A kind of alloy with adjustable expansion coefficient and preparation method thereof

Abstract

The present invention relates to the technical field of alloy materials, and specifically to an alloy with adjustable expansion coefficient and a preparation method thereof, comprising: preparing raw materials according to the atomic percentage of the alloy; placing the prepared raw materials into an arc melting furnace for repeated smelting to obtain a first material; hot-rolling the first material into a plate, and then performing a solid solution treatment to obtain a second material; performing a cold rolling process on the second material to obtain a third material; and performing thermomechanical cycle training on the third material to obtain an alloy. The present invention achieves an adjustable reversible negative thermal expansion coefficient and an ultra-large negative thermal expansion coefficient by thermomechanical cycle training of the prepared alloy; by controlling key parameters such as temperature and pressure during thermomechanical cycle training, the alloy undergoes changes in its microstructure, thereby obtaining excellent negative thermal expansion performance. The negative thermal expansion coefficient of the material is regulated to meet the needs of different application scenarios.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and in particular to an alloy with adjustable expansion coefficient and a preparation method thereof. Background Art

[0002] Thermal expansion, an inherent property of materials, refers to the phenomenon in which the volume or length of a material changes with temperature. Most materials expand when heated and contract when cooled, a phenomenon we understand as "thermal expansion and contraction." However, a few materials can achieve both thermal expansion and contraction. Negative thermal expansion materials or zero thermal expansion materials can effectively mitigate failures caused by positive thermal expansion during use. With technological advancements and improved manufacturing standards, instrumentation demands higher temperature stability, placing a higher demand on materials with even lower or even negative thermal expansion coefficients.

[0003] However, most of these current negative thermal expansion materials are non-metallic compounds, which are inherently flexible, brittle, and have poor processability. Furthermore, while these non-metallic materials exhibit negative thermal expansion, they lack the alloy properties required for strength support. Compared to inorganic and organic negative thermal expansion materials, metallic negative thermal expansion materials offer superior processability, thermal conductivity (strong thermal shock resistance), and mechanical properties, offering broader application prospects. Summary of the Invention

[0004] (1) Purpose of the invention

[0005] The purpose of the present invention is to provide an alloy with adjustable expansion coefficient capable of increasing the negative thermal expansion coefficient of the alloy and a preparation method thereof.

[0006] (2) Technical solution

[0007] To solve the above problems, the present invention provides a method for preparing an alloy with adjustable expansion coefficient, comprising:

[0008] Step 100: preparing raw materials according to the atomic percentage of the alloy;

[0009] Step 200: placing the prepared raw materials into an arc melting furnace for repeated melting to obtain a first material;

[0010] Step 300: hot-rolling the first material into a plate, and then performing a solution treatment to obtain a second material;

[0011] Step 400: performing a cold rolling process on the second material to obtain a third material;

[0012] Step 500: Perform thermomechanical cycle training on the third material to obtain an alloy.

[0013] In another aspect of the present invention, preferably, the alloy in step 100 comprises titanium and niobium, and the atomic percentages of titanium and niobium in the alloy satisfy the following ratio: titanium:niobium = 3:1.

[0014] In another aspect of the present invention, preferably, step 200 of placing the prepared raw materials into an arc melting furnace for repeated melting to obtain the first material comprises:

[0015] The prepared raw materials are placed in the arc melting furnace and vacuumed to a preset vacuum degree, which is less than or equal to 4.5×10 -3 Pa;

[0016] Fill the chamber with argon gas to a preset pressure of 0.4×10 5 Pa~0.6×10 5 Pa;

[0017] Repeated smelting is performed, wherein the smelting temperature is 2500° C. to 2900° C. and the number of smelting is greater than or equal to 5 times.

