Titanium alloy bearing material and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of cladding coatings on material surfaces, and particularly relates to a titanium alloy bearing material and a preparation method thereof. The titanium alloy bearing material comprises a titanium alloy substrate and a NiTi alloy coating cladding the titanium alloy substrate, and the NiTi alloy coating is composed of, by mass, 33-40% of Ti and the balance Ni; niTi structures at the joint of the NiTi alloy coating and the titanium alloy substrate are planar crystals and cellular crystals, and the NiTi structures above the joint are columnar crystals and columnar dendritic crystals. The NiTi structure with specific characteristics is formed on the surface of the titanium alloy substrate, the highest hardness reaches 677.41 HV0.2 and is 2.05 times that of the titanium alloy substrate, and the wear resistance is improved by 53% compared with that of the titanium alloy substrate. On the whole, the cladding coating effectively improves the wear resistance and the bearing capacity of the titanium alloy surface.

Description

Technical Field

[0001] This invention belongs to the field of cladding coating preparation technology for material surfaces, specifically relating to a titanium alloy bearing material and its preparation method. Background Technology

[0002] Driven by both technological innovation and green development, lightweight design has emerged. Lightweight design is the process of reducing the overall weight of components without sacrificing reliability or functionality, often resulting in significant improvements in performance, reduced carbon emissions, cost savings, and increased product value. Titanium alloys possess a range of significant advantages, such as low density, high specific strength, excellent corrosion resistance, and superior biocompatibility, making them widely used in various fields as components for critical structures.

[0003] Titanium alloys exhibit certain shortcomings under specific conditions, including relatively low hardness, a high coefficient of friction, and poor wear resistance. These defects, to some extent, limit the further development and application of titanium alloys. In the field of titanium alloy bearings, NSK Corporation has developed a new titanium alloy bearing material. Both its inner and outer rings are made of a novel titanium alloy, and after solution treatment and aging, its hardness approaches 500 HV, superior to beryllium bronze and non-magnetic stainless steel. However, the hardness of this titanium alloy bearing is still 200 HV lower than that of commonly used GCr15 bearing steel. Therefore, this new titanium alloy bearing can only meet the application requirements of low load and low speed; during life testing, the load was only 59 N, and the speed was 1200 r / min.

[0004] Commonly used titanium alloys, such as TC4 (Ti-6Al-4V), have a hardness of only around 320 HV and a shear modulus that is half that of bearing steel (44 GPa). This low hardness and shear modulus result in poor wear resistance, and wear is a common failure mode in bearings. The yield strength and ultimate strength, corresponding to the hardness, are also relatively low, limiting the load-bearing capacity of titanium alloy bearings. Therefore, improving the surface hardness and wear resistance of titanium alloys is a challenge for their use as bearing materials.

[0005] Surface modification of titanium alloys is one of the main ways to improve hardness and wear resistance. Chinese invention patent application CN 118996413 A, published on November 22, 2024, discloses a method for preparing an ultrasonic-assisted laser cladding composite coating on a titanium alloy surface. After pretreating the titanium alloy substrate, Ti powder, Al powder, Si powder, Ni powder, and ceramic powder are weighed, mixed, and dried to prepare a mixed powder. Then, the mixed powder is poured into the powder feeding cylinder of a laser cladding machine, and a laser cladding composite coating is obtained through ultrasonic-assisted laser cladding.

[0006] The above method utilizes a surface strengthening technique combining laser cladding and ultrasonic vibration to reduce numerous microscopic defects and residual stress, promote the diffusion of alloying elements, improve the distribution of ceramic hard particles, refine grains, reduce cladding defects, and homogenize the microstructure, thereby enhancing the wear resistance and corrosion resistance of the cladding layer. Specifically, the in-situ generated Ti5Si3 ceramic hard reinforcing phase and Ti-Al two-phase intermetallic compound, along with the TaC and Nd2O3 ceramic phases added to the coating, construct a multi-component synergistic reinforcing microstructure.

