Iron-manganese-aluminum-nickel-tantalum-based super-elastic polycrystalline alloy with wide temperature range and low elastic modulus and preparation method thereof

Abstract

The invention discloses an iron-manganese-aluminum-nickel-tantalum-based super-elastic polycrystalline alloy with a wide temperature range and a low elastic modulus and a preparation method of the iron-manganese-aluminum-nickel-tantalum-based super-elastic polycrystalline alloy. The preparation method of the iron-manganese-aluminum-nickel-tantalum-based super-elastic polycrystalline alloy with the wide temperature range and the low elastic modulus comprises the following steps that an iron source and a tantalum source are smelted at the temperature of 2300-3000 DEG C, an aluminum source, a nickel source and a manganese source are added after smelting, uniform mixing is conducted, alloy melt is obtained, the alloy melt is smelted at the temperature of 1500-1700 DEG C, furnace cooling is conducted, and a cast ingot is obtained; carrying out homogenization treatment on the cast ingot at 900-1100 DEG C, and carrying out furnace cooling to obtain a homogenized cast ingot; under the inert atmosphere, the homogenized cast ingot is subjected to solution treatment at the temperature of 950-1300 DEG C, water quenching is conducted, and the cast ingot subjected to solution treatment is obtained; and the cast ingot subjected to solution treatment is subjected to aging treatment at the temperature of 200-600 DEG C, water quenching is conducted, and the iron-manganese-aluminum-nickel-tantalum-based super-elastic polycrystalline alloy with the wide temperature range and the low elastic modulus is obtained. The manganese-aluminum-nickel-tantalum-based hyperelastic polycrystalline alloy has high hyperelasticity in a wide temperature range.

Description

Technical Field

[0001] The present invention belongs to the field of iron-based functional materials, and in particular relates to an iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus and a preparation method thereof. Background Art

[0002] Superelastic alloys belong to a type of shape memory alloys, which have both shape memory effect and superelastic properties. The shape memory effect is the recovery of deformation by temperature-induced martensitic reverse transformation. The superelastic property is the recovery of deformation by stress-induced martensitic reverse transformation. Therefore, superelastic alloys have a wide range of applications in many fields such as aerospace, electronic machinery and civil engineering.

[0003] Superelastic alloys are mainly divided into NiTi-based, Cu-based and Fe-based superelastic alloys. Among them, the most widely used NiTi-based superelastic alloy has poor machinability and high cost; the superelastic thermal stability of Cu-based superelastic alloys is low; while the iron-based superelastic alloy has good machinability and low cost, and has attracted extensive attention from researchers. Since the presence of a large number of grain boundaries in the polycrystalline state usually reduces the elastic limit of the matrix, the excellent strain recovery characteristics presented by the FeMnAlNi-based superelastic alloy are usually obtained in a single crystal or columnar crystal state, and the realization of the single crystal state is generally achieved through high-energy cyclic heat treatment, directional solidification, complex thermo-mechanical treatment or alloying treatment (adding alloying elements such as Ti, etc.) to improve the efficiency of single crystal preparation. The first two methods are complex and energy-intensive, while the latter will inhibit the precipitation of the γ phase, resulting in a significant increase in the tendency of intergranular fracture. In addition, obtaining stable high superelasticity in a wide temperature range is highly related to reducing the dependence of critical stress on temperature. Recently, some studies have reported that adding Cr to FeMnAlNi-based superelastic alloys can significantly reduce the temperature dependence of critical stress in a wide temperature range, but the addition of Cr inhibits grain growth and directly reduces the preparation efficiency of single crystals.

[0004] Adding V to FeMnAlNi-based superelastic alloy can significantly reduce quenching sensitivity, inhibit the precipitation process of non-transformed γ phase, and significantly reduce the tendency of intergranular fracture, but obtaining single crystals still relies on high-energy cyclic heat treatment or directional solidification methods, which are complex and energy-intensive. Adding Mo can significantly improve the preparation efficiency of single crystals, but at the same time inhibits the formation of γ phase and induces intergranular fracture.

[0005] In summary, the current FeMnAlNi-based alloy preparation process of single crystals with high superelasticity by cyclic heat treatment, directional solidification and thermo-mechanical treatment is complex and energy-consuming. The alloying treatment obtains high superelasticity and low temperature dependence, but it will increase the cracking tendency or reduce the efficiency of single crystal preparation. This also limits the mass production and wide application of such alloys in advanced industries in many fields. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide an iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus.

