CN111979541B - Titanium alloy with Ti-Nb alloy coating and preparation method and application thereof - Google Patents

Abstract

The invention relates to a titanium alloy with a Ti-Nb alloy coating, and a preparation method and application thereof. The Ti-Nb coating is attached to the titanium alloy substrate; the titanium alloy matrix is a nickel-rich shape memory alloy and is an austenite phase; the near surface of the Ti-Nb coating does not contain Ni elements, the microstructure of the coating contains (Ti, Nb) phases, and the (Ti, Nb) phases are beta-Ti structures. The Ti-Nb coating is prepared on the titanium alloy matrix in a coaxial powder feeding and laser cladding mode. The coating has low tissue dilution rate and excellent biocompatibility, is in good metallurgical bonding with a base material, and has microhardness of 470 +/-12.5 HV. The preparation process is simple and controllable, and the obtained product has excellent performance and low cost and is convenient for large-scale application. Meanwhile, the material designed and prepared by the invention is particularly suitable for being used as a biomedical material and a high-temperature-resistant and corrosion-resistant material.

Description

A kind of titanium alloy with Ti-Nb alloy coating, preparation method and application thereof

technical field

The invention relates to a titanium alloy with a Ti-Nb alloy coating, a preparation method and application thereof, and belongs to the technical field of surface treatment.

Background technique

Titanium alloys are widely used in aerospace, automotive, military, life and biomedical fields due to their low elastic modulus, high corrosion resistance, friction and wear resistance, high damping and excellent biocompatibility. Among them, nickel-titanium alloy has special shape memory effect and superelasticity, and it is a good implant material in clinic. However, during long-term implantation, toxic nickel ions are released, and the corrosion resistance and friction and wear resistance of the implant surface decrease. These problems limit the application of NiTi alloys in biomedical materials to a certain extent.

The surface properties and quality of biomedical materials usually have a certain influence on the biocompatibility of the materials, and the ideal surface coating should have special surface structure and properties, strong bonding strength with the substrate, and excellent mechanical phase. compatibility and biocompatibility. For many years, many excellent scientists have made a lot of efforts on these issues, but it is necessary to have both the excellent properties of nickel-titanium alloy itself, and solve its application defects, and also consider the preparation cost, which brings scientific research workers. many challenges.

In recent years, it has been proposed that Ti-Nb alloys with a certain niobium content also have shape memory effect and superelasticity, and have better corrosion resistance and excellent mechanical biocompatibility, which can replace nickel-titanium alloy applications. in the biomedical field. However, because niobium is extremely expensive, its large-scale application and complete replacement of nickel-titanium alloys are limited.

Laser cladding technology is an emerging surface modification and repair technology. The working principle of the coaxial powder feeding type is that the powder is sent out through the nozzle under the protection of gas, the laser is scanned coaxially, and formed in one step, and multiple multi-layer cladding coatings can be prepared. It can significantly improve the wear resistance, corrosion resistance, heat resistance, oxidation resistance and electrical properties of the base surface to achieve the purpose of surface modification or repair. It has the advantages of small penetration depth of substrate, metallurgical combination of coating and substrate, many suitable cladding materials, large variation in particle size and content, high efficiency, low cost, etc. Therefore, the application prospect of laser cladding technology is very broad. So far, few people have thought of using the excellent superelasticity and biocompatibility of Ti-Nb alloys to surface modify titanium alloys.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is: in view of the current clinical defects of titanium alloys, a titanium alloy with Ti-Nb alloy coating and its preparation method and application are proposed to solve the surface strengthening problem of long-term implantation of biomedical implants . At the same time, the invention also solves the problems of cracks and uneven surface of the Ti-Nb coating.

The present invention is a titanium alloy with a Ti-Nb alloy coating; a titanium alloy base material is used; the Ti-Nb coating is attached to the base; the base is a nickel-rich shape memory alloy, which is an austenite phase; The Ti-Nb coating does not contain Ni atoms, and the microstructure of the coating mainly contains a (Ti, Nb) phase, and the (Ti, Nb) phase is a β-Ti structure.

