CN104630562A - Application of high-damping shape memory alloy - Google Patents

Abstract

The invention discloses the application of a high-damping shape memory alloy. The chemical formula of the shape memory alloy is Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ . According to the stoichiometric ratio of Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ , the single substances of Ni, Fe, Mn and Ga are put into the arc melting furnace, vacuumized and filled with argon, and the final ingot is smelted and subjected to high temperature solution treatment After quenching to room temperature, a shape memory alloy is obtained. The damping test of the Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ shape memory alloy system shows that the alloy sample has a high damping plateau (Q ^-1 ≥ 0.05). When x=0, a high-damping alloy with a wide temperature range of 150K-340K is obtained; when 0<x≤2, due to the appearance of intermediate martensitic transformation caused by Fe doping, the doped alloy can be used at a wider temperature It has a large magnetron damping effect within the range of 215K-275K, that is, its damping value increases with the increase of the magnetic field.

Description

Application of a High Damping Shape Memory Alloy

【Technical field】

The invention belongs to the field of damping alloy materials, and in particular relates to the application of a high damping shape memory alloy.

【Background technique】

Damping or internal friction (Damping) refers to the physical properties of materials that lose vibration energy or sound energy and convert them into other forms of energy such as heat energy. Together with superplasticity and shape memory properties, they are called the three major functional properties of materials. With the rapid development of science and technology, the requirements for miniaturization, intelligence and precision of devices are getting higher and higher, and various functional materials are urgently needed, especially damping functional materials with noise reduction ability. Therefore, the development of new damping functional materials is an arduous task faced by contemporary material researchers.

Damping alloy is one of the important branches of many damping materials. According to the strength of damping ability, it can be divided into two categories: one is metals such as aluminum alloy, copper alloy, titanium alloy and steel, which have low damping performance (Q ^-1 ≤10 ^-2 ); the other is Mg, Fe, Ni, Zn-Al, Mg-Zr, Mn-Cu and other special metal materials have high damping performance (Q ^-1 ≥10 ^-2 ). There are four damping mechanisms for this type of high damping alloy: (1) phase boundary or grain boundary viscosity (Fe-C-Si, Al-Zn, etc.); (2) irreversible displacement of magnetic domain walls (Fe-Cr, Fe-Cr-Al, Co-Ni and Fe, Ni, etc.); (3) Dislocation movement and interaction between dislocations and point defects (Mg, Mg-Zr, etc.); (4) Mobility of martensitic twin boundaries (Mn-Cu, Mn-Cu-Al, Cu-Al-Ni, Cu-Zn-Al and Ni-Ti, etc.). Among them, the twin-type damping effect due to the mobility of the martensitic twin boundary has the advantages of high stability, wide temperature range, and simple preparation method, and has been deeply studied.

Twin damping exists in shape memory alloys undergoing thermoelastic martensitic transformation. Generally speaking, the mobility of martensitic twin boundaries will make the internal friction value of the martensitic state higher than that of the parent phase, but how Only in order to obtain high damping and how to adjust the damping performance has been the focus of research in shape memory alloys. Due to the interaction between H and twin boundaries in Ti-Ni-based shape memory alloys, the relaxation damping value can be between 0.04-0.2, and the temperature range is 200-260K. [References: (1) Genlian Fan, YumeiZhou, Kazuhiro Otsuka, and Xiaobing Ren. Ultrahigh damping in R-phase state of Ti–Ni–Fe alloy[J]. APPLIED PHYSICS LETTERS 89, 161902(2006).(2) G.Fan,Y.Zhou,K.Otsuka,et al.Effects offrequency,composition,hydrogen and twin boundary density on the internal friction of Ti ₅₀ Ni _50-x Cu _x shape memory alloys[J].Acta Materialia 54(2006 ) 5221–5229.] Mn-30Cu shape memory alloy has high damping characteristics below 300K (Q ^-1 >0.04). [References: FXYin, T.Sakaguchi, QCTian, A.Sakurai, K.Nagai, Mater.Trans.46(2005) 2164.] It has been reported that Ti–45Pd–5Cr alloy has A high damping platform (Q ^-1 ≈0.05) appears; when the Ti–45Pd–5Cr alloy is doped with H, the damping peak Q ^-1 can increase to 0.09, and the temperature range is 305K-370K. [References: Y.Zhou, G.Fan, D.Xue, et al. High damping capacity in a wide ambient-temperature range in hydrogen-doped and hydrogen-free Ti–45Pd–5Cr martensitic alloy[J].Scripta Materialia 61 (2009)805–808.] Although the above traditional shape memory alloys have good damping properties, their damping properties are not intelligent enough. Once the alloy composition is determined, the damping value will be fixed accordingly, which is not in line with the development trend of intelligent damping materials. In recent years, the damping behavior of ferromagnetic shape memory alloys has received extensive attention, especially Ni-Mn-Ga ferromagnetic shape memory alloys. Ni _52.3 Mn _27.4 Ga _20.3 single crystal sample has a very high twin-type damping peak (Q ^-1 >0.1) around 370K. [References: I.Aaltio, M.Lahelin, O.Soderberg et al. 】More importantly, the study found that when a 0.4T magnetic field is applied, the Ni ₅₂ Mn ₂₄ Ga ₂₄ single crystal sample will appear a magnetic field-induced damping peak (Q ^-1 ≈ 0.2) when the temperature is lower than 273K. 【Reference: WHWang, GDLiu and GHWu.Magnetically controlled high damping in ferromagnetic Ni ₅₂ Mn ₂₄ Ga ₂₄ single crystal[J].Appl.Phys.Lett.89,101911(2006).】Although magnetic Ni-Mn-Ga single crystal The single crystal has good damping performance, and the magnetron damping effect can appear, but the preparation process of the single crystal is complicated, and the practical applicability is restricted. Therefore, it is particularly urgent to develop magnetically controlled high-damping shape memory alloys that can be magnetized, have a wide temperature range, are low in cost, and have a simple preparation method and are suitable for mass production.