[0007] Another object of the present invention is to provide a method for preparing an iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus. The preparation method introduces tantalum (Ta) element into the prototype alloy FeMnAlNi series superelastic alloy to obtain an iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus.

[0008] The purpose of the present invention is achieved through the following technical solutions.

[0009] A superelastic polycrystalline iron-manganese-aluminum-nickel-tantalum alloy with a wide temperature range and low elastic modulus. a Mn b Al c Ni d Ta e , a+b+c+d+e=100%, a=40~50%, b=30~40%, c=13~17%, d=6~8%, e=0.05~4%.

[0010] In the above technical solution, the e is preferably 3%.

[0011] A method for preparing an iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus comprises the following steps:

[0012] Step 1), mixing an iron source and a tantalum source and smelting them at 2300-3000° C. for 3-5 minutes, adding an aluminum source, a nickel source and a manganese source after smelting and mixing them evenly to obtain an alloy melt, smelting the alloy melt at 1500-1700° C. for 5-10 minutes, and cooling the furnace to room temperature to obtain an ingot;

[0013] In step 1, the ratio of iron in the iron source, manganese in the manganese source, aluminum in the aluminum source, nickel in the nickel source and tantalum in the tantalum source is (40-50) in atomic percentage: (30-40) : (13-17) : (6-8) : (0.05-4) .

[0014] In step 1, the iron source is industrial pure iron, the tantalum source is electrolytic tantalum, the aluminum source is electrolytic aluminum, the nickel source is electrolytic nickel, and the manganese source is electrolytic manganese.

[0015] Step 2), homogenizing the ingot at 900-1100° C., and furnace cooling to room temperature to obtain a homogenized ingot;

[0016] In step 2, the homogenization time is 8 to 24 hours.

[0017] Step 3), in an inert atmosphere, solution treating the homogenized ingot at 950-1300° C. for 30-180 minutes, and quenching with water to room temperature to obtain a solution treated ingot;

[0018] In the step 3, the temperature of the solution treatment is preferably 1250-1300° C., and the time of the solution treatment is preferably 50-70 minutes.

[0019] Step 4), placing the solution treated ingot at 200-600° C. for aging treatment for 0.5-24 hours, and quenching with water to room temperature to obtain an iron-manganese-aluminum-nickel-tantalum based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus.

[0020] In the step 4, the temperature of the aging treatment is preferably 400 to 600° C., and the time of the aging treatment is preferably 3 to 15 hours.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The preparation method of the present invention can reduce the elastic modulus of the matrix in a wide temperature range by optimizing the alloy composition, improve the flexibility of the polycrystalline alloy while maintaining its superelasticity, reduce the cracking tendency of the alloy, and thus simplify the preparation and processing technology, and obtain the superelastic polycrystalline alloy only through the solid solution-aging heat treatment process. The preparation method and processing technology of the present invention are fully compatible with the steel industry. The manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy prepared by the preparation method has high superelasticity in a wide temperature range, and is expected to replace the expensive NiTi-based superelastic alloy, and be applied to the fields of automotive machinery, aerospace, and civil engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an orientation imaging diagram of backscattered electron diffraction of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5;

[0024] Figure 2 The inverse pole figure of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5;

[0025] Figure 3 The stress-strain curve of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5;

[0026] Figure 4 This is a storage modulus-temperature relationship curve of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0028] In the following examples, industrial pure iron (purity: 99.99%), electrolytic tantalum (purity: 99.95%), electrolytic aluminum (purity: 99.99%), electrolytic nickel (purity: 99.96%) and electrolytic manganese (purity: 99.8%) are all commercial metals purchased from Qingdao Aikotech Trading Co., Ltd.