[0007] The above methods use a variety of raw materials, including expensive ceramic powders such as TaC and Nd2O3, and require the use of ultrasonic assistance to achieve the distribution of ceramic particles and reduce defects. The overall process is complex and costly, and is not suitable for industrial surface modification of titanium alloys. Summary of the Invention

[0008] The purpose of this invention is to provide a titanium alloy bearing material to solve the problem that the surface hardness and wear resistance of existing titanium alloy materials need to be improved.

[0009] A second objective of this invention is to provide a method for preparing the aforementioned titanium alloy bearing material in order to solve the above-mentioned problems.

[0010] To achieve the above objectives, the technical solution for the titanium alloy bearing material of this invention is as follows: A titanium alloy bearing material includes a titanium alloy substrate and a NiTi alloy coating clad on the titanium alloy substrate. The NiTi alloy coating is composed of the following components by mass fraction: Ti 33-40%, with the balance being Ni. The NiTi microstructure at the junction of the NiTi alloy coating and the titanium alloy substrate is planar and cellular, while the NiTi microstructure above the junction is columnar and columnar dendrite.

[0011] This invention is groundbreaking, forming a NiTi microstructure with specific characteristics on the surface of a titanium alloy substrate. This structure comprises planar and cellular NiTi microstructures at the bonding sites, as well as columnar and columnar dendritic NiTi microstructures above the bonding sites, constituting a densified and reinforced microstructure with a maximum hardness of 677.41 HV. 0.2 The hardness is 2.05 times that of the titanium alloy substrate. Friction and wear tests under a certain load show that its wear resistance is 53% higher than that of the titanium alloy substrate. Overall, the above-mentioned cladding coating effectively improves the wear resistance and load-bearing capacity of the titanium alloy surface.

[0012] Preferably, the NiTi alloy coating is composed of the following components by mass fraction: Ti 33-35%, with the balance being Ni.

[0013] Preferably, the thickness of the NiTi alloy coating is 1.2-1.4 mm.

[0014] Preferably, the titanium alloy substrate is TC4 titanium alloy.

[0015] The technical solution of the preparation method of the titanium alloy bearing material of the present invention is as follows: A method for preparing a titanium alloy bearing material includes the following steps: preparing a mixed powder composed of Ni powder and Ti powder, and cladding the mixed powder onto the surface of a titanium alloy substrate by plasma arc melting; wherein the mass percentage of Ti powder in the mixed powder is 33-40%.

[0016] The present invention discloses a method for preparing titanium alloy bearing materials. This method employs plasma arc cladding technology to prepare a NiTi alloy coating, achieving millimeter-thickness coatings that exhibit high hardness and wear resistance throughout the entire thickness range, demonstrating excellent long-term protection for the titanium alloy substrate. Furthermore, the entire process is simple, easy to operate, and can be performed using ordinary industrial equipment, without being limited by processing equipment. This low processing cost lays the foundation for the industrialization of high-load-bearing, lightweight titanium alloys.

[0017] Preferably, the plasma arc cladding has a spray distance of 10-14 mm, a powder feeding voltage of 10-16 V, and a cladding current of 90-140 A.

[0018] More preferably, the ion gas, powder feeding gas, and protective gas used in the plasma arc cladding are all argon, with flow rates of 250-350 L / h, 250-350 L / h, and 700-900 L / h, respectively.

[0019] Preferably, the mass percentage of Ti powder in the mixed powder is 33-35%.

[0020] Preferably, both the Ni powder and Ti powder are spherical with a diameter between 53 and 154 μm.

[0021] Preferably, the titanium alloy substrate is TC4 titanium alloy. Attached Figure Description

[0022] Figure 1 The microstructure of the coating obtained in Example 1 of this invention is shown at the bonding site. Figure 2 The microstructure of the coating obtained in Example 1 of this invention is shown above the joint. Figure 3 The microstructure of the coating obtained in Example 2 of this invention is shown at the bonding site. Figure 4 The microstructure of the coating obtained in Example 2 of this invention is shown above the joint. Figure 5 The microstructure of the coating obtained in Example 3 of this invention is shown at the bonding site. Figure 6The microstructure of the coating obtained in Example 3 of this invention is shown above the joint. Figure 7 The microstructure of the coating obtained in Example 4 of this invention is shown at the bonding site. Figure 8 The microstructure of the coating obtained in Example 4 of this invention is shown above the joint. Figure 9 These are curves showing the change in hardness of the coating cross-section obtained from different embodiments; Figure 10 Bar charts showing the wear rate of coatings obtained in different embodiments under different loads; Figure 11 The microstructure of the cladding layer in Comparative Example 1 is shown. Figure 12 The microstructure of the cladding layer in Comparative Example 2 is shown. Detailed Implementation

[0023] (I) Preferred embodiments of the titanium alloy bearing material and its preparation method of the present invention are described. For surface modification of titanium alloys, although thermal oxidation and nitriding processes can achieve surface hardness above 1000 HV, the hardened layer thickness is only about 10 μm. Once the hardened layer is worn through, the tribological properties deteriorate sharply, and the protection effect on the substrate is limited. In contrast, ceramic-reinforced coatings such as TiB, TiN, and TiC often exhibit high wear resistance under low loads. However, under high loads, the wear rate increases sharply as the aforementioned TiB, TiN, and TiC ceramic phases detach.

[0024] This invention utilizes a plasma spraying machine to form NiTi alloy microstructures with different morphologies at the interface and above the interface by strictly controlling the Ni content in the NiTi alloy coating. The NiTi microstructure at the interface exhibits planar and cellular crystals, which strengthens the bond with the titanium alloy substrate and the upper microstructure. The microstructure above the interface exhibits uniform and fine columnar crystals and columnar dendrites, which become the main reinforcing phase, providing strong support for the hardness and wear resistance of the coating.

[0025] The thickness of the aforementioned NiTi alloy coating can reach 1.2-1.4 mm. It exhibits high hardness and wear resistance throughout its thickness range. Furthermore, the NiTi alloy coating demonstrates good adaptability to wear resistance under different loads, exhibiting stable wear resistance under various load conditions, effectively improving the performance of titanium alloy bearings in various applications.

[0026] Based on the high surface hardness and excellent wear resistance under high load conditions of the aforementioned titanium alloy bearing materials, they are suitable for applications including but not limited to bearings.

[0027] The preparation method of the above-mentioned titanium alloy bearing material adopts the following steps: After pretreating the titanium alloy substrate, a NiTi alloy coating is prepared by plasma arc cladding of a mixed powder composed of Ti powder and Ni powder onto the surface of the pretreated titanium alloy substrate.

[0028] Pretreatment of the titanium alloy substrate is to prepare the substrate for plasma arc cladding, such as removing the surface oxide layer and contaminants. This can be achieved by grinding to smooth the surface and by using ultrasonic cleaning to remove various contaminants.

[0029] Ti and Ni powders are preferably spherical powders with a purity of 99.8% or higher to achieve better flowability. The particle size is preferably between 53-154 μm. After the Ti and Ni powders are mixed evenly, they can be further vacuum dried to reduce the presence of moisture. The vacuum drying temperature can be 100-120℃, and the time can be more than 2 hours, for example, 2-4 hours.

[0030] During plasma arc cladding, appropriate cladding parameters can be controlled to form a dense structure and avoid defects such as cracks and porosity. For example, specific parameters can be controlled as follows: spray distance of 10-14 mm, powder feeding voltage of 10-16 V, and cladding current controlled between 90-140 A; argon is used for the ionizing gas, powder feeding gas, and protective gas, with flow rates of 250-350 L / h, 250-350 L / h, and 700-900 L / h, respectively; longitudinal cladding speed is 80-120 mm / min, transverse oscillation speed is 800-1200 mm / min, and oscillation width is 8-15 mm, resulting in a final coating thickness greater than 1.2 mm, for example, 1.2-1.4 mm.

[0031] The preferred embodiments described above are illustrated below with specific examples. In the following embodiments, unless otherwise specified, all raw materials used are commercially available, and all processing techniques are conventional. Unless otherwise specified, "%" refers to percentages by mass.

[0032] Example 1 The preparation method of the titanium alloy bearing material in this embodiment adopts the following steps: (1) Take TC4 plate and cut the alloy rod into samples with dimensions of 50 mm × 40 mm × 12 mm using a wire cutting machine. Polish them with 80#, 400#, 800#, 1200#, 1500# and 2000# sandpaper respectively to remove the surface oxide layer. Then place them in an ultrasonic cleaner and vibrate for 10 minutes to remove dirt. Then wash them with anhydrous ethanol and blow them dry.

[0033] (2) Spherical Ni powder and Ti powder were used as raw materials for coating preparation. The purity of the powder materials was above 99.8%, and the diameter of the spherical powder was between 53-154 μm. 100-mesh and 200-mesh sieves were used for screening to prevent the powder particles from being too large or too small and clogging the powder feeding pipe. After screening, the Ni powder and Ti powder were weighed according to 60% Ni and 40% Ti. The powder was mixed using a micro stainless steel mixer with a speed of 20 r / min. The mixer was rotated in the opposite direction every 20 min and the powder was continuously mixed for more than 8 h to ensure that the Ni powder and Ti powder were mixed evenly. The powder was then placed in a vacuum drying oven and dried at 120 ℃ for 2 h. It was then vacuum stored for later use.

[0034] (3) Using the treated sample as the substrate, a PTA-400E4-ST-4 plasma spraying machine was used to clad the uniformly mixed powder material onto the substrate surface to form a 60NiTi alloy coating under synchronous powder feeding mode and with Ar gas as the protective gas. The specific parameters are as follows: the spraying distance is 10 mm, the powder feeding voltage is 12 V, the cladding current is controlled at 90 A, the ion gas, powder feeding gas and protective gas are all high-purity argon, with flow rates of 300 L / h, 300 L / h and 800 L / h, respectively, the longitudinal cladding speed is 100 mm / min, the transverse oscillation speed is 1000 mm / min, and the oscillation width is 10 mm, thus obtaining a titanium alloy material with a 60NiTi alloy coating on the surface.

[0035] Example 2 The preparation method of the titanium alloy bearing material in this embodiment adopts the following steps: (1) Take TC4 plate and cut the alloy rod into samples with dimensions of 50 mm × 40 mm × 12 mm using a wire cutting machine. Polish them with 80#, 400#, 800#, 1200#, 1500# and 2000# sandpaper respectively to remove the surface oxide layer. Then place them in an ultrasonic cleaner and vibrate for 10 minutes to remove dirt. Then wash them with anhydrous ethanol and blow them dry.

[0036] (2) Spherical Ni powder and Ti powder were used as raw materials for coating preparation. The purity of the powder materials was above 99.8%, and the diameter of the spherical powder was between 53-154 μm. 100-mesh and 200-mesh sieves were used for screening to prevent the powder particles from being too large or too small and clogging the powder feeding pipe. After screening, the Ni powder and Ti powder were weighed according to 63% Ni and 37% Ti. The powder was mixed using a micro stainless steel mixer with a speed of 25 r / min. The mixer was rotated in the opposite direction every 20 min and the powder was continuously mixed for more than 8 h to ensure that the Ni powder and Ti powder were mixed evenly. The powder was then placed in a vacuum drying oven and dried at 120 ℃ for 2 h. It was then vacuum stored for later use.

[0037] (3) Using the treated sample as the substrate, a PTA-400E4-ST-4 plasma spraying machine was used to melt and coat the uniformly mixed powder material onto the substrate surface to form a 63NiTi alloy coating under synchronous powder feeding mode and Ar gas as the shielding gas. The specific parameters are as follows: the spraying distance is 14 mm, the powder feeding voltage is 16 V, the cladding current is controlled at 140 A, the ion gas, powder feeding gas and shielding gas are all high-purity argon, with flow rates of 350 L / h, 350 L / h and 900 L / h, respectively, the longitudinal cladding speed is 120 mm / min, the transverse oscillation speed is 1200 mm / min, and the oscillation width is 15 mm, thus obtaining a titanium alloy material with a 63NiTi alloy coating on the surface.