The present invention is a titanium alloy with a Ti-Nb alloy coating; the atomic ratio of Nb in the Ti-Nb coating is 15-35%, preferably 20-30%, more preferably 23%; the balance is Ti .

As a preferred solution, the present invention provides a titanium alloy with a Ti-Nb alloy coating; the titanium alloy is a nickel-titanium alloy.

The invention relates to a titanium alloy with a Ti-Nb alloy coating; the bonding interface between the coating and the base material is dense and smooth, showing metallurgical bonding, and the coating surface is smooth and dense; the hardness of the coating is 470±12.5HV. The unlapped area of the coating is 1-3um grains and a large number of nanocrystals, and the overlapped area has larger grains, mainly 3-10um grains.

The invention relates to a titanium alloy with a Ti-Nb alloy coating; the thickness of the single-layer cladding coating is 1.0-1.5 mm.

The invention relates to a titanium alloy with a Ti-Nb alloy coating; the Ti-Nb alloy coating is formed on the surface of a nickel base by laser cladding.

The invention relates to a preparation method of a titanium alloy with a Ti-Nb alloy coating; a titanium alloy with a clean and dry surface is used as a base material; a mixed powder of Ti and Nb elements is used as a raw material; by laser cladding, the Ti and Nb elements are mixed The powder is coated on the base material to obtain a product; during laser cladding, the laser power is controlled to be 250-450W, preferably 350-400W, the laser power is 1.6-3.6mm/s, preferably 2.0-3.0mm/s, and the spot The diameter is 2.0mm, the overlap ratio is 30-60%, preferably 50%, and the powder feeding rate is 0.08-0.15g/s, preferably 0.1g/s. As a preferred solution, in the present invention, the cladding path is unidirectional cladding, and the laser is idling. The coating surface is remelted again. Input g code, the whole process is controlled by computer.

The invention relates to a preparation method of a titanium alloy with a Ti-Nb alloy coating; the titanium alloy with a clean and dry surface is obtained by the following treatment method: firstly, the titanium alloy substrate is ground flat by a water grinder, and then soaked with cotton respectively. Wipe the surface of the substrate with deionized water, acetone, deionized water and absolute ethanol, and clean the surface stains strictly in this order.

The invention relates to a method for preparing a titanium alloy with a Ti-Nb alloy coating; the atomic ratio of Nb in the mixed powder of Ti and Nb elements is 15-35%, preferably 20-30%, more preferably 23%; the remainder for Ti.

The present invention is a preparation method of a titanium alloy with a Ti-Nb alloy coating; the mixed powder of Ti and Nb elements is prepared through the following steps:

The present invention is a method for preparing a titanium alloy with a Ti-Nb alloy coating; further, the particle size of the titanium powder is 53-125 μm, the oxygen content is less than or equal to 0.18 wt.%, and the average particle size is 83 μm. The particle size of the niobium powder is 50-120 μm, the average particle size is 77 μm, and the oxygen content is less than or equal to 0.32%.

The invention relates to a preparation method of a titanium alloy with a Ti-Nb alloy coating; the Ti and Nb element powders are irregularly shaped Ti and Nb element powders. The titanium powder and niobium powder are distributed according to the design composition, and the powder is strictly placed in a protective atmosphere of argon to prevent the introduction of oxygen. And, mix for 9 hours to achieve the effect of powder mixing evenly.

The invention relates to a preparation method of a titanium alloy with a Ti-Nb alloy coating; the powder is fed by coaxial powder feeding.

The preparation process used in the present invention does not have high requirements on the fluidity of the powder.

The coating preparation process of the present invention can adopt a fully automatic mode or a semi-automatic mode. Note, operate in strict accordance with the following requirements: First, before laser cladding, be sure to open the gas cylinder before feeding powder; after the experiment is over, stop feeding powder and then close the gas cylinder. Second, if the experiment stops in the middle, be sure to turn off the laser and then open the cabin.