[0029] Examples 1 to 5

[0030] A method for preparing an iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus comprises the following steps:

[0031] Step 1), mixing an iron source and a tantalum source and smelting them at 2980° C. for 4 minutes, adding an aluminum source, a nickel source and a manganese source after smelting and mixing them evenly to obtain an alloy melt, smelting the alloy melt at 1500° C. for 7 minutes, cooling the furnace to room temperature of 20 to 25° C., and obtaining an ingot, wherein the iron source is industrial pure iron, the tantalum source is electrolytic tantalum, the aluminum source is electrolytic aluminum, the nickel source is electrolytic nickel, and the manganese source is electrolytic manganese, and the ratio of iron in the iron source, manganese in the manganese source, aluminum in the aluminum source, nickel in the nickel source and tantalum in the tantalum source is W in terms of atomic percentage content;

[0032] Step 2), placing the ingot in a vacuum furnace, homogenizing it at 900° C. for 24 hours, and cooling the furnace to room temperature to obtain a homogenized ingot;

[0033] Step 3), placing the homogenized ingot in a quartz tube under an argon atmosphere, solution treating it at T1°C for H1 minute, and quenching it with water to room temperature to obtain a solution treated ingot;

[0034] Step 4), cut the solution treated ingot into strip samples (size: 20 mm×20 mm×100 mm), place them at T2°C for aging treatment for H2 hours, and water quench them to room temperature to obtain an iron-manganese-aluminum-nickel-tantalum based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus.

[0035] The W, T1, H1, T2 and H2 of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloys with a wide temperature range and low elastic modulus prepared in Examples 1 to 5 are shown in Table 1.

[0036] Table 1

[0037] Example W <![CDATA[T1℃]]> <![CDATA[H1 minute]]> <![CDATA[T2℃]]> <![CDATA[H2 hours]]> Example 1 43.5：35.15：14.2：7.1：0.05 1250℃ 60 minutes 500℃ 6 hours Example 2 43.2：35.3：14.2：7.2：0.1 1300℃ 120 minutes 600℃ 3 hours Example 3 42.6：35.2：14.1：7.1：1 1250℃ 120 minutes 400℃ 12 hours Example 4 41.5：35.2：14.1：7.2：2 1250℃ 120 minutes 600℃ 3 hours Example 5 40.5：35.1：14.1：7.3：3 1250℃ 60 minutes 400℃ 3 hours

[0038] Comparative Example 1

[0039] A preparation method of an iron-manganese-aluminum-nickel-tantalum-boron based alloy, see Xinyu Che, Deshan Sun, Yulin Chen, Zhizhong Dong. A novel Fe-Mn-Al-Ni-Ta-B superelastic polycrystalline alloy with high stability and low thermal hysteresis, Journal of Alloys and Compounds, 2024, 997 174954.

[0040] The orientation imaging of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 was performed by backscattered electron diffraction, and the orientation imaging diagram and inverse pole figure of the backscattered electron diffraction were obtained. The orientation imaging diagram is shown in FIG. Figure 1 As shown by Figure 1 It can be seen that Figure 1 The line in the middle is the grain boundary. There is no obvious γ phase on the grain boundary, indicating that there is almost no tendency of intergranular fracture. The inverse pole figure of the x-axis direction of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 is shown in FIG. Figure 2 As shown in "X1", the inverse pole figure in the y-axis direction is as follows Figure 2 As shown in "Y1", the inverse pole figure in the z-axis direction is as follows Figure 2 As shown in "Z1", Figure 2 It can be seen that the grain orientations in the directions of the three coordinate axes x, y and z are all different. The iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 has no specific grain orientation in the 001, 101 and 111 crystal plane indices, indicating that after solution-aging heat treatment, the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 is polycrystalline.

[0041] The iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloys with a wide temperature range and low elastic modulus prepared in Examples 1 to 5 and the iron-manganese-aluminum-nickel-tantalum-boron-based alloy prepared in Comparative Example 1 were cut into Φ4×6 mm cylinders (Φ represents the diameter) by a wire cutting machine, and compressed by a universal testing machine at room temperature of 25°C. After the compression strain reached 5%, the applied load was unloaded to obtain a stress-strain curve. The recoverable strains of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloys with a wide temperature range and low elastic modulus prepared in Examples 1 to 5 and the iron-manganese-aluminum-nickel-tantalum-boron-based alloy prepared in Comparative Example 1 are shown in Table 2. The stress-strain curve of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 is shown in Table 2. Figure 3 shown.

[0042] Table 2

[0043] Example Resilience Example 1 3.65％ Example 2 3.8％ Example 3 3.7％ Example 4 3.9％ Example 5 4.2％ Comparative Example 1 4.2％

[0044] Depend on Figure 3 It can be seen that the recovery strain of the iron-manganese, aluminum-nickel, tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 is 4.2%, indicating that the iron-manganese, aluminum-nickel, tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 has high superelastic properties and can maintain a certain elastic recovery ability within a larger strain range.

