to claim 1, wherein the thickness of the TiAl coating is 2-15 μm.

3. The preparation method of the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to any one of claims 1-2, characterized by comprising the following steps: TiAl alloy target and alpha-AlF₃The target material is used as a raw material, and magnetron sputtering deposition is carried out on the surface of the substrate to prepare the coating.

4. The method for preparing the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to claim 3, wherein the preparation method of the TiAl alloy target material comprises the following steps: ti powder and Al powder are used as raw materials, and after uniform mixing, hot isostatic pressing is carried out to obtain a TiAl alloy target material; the alpha-AlF₃The preparation method of the target material comprises the following steps: alpha-AlF₃Hot isostatic pressing of ceramic powders to obtain alpha-AlF₃A target material.

5. The method for preparing the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to claim 4, wherein the particle size of the Ti powder and the Al powder is 1-50 μm, the amount of the Al powder is 35-45 at% of the total amount of the Ti powder and the Al powder, and the alpha-AlF is₃The purity of the ceramic powder is greater than 99.99%.

6. The preparation method of the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to claim 4, wherein the mixing operation is to mix Ti powder and Al powder at a rotating speed of 80-150 r/min for 4-10 h; the pressure maintaining temperature of the hot isostatic pressing of the Ti powder and Al powder mixed material is 1100-1300 ℃, the isostatic pressure is 130-190 MPa, and the heat and pressure maintaining time is 2-6 h.

7. The method for preparing the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to claim 4, wherein the alpha-AlF₃The pressure maintaining temperature of the ceramic powder hot isostatic pressing is 1700-1800 ℃, the isostatic pressure is 130-190 MPa, and the heat and pressure maintaining time is 1-5 h.

8. The method for preparing the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to claim 3, wherein the magnetron sputtering is dual-target co-sputtering, the substrate temperature during sputtering is 150 ℃, the TiAl alloy target material is subjected to direct-current sputtering, the power is 0.5-2 kW, and the power is alpha-AlF₃The target material is subjected to radio frequency sputtering, and the power is 0.07-0.2 kW.

9. The method for preparing the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to claim 8, wherein the sputtering time of the twin-target co-sputtering is 8-20 h, and the twin-target co-sputtering is performed in an environment with Ar gas pressure of 0.5-3 Pa.

10. The preparation method of the novel TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy according to claim 3, further comprising coating post-treatment, and the specific steps comprise: and carrying out heat treatment on the coating prepared by magnetron sputtering deposition, wherein the temperature of the heat treatment is 600-800 ℃, and the time is 5-20 h.

Technical Field

The invention belongs to the technical field of titanium alloy high-temperature protection, and particularly relates to a TiAl coating capable of improving high-temperature oxidation resistance of a titanium alloy and a preparation method thereof.

Background

High-temperature oxidation resistance is an important challenge for maintaining long-term stable service of titanium alloy parts in aircraft engines, and the maximum use temperature of the solid solution strengthened titanium alloy is still 600 ℃. The TiAl coating has the similar components and smaller thermal expansion coefficient difference with the titanium alloy, so the TiAl coating has important application prospect in the anti-oxidation protection of the titanium alloy surface. However, as the indexes of the power system of the new-generation aero-engine tend to be extremely enhanced, the high-temperature oxidation resistance of the TiAl coating needs to be further improved.

Increasing Al content is one of the traditional methods for improving the oxidation resistance of TiAl coatings, but for TiAl binary coatings, the oxidation forms alpha-Al with protection₂O₃The critical Al content required by the film is as high as 60-70 at.%, and the coating is brittle TiAl₂And TiAl₃The phase is main, and the coating is easy to form penetrating cracks, so that the peeling of the coating is accelerated, and the service life of the coating is shortened. Therefore, researchers can improve the Al activity by introducing a third component such as metal elements including Cr, Nb and Si and non-metal elements including Cl, P and F into the TiAl coating with low Al content, so as to improve the oxidation resistance of the TiAl coating and ensure the mechanical property of the TiAl coating. The F modified TiAl coating is highly concerned by domestic and foreign scholars, and is obtained by preparing a TiAl binary coating on the surface of a titanium alloy through diffusion Al infiltration or magnetron sputtering and then infiltrating F atoms by using plasma immersion ion implantation or liquid phase spraying fluorine-containing organic matter and other methods. Compared with other element modified TiAl coatings, the F modified TiAl coating has the following advantages: low density and high temperature (>600 ℃) is adopted to replace the traditional solid phase, the solid solution state F atoms in the coating form gas phase AlF by combining with Al atomsThe Al atom is used as an aluminum source carrier, the diffusion rate and activity of Al are obviously improved, and the critical Al content required by the growth of a protective oxide film of the coating is reduced to 40 at.%. However, the coating has the following disadvantages: in the temperature rise process (400-600 ℃), solid solution F atoms are easy to combine with Ti atoms to form volatile TiF₄The residual F content is obviously reduced (the maximum F content is reduced from 28 at.% to 2 at.%), so that the exertion of the maximum activation effect of F on Al is restricted, and the improvement of the oxidation resistance is influenced. Therefore, the method has great significance for finding a TiAl coating preparation technology which can reduce F loss and greatly improve the oxidation resistance of the titanium alloy.