[0018] In another aspect of the present invention, preferably, the step 300 of hot-rolling the first material into a plate and then performing a solution treatment to obtain the second material comprises:

[0019] The hot rolling temperature of the first material is 800° C. to 900° C.;

[0020] encapsulating the hot-rolled first material in a quartz tube for solution treatment;

[0021] The vacuum degree in the packaged quartz tube is less than or equal to 1×10 -4 Pa, the temperature of the solution treatment is 1100°C, and the time of the solution treatment is greater than or equal to 24h.

[0022] In another aspect of the present invention, preferably, step 400 of performing a cold rolling process on the second material to obtain a third material includes:

[0023] The deformation amount of the cold rolling process is 90%;

[0024] The second material that has undergone the cold rolling process is cut into a dog bone shape to obtain a third material.

[0025] In another aspect of the present invention, preferably, step 500 of performing thermomechanical cycle training on the third material to obtain an alloy comprises:

[0026] heating the third material to a preset temperature under a preset training load;

[0027] applying an axial force in a rolling direction to the third material in a heated state to stretch it;

[0028] cooling the third material in a stretched state;

[0029] After the temperature drops to room temperature, unload the axial force;

[0030] Repeat step 500 to a preset number of training times to obtain an alloy.

[0031] In another aspect of the present invention, preferably, when the preset training loads are 300 MPa and 450 MPa, the preset temperatures are 50°C, 100°C, and 150°C, and the preset training times are 5 and 10, respectively, the prepared alloy has a strength of -10.1×10 -6 K -1 ~-40.6×10 -6 K -1 Reversible negative thermal expansion coefficient.

[0032] In another aspect of the present invention, preferably, when the preset training load is 300 MPa, 450 MPa, the preset temperatures are 50°C, 100°C, 150°C, and the preset training times are 5 and 10, respectively, the prepared alloy has a -87×10 -6 K -1 ~-216.2×10 -6 K -1 Adjustable negative thermal expansion coefficient.

[0033] In another aspect of the present invention, preferably, an alloy with adjustable expansion coefficient is prepared by the preparation method as described above.

[0034] In another aspect of the present invention, the alloy preferably has a thermal conductivity of -10.1×10 -6 K -1 ~-40.6×10 -6 K -1 The alloy has a reversible negative thermal expansion coefficient of -87×10 -6 K -1 ~-216.2×10 -6 K -1 Adjustable negative thermal expansion coefficient.

[0035] (3) Beneficial effects

[0036] The above technical solution of the present invention has the following beneficial technical effects:

[0037] The present invention achieves a controllable, reversible negative thermal expansion coefficient and an ultra-large negative thermal expansion coefficient through thermomechanical cyclic training of the prepared alloy. By controlling key parameters such as temperature and pressure during thermomechanical cyclic training, the alloy undergoes microstructural changes, thereby achieving excellent negative thermal expansion performance. By adjusting the thermomechanical cyclic training parameters, the present invention regulates the negative thermal expansion coefficient of the material to meet the needs of different application scenarios. The preparation process of the present invention is simple, efficient, and easy to implement on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is an overall flow chart of an embodiment of the present invention;

[0039] Figure 2 1 is a thermal expansion test curve of thermomechanical cycle training with different training loads according to Example 1 of the present invention;

[0040] Figure 3 1 is a thermal expansion test curve of thermomechanical cycle training with different training times according to Example 2 of the present invention;

[0041] Figure 4 This is a thermal expansion test curve of thermomechanical cycle training at different training temperatures in Example 3 of the present invention. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0043] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be noted that the terms "first", "second" and "third" are only used for descriptive purposes and should not be understood as indicating or implying relative importance.

