Titanium alloy blade tip composite wear-resistant coating and preparation method thereof

Abstract

The invention relates to the technical field of surface engineering, in particular to a titanium alloy blade tip composite wear-resistant coating and a preparation method thereof.The coating comprises an interface transition layer and a wear-resistant surface layer which are sequentially stacked from bottom to top, and the interface transition layer comprises toughening particles and nickel-based brazing filler metal powder; the wear-resistant surface layer comprises toughening particles, nickel-based brazing filler metal powder and hard particles. The titanium alloy blade tip composite wear-resistant coating and the preparation method thereof aim at solving the problems that a titanium alloy blade tip composite wear-resistant coating is prone to stripping and insufficient in hardness.

Description

Technical Field

[0001] The invention relates to the technical field of surface engineering, and in particular to a titanium alloy blade tip composite wear-resistant coating and a preparation method thereof. Background Art

[0002] Titanium alloy integral blades reduce the weight and number of parts of aircraft engine structures, eliminate the airflow leakage loss between traditional blades and disks, and avoid micro-motion damage and accidental damage caused by traditional blade-disk mechanical connections. The application of titanium alloy integral blades is of great significance to improving the aerodynamic performance of aircraft engines and increasing their service life.

[0003] During service, the titanium alloy integral blade disk will inevitably rub against the sealing coating on the inner surface of the casing. Due to the low plastic shear resistance and poor work hardening ability of titanium alloy, the surface oxide film TiO2 is easy to peel off, resulting in insufficient wear resistance, poor reliability and shortened service life of the titanium alloy integral blade disk.

[0004] In order to improve the reliability and service life of titanium alloy integral blade disk components, since the 1990s, developed countries in Europe and the United States have developed a number of blade tip wear-resistant coating technologies, mainly using cubic boron nitride, zirconium oxide or aluminum oxide as hard particles, and using electroplating, chemical plating (CVD), plasma spraying or supersonic flame spraying, electrospark deposition, physical vapor deposition (PVD, such as multi-arc ion plating, magnetron sputtering and other technologies to prepare blade tip wear-resistant coatings. Electroplating, CVD and PVD have low efficiency and thin coatings. At the same time, electroplating is prone to cause "hydrogen embrittlement" of titanium alloys; plasma spraying or supersonic flame spraying composite wear-resistant coatings are mechanically combined with the substrate, which is easy to fall off and has a short service life. In the process of developing EJ200, the German MTU company used laser cladding to prepare MCrAlY+cBN composite wear-resistant coatings on the blade tips of titanium alloy compressors.

[0005] Therefore, the inventor provides a titanium alloy blade tip composite wear-resistant coating and a preparation method thereof. Summary of the invention

[0006] (1) Technical issues to be solved

[0007] The embodiment of the present invention provides a titanium alloy blade tip composite wear-resistant coating and a preparation method thereof, which solves the technical problems that the titanium alloy blade tip composite wear-resistant coating is easy to peel off and has insufficient hardness.

[0008] (2) Technical solution

[0009] The first aspect of the present invention provides a titanium alloy blade tip composite wear-resistant coating, comprising an interface transition layer and a wear-resistant surface layer stacked in sequence from bottom to top, wherein the components of the interface transition layer include toughening particles and nickel-based brazing filler metal powder, and the components of the wear-resistant surface layer include toughening particles, nickel-based brazing filler metal powder and hard particles.

[0010] Furthermore, the mass fraction of the toughening particles in the interface transition layer is 40 to 90 wt.%.

[0011] Furthermore, the mass fraction of the nickel-based solder powder in the interface transition layer is 10 to 60 wt.%.

[0012] Furthermore, the mass fraction of the toughening particles in the wear-resistant surface layer is 40 to 80 wt.%.

[0013] Furthermore, the mass fraction of the nickel-based solder powder in the wear-resistant surface layer is 10 to 40 wt.%.

[0014] Furthermore, the mass fraction of hard particles in the wear-resistant surface layer is 10-20wt.%.