【Content of invention】

The purpose of the present invention is to provide an application of a high damping shape memory alloy. The prepared shape memory alloy has high damping performance in a wide temperature range, and its damping value can be significantly improved after applying a magnetic field, that is, magnetron damping effect, and the preparation method of the present invention has simple preparation process and low raw material price.

To achieve the above object, the present invention adopts the following technical solutions:

An application of a high-damping shape-memory alloy for preparing damping devices, the chemical formula of the high-damping shape-memory alloy is Ni _{55-x Fex} Mn ₂₀ Ga ₂₅ , where 0≤x≤2.

Preferably, 0<x≤2.

Preferably, 0.5<x≤2.

Preferably, 0<x≤2, the damping device is a magnetron damping device.

The preparation method of the high damping shape memory alloy of the present invention comprises the following steps: according to the stoichiometric ratio of Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ (0≤x≤2), Ni, Fe, Mn and Ga simple substances are put into the electric arc In the smelting furnace, after vacuuming, fill it with argon for smelting, and melt it under the condition of current 90-150A to obtain ingots, and then smelt the ingots repeatedly, then perform high-temperature solid solution treatment and quench to room temperature, and obtain a magnetically controlled high-damping shape memory alloy.

The purity of the Ni, Fe, Mn and Ga elemental substances are all greater than 99.9%; the vacuum is evacuated to a vacuum degree of less than 4.5×10 ^-3 Pa; the purity of the argon is 99.99%;

The melting time is 30s-90s.

The number of repeated smelting is three to six times.

The temperature of the high temperature solution treatment is 800-900°C.

Compared with the prior art, the present invention has the advantages: the present invention selects Ni ₅₅ Mn ₂₀ Ga ₂₅ as the matrix and replaces Ni with Fe to obtain Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ polycrystalline alloy, and its raw material price is low, The preparation process is simple, and large-scale production can be realized. The damping test of the as-prepared Ni _{55-x Fex} Mn ₂₀ Ga ₂₅ samples shows that the samples all have a damping plateau in a wide temperature range (Q ^-1 ≥ 0.05) and high temperature stability. Moreover, the Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ (0<x≤2) alloy sample has magnetron damping characteristics due to the introduction of intermediate martensite. When x=2, it can be compared at a frequency of 1 Hz. When the magnetic field is 475Oe, the internal friction value increases by about 20%; when the external magnetic field reaches 900Oe, the internal friction value can increase by about 36%. In the present invention, a polycrystalline alloy with a large magnetron damping effect is obtained, which has strong practical applicability.

【Description of drawings】

Fig. 1 is the internal friction curve of Ni ₅₅ Mn ₂₀ Ga ₂₅ alloy;

Figure 2 is the internal friction curve of Ni ₅₃ Fe ₂ Mn ₂₀ Ga ₂₅ alloy;

Fig. 3 is the internal friction curve of Ni ₅₃ Fe ₂ Mn ₂₀ Ga ₂₅ alloy under different magnetic fields.

【Detailed ways】

In the high damping shape memory alloy of the present invention, Ni ₅₅ Mn ₂₀ Ga ₂₅ is selected as the matrix and Ni is replaced by Fe, that is, Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ alloy. The innovative design idea of this unique alloy system is as follows: First, the temperature of the twin-type internal friction peak of Ni ₅₅ Mn ₂₀ Ga ₂₅ alloy is close to the martensitic transformation point. At this time, the martensitic modulus is low and the lattice is soft. As a result, the martensitic twin boundaries are easy to move under external force, and the base composition with a large damping effect is obtained. Secondly, the purpose of doping the alloy with Fe is to introduce the intermediate martensitic phase transformation, thereby producing a good magnetron damping effect. The main reason for the magnetron damping is that the twin-type damping peak is located between the intermediate martensitic phase transition damping peak and the martensite phase transition damping peak, and the unstable intermediate martensite is easy to reorient under the magnetic field, and the twinning The mobility of the boundary is enhanced, which in turn leads to the enhancement of its twin-type damping peak under the magnetic field. Finally, replacing Ni with an appropriate amount of Fe in the Ni ₅₅ Mn ₂₀ Ga ₂₅ alloy can also improve the toughness of Ni ₅₅ Mn ₂₀ Ga ₂₅ , improve its mechanical properties, and enhance its practicality.