[0038] Example 3 The preparation method of the titanium alloy bearing material in this embodiment adopts the following steps: (1) Take TC4 plate and cut the alloy rod into samples with dimensions of 50 mm × 40 mm × 12 mm using a wire cutting machine. Polish them with 80#, 400#, 800#, 1200#, 1500# and 2000# sandpaper respectively to remove the surface oxide layer. Then place them in an ultrasonic cleaner and vibrate for 10 minutes to remove dirt. Then wash them with anhydrous ethanol and blow them dry.

[0039] (2) Spherical Ni powder and Ti powder were used as raw materials for coating preparation. The purity of the powder materials was above 99.8%, and the diameter of the spherical powder was between 53-154 μm. 100-mesh and 200-mesh sieves were used for screening to prevent the powder particles from being too large or too small and clogging the powder feeding pipe. After screening, the Ni powder and Ti powder were weighed according to 65% Ni and 35% Ti. The powder was mixed using a micro stainless steel mixer with a speed of 25 r / min. The mixer was rotated in the opposite direction every 20 min and the powder was continuously mixed for more than 8 h to ensure that the Ni powder and Ti powder were mixed evenly. The powder was then placed in a vacuum drying oven and dried at 120 ℃ for 2 h. It was then vacuum stored for later use.

[0040] (3) Using the treated sample as the substrate, a PTA-400E4-ST-4 plasma spraying machine was used to melt and coat the uniformly mixed powder material onto the substrate surface to form a 65NiTi alloy coating under synchronous powder feeding mode and with Ar gas as the protective gas. The specific parameters are as follows: the spraying distance is 10 mm, the powder feeding voltage is 10 V, the cladding current is controlled at 90 A, the ion gas, powder feeding gas and protective gas are all high-purity argon, the flow rates are 250 L / h, 250 L / h and 700 L / h respectively, the longitudinal cladding speed is 80 mm / min, the transverse oscillation speed is 800 mm / min, and the oscillation width is 8 mm, so as to obtain a titanium alloy material with a 65NiTi alloy coating on the surface.

[0041] Experiment Example 4 The preparation method of the titanium alloy bearing material in this embodiment adopts the following steps: (1) Take TC4 plate and cut the alloy rod into samples with dimensions of 50 mm × 40 mm × 12 mm using a wire cutting machine. Polish them with 80#, 400#, 800#, 1200#, 1500# and 2000# sandpaper respectively to remove the surface oxide layer. Then place them in an ultrasonic cleaner and vibrate for 10 minutes to remove dirt. Then wash them with anhydrous ethanol and blow them dry.

[0042] (2) Spherical Ni powder and Ti powder were used as raw materials for coating preparation. The purity of the powder materials was above 99.8%, and the diameter of the spherical powder was between 53-154 μm. 100-mesh and 200-mesh sieves were used for screening to prevent the powder particles from being too large or too small and clogging the powder feeding pipe. After screening, the Ni powder and Ti powder were weighed according to 67% Ni and 33% Ti. The powder was mixed using a micro stainless steel mixer at a speed of 25 r / min. The mixer was rotated in the opposite direction every 20 min and the powder was continuously mixed for more than 8 h to ensure that the Ni powder and Ti powder were mixed evenly. The powder was then placed in a vacuum drying oven at a temperature of 120 ℃ and dried for 2 h. It was then vacuum stored for later use.