[0015] Furthermore, the toughening particles are MCrAlY toughening particles; wherein M is at least one of Ni and Co, and the content of M is 40 to 80 at.%.

[0016] Furthermore, the hard particles include at least one of cubic boron nitride, WC, TiC and SiC.

[0017] The second aspect of the present invention also provides a method for preparing the above-mentioned titanium alloy blade tip composite wear-resistant coating, comprising the following steps:

[0018] Surface grinding of the tip of the titanium alloy blade;

[0019] Using a cold spraying method, the toughening particles and nickel-based brazing filler metal powder mixed in proportion are sprayed onto the tip surface of the polished titanium alloy blade to form an interface transition layer;

[0020] The toughening particles, nickel-based solder powder and hard particles mixed in proportion are sprayed onto the surface of the interface transition layer by cold spraying to form a wear-resistant surface layer, and the interface transition layer and the wear-resistant surface layer form a composite wear-resistant coating;

[0021] High-frequency induction heating is used to heat the composite wear-resistant coating to achieve metallurgical diffusion bonding between the tip surface of the titanium alloy blade and the interior of the composite wear-resistant coating.

[0022] Furthermore, the thickness of the composite wear-resistant coating is 0.2-0.8 mm.

[0023] (3) Beneficial effects

[0024] In summary, the present invention adopts a double-layer structure, and the interface transition layer not only ensures the improvement of the bonding effect between the wear-resistant surface layer and the titanium alloy blade tip, but also avoids the damage caused by the direct contact of hard particles with the blade tip during the cold spraying of the wear-resistant surface layer; at the same time, toughening particles are added to the interface transition layer and the wear-resistant surface layer, thereby avoiding the problem of low deposition efficiency of nickel-based brazing alloys containing brittle phases during cold spraying, alleviating the thermal mismatch characteristics between the titanium alloy blades and the wear-resistant surface layer, and improving the thermal shock life of the composite wear-resistant coating; adding nickel-based brazing alloys to the wear-resistant surface layer avoids the decrease in hardness of the low-melting point brazing alloys. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic structural diagram of a titanium alloy blade tip composite wear-resistant coating provided by an embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of the coating position of a titanium alloy blade tip composite wear-resistant coating provided by an embodiment of the present invention;

[0028] Figure 3 It is a schematic flow chart of a method for preparing a composite wear-resistant coating on a titanium alloy blade tip provided in an embodiment of the present invention.

[0029] In the figure:

[0030] 1-interface transition layer; 2-wear-resistant surface layer; 3-toughening particles; 4-nickel-based solder powder; 5-hard particles; 100-titanium alloy blade; 200-composite wear-resistant coating. DETAILED DESCRIPTION

[0031] The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0032] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] Figure 1 is a schematic diagram of the structure of a titanium alloy blade tip composite wear-resistant coating provided by an embodiment of the present invention, see Figure 1The composite wear-resistant coating 200 may include an interface transition layer 1 and a wear-resistant surface layer 2 stacked in sequence from bottom to top, the components of the interface transition layer 1 include toughening particles 3 and nickel-based solder powder 4, and the components of the wear-resistant surface layer 2 include toughening particles 3, nickel-based solder powder 4 and hard particles 5.

[0034] In the above embodiment, a double-layer structure of the interface transition layer 1 and the wear-resistant surface layer 2 is adopted, and the interface transition layer 1 not only ensures the improvement of the bonding effect between the wear-resistant surface layer 2 and the titanium alloy blade tip, but also avoids the damage caused by the hard particles 5 directly contacting the blade tip during the cold spraying of the wear-resistant surface layer 2. Adding toughening particles 3 to the interface transition layer 1 and the wear-resistant surface layer 2 avoids the problem of low deposition efficiency during the cold spraying of nickel-based brazing alloys containing brittle phases; alleviates the thermal mismatch characteristics between the titanium alloy blade 100 and the wear-resistant surface layer 2, and improves the thermal shock life of the composite wear-resistant coating 200. Adding nickel-based brazing alloy 4 to the wear-resistant surface layer 2 avoids the disadvantage of reduced hardness of low-melting-point brazing alloys.

