Laves phase intermetallic compound with room-temperature negative expansion and preparation and application of Laves phase intermetallic compound

Abstract

The invention discloses a Laves phase intermetallic compound with room-temperature negative expansion as well as preparation and application of the Laves phase intermetallic compound. The chemical formula of the Laves phase intermetallic compound with the room-temperature negative expansion is Hfx and Taa-xNbbFe2, x is larger than or equal to 0.8525 and smaller than or equal to 0.875, a is larger than or equal to 0.94 and smaller than or equal to 0.95, a is larger than or equal to 0.05 and smaller than or equal to 0.06, the crystal structure is a hexagonal system, the space group is P63 / mmc, the negative expansion characteristic is shown in the 219K-325K temperature interval, and the linear expansion coefficient alpha l is smaller than or equal to-23 * 10 <-6 > K <-1 >. And the negative expansion temperature zone is effectively widened. The synthesis method disclosed by the invention is simple and easy to realize, and can be compounded with a positive expansion material to realize room-temperature zero thermal expansion of the composite material, so that the composite material has potential room-temperature application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and in particular relates to a Laves phase intermetallic compound with negative expansion at room temperature, and its preparation and application. Background Art

[0002] In the field of materials science, conventional materials generally follow the principle of thermal expansion and contraction, which can cause problems such as dimensional mismatch and precision loss. The emergence of negative expansion materials has provided a new direction for solving the thermal mismatch problem. Controlling or compounding zero-expansion materials is expected to solve this problem. With the rapid development of industries such as aerospace, electronic information, and precision instruments, dimensional changes caused by thermal expansion of materials when equipment operates in extreme temperature environments can cause component deformation, performance degradation, and even failure. For example, thermal stress cracking occurs between chips and substrates in electronic packaging due to mismatched thermal expansion coefficients, and fatigue damage occurs in aircraft engine components due to thermal cycling.

[0003] Due to their unique crystal structure, negative expansion intermetallic compounds exhibit negative thermal expansion properties due to their lattice contraction when the temperature rises. This property effectively offsets the positive thermal expansion of other materials, enabling precise control of the thermal expansion coefficient. However, these materials currently face technical bottlenecks such as brittleness, high preparation costs, a temperature range limited to low temperatures, and insufficient long-term stability, which restrict their large-scale application. There is an urgent need to develop new composition designs and preparation processes to fully leverage the performance advantages of negative expansion intermetallic compounds and meet the urgent demand for thermally stable materials in high-end precision equipment. Summary of the Invention

[0004] The present invention discloses a Laves phase intermetallic compound with negative expansion at room temperature, and its preparation and application, so as to solve any of the above and other potential problems in the prior art.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: a room temperature negative expansion Laves phase intermetallic compound, the chemical formula of the room temperature negative expansion Laves phase intermetallic compound is: Hf x ,Ta a-x Nb b Fe2, wherein 0.8525≤x≤0.875, 0.94≤a≤0.95, 0.05≤b≤0.06, and the Laves phase intermetallic compound with negative room temperature expansion has a hexagonal crystal structure, a space group of P63 / mmc, and exhibits negative expansion characteristics in the temperature range of 219K~325K.

[0006] Furthermore, the linear expansion coefficient α of the Laves phase intermetallic compound having negative expansion at room temperature is l ≤-23×10 - 6 K -1, with ferromagnetism and obvious preferred orientation.

[0007] Furthermore, the chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is: Hf 0.875 Nb 0.05 Ta 0.075 Fe2 exhibits negative expansion characteristics in the temperature range of 265~325K, and the linear expansion coefficient is α l -27×10 - 6 K -1 .

[0008] Furthermore, the chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is Hf 0.8625 Nb 0.05 Ta 0.0875 Fe2 exhibits negative expansion characteristics in the temperature range of 252~306K, and the linear expansion coefficient is α l -31×10 - 6 K -1 .

[0009] Furthermore, the chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is Hf 0.8525 Nb 0.06 Ta 0.0875 Fe2 exhibits negative expansion characteristics in the temperature range of 219K~290K, and the linear expansion coefficient is α l -27×10 -6 K -1 .

[0010] Furthermore, the chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is Hf 0.865 Nb 0.06 Ta 0.075 Fe2 exhibits negative expansion characteristics in the temperature range of 248K~313K, and the linear expansion coefficient is α l -23×10 - 6 K -1 .

[0011] Another object of the present invention is to provide a method for preparing the above-mentioned Laves phase intermetallic compound having negative room temperature expansion, the method specifically comprising the following steps: S1) According to the room temperature negative expansion Laves phase intermetallic compound Hf x ,Ta a-x Nb b Fe2 prepares the corresponding raw materials; S2) mixing the raw materials prepared in S1); S3) melting the mixed raw materials in S2) for no less than four times in an electric arc furnace; S4) annealing the uniformly melted sample under a protective atmosphere; S5) After annealing, the mixture is quenched in ice water to obtain a Laves phase intermetallic compound with negative expansion at room temperature.