The present invention will be described in detail below through specific examples.

Embodiments 1 to 3 of the present invention all adopt the following test conditions: adopt the U.S. TA company Q800 dynamic mechanical analysis instrument (Dynamic Mechanical Analysis) to the sample in the embodiment 1 to 3, carried out internal friction test, select the single cantilever beam for use in the test process For the fixture, the amplitude during the test is 5 μm, and the frequency is 0.2/0.4/1/4/10/20Hz in turn. The NdFeB magnet was installed on the dynamic mechanical analyzer, and the same experimental parameters were used to test the samples, and the internal friction curves under the magnetic fields of 475Oe and 900Oe were obtained.

Example 1:

A high damping shape memory alloy, the chemical formula of the shape memory alloy is Ni ₅₅ Mn ₂₀ Ga ₂₅ .

The preparation method of the shape memory alloy in this example is as follows: according to the stoichiometric ratio of Ni ₅₅ Mn ₂₀ Ga ₂₅ , put the simple substances of Ni, Mn and Ga into the arc melting furnace, and evacuate to below 4.5×10 ^-3 Pa, Then quickly fill it with high-purity argon for smelting, and smelt it for 60 seconds under the condition of a current of 110A to obtain an ingot. The ingot was subjected to high-temperature solution treatment at 900°C and then quenched to room temperature to obtain a high-damping shape memory alloy.

The internal friction test was carried out on the sample with x=0, and the measurement results shown in Figure 1 were obtained. It can be seen from Figure 1 that there are two internal friction peaks on the internal friction curve of the undoped Ni ₅₅ Mn ₂₀ Ga ₂₅ alloy, one is the internal friction peak (IF _TM ) related to the martensitic transformation that appears in the high temperature region; The other is the twin-type internal friction peak (IF _TBM ), and its internal friction peak is Q ^-1 ≈ 0.11070 at 330K. Because the martensitic transformation point is close to the temperature range of the twin internal friction peak, a high damping platform (Q ^-1 ≥ 0.05) with a wide temperature range of 150K-340K can be obtained.

Example 2:

A magnetically controlled high damping shape memory alloy, the chemical formula of which is Ni ₅₃ Fe ₂ Mn ₂₀ Ga ₂₅ .

The preparation method of the shape memory alloy in this example is as follows: According to the stoichiometric ratio of Ni ₅₃ Fe ₂ Mn ₂₀ Ga ₂₅ , put Ni, Fe, Mn and Ga into the arc melting furnace, and vacuumize to 4.5×10 ^{- 3} Pa, and then quickly filled with high-purity argon for smelting, smelting at a current of 110A for 60s to obtain ingots. During the smelting process, in order to ensure uniform alloy composition, the smelted ingots were repeatedly smelted five times. The cast ingot is subjected to high-temperature solution treatment at 900°C and then quenched to room temperature to obtain a magnetically controlled high-damping shape memory alloy.

The internal friction test was carried out on the test sample with x=2, and the measurement results shown in Figure 2 were obtained. It can be seen from Fig. 2 that two internal friction peaks appear on the internal friction curve of Fe-doped Ni ₅₃ Fe ₂ Mn ₂₀ Ga ₂₅ alloy. Comparing Figure 1, it can be seen that the internal friction peak (IF _TM ) related to the martensitic transformation moves to around 300K at room temperature, while the internal friction peak (IF _ITM ) of the intermediate martensitic transformation caused by Fe element doping is located at around 210K.

The internal friction test under different magnetic fields (475Oe/900Oe) was carried out on the same sample with x=2. During the test, the experimental parameters remained unchanged, and the measurement results shown in Figure 3 were obtained. By comparing the 1Hz internal friction curve in Figure 3, it can be known that the intermediate martensitic twin-type damping peak (IF _TBM ) increases with the increase of the magnetic field in a wide temperature range of 215K-275K. When the magnetic field is 475Oe, the internal friction value Increase about 20%, when the magnetic field is 900Oe, the internal friction value increases about 36%. A good magnetron high damping characteristic is obtained. At the same time, the magnetic field has little effect on the internal friction curve in the temperature range of 130K-180K after the intermediate martensitic transformation, and still maintains its high damping performance.

Example 3

A magnetic control high damping shape memory alloy, the chemical formula of the shape memory alloy is Ni ₅₄ Fe _0.5 Mn ₂₀ Ga ