阅读说明：本技术 一种基于镀层与热扩散退火制备TiNi形状记忆合金箔材的方法 (Method for preparing TiNi shape memory alloy foil based on plating and thermal diffusion annealing ) 是由 左舜贵 许铎 孙家麟 于 2021-01-12 设计创作，主要内容包括：本发明公开了基于镀镍与热扩散退火制备TiNi形状记忆合金箔材的方法,以纯钛箔材为基底,在上面镀以纯镍,或纯镍箔材为基底,在上面镀钛；再在真空或者惰性气体保护环境下进行热扩散退火,最后形成钛镍形状记忆合金箔材。所述纯钛或纯镍箔材基底的厚度在0.001毫米～0.2毫米之间。本发明提供的TiNi形状记忆合金箔材制备方法通过控制镀镍层与钛箔基底的厚度比以控制最终的TiNi合金成分,具有工艺简单,成分控制方便的优点,较好地解决了当前生产超薄TiNi形状记忆合金箔材面临的合金冷轧性能差,热轧时又会让合金箔材表面氧化的难题。(The invention discloses a method for preparing a TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing, which comprises the steps of taking a pure titanium foil as a substrate, plating pure nickel on the pure titanium foil or taking the pure nickel foil as the substrate, and plating titanium on the pure titanium foil; and then carrying out thermal diffusion annealing in a vacuum or inert gas protective environment to finally form the titanium-nickel shape memory alloy foil. The thickness of the pure titanium or pure nickel foil substrate is between 0.001 mm and 0.2 mm. The method for preparing the TiNi shape memory alloy foil controls the final TiNi alloy component by controlling the thickness ratio of the nickel-plated layer to the titanium foil substrate, has the advantages of simple process and convenient component control, and better solves the problems that the prior ultrathin TiNi shape memory alloy foil produced has poor alloy cold rolling performance and the surface of the alloy foil is oxidized during hot rolling.)

1. A method for preparing TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing is characterized in that pure titanium foil is used as a substrate, pure nickel is plated on the pure titanium foil, or the pure nickel foil is used as the substrate, and titanium is plated on the pure titanium foil; and then carrying out thermal diffusion annealing in a vacuum or inert gas protective environment to finally form the titanium-nickel shape memory alloy foil.

2. The method for preparing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing according to claim 1, wherein the method comprises the following steps: the thickness of the pure titanium or pure nickel foil substrate is between 0.001 mm and 0.2 mm.

3. The method for preparing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing according to claim 1, wherein the method comprises the following steps: the final composition range of the prepared TiNi shape memory alloy foil is 46.9-43.0 percent of titanium by mass percent and 53.1-57.0 percent of nickel by mass percent, and the final alloy composition is controlled by controlling the mass percent of the nickel-plated layer per unit area and the titanium foil.

4. The method for preparing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing according to claim 1, wherein the method comprises the following steps: the nickel plating method is electrochemical nickel plating or physical vapor deposition nickel plating.

5. The method for preparing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing as claimed in claim 1 or 4, wherein: the physical vapor deposition method is a nickel plating method such as magnetron sputtering coating, ion coating and the like, and also comprises CVD, powder metal covering, vacuum evaporation, ion beam plating and the like.

6. The method for preparing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing according to claim 4, wherein the method comprises the following steps: the nickel plating treatment may be nickel plating on one surface of the titanium foil, or nickel plating on both surfaces of the titanium foil.

7. The method for preparing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing according to claim 4, wherein the method comprises the following steps: the final alloy composition is controlled by controlling the mass percentage of the nickel plating layer (nickel plating amount is controlled by nickel plating time, nickel plating speed and the like) and the titanium foil in unit area.

8. The method for preparing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing according to one of claims 1 to 7, wherein the method comprises the following steps: the preparation method of the TiNi shape memory alloy foil comprises the step of thermal diffusion annealing, wherein the thermal diffusion annealing is carried out in a vacuum or inert gas protection environment, and the inert gas is helium, argon, neon or a mixed gas of the helium, the argon and the neon. The thermal diffusion annealing temperature is a certain temperature between 500 ℃ and 1200 ℃.

9. The method of claim 8 for preparing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing, wherein the method comprises the following steps: the thermal diffusion annealing time depends on the thickness of the foil, the thicker the thickness, the longer the annealing time required at the same temperature.

Technical Field

The invention relates to the technical field of shape memory alloy preparation, in particular to a preparation method of a TiNi shape memory alloy foil. The TiNi shape memory alloy foil prepared by the method has the advantages of simple production process and convenient component control.