[0012] Furthermore, the purity of the Hf, Ta, Nb, and Fe metal raw materials in S1) is >99.9%.

[0013] Furthermore, the specific annealing process in S4) is: annealing at a temperature not lower than 1200° C. for at least 24 hours; the protective atmosphere is an inert gas.

[0014] The above-mentioned Laves phase intermetallic compound with negative room temperature expansion is used in the fields of electronic packaging and integrated circuits, precision optics and aerospace devices.

[0015] The technical effect of the present invention is as follows: Due to the adoption of the above technical solution, the present invention introduces Ta element into Hf-Fe2Laves metal to enhance its negative expansion, and introduces Nb element to effectively broaden its negative expansion temperature range. It exhibits low expansion characteristics in the temperature range of 219~325K, has excellent thermal stability and high precision, and its notable feature is that its shape and size can shrink with the increase of temperature in a specific temperature range, that is, negative thermal expansion characteristics, linear expansion coefficient (α l ) are -31×10 -6 K -1 、-27×10 -6 K -1 、-27×10 -6 K -1 、-23×10 -6 K -1 , and has both ferromagnetism and obvious preferred orientation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 The X-ray diffraction pattern of the Nb and Ta doped Laves phase intermetallic compound prepared by the method of the present invention at 300K; Figure 2 This is an embodiment of the present invention Hf 0.875 Nb 0.05 Ta 0.075Synchrotron X-ray diffraction structure of Fe2 compound powder at 300K; Figure 3 This is an embodiment of the present invention Hf 0.875 Nb 0.05 Ta 0.075 Electron backscatter diffraction pattern of Fe2 intermetallic compound; Figure 4 This is an embodiment of the present invention Hf 0.875 Nb 0.05 Ta 0.075 Magnetothermal curve of Fe2 intermetallic compound; Figure 5 This is an embodiment of the present invention Hf 0.875 Nb 0.05 Ta 0.075 Temperature-dependent magnetization curve of Fe2 intermetallic compound; Figure 6 It is a linear expansion curve diagram of Nb and Ta doped Laves phase intermetallic compound prepared by the method of the present invention. DETAILED DESCRIPTION

[0018] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0019] It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The singular forms "a", "an", "the" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0021] The present invention provides a Laves phase intermetallic compound with negative expansion at room temperature. The chemical formula of the Laves phase intermetallic compound with negative expansion at room temperature is: Hf x ,Ta a-x Nb b Fe2, wherein 0.8525≤x≤0.875, 0.94≤a≤0.95, 0.05≤b≤0.06, and the Laves phase intermetallic compound with negative room temperature expansion has a hexagonal crystal structure and a space group of P63 / mmc, and exhibits negative expansion characteristics in the temperature range of 219K~325K.

[0022] The preparation method comprises the following steps: S1) According to the room temperature negative expansion Laves phase intermetallic compound Hf x ,Ta a-x Nb b Fe2 phase preparation corresponding raw materials S2) mixing the raw materials prepared in S1); S3) melting the mixed raw materials in an electric arc furnace for not less than four times; S4) annealing the uniformly melted sample under a protective atmosphere at a temperature not lower than 1200° C. for at least 24 hours; S5) After annealing, a Laves phase intermetallic compound with negative expansion at room temperature is obtained.

[0023] The protective atmosphere is an inert atmosphere.

[0024] Example 1: Preparation of the present invention is the component Hf 0.8625 Nb 0.05 Ta 0.0875 The Fe2 intermetallic compound blocks with negative room temperature expansion Laves phase were synthesized by electric arc furnace melting method: The specific operation is as follows: Weigh 5 g of Hf, Nb, Ta, and Fe raw materials with a molar ratio of 0.8625:0.05:0.0875:2. Mix the raw materials in an electric arc furnace and evacuate the furnace to a vacuum degree of <2×10 -3 Pa), and then repeatedly melted twice under the protection of inert gas Ar, each time for 2 minutes. The obtained sample was placed in an inert atmosphere and annealed at a temperature of 1200℃ for 24 hours. X-ray diffraction results show that the obtained product is Hf 0.8625 Nb 0.05 Ta 0.0875 Fe2 pure phase, without other impurities, its hexagonal phase compound also shows obvious preferential orientation, magnetic test shows the existence of ferromagnetism, the magnetization intensity value at 200K is 48.2emu / g, and it shows negative expansion characteristics in the temperature range of 252~306K, and the linear expansion coefficient α l -31×10 -6 K -1 .

[0025] Example 2: Preparation of the present invention is the component Hf 0.875 Nb 0.05 Ta 0.075 The Fe2 intermetallic compound blocks with negative room temperature expansion Laves phase were synthesized by electric arc furnace melting method: The specific operation is as follows: Weigh 5 g of Hf, Nb, Ta, and Fe raw materials with a molar ratio of 0.875:0.05:0.075:2. Mix the raw materials in an electric arc furnace and evacuate the furnace to a vacuum degree of <2×10 -3 Pa), and then repeatedly melted under the protection of inert gas Ar for 3 times, each time for 2 minutes. The obtained sample was placed in an inert atmosphere and annealed at a temperature of 1220℃ for 24 hours. X-ray diffraction results showed that the obtained product was Hf 0.875 Nb 0.05 Ta 0.075 Fe2 pure phase, without other impurities, such as Figure 1 and Figure 2 As shown, its hexagonal phase compound also shows obvious preferred orientation, such as Figure 3 As shown, magnetic tests show the presence of ferromagnetism, such as Figure 4 As shown in the figure, it shows that its magnetic transition temperature is 310K, the magnetization intensity value at 200K is 54.7emu / g, and it shows negative expansion characteristics in the temperature range of 265~325K. The linear expansion coefficient α l -27×10 -6 K -1 .

[0026] Example 3: Preparation of the present invention is the component Hf 0.8525 Nb 0.06 Ta 0.0875 The Fe2 intermetallic compound blocks with negative room temperature expansion Laves phase were synthesized by electric arc furnace melting method: The specific operation is as follows: Weigh 5 g of Hf, Nb, Ta, and Fe raw materials with a molar ratio of 0.8525:0.06:0.0875:2. Mix the raw materials in an electric arc furnace and evacuate the furnace to a vacuum degree of <2×10 -3 Pa), and then repeatedly melted twice under the protection of inert gas Ar, each time for 2 minutes. The obtained sample was placed in an inert atmosphere and annealed at a temperature of 1210 ° C for 36 hours. X-ray diffraction results show that the obtained product is Hf 0.8525 Nb 0.06 Ta 0.0875 Fe2 is pure phase, without other impurities. Its hexagonal phase compound also shows obvious preferential orientation. Magnetic tests show the presence of ferromagnetism. The magnetization intensity value at 200K is 48.7emu / g. It exhibits negative expansion characteristics in the temperature range of 219K~290K. The linear expansion coefficient α l -27×10 -6 K -1 .

[0027] Example 4: Preparation of the present invention is the component Hf 0.865 Nb 0.06 Ta 0.075 The Fe2 intermetallic compound blocks with negative room temperature expansion Laves phase were synthesized by electric arc furnace melting method: The specific operation is as follows: Weigh 5 g of Hf, Nb, Ta, and Fe raw materials with a molar ratio of 0.865:0.06:0.075:2. Mix the raw materials in an electric arc furnace and evacuate the furnace to a vacuum degree of <2×10 -3 Pa), and then repeatedly melted under the protection of inert gas Ar for 4 times, each time for 1 minute. The obtained sample was placed in an inert atmosphere and annealed at a temperature of 1250℃ for 48 hours. X-ray diffraction results show that the obtained product is Hf 0.865 Nb 0.06 Ta 0.075 Fe2 pure phase, without other impurities, its hexagonal phase compound also shows obvious preferential orientation, magnetic test shows the existence of ferromagnetism, the magnetization intensity value at 200K is 49.7emu / g, and it shows negative expansion characteristics in the temperature range of 248K~313K, and the linear expansion coefficient α l -23×10 -6 K -1 .

[0028] Example 5: Preparation of the present invention is the component Hf 0.865 Nb 0.055 Ta 0.075 The Fe2 intermetallic compound blocks with negative room temperature expansion Laves phase were synthesized by electric arc furnace melting method: The specific operation is as follows: Weigh 5 g of Hf, Nb, Ta, and Fe raw materials with a molar ratio of 0.86:0.055:0.095:2. Mix the raw materials in an electric arc furnace and evacuate the furnace to a vacuum degree of <2×10 -3 Pa), and then repeatedly melted under the protection of inert gas Ar for 4 times, each time for 1.5 minutes. The obtained sample was placed in an inert atmosphere and annealed at a temperature of 1260℃ for 46 hours. X-ray diffraction results show that the obtained product is Hf 0.86 Nb 0.055 Ta 0.095 Fe2 is pure phase, without other impurities, and its hexagonal phase compound also shows obvious preferred orientation, and magnetic tests show the presence of ferromagnetism.

[0029] The Laves phase intermetallic compound Hf with negative room temperature expansion obtained in Examples 1, 2, 3, and 4 0.8625 Nb 0.05 Ta0.0875 Fe2、Hf 0.875 Nb 0.05 Ta 0.075 Fe2、Hf 0.8525 Nb 0.06 Ta 0.0875 Fe2、Hf 0.865 Nb 0.06 Ta 0.075 Fe2 measured linear expansion, which showed negative expansion characteristics in the temperature ranges of 252~306K, 265~325K, 219K~290K, and 248K~313K, respectively. The thermal expansion coefficient was -31×10 -6 K -1 <α l <-23×10 -6 K -1 ,like Figure 6 As shown, the hexagonal phase compound also shows obvious preferred orientation, and the magnetic test shows the presence of ferromagnetism. The magnetization intensity values of the 200K curve at 30kOe are 48.2emu / g, 54.7emu / g, 48.7emu / g, and 49.7emu / g, respectively. Figure 5 shown.

[0030] The above describes in detail the room-temperature negative expansion Laves-phase intermetallic compounds, their preparation, and applications, provided in the examples of this application. The description of the above examples is intended only to facilitate understanding of the methods and core concepts of this application. Furthermore, those skilled in the art will appreciate that variations in the specific implementation methods and scope of application are possible based on the concepts of this application. Therefore, this description should not be construed as limiting this application.

[0031] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" and "comprising" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problems within a certain error range and basically achieve the technical effects. The subsequent description in the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be as defined in the attached claims.

[0032] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.

[0033] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0034] The above description shows and describes several preferred embodiments of the present application. However, as previously mentioned, it should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application can be used in various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein through the above teachings or technology or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present application should be protected by the claims appended hereto.

Claims

1. A Laves phase intermetallic compound with negative room temperature expansion, characterized in that: The chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is: Hf x ,Ta a-x Nb b Fe2, wherein 0.8525≤x≤0.875, 0.94≤a≤0.95, 0.05≤b≤0.06, and the Laves phase intermetallic compound with negative room temperature expansion has a hexagonal crystal structure, a space group of P63 / mmc, and exhibits negative expansion characteristics in the temperature range of 219K~325K.

2. The Laves phase intermetallic compound with negative room temperature expansion according to claim 1, characterized in that: The linear expansion coefficient α of the Laves phase intermetallic compound having negative expansion at room temperature l ≤-23×10 -6 K -1 , with ferromagnetism and obvious preferred orientation.

3. The Laves phase intermetallic compound with negative room temperature expansion according to claim 1, characterized in that: The chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is: Hf 0.875 Nb 0.05 Ta 0.075 Fe2 exhibits negative expansion characteristics in the temperature range of 265~325K, and the linear expansion coefficient is α l -27×10 -6 K -1 .

4. The Laves phase intermetallic compound with negative room temperature expansion according to claim 1, characterized in that: The chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is Hf 0.8625 Nb 0.05 Ta 0.0875 Fe2 exhibits negative expansion characteristics in the temperature range of 252~306K, and the linear expansion coefficient is α l -31×10 -6 K -1 .

5. The Laves phase intermetallic compound with negative room temperature expansion according to claim 1, characterized in that: The chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is Hf 0.8525 Nb 0.06 Ta 0.0875 Fe2 exhibits negative expansion characteristics in the temperature range of 219K~290K, and the linear expansion coefficient is α l -27×10 -6 K -1 .

6. The Laves phase intermetallic compound with negative room temperature expansion according to claim 1, characterized in that: The chemical formula of the Laves phase intermetallic compound with negative room temperature expansion is Hf 0.865 Nb 0.06 Ta 0.075 Fe2 exhibits negative expansion characteristics in the temperature range of 248K~313K, and the linear expansion coefficient is α l -23×10 -6 K -1 .

7. A method for preparing a Laves phase intermetallic compound having negative room temperature expansion as claimed in any one of claims 1 to 6, characterized in that: The method specifically comprises the following steps: S1) According to the room temperature negative expansion Laves phase intermetallic compound Hf x ,Ta a-x Nb b Fe2 prepares the corresponding raw materials; S2) mixing the raw materials prepared in S1) to obtain a mixture; S3) melting the mixture obtained in S2) at least four times in an electric arc furnace to obtain a uniformly melted sample; S4) annealing the uniformly melted sample obtained in S3) under a protective atmosphere; S5) After the annealing, the sample is placed in ice water for quenching, thereby obtaining a Laves phase intermetallic compound with negative expansion at room temperature.

8. The method according to claim 7, characterized in that The purity of the Hf, Ta, Nb and Fe metal raw materials in S1) is >99.9%.

9. The method according to claim 7, characterized in that The specific annealing process in S4) is: annealing at a temperature not lower than 1200° C. for at least 24 hours; the protective atmosphere is an inert gas.

10. Application of the Laves phase intermetallic compound with negative room temperature expansion as claimed in any one of claims 1 to 6 in the fields of electronic packaging and integrated circuits, precision optics and aerospace devices.

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