[0045] The iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 was subjected to dynamic thermomechanical testing according to the procedure to obtain a storage modulus-temperature relationship curve. The storage modulus in the wide temperature range was analyzed according to the storage modulus-temperature relationship curve, and the storage modulus under dynamic loading also reflects the change of the elastic modulus under different mechanical forms. The elastic modulus of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 was also determined. The storage modulus-temperature relationship curve is as shown in FIG. Figure 4 As shown by Figure 4 It can be known that the storage modulus of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 continues to decrease with the increase of temperature in the temperature range of 170K-620K. When the temperature is 298K, the storage modulus is 59GPa, which is lower than the storage modulus (62GPa) of the iron-manganese-aluminum-nickel-tantalum-boron-based alloy prepared in Comparative Example 1. Compared with the storage modulus of the iron-manganese-aluminum-nickel-tantalum-boron-based alloy prepared in Comparative Example 1, which is about 49GPa at 500K, the storage modulus of the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 is only about 49GPa at 600K and above, which is similar to NiTi alloy. It shows that the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 maintains high flexibility and high superelasticity in a wider temperature range, and can reduce the dependence on regulating the γ phase, thereby avoiding cracks.

[0046] Compared with Comparative Example 1, the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 does not require microalloying of the boron (B) element. By slightly increasing the content of the tantalum (Ta) element, the same recoverable strain and a lower elastic modulus in a wide temperature range can be obtained only through solid solution-aging heat treatment. Compared with the iron-manganese-aluminum-nickel-tantalum-based boron-based alloy prepared in Comparative Example 1, the iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus prepared in Example 5 has the same strain recovery characteristics and room temperature superelastic properties, a lower elastic modulus in a wide temperature range, and the present invention further simplifies the smelting and control process.

[0047] The present invention is described above by way of example. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by those skilled in the art without inventive effort falls within the protection scope of the present invention.

Claims

1. A superelastic polycrystalline iron-manganese-aluminum-nickel-tantalum alloy with a wide temperature range and low elastic modulus, characterized in that: Its general structural formula is Fe a Mn b Al c Ni d Ta e , a+b+c+d+e=100%, a=40~50%, b=30~40%, c=13~17%, d=6~8%, e=0.05~4%.

2. The iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy according to claim 1, characterized in that: e is preferably 3%.

3. A method for preparing an iron-manganese-aluminum-nickel-tantalum-based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus, characterized in that: The following steps are involved: Step 1), mixing an iron source and a tantalum source and smelting them at 2300-3000° C. for 3-5 minutes, adding an aluminum source, a nickel source and a manganese source after smelting and mixing them evenly to obtain an alloy melt, smelting the alloy melt at 1500-1700° C. for 5-10 minutes, and cooling the furnace to room temperature to obtain an ingot; Step 2), homogenizing the ingot at 900-1100° C., and furnace cooling to room temperature to obtain a homogenized ingot; Step 3), in an inert atmosphere, solution treating the homogenized ingot at 950-1300° C. for 30-180 minutes, and quenching with water to room temperature to obtain a solution treated ingot; Step 4), placing the solution treated ingot at 200-600° C. for aging treatment for 0.5-24 hours, and quenching with water to room temperature to obtain an iron-manganese-aluminum-nickel-tantalum based superelastic polycrystalline alloy with a wide temperature range and low elastic modulus.

4. The preparation method according to claim 3, characterized in that: Calculated by atomic percentage, the ratio of iron in the iron source, manganese in the manganese source, aluminum in the aluminum source, nickel in the nickel source and tantalum in the tantalum source is (40-50): (30-40): (13-17): (6-8): (0.05-4).

5. The preparation method according to claim 3, characterized in that: The iron source is industrial pure iron, the tantalum source is electrolytic tantalum, the aluminum source is electrolytic aluminum, the nickel source is electrolytic nickel, and the manganese source is electrolytic manganese.

6. The preparation method according to claim 3, characterized in that: The homogenization time is 8 to 24 hours.

7. The preparation method according to claim 3, characterized in that: The temperature of the solution treatment is preferably 1250 to 1300° C., and the time of the solution treatment is preferably 50 to 70 minutes.

8. The preparation method according to claim 3, characterized in that: The temperature of the aging treatment is preferably 400 to 600° C., and the time of the aging treatment is preferably 3 to 15 hours.

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