Disclosure of Invention

The invention aims to provide different TiAl coatings and a preparation method thereof aiming at the problem that the activation of Al is limited because solid solution F atoms are easy to combine with Ti in an F modified TiAl coating, and particularly comprises alpha-AlF₃A nano-particle modified TiAl coating and a double-target magnetron sputtering deposition technology thereof, which adopts alpha-AlF₃The nano particles replace solid solution F atoms as a fluorine source, and the obtained coating enables the titanium alloy matrix to have excellent oxidation resistance at 670 ℃.

One of the technical schemes of the invention is a TiAl coating capable of improving high-temperature oxidation resistance of titanium alloy, wherein the coating comprises alpha-AlF₃Nanoparticles, alpha-AlF₃The content of the nano particles is 5-30 vol.% of TiAl coating.

Further, the thickness of the TiAl coating is 2-15 μm.

When the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy is subjected to a constant-temperature oxidation test for 500 hours at 670 ℃, the oxidation weight gain of the coating is not more than 0.1mg/cm²。

The second technical scheme of the invention is a preparation method of the TiAl coating capable of improving the high-temperature oxidation resistance of the titanium alloy, which comprises the following steps: TiAl alloy target and alpha-AlF₃The target material is used as a raw material, and magnetron sputtering deposition is carried out on the surface of the substrate to prepare the coating.

Further, the preparation method of the TiAl alloy target material comprises the following steps: ti powder and Al powder are used as raw materials, and after uniform mixing, hot isostatic pressing is carried out to obtain TiAl alloyA target material; the alpha-AlF₃The preparation method of the target material comprises the following steps: alpha-AlF₃Hot isostatic pressing of ceramic powders to obtain alpha-AlF₃A target material.

Further, the particle size of the Ti powder and the Al powder is 1-50 μm, the using amount of the Al powder is 35-45 at% of the total amount of the Ti powder and the Al powder, and the alpha-AlF is₃The purity of the ceramic powder is greater than 99.99%.

Further, the particle size of the Ti powder is preferably 44 μm, and the particle size of the Al powder is preferably 37 μm.

Further, the mixing operation is to mix Ti powder and Al powder for 4-10 hours at a rotating speed of 80-150 r/min; the pressure maintaining temperature of the hot isostatic pressing of the Ti powder and Al powder mixed material is 1100-1300 ℃, the isostatic pressure is 130-190 MPa, and the heat and pressure maintaining time is 2-6 h.

Further, the alpha-AlF₃The pressure maintaining temperature of the ceramic powder hot isostatic pressing is 1700-1800 ℃, the isostatic pressure is 130-190 MPa, and the heat and pressure maintaining time is 1-5 h.

Further, the titanium alloy base material is a Ti60 titanium alloy matrix with a surface being pretreated, and the surface pretreatment specifically comprises the following operations: sequentially grinding with 800# and 1500# sandpaper, and then ultrasonically cleaning with acetone and alcohol, and drying.

Further, the magnetron sputtering is double-target co-sputtering, the substrate temperature during sputtering is 150 ℃, the TiAl alloy target material adopts direct current sputtering, the power is 0.5-2 kW, and the alpha-AlF₃The target material is subjected to radio frequency sputtering, and the power is 0.07-0.2 kW.

Further, the sputtering time of the double-target co-sputtering is 8-20 h, and the double-target co-sputtering is carried out in an environment with Ar gas pressure of 0.5-3 Pa.

Further, the coating prepared by double-target co-sputtering also comprises coating post-treatment, and the specific steps comprise the step of carrying out heat treatment on the coating prepared by double-target co-sputtering, wherein the heat treatment temperature is 600-800 ℃, and the time is 5-20 hours.

Further, before the heat treatment, a vacuum-pumping operation is performed to a pressure of 0.05 Pa.