[0043] (3) Using the treated sample as the substrate, a PTA-400E4-ST-4 plasma spraying machine was used to melt and coat the uniformly mixed powder material onto the substrate surface to form a 67NiTi alloy coating under synchronous powder feeding mode and Ar gas as the protective gas. The specific parameters are as follows: the spraying distance is 10 mm, the powder feeding voltage is 12 V, the cladding current is controlled at 110 A, the ion gas, powder feeding gas and protective gas are all high-purity argon, with flow rates of 300 L / h, 300 L / h and 800 L / h, respectively, the longitudinal cladding speed is 100 mm / min, the transverse oscillation speed is 1000 mm / min, and the oscillation width is 10 mm, thus obtaining a titanium alloy material with a 67NiTi alloy coating on the surface.

[0044] Example 5 The titanium alloy bearing material of this embodiment corresponds to the titanium alloy material obtained by the preparation methods of embodiments 1-4 above. It consists of a TC titanium alloy substrate and a NiTi alloy coating fused onto the titanium alloy substrate. The mass fraction of Ni in the NiTi alloy coating is 60%, 63%, 65%, and 67%, respectively.

[0045] The NiTi microstructure at the junction of the NiTi alloy coating and the titanium alloy substrate consists of planar and cellular crystals, while the NiTi microstructure above the junction consists of columnar and columnar dendrites.

[0046] (II) Experimental Examples Experimental Example 1 The microstructure of the titanium alloy bearing materials in Examples 1-4, at and above the joint, was analyzed, and the results are as follows: Figures 1-8 As shown.

[0047] Depend on Figures 1-8 It can be seen that, although the Ni content of the titanium alloy bearing materials in Examples 1 to 4 is different, the overall microstructure of each coating is similar. The NiTi structure at the interface is planar crystal and cellular crystal, while the NiTi structure above the interface is columnar crystal and columnar dendrite.

[0048] The coating phase consists of a toughening phase and a reinforcing phase. As the effect of dilution rate gradually increases, the number of reinforcing phases in the coating gradually increases. When the Ni content is 67%, the effect of dilution rate is the greatest, and the number of reinforcing phases in the coating increases to the maximum. It is expected that the improvement in hardness will be the most significant.

[0049] Experiment Example 2 The hardness of the titanium alloy bearing materials in Examples 1-4 was tested according to standard GB / T4340.1-2024, and the results are as follows. Figure 9 As shown in the figure. "Coating" represents the NiTi alloy coating, "HAZ" represents the heat-affected zone, and "Substrate" represents the TC4 titanium alloy substrate.

[0050] The coating thickness of the titanium alloy bearing materials in Examples 1-4 is all greater than 1.2 mm, and the average hardness of the coating in Example 1 is 626.18 Hv. 0.2 The average hardness of the coating in Example 2 was 651.54 Hv. 0.2 The average hardness of the coating in Example 3 was 666.46 Hv. 0.2 The average hardness of the coating in Example 4 was 677.41 Hv. 0.2 .

[0051] At the same time, by Figure 9 The hardness performance at different coating thicknesses shows that the coating hardness does not change much across the entire thickness range, and it is significantly improved compared to the titanium alloy substrate. The wear resistance is not affected by the partial wear through the coating, and it can achieve long-term protection for the titanium alloy substrate.

[0052] Experimental Example 3 Friction and wear tests were conducted on the titanium alloy bearing materials and TC4 titanium alloy substrates of Examples 1-4 using a ball-and-disc wear testing machine under loads of 5-20 N. The results are as follows: Figure 10 As shown.

[0053] Depend on Figure 10It can be seen that, under different loads, the average wear rate of the NiTi alloy coatings in Examples 1-4 is significantly lower than that of the substrate, indicating a significant improvement in wear resistance. Specifically, under a 20N load, the wear rate of the TC4 substrate is 7.88 × 10⁻⁶. -4 mm 3 ·( Nm ) -1 The wear rate of the 67NiTi coating is 2.74 × 10⁻⁶. -4 mm 3 ·( Nm ) -1 Its wear resistance is significantly improved compared to the substrate, increasing by about 53%, which can effectively improve the wear resistance and load-bearing capacity of titanium alloy surfaces.