The invention relates to a method for preparing a titanium alloy with a Ti-Nb alloy coating; multiple layers of 1-3 layers of Ti-Nb alloy coating are obtained by laser cladding; the total thickness of the Ti-Nb alloy coating is 1.0 -3.0mm.

As a general technical concept, the present invention also provides an application of laser cladding Ti-Nb alloy coating on the surface of titanium alloy in biomedicine. Dental braces. At the same time, the materials designed and prepared by the present invention can also be used as high temperature and corrosion resistant materials. Due to the characteristics of the materials designed and prepared in the present invention, it is also feasible to use them as biomedical materials, aerospace industry materials, and automobile industry materials.

The invention uses the mixed powders of Ti and Nb elements to mix, and forms a Ti-Nb alloy coating on the surface of the nickel-titanium alloy by laser cladding. The particles are fine and the coating surface is smooth. The coating has the characteristics of superelasticity, high strength, abrasion resistance, corrosion resistance, etc. It can effectively prevent the release of nickel ions, improve the biocompatibility of nickel-titanium alloys, and be used in superelasticity and shape memory applications of nickel-titanium alloys. medium, not easy to fall off.

To sum up, due to the adoption of the above-mentioned technical solutions, the beneficial effects of the present invention are:

(1) The Ti-Nb alloy material of the present invention satisfies the biocompatibility and also improves the wear resistance and corrosion resistance, and successfully prevents the release of nickel ions; the Ti, Nb mixed powder material of the present invention has low oxygen content , the preparation method is simple, and the coating mainly contains β-Ti phase, which has a good metallurgical bond with the substrate.

(2) The coating is prepared by laser cladding technology, and the laser process parameters (laser power, laser scanning rate, laser spot size, overlap rate, powder feeding rate, etc.) can be controlled to control the coating quality, and different layers can be selected. The coating then regulates the surface structure and mechanical properties of the coating.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are the For some embodiments of the invention, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the mixed powder of elements prepared in Example 1 of the present invention, the spectrum obtained by scanning with an energy spectrometer.

FIG. 2 is an overall metallographic diagram of the coating obtained in Example 1 of the present invention.

3 is a scanning electron microscope image of the interface between the coating and the base material in the product prepared in Example 1 of the present invention.

FIG. 4 is a metallographic diagram of the interface between the coating and the base material in the product prepared in Example 2 of the present invention.

5 is a scanning electron microscope image of the interface between the coating and the base material in the product prepared in Example 2 of the present invention.

FIG. 6 is a metallographic photograph of the surface of the coating prepared in Example 2 of the present invention.

Detailed ways

The present invention will now be illustrated by the following best embodiments, but not intended to limit the scope of the present invention.

Example 1

The extraction was carried out according to the following atomic ratios: 77% irregularly shaped titanium powder, 23% irregularly shaped niobium powder. The average particle size of niobium powder is smaller than that of titanium powder. The particle size of titanium is 53-125 μm, the average particle size is 83 μm, and the particle size of niobium powder is 50-120 μm, and the average particle size is 77 μm. It is strictly carried out in a hypoxic glove box and filled with protective gas, such as argon used in the present invention. In order to prevent oxygen from entering during powder mixing, it should be strictly sealed in the glove box, and then the powder should be mixed in a mixer for 9 hours. After mixing the powder, take a small amount of powder in the glove box for scanning electron microscope analysis, equipped with energy spectrometer analysis, it can be found that the Ti and Nb powders are evenly distributed (as shown in Figure 1), and the energy spectrometer results are close to the proportion of ingredients.