Further, a process flow of the preparation process of the TiAl coating capable of improving the high temperature oxidation resistance of the titanium alloy is shown in fig. 1.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention obtains nano alpha-AlF on the surface of the titanium alloy by a double-target magnetron co-sputtering technology₃Particle-modified TiAl coating in which the element F is alpha-AlF₃The form of the nano particles exists, and the problem that the maximum activation effect of F on Al is restricted due to the fact that active solid-solution F atoms are easy to react with Ti in the prior art is solved; the invention carries out high-temperature heat treatment operation after the double-target magnetron co-sputtering deposition, eliminates the thermal stress generated in the coating preparation process, and causes Al and Ti elements to mutually diffuse at the coating-substrate interface to form metallurgical bonding, thereby improving the interface bonding force. When the coating prepared by the invention is subjected to a constant temperature oxidation test for 500h at 670 ℃, the oxidation weight gain of the coating is not more than 0.1mg/cm²The coating is attached to the surface of the titanium alloy matrix, so that the titanium alloy matrix still has excellent oxidation resistance at 670 ℃, and can be used for high-temperature protection of titanium alloy parts of aircraft engines. The preparation method can realize the simultaneous construction of the TiAl coating and the fluorine source in one step, and is simple, convenient and efficient.

(2) According to the invention, before magnetron sputtering is carried out on the titanium alloy matrix, the surface of the matrix is sequentially polished by 800# and 1500# abrasive paper, and then is sequentially subjected to pretreatment of ultrasonic cleaning by acetone and alcohol and drying, so that impurities on the surface of the matrix are removed, the surface of the matrix is clean and flat, the surface of the matrix has good adhesion with a deposited coating, and the bonding strength of the coating is improved.

(3) The invention adopts a double-target co-sputtering method to sputter the coating, the TiAl alloy target material adopts direct current sputtering and alpha-AlF₃The target material adopts radio frequency sputtering, and direct current sputtering is suitable for conductor target materials such as metal, alloy and the like, and the deposition rate is high; while radio frequency sputtering is suitable for metal conductors, semiconductors and insulators, but the deposition rate is slower; TiAl alloy as conductor, alpha-AlF₃Is an insulator, and the alpha-AlF in the coating₃Is relatively low, so that the TiAl target adopts direct current sputtering and AlF₃Radio frequency sputtering is adopted. The magnitude and magnitude of the power of the twoInfluence the respective deposition rate and further influence the alpha-AlF in the composite coating₃The content of (a). While alpha-AlF in the composite coating₃The content of the nano particles affects the performance of the coating, if the content of the nano particles is too small, the nano particles are difficult to react with TiAl to generate enough gas-phase AlF so as to be further oxidized to form aluminum oxide, and the oxidation resistance of the coating cannot be effectively improved; and if the content of the nanoparticles is too high, a large amount of gas-phase AlF is easily and quickly formed, so that the coating is unstable, and the mechanical property of the coating is deteriorated if the content of the nanoparticles is too high. The invention obtains the alpha-AlF by controlling the type and the power of the magnetron sputtering of the target material₃The coating with excellent performance is obtained by the better content range of the nano particles.

(4) In the preparation process of the invention, the granularity of Ti and Al powder and alpha-AlF₃The purity of the ceramic powder, the parameters of hot isostatic pressing, etc. also have a certain influence on the properties of the coating. The granularity of Ti and Al powder can influence the compactness and the grain size of the TiAl target, thereby influencing the deposition quality (with or without defects) and the grain size of the coating; alpha-AlF₃The purity of the ceramic powder can affect the deposition quality of the coating, if more impurities exist, the deposition is not easy to be uniform, and the obtained coating has poor compactness; the hot isostatic pressing parameters directly influence the density and grain size of the target material, and further influence the deposition quality and microstructure of the coating. The invention obtains the granularity of Ti and Al powder and alpha-AlF through a plurality of tests₃The purity of the ceramic powder and the optimal parameter range of the hot isostatic pressing process are combined with the pretreatment of the substrate, the magnetron sputtering process and the high-temperature heat treatment, and the coating with excellent oxidation resistance is obtained by cooperatively adjusting the parameters of all the processes.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a process flow diagram of a preparation method of a TiAl coating for improving high temperature oxidation resistance of a titanium alloy;

FIG. 2 shows AlF₃Standard gibbs reaction free energy curve with Al atoms in the coating;

FIG. 3 is AlF₃Standard gibbs reaction free energy curve with Ti atoms in the coating;

FIG. 4 is a scanning transmission electron microscopy analysis of the coating prepared in example 1.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