Background

The shape memory alloy has three characteristics of superelasticity, shape memory effect and damping, and when the thickness of the shape memory alloy is reduced to a certain degree, the flexibility of the shape memory alloy is further improved, so that the shape memory alloy has wide application prospects in the fields of flexible electronic devices, micro-electro-mechanical actuator devices, medical instruments, lithium battery substrates, outer packaging materials and the like. At present, the shape memory alloy with the most excellent comprehensive performance is TiNi shape memory alloy, but the TiNi-based shape memory alloy has poor cold processing performance and faces the problem of surface oxidation through hot rolling, and when the thickness of a foil is reduced to be less than 100 micrometers, the influence of the surface oxidation on the flexibility and the bending fatigue performance of the foil is particularly serious, which is also a key problem for restricting the preparation of the TiNi-based shape memory alloy ultrathin foil. The minimum thickness of the commercial TiNi-based shape memory alloy foil which can be obtained at home at present is about 80 microns, and the components are limited to a few limited components. How to prepare the TiNi-based shape memory alloy foil with thinner thickness and easily regulated and controlled components in a low-cost mode is the key for widening the wide application of the shape memory alloy in the fields of flexible electronic devices, micro electromechanical systems and the like.

Disclosure of Invention

The invention aims to overcome the problems in the field of preparation of the TiNi shape memory alloy ultrathin foil, and provides a preparation method of the TiNi shape memory alloy foil, which is used for solving the problems of difficulty in cold rolling, easiness in oxidation in hot rolling and inconvenience in component regulation of the TiNi shape memory alloy foil.

The technical scheme of the invention is that a method for preparing TiNi shape memory alloy foil based on nickel plating and thermal diffusion annealing is characterized in that pure titanium foil is used as a substrate, pure nickel is plated on the pure titanium foil, or pure nickel foil is used as a substrate, and titanium is plated on the pure nickel foil; and then carrying out thermal diffusion annealing in a vacuum or inert gas protective environment to finally form the titanium-nickel shape memory alloy foil.

The thickness of the pure titanium or pure nickel foil substrate is between 0.001 mm and 0.2 mm.

Or plating titanium on the pure nickel foil as a substrate, and mainly comprises the following steps: performing surface pretreatment on a pure titanium (pure nickel) foil → plating nickel (titanium) on a pure titanium (pure nickel) foil substrate → thermal diffusion annealing in a vacuum or inert gas protection environment. The TiNi shape memory alloy can be formed by thermal diffusion annealing, and then the foil is formed by rolling.

The surface pretreatment (cleaning treatment) of the pure titanium or the pure nickel foil generally comprises three main steps of deoiling, pickling and activation. Activation may also be omitted.

The deoiling treatment adopts a chemical deoiling method.

Preferably, the chemical oil removal is carried out in an ultrasonic cleaner, and the oil removal liquid is NaOH and Na₂CO₃The mixed solution of (1).

The acid cleaning treatment adopts a mixed solution of hydrofluoric acid, nitric acid and water.

Preferably, the volume ratio of the mixed solution is HF to HNO₃∶H₂O＝1∶2∶10。

The solution adopted by the activation treatment is fluorine-containing solution.

The nickel (titanium) plating treatment can be electrochemical deposition nickel (titanium) plating or physical vapor deposition nickel (titanium) plating, and the physical vapor deposition method can be magnetron sputtering coating, ion coating, CVD, powder metal covering, vacuum evaporation, ion beam plating and the like. Preferably, the physical vapor deposition nickel plating adopts a magnetron sputtering method.

The physical vapor deposition method can be a nickel plating method such as magnetron sputtering coating, ion coating and the like; the surface of the nickel (titanium) plating layer can be treated by an activating solution during electrochemical deposition; if the acid-washed titanium foil is put into activation solution containing fluorinion for activation, the activation solution is prepared by ZnSO₄·7H₂O (13g/L), HF (40% mass concentration) 22mL/L, CH₃(CH₂)₁₃(CH₃)₃NBr (25mg/L), ultrasonic can be added in the activation process, and the activation time is shortened to about 15 seconds.

The thickness of the nickel (titanium) plated layer is related to the thickness of the titanium or nickel foil and the target composition of the TiNi alloy foil, and the thickness of the pure titanium or nickel foil substrate can be between 0.001 and 0.2 mm. After nickel plating, the mass percent of the titanium foil per unit area is 46.9-43.0%, the mass percent of the nickel (titanium) plated layer per unit area is 53.1-57.0%, and the final alloy components are controlled by controlling the mass percent of the nickel plated layer per unit area and the titanium foil.