After the nickel-rich NiTi alloy substrate was polished by a water grinder, the surface of the substrate was cleaned in the order of deionized water→acetone→deionized water→absolute ethanol with medical cotton respectively. Then it was placed in the chamber of the laser metal depositor, the chamber was evacuated by a vacuum pump, and the chamber was filled with argon to maintain a low-oxygen environment. The mixed powder of Ti and Nb elements is placed in the powder feeder for powder feeding. Set the laser process parameters: laser power 350W, laser rate 3.0mm/s, spot diameter 2mm, lap rate 70%, powder feeding rate 0.1g/s. Then laser cladding is carried out with eight single-layer Ti-Nb alloy coatings. The cladding path is one-way cladding, and the laser returns to the origin in an empty space, and the whole process is intelligently controlled by computer. Retain the substrate with a certain thickness, cut the laser cladding sample along the cross section, chemically corrode the grain boundaries after grinding and polishing, and grind with ₂₀₀₀ mesh _sandpaper . Water polishing; the etching solution is configured as HF:HNO ₃ :HO ₂ =10:15:75, the etching time is 15s, it cannot be corroded for a long time, otherwise it is too corroded and needs to be re-sampled. Take a metallographic photograph under an optical microscope to obtain a metallographic photograph of the overall Ti-Nb alloy coating (as shown in Figure 2), and then use a scanning electron microscope to characterize the bonding interface between the coating and the base material (as shown in Figure 3). It can make the bonding interface between the coating and the base material dense and smooth. It can be found that the surface of the laser cladding single-layer Ti-Nb coating is relatively smooth. Nickel atoms diffuse into the coating and then gradually disappear. The microhardness analysis of the coating was carried out. Under the load of 200g and maintained for 10s, the microhardness of the Ti-Nb coating in the heat affected zone of the substrate was the largest, reaching 500.28HV, and the surface hardness of the coating was 430.01HV, about It is twice that of the base material, and the microhardness of the base material is 235.14HV. The corrosion resistance of NiTi alloy with Ti-Nb alloy coating is higher than that without coating, and the nickel ion release rate of the former is also much lower.

Embodiment 2

The powder ratio, powder mixing conditions, substrate surface treatment and laser cladding conditions are all the same as in Example 1, except that the laser process parameters are set: laser power 400W, laser rate 3.0mm/s, spot diameter 2mm, overlap rate 50%, send The powder rate was 0.1 g/s. Then laser cladding is carried out with eight single-layer Ti-Nb alloy coatings. The cladding path is one-way cladding, and the laser returns to the origin in an empty space, and the whole process is intelligently controlled by computer. Retaining the substrate of a certain thickness, the laser cladding sample was cut along the cross section, and the grain boundaries were chemically corroded after grinding and polishing, and the treatment process was the same as that of Example 1. The metallographic structure was photographed under an optical microscope to obtain a metallographic photograph of the bonding interface between the Ti-Nb alloy coating and the NiTi substrate (as shown in Figure 4). ), the preparation method of the present invention can make the bonding interface between the coating and the base material compact and smooth, and form a good metallurgical bond. In particular, nickel atoms diffused onto the coating and then gradually diminished. According to the metallography of the surface of the coating (as shown in Figure 6), it can be found that the surface of the laser cladding Ti-Nb coating is smooth and flat. The microhardness analysis of the coating was carried out. When the load was 200g and kept for 10s, the microhardness of the Ti-Nb coating in the heat-affected zone of the substrate was the largest, reaching 580HV, and the surface hardness of the coating was 470.09HV, which was the base. The microhardness of the base material is 235.14HV. The Ti-Nb-coated titanium alloy was immersed in simulated human body fluids for ten days, and no toxic nickel ions were released. The Ti-Nb-coated titanium alloy and the uncoated titanium alloy were electrochemically corroded for two hours in a simulated human body solution, respectively. It was found that the former has a lower corrosion current and a higher corrosion potential, indicating that the former has better corrosion resistance. sex.