Example 1

(1) Preparing a target material:

the alloy elements are prepared according to the following components: al: 40 at.%; ti: the rest (the particle size is 44 μm), the powder is mixed in a ball milling tank at the rotating speed of 110r/min for 6h and then is pressed into phi 20 x 3mm by a hot isostatic pressing machine³The TiAl target material has the pressure maintaining temperature of 1250 ℃, the isostatic pressure of 160MPa, and the heat and pressure maintaining time of 3 hours. Mixing high-purity alpha-AlF₃Drying ceramic powder (with particle size of 37 μm), and pressing with hot isostatic press to obtain powder with diameter of 20 × 3mm³alpha-AlF of (2)₃Keeping the pressure of the target material at 1750 ℃, keeping the heat equal pressure at 160MPa, and keeping the temperature and the pressure for 2 h.

(2) Preparing a coating:

the TiAl target and alpha-AlF are prepared₃Mounting a Ti60 titanium alloy matrix with surface pretreatment (sequentially polishing with No. 800 and No. 1500 abrasive paper, sequentially ultrasonically cleaning with acetone and alcohol, and drying) on a magnetron coating instrument, and adjusting the target-base distance to be 12 cm; pumping the background vacuum degree to 1 × 10 by using a mechanical pump and a diffusion pump^-4Pa; heating the substrate to 150 ℃; opening the flowmeter, and introducing argon to make the working pressure reach 0.7 Pa; simultaneously opening respectively corresponding TiAl target and alpha-AlF₃The direct current power supply and the radio frequency power supply of the target respectively have the power of 1.0kW and 0.12kW, and the sputtering lasts for 10 hours; the vacuum state in the vacuum chamber is kept until the temperature is cooled to the room temperature, and the sample is taken out.

(3) And (3) post-treatment of the coating:

and putting the sample into a high-temperature vacuum furnace, vacuumizing until the air pressure is 0.05Pa, heating to 650 ℃, preserving the temperature for 15h, and cooling to room temperature along with the furnace to obtain the novel TiAl coating.

The coating thickness was measured to be 12.3 μm.

Calculation of AlF in coating₃The free energy of the standard Gibbs reaction with Al atoms and Ti atoms is plotted, and the specific method is as follows:

first, AlF is determined separately₃Chemical reaction equation with Al atom and Ti atom is AlF₃(s) +2al(s) ═ 3AlF (g) and 4AlF₃(s)+3Ti(s)＝3TiF₄(g) And +4Al(s), then searching specific heat capacity, phase transition heat capacity and formation enthalpy and entropy of each reactant and product along with temperature change in a practical inorganic thermodynamic data handbook, then calculating reaction enthalpy and reaction entropy under 298K according to a chemical reaction equation and considering a functional relation between the specific heat capacity and temperature of phase transition, and finally obtaining Gibbs free energy along with temperature change according to relational expressions between the Gibbs free energy and the specific heat capacity, the temperature and the reaction enthalpy and the reaction entropy under 298K.

The AlF thus obtained₃The standard Gibbs reaction free energy curve with Al atoms in the coating is shown in FIG. 2, AlF₃The standard Gibbs reaction free energy curve with Ti atoms in the coating is shown in FIG. 3.

The thermodynamic calculation result shows that the alpha-AlF₃Heated to a temperature of more than 454 ℃ and converted into beta-AlF₃The latter can be combined with Al atoms to generate a gas-phase AlF aluminum source carrier, so that the activity of Al is obviously improved (see figure 2); and alpha-AlF₃And beta-AlF₃Do not react with Ti (see figure 3), so that F can exert the maximum activation effect on Al, and the oxidation resistance of the coating is further remarkably improved. It can be seen that a more stable alpha-AlF is utilized₃The nano particles replace solid solution F atoms to serve as a fluorine source, and the method is an effective measure for overcoming the limitation of the activation degree of Al in the F modified TiAl coating and improving the oxidation resistance.

Analysis of AlF in the coating by scanning-Transmission Electron microscopy₃The distribution of (c) is shown in fig. 4. The results of the EDS analysis of the locations marked in fig. 4 are shown in table 1:

TABLE 1

As can be seen from the above table, F is mainly AlF₃The compound exists in a form (the atomic ratio of Al to F is about 1: 3) and is distributed at TiAl crystal boundary. The Al content of the matrix phase in the coating is about38.6 at.%. AlF is obtained according to statistics of image processing technology₃The nanoparticle content was about 18.0 vol.% (the content of F atoms in the coating was 8.3 at.% by conversion, the conversion formula is:x is AlF₃Volume content of particles). Coating the surface of the sample except the coating with a high-temperature oxidation resistant coating, drying, weighing, placing in a high-temperature tube furnace, keeping the temperature at 670 ℃ for 500h, air-cooling to room temperature, observing that the surface of the sample is complete and has no peeling, and weighing to obtain the coating with the oxidation weight increment of 0.08mg/cm per unit area²。

Example 2

The difference from example 1 is that alpha-AlF₃The power supply power of the target was 0.18 kW.