The thermal diffusion annealing is carried out in a vacuum environment or an inert gas protection environment.

The temperature of the thermal diffusion annealing is 500-1200 ℃. Preferably, the temperature of the thermal diffusion annealing is 900 ℃.

The time of the thermal diffusion annealing depends on the thickness of the TiNi shape memory alloy foil to be prepared and the thermal diffusion temperature: the larger the thickness of the foil is, the longer the required thermal diffusion treatment time is; the lower the temperature of the thermal diffusion treatment is, the longer the thermal diffusion treatment time is required, and uniform alloying is facilitated. Generally, the time is more than 4 hours.

The final composition range of the prepared TiNi shape memory alloy foil is 46.9-43.0 percent by mass of titanium and 53.1-57.0 percent by mass of nickel, and the final alloy composition is controlled by controlling the mass percent of a nickel plating layer (nickel plating time, nickel plating speed and the like control the nickel plating amount) and the titanium foil in unit area. The pure nickel foil substrate is coated with titanium, which is an extension of the invention, but the cost of titanium coating is higher, and the embodiment and the practical application have more industrial advantages by adopting the pure titanium foil substrate to coat nickel.

The foregoing is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to explain the technical solutions according to the contents of the description, the following detailed description of the preferred embodiments of the present invention is given below.

The method for preparing the TiNi shape memory alloy foil is particularly used for solving the problems that the thickness of a strip is about 100 microns or less, the TiNi shape memory alloy foil with the thickness of 10 microns can be conveniently prepared, and the problems that the TiNi shape memory alloy foil is difficult to cold roll, easy to oxidize during hot rolling and inconvenient in component regulation and control are solved. The TiNi shape memory alloy can be prepared into the TiNi shape memory alloy with high-precision component control and low preparation cost, and only titanium or nickel with higher purity is needed to be used as a base material.

Drawings

FIG. 1 is a technical route for preparing TiNi shape memory alloy foil based on electroplating thermal diffusion.

FIG. 2 is a schematic illustration of the electrochemical plating of nickel on a titanium foil substrate.

FIG. 3 is a schematic of the plating current output used when plating nickel on a titanium foil substrate using an electrochemical process.

Fig. 4 is a schematic diagram of a TiNi alloy foil formed after thermal diffusion annealing of a nickel-plated titanium foil.

Detailed Description

The following detailed description of embodiments of the invention is provided in connection with the accompanying drawings and examples. It should be understood that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. Reference numerals: 1 is an electrochemical nickel plating bath. 2 is Ti foil. And 3 is a nickel plating layer. 4 is TiNi alloy foil.

Fig. 1 is a process for preparing a TiNi shape memory alloy foil according to the present invention, and the following describes an operation flow of each step with a specific embodiment.

The physical vapor deposition method can be a nickel plating method such as magnetron sputtering coating, ion coating and the like. The nickel plating treatment may be nickel plating on one surface of the titanium foil, or nickel plating on both surfaces of the titanium foil. Including CVD, powder metal overlay, vacuum evaporation, ion beam plating, and the like.

The first embodiment is as follows:

(1) selecting a Ti foil with the thickness of 25 microns, firstly carrying out chemical degreasing treatment on the Ti foil, wherein the chemical degreasing is carried out in an ultrasonic cleaner, and degreasing liquid is NaOH (40g/L) and Na₂CO₃(20g/L) of the mixed solution, and ultrasonically cleaning the mixed solution at room temperature for 20 minutes.

(2) And carrying out acid cleaning treatment on the Ti foil subjected to chemical degreasing to remove a surface oxide layer. The pickling solution is HF and HNO₃Mixed solution with deionized water, HF, HNO₃The volume ratio of the deionized water to the deionized water is HF to HNO₃∶H₂And O is 1: 2: 10, the Ti foil is ultrasonically cleaned in acetone for 20 minutes after being acid-washed, then cleaned by alcohol, and the alcohol is dried by blowing.

(3) Activating the acid-washed titanium foil in activating solution containing fluorine ions, wherein ZnSO is adopted for the configuration of the activating solution₄·7H₂O (13g/L), HF (40% mass concentration) 22mL/L, CH₃(CH₂)₁₃(CH₃)₃NBr (25mg/L), ultrasonic is added in the activation process, and the activation time is 15 seconds.