[0035] Specifically, the mass fraction of the toughening particles 3 in the interface transition layer 1 is 40-90wt.%, and the mass fraction of the nickel-based solder powder 4 in the interface transition layer 1 is 10-60wt.%. The mass fraction of the toughening particles 3 in the wear-resistant surface layer 2 is 40-80wt.%, and the mass fraction of the nickel-based solder powder 4 in the wear-resistant surface layer 2 is 10-40wt.%, and the mass fraction of the hard particles 5 in the wear-resistant surface layer 2 is 10-20wt.%. The specific coating position of the composite wear-resistant coating 200 on the titanium alloy blade 100 is detailed in Figure 2 .

[0036] Furthermore, the toughening particles 3 are MCrAlY toughening particles, wherein M is at least one of Ni and Co, and the content of M is 40-80 at.%. The hard particles 5 include at least one of cubic boron nitride, WC, TiC and SiC. The nickel-based brazing filler metal may be NiCrCoAlTaB or other nickel-based brazing filler metals, which are not specifically limited here.

[0037] Figure 3 is a schematic diagram of a method for preparing the titanium alloy blade tip composite wear-resistant coating according to an embodiment of the present invention, see Figure 3 , the method may include the following steps:

[0038] S100, performing surface grinding treatment on the tip of the titanium alloy blade 100.

[0039] S200, using a cold spraying method to spray toughening particles 3 and nickel-based brazing filler metal powder 4 mixed in proportion onto the tip surface of the polished titanium alloy blade 100 to form an interface transition layer 1.

[0040] S300, using cold spraying method to spray toughening particles 3, nickel-based solder powder 4 and hard particles 5 mixed in proportion onto the surface of the interface transition layer 1 to form a wear-resistant surface layer 2, and the interface transition layer 1 and the wear-resistant surface layer 2 form a composite wear-resistant coating 200.

[0041] S400 , high-frequency induction heating is used to heat the composite wear-resistant coating 200 to achieve metallurgical diffusion bonding between the tip surface of the titanium alloy blade 100 and the interior of the composite wear-resistant coating 200 .

[0042] Specifically, through the later vacuum high-frequency induction heat treatment, local metallurgical bonding inside the coating is achieved; the cohesive strength of the wear-resistant surface layer 2 is improved, and the hardness and wear resistance of the wear-resistant surface layer 2 are further improved. Through vacuum or gas-protected high-frequency induction heating of the composite wear-resistant coating 200 with brazing material, metallurgical diffusion bonding between the interface and the inside of the coating is achieved, and the coating bonding effect is improved; at the same time, the "skin effect" of induction heating is used to reduce the negative impact on the mechanical properties of the titanium alloy blade 100.

[0043] Furthermore, the thickness of the interface transition layer 1 is 0.1-0.3 mm, the thickness of the wear-resistant surface layer 2 is 0.1-0.5 mm, and the thickness of the composite wear-resistant coating 200 is 0.2-0.8 mm.

[0044] Example 1

[0045] Take the preparation of composite wear-resistant coating of TC4 titanium alloy blade as an example:

[0046] 1. Prepare the powder F1 of the interface transition layer 3 and the powder F2 of the wear-resistant surface layer 4 according to the proportions shown in the technical solution, and use a three-dimensional powder mixer to homogenize for 4 hours;

[0047] 2. Use a stainless steel wire brush to polish the tip of the TC4 titanium alloy blade to remove the original oxide scale and expose the fresh surface;

[0048] 3. On the tip surface of TC4 titanium alloy blade 1, F1 powder is sprayed onto the tip surface using a cold spray system (Impact5 / 11) to form an interface transition layer 3 of 0.2-0.3 mm. The process parameters are as follows: the main gas flow rate is 80-90 m 3 / hour, temperature is 800~850℃, pressure is 4.0~4.5MPa, powder feeding speed is 1~3 rpm, carrier gas flow rate is 2~4m 3 / hour, spraying distance is 20-30mm;