[0054] (III) Comparative Example Comparative Example 1 The titanium alloy bearing material of Comparative Example 1 consists of a TC titanium alloy substrate and a cladding layer clad onto the titanium alloy substrate. The powder used to prepare the cladding layer has a composition of 70% Ni and 30% Ti. The cladding layer is prepared according to the preparation method of Example 1, and the specific cladding parameters are as follows: spray distance is 10 mm, powder feeding voltage is 12 V, cladding current is controlled at 110 A, ion gas, powder feeding gas and protective gas are all high-purity argon, with flow rates of 300 L / h, 300 L / h and 800 L / h, respectively, longitudinal cladding speed is 100 mm / min, transverse oscillation speed is 1000 mm / min, and oscillation width is 10 mm; other aspects not specified are the same as in Example 1.

[0055] Comparative Example 2 Comparative Example 2 describes a titanium alloy bearing material composed of a TC titanium alloy substrate and a cladding layer deposited on the substrate. The powder used to prepare the cladding layer consisted of 65% Ni and 35% Ti. The cladding layer was prepared according to the method described in Example 1, with the following specific cladding parameters: spray distance of 10 mm, powder feeding voltage of 18 V, cladding current controlled at 85 A, ionizing gas, powder feeding gas, and protective gas all being high-purity argon with flow rates of 300 L / h, 300 L / h, and 800 L / h, respectively; longitudinal cladding speed of 60 mm / min; transverse oscillation speed of 600 mm / min; and oscillation width of 12 mm. Other parameters not specified are the same as in Example 1.

[0056] The metallographic structures of the cladding layers obtained in Comparative Example 1 and Comparative Example 2 are as follows: Figure 11 and Figure 12 As shown. From Figure 11 and Figure 12 It can be seen that the numerous cracks and defects at the interface of the cladding layer led to the scrapping of the workpiece.

[0057] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A titanium alloy bearing material, characterized in that, The invention includes a titanium alloy substrate and a NiTi alloy coating clad on the titanium alloy substrate. The NiTi alloy coating is composed of the following components by mass fraction: Ti 33-40%, with the balance being Ni. The NiTi microstructure at the junction of the NiTi alloy coating and the titanium alloy substrate is planar and cellular, while the NiTi microstructure above the junction is columnar and columnar dendrite.

2. The titanium alloy bearing material as described in claim 1, characterized in that, The NiTi alloy coating is composed of the following components by mass fraction: Ti 33-35%, with the balance being Ni.

3. The titanium alloy bearing material as described in claim 1, characterized in that, The thickness of the NiTi alloy coating is 1.2-1.4 mm.

4. The titanium alloy bearing material as described in claim 1, 2, or 3, characterized in that, The titanium alloy substrate is TC4 titanium alloy.

5. A method for preparing a titanium alloy bearing material, characterized in that, Includes the following steps: A mixed powder consisting of Ni powder and Ti powder is prepared, and the mixed powder is clad onto the surface of a titanium alloy substrate by plasma arc fusion; the mass ratio of Ti powder in the mixed powder is 33-40%.

6. The method for preparing titanium alloy bearing material as described in claim 5, characterized in that, The plasma arc cladding has a spray distance of 10-14 mm, a powder feeding voltage of 10-16 V, and a cladding current of 90-140 A.

7. The method for preparing titanium alloy bearing material as described in claim 5 or 6, characterized in that, The plasma arc cladding uses argon gas for ionization, powder feeding, and protective gas, with flow rates of 250-350 L / h, 250-350 L / h, and 700-900 L / h, respectively.

8. The method for preparing titanium alloy bearing material as described in claim 5, characterized in that, The mass percentage of Ti powder in the mixed powder is 33-35%.

9. The method for preparing titanium alloy bearing material as described in claim 5 or 8, characterized in that, Both the Ni powder and Ti powder are spherical with a diameter between 53 and 154 μm.

10. The method for preparing titanium alloy bearing material as described in claim 5, characterized in that, The titanium alloy substrate is TC4 titanium alloy.

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