[0045] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] Example

[0047] A method for preparing an alloy with adjustable expansion coefficient, Figure 1 The overall preparation method flow chart of one embodiment of the present invention is shown as follows: Figure 1 Shown, including:

[0048] Step 100: preparing raw materials according to the atomic percentage of the alloy; the alloy includes titanium and niobium, and the atomic percentage of titanium and niobium in the alloy satisfies the following ratio: titanium:niobium = 3:1;

[0049] Step 200: placing the prepared raw materials into an arc melting furnace for repeated melting to obtain a first material, including:

[0050] The prepared raw materials are placed in the arc melting furnace and vacuumed to a preset vacuum degree, which is less than or equal to 4.5×10 -3 Pa;

[0051] Fill the chamber with argon gas to a preset pressure of 0.4×10 5 Pa~0.6×10 5 Pa;

[0052] Repeated smelting is performed, wherein the smelting temperature is 2500° C. to 2900° C. and the number of smelting is greater than or equal to 5 times;

[0053] Step 300: hot-rolling the first material into a plate, and then performing a solution treatment to obtain a second material, including:

[0054] The hot rolling temperature of the first material is 800°C to 900°C;

[0055] encapsulating the hot-rolled first material in a quartz tube for solution treatment;

[0056] The vacuum degree in the packaged quartz tube is less than or equal to 1×10 -4 Pa, the temperature of the solution treatment is 1100°C, and the solution treatment time is greater than or equal to 24h;

[0057] Step 400: performing a cold rolling process on the second material to obtain a third material, including:

[0058] The deformation amount of the cold rolling process is 90%;

[0059] cutting the second material subjected to the cold rolling process into a dog bone shape to obtain a third material;

[0060] Step 500: performing thermomechanical cycle training on the third material to obtain an alloy, comprising:

[0061] heating the third material to a preset temperature under a preset training load;

[0062] applying an axial force in a rolling direction to the third material in a heated state to stretch it;

[0063] cooling the third material in a stretched state;

[0064] After the temperature drops to room temperature, unload the axial force;

[0065] Repeat step 500 to a preset number of training times to obtain an alloy.

[0066] Furthermore, in this embodiment, when the preset training load is 300 MPa and 450 MPa, the preset temperatures are 50°C, 100°C, and 150°C, and the preset training times are 5 and 10, respectively, the prepared alloy has a strength of -10.1×10 -6 K -1 ~-40.6×10 -6 K -1 Reversible negative thermal expansion coefficient.

[0067] Furthermore, in this embodiment, when the preset training load is 300MPa and 450MPa, the preset temperatures are 50℃, 100℃, and 150℃, and the preset training times are 5 and 10, respectively, the prepared alloy has a -87×10 -6 K -1 ~-216.2×10 -6 K -1 Adjustable negative thermal expansion coefficient.

[0068] An alloy with adjustable expansion coefficient is prepared by the above preparation method, wherein the alloy has an expansion coefficient of -10.1×10 -6 K -1 ~-40.6×10 -6 K -1 The alloy has a reversible negative thermal expansion coefficient of -87×10 -6 K -1 ~-216.2×10 -6 K -1 Adjustable negative thermal expansion coefficient.

[0069] The present invention achieves a controllable, reversible negative thermal expansion coefficient and an ultra-large negative thermal expansion coefficient through thermomechanical cyclic training of the prepared alloy. By controlling key parameters such as temperature and pressure during thermomechanical cyclic training, the alloy undergoes microstructural changes, thereby achieving excellent negative thermal expansion performance. By adjusting the thermomechanical cyclic training parameters, the present invention regulates the negative thermal expansion coefficient of the material to meet the needs of different application scenarios. The preparation process of the present invention is simple, efficient, and easy to implement on a large scale.