Embodiment 3

The powder ratio, powder mixing conditions, substrate surface treatment and laser cladding conditions are all the same as in Example 1, except that the laser process parameters are set: laser power 350W, laser rate 3.0mm/s, spot diameter 2mm, overlap rate 50%, send The powder rate was 0.1 g/s. Sixteen three-layer Ti-Nb alloy coatings were then laser clad, layer by layer. The cladding path is one-way cladding, and the laser returns to the origin. The process parameters remain unchanged, powder feeding is stopped, the laser surface is remelted, and the whole process is controlled by computer intelligently. Retain the substrate of a certain thickness, cut the laser cladding sample along the cross section, and chemically corrode the grain boundaries after grinding and polishing. Similarly, the processing process is the same as that of Example 1. The metallographic structure is photographed under an optical microscope to obtain the metallographic photograph of the bonding interface between the Ti-Nb alloy coating and the NiTi base material, and the scanning electron microscope is used to characterize the bonding interface between the coating and the base material. The preparation method of the invention can make the coating The bonding interface between the layer and the base material is dense and smooth, forming a good metallurgical bond. In particular, nickel atoms diffused onto the coating and then disappeared gradually, and no nickel atoms appeared on the surface of the coating. According to the metallography of the surface of the coating, it can be found that the surface of the laser cladding Ti-Nb coating is smooth and flat. The microhardness analysis of the coating was carried out. When the load was 200g and held for 10s, the microhardness of the Ti-Nb coating in the heat affected zone of the substrate was the largest, reaching 550.20HV, and the surface hardness of the coating was 482.5HV, which is More than double that of the base material, the microhardness of the base material is 235.14HV. The Ti-Nb-coated titanium alloy was immersed in simulated human body fluids for ten days, and no toxic nickel ions were released. The titanium alloy with Ti-Nb alloy coating and the titanium alloy without Ti-Nb alloy coating were electrochemically corroded in the human body simulated solution for two hours. It was found that the former has a lower corrosion current and a higher corrosion potential. It shows that the former has better corrosion resistance. The coating has higher corrosion resistance and higher friction and wear resistance.

Embodiment 4

The powder ratio, powder mixing conditions, substrate surface treatment and laser cladding conditions are all the same as in Example 1, except that the laser surface remelting parameters are set: laser power 400W, laser rate 3.0mm/s, spot diameter 2mm, overlap rate 50% . Then laser cladding three layers of Ti-Nb alloy coating layer by layer, the surface is remelted once. Full computer intelligent control. Wire cut samples. The sample surface is clean and smooth. After the cross-section is ground and polished, the grain boundaries are chemically corroded. Similarly, the treatment process is the same as that of the first embodiment. The metallographic structure of the remelted zone is photographed under an optical microscope, and the microstructure of the remelted zone is characterized by a scanning electron microscope. The preparation method of the present invention can make the surface of the NiTi alloy base material sample clean and smooth, with few defects. The microhardness analysis of the surface of the base material shows that under the load of 200g and held for 10s, the microhardness is as high as 580.26HV, which is more than double that of the base material, and the microhardness of the base material is 235.14HV. The surface-remelted NiTi alloy and the untreated NiTi alloy were respectively placed in the simulated body fluid of the human body and soaked for ten days, and it was found that the release of nickel ions in the former was reduced. The surface-remelted NiTi alloy and the surface-treated NiTi alloy were electrochemically corroded in a simulated human body solution for two hours. It was found that the former had lower corrosion current and higher corrosion potential, indicating that the former had better corrosion resistance.

Comparative Example 1

The extraction was carried out according to the following atomic ratios: 77% irregularly shaped titanium powder, 23% irregularly shaped niobium powder. The average particle size of niobium powder is smaller than that of titanium powder. The particle size of titanium is 53-125 μm, the average particle size is 83 μm, and the particle size of niobium powder is 50-120 μm, and the average particle size is 77 μm. Strictly in a hypoxic glove box filled with protective gas argon. In order to prevent oxygen from entering during powder mixing, it is strictly sealed in the glove box, and then the powder is mixed in the mixer for 2 hours. After mixing the powder, take a small amount of powder in the glove box for scanning electron microscope analysis, equipped with energy spectrometer analysis, it can be found that the distribution of Ti and Nb powder is uneven, and the powder of one element is aggregated. The Ti-Nb alloy coating prepared from this powder has uneven microstructure distribution and is mostly pure titanium phase, which reduces the mechanical quality and corrosion resistance. Moreover, the coating elasticity is worse than that of the examples.