The coating thickness was measured to be 12.4 μm, the matrix phase Al content in the coating was about 38.7 at.%, AlF₃The nanoparticle content was about 25.4 vol.% (F atom content was 12.1 at.%). Coating the surface of the sample except the coating with a high-temperature oxidation resistant coating, drying, weighing, placing in a high-temperature tube furnace, keeping the temperature at 670 ℃ for 500h, air-cooling to room temperature, observing the sample, ensuring that the coating is not peeled off, and weighing to obtain the coating with the oxidation weight increment of 0.05mg/cm in unit area²。

Example 3

The difference from example 1 is that the TiAl target has a power supply power of 0.6 kW.

The coating thickness was measured to be 7.3 μm, the matrix phase Al content in the coating was about 38.4 at.%, AlF₃The nanoparticle content was about 28.4 vol.%. Coating the surface of the sample except the coating with a high-temperature oxidation resistant coating, drying, weighing, placing in a high-temperature tube furnace, keeping the temperature at 670 ℃ for 500h, air-cooling to room temperature, observing the sample, ensuring that the coating is not peeled off, and weighing to obtain the coating with the oxidation weight increment of 0.09mg/cm per unit area²。

Example 4

The difference from example 1 is that the formulation of the TiAl target is Al: 43 at.%, Ti: and (4) the balance.

The coating thickness was measured to be 12.3 μm, in the coatingMatrix phase Al content of about 41.2 at.%, AlF₃The nanoparticle content was about 18.1 vol.%. Coating the surface of the sample except the coating with a high-temperature oxidation resistant coating, drying, weighing, placing in a high-temperature tube furnace, keeping the temperature at 670 ℃ for 500h, air-cooling to room temperature, observing the sample, ensuring that the coating is not peeled off, and weighing to obtain the coating with the oxidation weight increment of 0.06mg/cm in unit area²。

Comparative example 1

The difference from example 3 is that the TiAl target and the alpha-AlF₃The targets all use radio frequency power supplies.

The coating thickness was measured to be 1.2 μm, the matrix phase Al content in the coating was about 38.3 at.%, AlF₃The nanoparticle content was about 47.5 vol.%. Coating the surface of the sample except the coating with a high-temperature oxidation resistant coating, drying, weighing, placing in a high-temperature tube furnace, keeping the temperature at 670 ℃ for 500h, air-cooling to room temperature, observing the sample, wherein the inside of the coating has a local cracking phenomenon, and weighing to obtain the coating with the oxidation weight gain of 3.1mg/cm in unit area²。

Comparative example 2

The difference from example 1 is that the formulation of the TiAl target is Al: 28 at.%, Ti: and (4) the balance.

The coating thickness was measured to be 12.3 μm, the matrix phase Al content in the coating was about 27.0 at.%, AlF₃The nanoparticle content was about 18.2 vol.%. Coating the surface of the sample except the coating with a high-temperature oxidation resistant coating, drying, weighing, placing in a high-temperature tube furnace, keeping the temperature at 670 ℃ for 500h, air-cooling to room temperature, observing the sample, obviously peeling off the oxide skin on the surface of the coating, weighing to obtain the coating with the oxidation weight gain of 2.1mg/cm per unit area²。

Comparative example 3

A TiAl coating was first deposited on a Ti60 titanium alloy substrate by the same process as in example 1, except that only a single TiAl target was sputtered, and AlF was not sputtered₃A target. Then, F atoms were implanted using a plasma immersion type plasma implantation apparatus with a plasma power supply of 500W and a bias voltage of 10kV using Ar/CH as a gas₂F₂The working pressure is 0.5Pa, the pulse width is 10 mus, and the injection is continued for 5 min.

The coating thickness was measured to be 12.3 μm, with the matrix phase Al content in the coating being about 38.7 at.%, and the F atom content being about 8 at.% (essentially corresponding to the F atom content in example 1). Coating the surface of the sample except the coating with a high-temperature oxidation resistant coating, drying, weighing, placing in a high-temperature tube furnace, keeping the temperature at 670 ℃ for 500h, air-cooling to room temperature, observing the sample, obviously peeling off the oxide skin on the surface of the coating, weighing to obtain the coating with the oxidation weight gain of 1.7mg/cm in unit area²。

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included therein.