[0070] Example 1

[0071] Ti of thermomechanical cycling training with different training loads 75 Nb 25 alloy;

[0072] The preparation method of the alloy with adjustable expansion coefficient in this embodiment is as follows: 75 Nb 25 The raw materials were prepared by atomic stoichiometric ratio, and Ti and Nb single-element raw materials with purity greater than 99.99% were placed in an arc melting furnace and vacuumed to 4.5×10 - 3 Pa below, when filled with argon gas at 0.4×10 5 Pa under the conditions of melting to obtain ingots, the melting temperature is 2500 ℃, and the ingots are repeatedly melted 6 times to obtain homogeneous ingots, and the ingots are hot rolled into plates at a temperature of 800 ℃, and then the plates are packaged in a vacuum chamber with a degree of vacuum of 1×10 -4 The plate was solution treated at 1100°C in a Pa quartz tube for 25 hours. The plate was cold rolled in the same direction at room temperature with a rolling deformation of 90%. The plate was cut into a dog-bone shape with a length of 20 mm and a width of 3 mm by wire electrospark cutting to obtain a third material. The third material obtained at this time is Sample 1 of the first embodiment. A universal testing machine was then used to fix the third material on a fixture and place the third material in an incubator for thermomechanical cycle training to obtain Samples 2 and 3 of the first embodiment.

[0073] The thermomechanical cycle training steps of the sample 2 of the first embodiment are divided into the following steps:

[0074] (1) heating the third material to 100° C.;

[0075] (2) Applying 300 MPa axial force for stretching at 100°C;

[0076] (3) Keeping the sample in a stretched state, cool the sample to room temperature;

[0077] (4) After the sample temperature drops to room temperature, unload the axial force;

[0078] (5) Repeat steps (1) to (4) 5 times.

[0079] The thermomechanical cycle training steps of the sample 3 of the first embodiment are divided into the following steps:

[0080] (1) heating the third material to 100° C.;

[0081] (2) Applying 450 MPa axial force for stretching at 100°C;

[0082] (3) keeping the third material in a stretched state, and cooling the third material to room temperature;

[0083] (4) After the temperature of the third material drops to room temperature, the axial force is unloaded;

[0084] (5) Repeat steps (1) to (4) 5 times.

[0085] Figure 2 The thermal expansion test curves of the thermomechanical cycle training with different training loads in Example 1 of the present invention are shown below. The thermal expansion coefficients of samples 1, 2, and 3 of the first embodiment were tested. Figure 2 The test results in (a)(b)(c). Figure 2 As can be seen from (a), the negative thermal expansion is completely reversible in the first and second temperature rise and fall cycles (-40 to 125 °C), and the average linear expansion coefficient at -40 to 60 °C is -10.1×10 -6 K -1 In the third temperature rise and fall cycle (-40~400℃), the maximum negative thermal expansion coefficient can be obtained, and the average linear expansion coefficient at 125~225℃ is -87×10 -6 K -1 .from Figure 2 As can be seen from (b), after thermomechanical cycle training, the average linear expansion coefficient at -40 to 60 ° C is -29.5×10 -6 K -1 The average linear expansion coefficient at 125-225°C is -166.5×10 -6 K -1 , its reversible negative thermal expansion coefficient and maximum negative thermal expansion coefficient values are increased compared with sample 1 without thermomechanical training. Figure 2 (c) can be obtained, compared with Figure 3 (b) After increasing the training load, sample 3 experienced a 0.5% strain contraction after the first test cycle, and the average linear expansion coefficient at -40 to 60 ° C was -10.6×10 -6 K -1 The average linear expansion coefficient at 125-225°C is -90×10 -6 K -1 Its reversible negative thermal expansion coefficient and maximum negative thermal expansion coefficient values are basically unchanged compared with sample 1 without thermomechanical training. The results show that the training load of 300MPa is the optimal thermomechanical training load.