Comparative Example 2

The powder ratio, powder mixing conditions, substrate surface treatment and laser cladding conditions are all the same as in Example 1, except that the laser process parameters are set: laser power 250W, laser rate 3.6mm/s, spot diameter 2mm, overlap rate 70%, send The powder rate was 0.1 g/s. Then laser cladding is carried out with eight single-layer Ti-Nb alloy coatings. The cladding path is one-way cladding, and the laser returns to the origin in an empty space, and the whole process is intelligently controlled by computer. Note that in order to prevent the occurrence of powder sticking during the experiment, strictly follow the following requirements: before laser cladding, be sure to open the gas cylinder before feeding powder; after the experiment, stop feeding powder and then close the gas cylinder. Second, if the experiment stops in the middle, be sure to turn off the laser and then open the cabin; third, too fast or too slow airflow will cause the experiment to fail.

Retaining the substrate of a certain thickness, the laser cladding sample was cut along the cross section, and the grain boundaries were chemically corroded after grinding and polishing, and the treatment process was the same as that of Example 1. The metallographic photograph of the whole Ti-Nb alloy coating is obtained under an optical microscope, and the bonding interface between the coating and the base material is characterized by a scanning electron microscope. The preparation method of the present invention can make the bonding interface between the coating and the base material possible. Dense and flat. There are many unmelted particles in the sample, and the surface quality is poor. The microhardness analysis of the coating shows that the microhardness of the Ti-Nb coating is the largest in the heat-affected zone of the substrate, but the surface hardness distribution of the coating is uneven and the difference is large. This is due to insufficient laser energy.

Comparative example three

The powder ratio, powder mixing conditions, substrate surface treatment and laser cladding conditions are all the same as in Example 1, except that the laser process parameters are set: laser power 450W, laser rate 1.6mm/s, spot diameter 2mm, overlap rate 70%, send The powder rate was 0.1 g/s. Then laser cladding is carried out with eight single-layer Ti-Nb alloy coatings. The cladding path is one-way cladding, and the laser returns to the origin in an empty space, and the whole process is intelligently controlled by computer. Retaining the substrate of a certain thickness, the laser cladding sample was cut along the cross section, and the grain boundaries were chemically corroded after grinding and polishing, and the treatment process was the same as that of Example 1. The metallographic photograph of the whole Ti-Nb alloy coating is obtained under an optical microscope, and the bonding interface between the coating and the base material is characterized by a scanning electron microscope. The preparation method of the present invention can make the bonding interface between the coating and the base material possible. Dense and flat. However, the cracks are entrenched in depth, or extend along the weld line, or deeper than the coating. Excessive energy density will bring the nickel of the substrate into the coating, which will lead to the segregation of the nickel-rich phase during the solidification process, and finally cause the corrosion resistance of the sample to decrease.

Comparative Example 4

The extraction was carried out according to the following atomic ratios: 90% irregularly shaped titanium powder, 10% irregularly shaped niobium powder. The average particle size of niobium powder is smaller than that of titanium powder. The particle size of titanium is 53-125 μm, the average particle size is 83 μm, and the particle size of niobium powder is 50-120 μm, and the average particle size is 77 μm. The two element powders are mixed uniformly under a protective atmosphere.

After the nickel-rich NiTi alloy substrate was polished by a water grinder, the surface of the substrate was cleaned in the order of deionized water → acetone → deionized water → absolute ethanol dipped in medical cotton. Then it was placed in the chamber of the laser metal depositor, the chamber was evacuated by a vacuum pump, and the chamber was filled with argon to maintain a low-oxygen environment. The mixed powder of Ti and Nb elements is placed in the powder feeder for powder feeding. Set the laser process parameters: laser power 350W, laser rate 3.0mm/s, spot diameter 2mm, overlap rate 50%, powder feeding rate 0.1g/s. Then laser cladding is carried out with eight single-layer Ti-Nb alloy coatings. The cladding path is one-way cladding, and the laser returns to the origin in an empty space, and the whole process is intelligently controlled by computer. Retain the substrate of a certain thickness, cut the laser cladding sample along the cross section, and chemically corrode the grain boundaries after grinding and polishing, as in Example 1. The metallographic photograph of the whole Ti-Nb alloy coating is obtained under an optical microscope, and the bonding interface between the coating and the base material is characterized by a scanning electron microscope. The preparation method of the present invention can make the bonding interface between the coating and the base material possible. Dense and flat. Nickel atoms diffuse into the coating and then gradually decrease. Tensile test results proved that the coating was not superelastic. The electrochemical corrosion test proves that the corrosion resistance of the coating is lower than that of other samples.