(4) The activated Ti foil (2 in fig. 2) is fixed in an electroplating bath 1, as shown in fig. 2, the positive electrode is a cleaned graphite sheet, the Ti foil is used as a negative electrode, and the electroless plating solution is: NiSO₄·6H₂O(0.98mol/L)，H₃BO₃(0.50mol/L), saccharin (phthalimide: C)₇H₅O₃NS, 2.5g/L), sodium dodecyl sulfate (C)₁₂H₂₅SO₄Na, 0.5g/L), pH 4.0, electrodeposition temperature 40 ℃. With a pulsed DC power supply, the output current versus time is shown in FIG. 3, peak current I_pIs 200 mA.cm^-2On time t of pulse current_on30 ms, closing time t_off270 milliseconds, an electrodeposition time of 2 hours, and a thickness of the finally deposited nickel layer of 16 microns. For example, Ti foil with thickness of 150 microns, Ni film with thickness of nearly 100 microns is plated by electroplatingThe thickness can be easily controlled by the inter-control.

(5) The foil after Ni plating on the Ti foil is shown in figure 4, wherein 2 in figure 4 is a Ti foil substrate, 3 in figure 4 is a Ni plating layer, the Ti foil plated with Ni is dried and then placed in a vacuum annealing furnace for annealing while vacuumizing, the thermal diffusion annealing temperature is 1000 ℃, the thermal diffusion annealing time is 12 hours, the TiNi alloy foil 4 with uniform components is formed after thermal diffusion, and the TiNi alloy 4 comprises the following components: ti (44.14 mass%), Ni (55.86 mass%).

Example two:

(1) selecting a Ti foil with the thickness of 10 microns, firstly carrying out chemical degreasing treatment on the Ti foil, wherein the chemical degreasing is carried out in an ultrasonic cleaner, and degreasing liquid is NaOH (40g/L) and Na₂CO₃(20g/L) of the mixed solution, and ultrasonically cleaning the mixed solution at room temperature for 20 minutes.

(2) And carrying out acid cleaning treatment on the Ti foil subjected to chemical degreasing to remove a surface oxide layer. The pickling solution is HF and HNO₃Mixed solution with deionized water, HF, HNO₃The volume ratio of the deionized water to the deionized water is HF to HNO₃∶H₂And O is 1: 2: 10, the Ti foil is ultrasonically cleaned in acetone for 20 minutes after acid cleaning, then cleaned by alcohol, and dried by the blow of the alcohol.

(3) Fixing the Ti foil after acid washing on a sample substrate of a magnetron sputtering instrument, performing magnetron sputtering Ni plating (using a pure nickel rod as a sputtering source) treatment on the Ti foil, wherein the sputtering power is 2.5kW, the sputtering gas pressure is 0.3Pa, the negative bias is 480V, the sputtering temperature is the common temperature, such as 100 ℃ and 300 ℃, the sputtering time is 1 hour, the thickness of the deposited Ni layer is 6.4 microns, and the sample after magnetron sputtering Ni plating is shown in figure 4, wherein 2 is a Ti foil substrate, and 3 is a magnetron sputtering Ni plating layer. If the thickness of Ti foil is 5 microns, Ni film with thickness of 3.2 microns is plated, and the thickness can be easily controlled by controlling sputtering time.

(5) Placing the sample plated with Ni by magnetron sputtering in a vacuum annealing furnace for thermal diffusion treatment, wherein the thermal diffusion annealing temperature is 1000 ℃, the thermal diffusion annealing time is 8 hours, and the TiNi alloy foil 4 with uniform components is formed after thermal diffusion, wherein the TiNi alloy 4 comprises the following components: ti (44.14 mass%), Ni (55.86 mass%).

The TiNi shape memory alloy can be formed by thermal diffusion annealing, and then the foil is formed by rolling. Reference may be made to the applicant's application for invention: a method for preparing nickel-titanium shape memory alloy cold-rolled ultrathin sheet material is disclosed, and the application number is 2020101107707.

The main difference between the first embodiment and the second embodiment is as follows: in the first embodiment, nickel is plated by an electrochemical method, in the second embodiment, nickel is plated by magnetron sputtering in a physical vapor deposition method, and in the second embodiment, the step of surface activation is not needed.

In conclusion, the method for annealing the TiNi shape memory alloy foil based on nickel plating and thermal diffusion provided by the invention overcomes the problems that the TiNi shape memory alloy is poor in cold rolling processing performance and the hot rolling can face surface oxidation.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.