[0086] Example 2

[0087] Ti of thermomechanical cycling training with different training times 75 Nb 25 alloy;

[0088] The preparation method of the alloy with adjustable expansion coefficient in this embodiment is as follows: 75 Nb 25 The raw materials were prepared by atomic stoichiometric ratio, and Ti and Nb single-element raw materials with purity greater than 99.99% were placed in an arc melting furnace and vacuumed to 4.5×10 - 3 Pa below, when filled with argon gas to 0.5×10 5 Pa, the ingot was melted and repeatedly melted 5 times to obtain a homogeneous ingot. The ingot was hot rolled into a plate at a temperature of 850 ° C, and then the plate was packaged in a vacuum chamber with a degree of vacuum of 1×10 -4 The plate was solution treated at 1100°C in a Pa quartz tube for 24 hours. The plate was cold rolled in the same direction at room temperature with a rolling deformation of 90%. The third material was stretched into a dog-bone shape with a length of 20 mm and a width of 3 mm by wire electrospark cutting to obtain Sample 1 of the second embodiment. The third material was then fixed on a fixture using a universal testing machine and placed in an incubator for thermomechanical cycle training to obtain Samples 2 and 3 of the second embodiment.

[0089] The thermomechanical cycle training steps of Sample 2 of the second embodiment are divided into the following steps:

[0090] (1) heating the third material to 100° C.

[0091] (2) Applying 300 MPa axial force for stretching at 100°C;

[0092] (3) keeping the third material in a stretched state, and cooling the third material to room temperature;

[0093] (4) After the temperature of the third material drops to room temperature, the axial force is unloaded;

[0094] (5) Repeat steps (1) to (4) 5 times.

[0095] The thermomechanical cycle training steps of Sample 3 of the second embodiment are divided into the following steps:

[0096] (1) heating the third material to 100° C.;

[0097] (2) Applying 300 MPa axial force for stretching at 100°C;

[0098] (3) keeping the third material in a stretched state, and cooling the third material to room temperature;

[0099] (4) After the sample temperature drops to room temperature, unload the axial force;

[0100] (5) Repeat steps (1) to (4) 10 times.

[0101] The thermal expansion coefficients of samples 1, 2 and 3 of the second embodiment were tested, and the following results were obtained: Figure 3 The test results in (a)(b)(c). Figure 3 As can be seen from (a), the negative thermal expansion is completely reversible in the first and second temperature rise and fall cycles (-40 to 125 °C), and the average linear expansion coefficient at -40 to 60 °C is -10.1×10 -6 K -1 In the third temperature rise and fall cycle (-40~400℃), the maximum negative thermal expansion coefficient can be obtained, and the average linear expansion coefficient at 125~225℃ is -87×10 -6 K -1 .from Figure 3 As can be seen from (b), after thermomechanical cycle training, the average linear expansion coefficient at -40 to 60 ° C is -29.5×10 -6 K -1 The average linear expansion coefficient at 125-225°C is -166.5×10 -6 K -1 , its reversible negative thermal expansion coefficient and maximum negative thermal expansion coefficient values are increased compared with sample 1 without thermomechanical training. Figure 3 (c) can be obtained, compared with Figure 3 (b) After increasing the number of training times, the average linear expansion coefficient at -40 to 60°C is -20.8×10 -6 K -1 The average linear expansion coefficient at 125-225°C is -124.4×10 -6 K -1 Its reversible negative thermal expansion coefficient and maximum negative thermal expansion coefficient values are both increased compared with sample 1 without thermomechanical training, but are reduced compared with the thermal expansion coefficient of sample 2. The results show that 5 training times is the optimal number of thermomechanical training times.

[0102] Example 3

[0103] Ti of thermomechanical cycling training at different training temperatures 75 Nb 25 alloy;

[0104] The preparation method of the alloy with adjustable expansion coefficient in this embodiment is as follows: 75 Nb 25 The raw materials were prepared by atomic stoichiometric ratio, and Ti and Nb single-element raw materials with purity greater than 99.99% were placed in an arc melting furnace and vacuumed to 4.5×10 - 3Pa below, when filled with argon gas at 0.6×10 5 Pa under the conditions of melting to obtain ingots, the temperature is 2900 ℃, and the ingots are repeatedly melted 5 times to obtain homogeneous ingots, and the ingots are hot rolled into plates at a temperature of 900 ℃, and then the plates are packaged in a vacuum chamber with a degree of vacuum of 1×10 -4 The plate was solution treated at 1100°C in a Pa quartz tube for 24 hours, and then cold rolled in the same direction at room temperature with a rolling deformation of 90%. The third material was stretched into a dog-bone shape with a length of 20 mm and a width of 3 mm by electric spark wire cutting to obtain sample 1 of the third embodiment. Subsequently, a universal testing machine was used to fix the third material on a fixture, and the third material was placed in an incubator for thermomechanical cycle training to obtain samples 2, 3 and 4 of the third embodiment.