Claims (8)

1. a titanium alloy with a Ti-Nb alloy coating; it is characterized in that: with a titanium alloy base material; the Ti-Nb coating is attached to the base; the base is a nickel-rich shape memory alloy, which is an Austrian alloy. Tensite phase; the Ti-Nb coating does not contain Ni atoms, and the microstructure of the coating contains a (Ti, Nb) phase, and the (Ti, Nb) phase is a β-Ti structure; The atomic ratio of Nb in the Ti-Nb coating is 15-35% and the balance is Ti; The Ti-Nb coating was prepared by the following scheme: The titanium alloy with clean and dry surface is used as the base material; the mixed powder of Ti and Nb elements is used as the raw material; the titanium powder and niobium powder are distributed according to the design composition, and the powder is strictly placed in a protective atmosphere of argon to prevent the introduction of oxygen, and, Mixing for 9 hours to achieve the effect of uniform powder mixing; obtain uniformly mixed powder; then Through laser cladding, the mixed powder of Ti and Nb elements is coated on the base material to obtain a product; during laser cladding, the laser power is controlled to be 350-400 W, the scanning rate is 2.0-3.0 mm/s, and the lap rate is 30-70%, the spot diameter is 2 mm, and the powder feeding rate is 0.08-0.15 g/s. 2 . The titanium alloy with a Ti-Nb alloy coating according to claim 1 , wherein the titanium alloy is a nickel-titanium alloy. 3 . 3. A kind of titanium alloy with Ti-Nb alloy coating according to claim 1; it is characterized in that: the interface between the coating and the base material is dense and smooth, showing metallurgical bonding, and the coating surface is smooth and dense; The hardness of the layer is 470±12.5 HV; the size of the unlapped area of the coating is less than or equal to 3 um, and the size of the grains in the overlapped area is greater than 3um and less than or equal to 10um. 4 . The titanium alloy with Ti-Nb alloy coating according to claim 1 , wherein the thickness of the single-layer cladding coating is 1.0-1.5 mm. 5 . 5. a kind of titanium alloy with Ti-Nb alloy coating according to claim 1; It is characterized in that: described surface clean and dry titanium alloy is obtained by following processing method: Polished and smoothed, and then wiped the surface of the substrate with cotton soaked in deionized water, acetone, deionized water and absolute ethanol respectively. 6. A kind of titanium alloy with Ti-Nb alloy coating according to claim 1; It is characterized in that: the atomic ratio of Nb in the mixed powder of Ti and Nb elements is 20-30%; the remainder is Ti; The Ti, Nb element mixed powder is prepared by the following steps: Allocation of titanium powder and niobium powder according to the design composition; uniform mixing under a protective atmosphere to obtain a mixed powder of Ti and Nb elements. 7. a kind of titanium alloy with Ti-Nb alloy coating according to claim 1; It is characterized in that: The Ti and Nb element powders are irregular-shaped mixed powders of Ti and Nb elements; Before laser cladding, open the gas cylinder and then feed powder; during laser cladding, use coaxial powder feeding to feed powder; after laser cladding is completed, stop powder feeding and then close the gas cylinder. 8. The application of a titanium alloy with Ti-Nb alloy coating according to any one of claims 1-5; it is characterized in that: the application includes using it as biomedical material, aerospace industry material , At least one of the automotive industry materials.

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