[0049] 4. On the surface of the interface transition layer 3, a cold spray system (Impact5 / 11) is used to spray F2 powder onto the surface of the interface transition layer 3 to form a 0.3-0.4 mm wear-resistant surface layer 4. The process parameters are as follows: the main gas flow rate is 80-90 m 3 / hour, temperature is 800~850℃, pressure is 4.0~4.5MPa, powder feeding speed is 1~2 rpm, carrier gas flow rate is 2~4m 3 / hour, spraying distance is 20-30mm;

[0050] 5. Use high-purity argon gas to protect high-frequency induction brazing, argon gas pressure 0.2 ~ 0.5MPa, induction power, 20 ~ 23kw, working distance 5 ~ 10mm, heating time 60 ~ 100s.

[0051] It should be clear that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. In addition, for the sake of brevity, a detailed description of known methods and technologies is omitted here.

[0052] The above are only embodiments of the present application and are not limited to the present application. For those skilled in the art, the present application may have various changes and variations without departing from the scope of the present invention. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A titanium alloy blade tip composite wear-resistant coating, characterized in that: The invention comprises an interface transition layer (1) and a wear-resistant surface layer (2) stacked in sequence from bottom to top, wherein the components of the interface transition layer (1) include toughening particles (3) and nickel-based solder powder (4), and the components of the wear-resistant surface layer (2) include toughening particles (3), nickel-based solder powder (4) and hard particles (5).

2. The titanium alloy blade tip composite wear-resistant coating according to claim 1, characterized in that: The mass fraction of the toughening particles (3) in the interface transition layer (1) is 40 to 90 wt.%.

3. The titanium alloy blade tip composite wear-resistant coating according to claim 2, characterized in that: The mass fraction of the nickel-based solder powder (4) in the interface transition layer (1) is 10 to 60 wt.%.

4. The titanium alloy blade tip composite wear-resistant coating according to claim 1, characterized in that: The mass fraction of the toughening particles (3) in the wear-resistant surface layer (2) is 40 to 80 wt.%.

5. The titanium alloy blade tip composite wear-resistant coating according to claim 4, characterized in that: The mass fraction of the nickel-based solder powder (4) in the wear-resistant surface layer (2) is 10 to 40 wt.%.

6. The titanium alloy blade tip composite wear-resistant coating according to claim 5, characterized in that: The mass fraction of the hard particles (5) in the wear-resistant surface layer (2) is 10 to 20 wt.%.

7. The titanium alloy blade tip composite wear-resistant coating according to any one of claims 1 to 6, characterized in that: The toughening particles (3) are MCrAlY toughening particles, wherein M is at least one of Ni and Co, and the content of M is 40 to 80 at.%.

8. The titanium alloy blade tip composite wear-resistant coating according to any one of claims 1 to 6, characterized in that: The hard particles (5) include at least one of cubic boron nitride, WC, TiC and SiC.

9. A method for preparing a titanium alloy blade tip composite wear-resistant coating according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: Performing surface grinding on the tip of the titanium alloy blade (100); Using a cold spraying method, toughening particles (3) and nickel-based brazing filler metal powder (4) mixed in proportion are sprayed onto the tip surface of the polished titanium alloy blade (100) to form an interface transition layer (1); Using a cold spraying method, toughening particles (3), nickel-based solder powder (4) and hard particles (5) mixed in proportion are sprayed onto the surface of the interface transition layer (1) to form a wear-resistant surface layer (2), and the interface transition layer (1) and the wear-resistant surface layer (2) form a composite wear-resistant coating (200); High-frequency induction heating is used to heat the composite wear-resistant coating (200) to achieve metallurgical diffusion bonding between the tip surface of the titanium alloy blade (100) and the interior of the composite wear-resistant coating (200).

10. The method for preparing the titanium alloy blade tip composite wear-resistant coating according to claim 9, characterized in that: The thickness of the composite wear-resistant coating (200) is 0.2-0.8 mm.

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