[0105] The thermomechanical cycle training steps of Sample 2 of the third embodiment are divided into the following steps:

[0106] (1) heating the third material to 50° C.;

[0107] (2) Applying 300 MPa axial force for stretching at 100°C;

[0108] (3) keeping the third material in a stretched state, and cooling the third material to room temperature;

[0109] (4) After the sample temperature drops to room temperature, unload the axial force;

[0110] (5) Repeat steps (1) to (4) 5 times.

[0111] The thermomechanical cycle training steps of Sample 3 of the third embodiment are divided into the following steps:

[0112] (1) heating the third material to 100° C.;

[0113] (2) Applying 300 MPa axial force for stretching at 100°C;

[0114] (3) keeping the third material in a stretched state, and cooling the third material to room temperature;

[0115] (4) After the temperature of the third material drops to room temperature, the axial force is unloaded;

[0116] (5) Repeat steps (1) to (4) 5 times.

[0117] The thermomechanical cycle training steps of Sample 4 of the third embodiment are divided into the following steps:

[0118] (1) heating the third material to 150° C.;

[0119] (2) Applying 300 MPa axial force for stretching at 100°C;

[0120] (3) keeping the third material in a stretched state, and cooling the third material to room temperature;

[0121] (4) After the temperature of the third material drops to room temperature, the axial force is unloaded;

[0122] (5) Repeat steps (1) to (4) 5 times.

[0123] The thermal expansion coefficients of samples 1, 2, 3 and 4 of the third embodiment were tested, and the following results were obtained: Figure 4 The test results in (a)(b)(c)(d). Figure 4 As can be seen from (a), the negative thermal expansion is completely reversible in the first and second temperature rise and fall cycles (-40 to 125 °C), and the average linear expansion coefficient at -40 to 60 °C is -10.1×10 -6 K -1 In the third temperature rise and fall cycle (-40~400℃), the maximum negative thermal expansion coefficient can be obtained, and the average linear expansion coefficient at 125~225℃ is -87×10 -6 K -1 .from Figure 4 As can be seen from (b), after thermomechanical cycle training, the average linear expansion coefficient at -40 to 60 ° C is -19.1×10 -6 K -1 The average linear expansion coefficient at 125-225°C is -216.2×10 -6 K -1 .from Figure 4 From (c), we can see that the average linear expansion coefficient at -40 to 60°C is -29.5×10 -6 K -1 The average linear expansion coefficient at 125-225°C is -166.5×10 -6 K -1 ,from Figure 4 As can be seen from (d), the average linear expansion coefficient at -40 to 60°C is -40.6×10 -6 K -1 The average linear expansion coefficient at 125-225°C is -143×10 -6 K -1 It can be seen that the three different thermomechanical training temperatures can increase the reversible negative thermal expansion coefficient and the maximum negative thermal expansion coefficient compared with sample 1 without thermomechanical training, but the maximum negative thermal expansion coefficient of sample 2 with a lower training temperature is the largest, and the reversible negative thermal expansion coefficient of sample 4 with a higher training temperature is the largest.

[0124] The present invention is to prepare Ti 75 Nb 25 The alloy was subjected to variable parameter thermomechanical cyclic training to obtain a controllable reversible negative thermal expansion coefficient and an ultra-large negative thermal expansion coefficient. In particular, for the sample with a training temperature of 50°C, a training load of 300 MPa, and 5 training times, the maximum negative thermal expansion coefficient reached was -216.2×10 -6 K -1 For the sample with a training temperature of 150°C, a training load of 300 MPa, and 5 training times, the reversible negative thermal expansion coefficient that can be achieved is -40.6×10 -6 K -1 , and obtained extremely excellent negative thermal expansion performance. In addition, its preparation process is simple, has strong practical application value, and can be produced on a large scale.

[0125] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

[0126] The present invention has been described above with reference to the embodiments thereof. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Those skilled in the art may make various substitutions and modifications without departing from the scope of the present invention, and such substitutions and modifications are intended to fall within the scope of the present invention.

[0127] Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

[0128] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing an alloy with adjustable expansion coefficient, characterized in that: include: Step 100: preparing raw materials according to the atomic percentage of the alloy, wherein the alloy includes titanium and niobium, and the atomic percentage of titanium and niobium in the alloy satisfies the following ratio: titanium:niobium = 3:1; Step 200: placing the prepared raw materials into an arc melting furnace for repeated melting to obtain a first material; Step 300: hot-rolling the first material into a plate, and then performing a solution treatment to obtain a second material; Step 400: performing a cold rolling process on the second material to obtain a third material; Step 500: performing thermomechanical cycle training on the third material to obtain an alloy; comprising: heating the third material to a preset temperature under a preset training load, wherein the preset training load includes 300 MPa and 450 MPa, and the preset temperature includes 50° C., 100° C., and 150° C.; applying an axial force in a rolling direction to the third material in a heated state to stretch it; cooling the third material in a stretched state; After the temperature drops to room temperature, unload the axial force; Repeat step 500 for a preset number of training times to obtain an alloy, wherein the preset number of training times includes 5 times and 10 times.

2. The preparation method according to claim 1, characterized in that The step 200 of placing the prepared raw materials into an arc melting furnace for repeated melting to obtain a first material includes: The prepared raw materials are placed in the arc melting furnace and vacuumed to a preset vacuum degree, which is less than or equal to 4.5×10 -3 Pa; Fill the chamber with argon gas to a preset pressure of 0.4×10 5 Pa~0.6×10 5 Pa; Repeated smelting is performed, the smelting temperature is: 2500℃~2900℃; the number of smelting times is greater than or equal to 5 times.

3. The preparation method according to claim 1, characterized in that The step 300: hot-rolling the first material into a plate, and then performing a solution treatment to obtain a second material, includes: The hot rolling temperature of the first material is 800°C to 900°C; encapsulating the hot-rolled first material in a quartz tube for solution treatment; The vacuum degree in the packaged quartz tube is less than or equal to 1×10 -4 Pa, the temperature of the solution treatment is 1100°C, and the time of the solution treatment is greater than or equal to 24h.

4. The preparation method according to claim 1, characterized in that The step 400 of cold-rolling the second material to obtain a third material includes: The deformation amount of the cold rolling process is 90%; The second material that has undergone the cold rolling process is cut into a dog bone shape to obtain a third material.

5. The preparation method according to claim 1, characterized in that The prepared alloy has a -10.1×10 -6 K -1 ~-40.6×10 -6 K -1 Reversible negative thermal expansion coefficient.

6. The preparation method according to claim 1, characterized in that The prepared alloy has a -87×10 -6 K -1 ~-216.2×10 -6 K -1 Adjustable negative thermal expansion coefficient.

7. An alloy with adjustable expansion coefficient, characterized in that: The alloy is prepared by the preparation method according to any one of claims 1 to 6.

8. The alloy according to claim 7, characterized in that The alloy has a -10.1×10 -6 K -1 ~-40.6×10 -6 K -1 The alloy has a reversible negative thermal expansion coefficient of -87×10 -6 K -1 ~-216.2×10 -6 K -1 Adjustable negative thermal expansion coefficient.

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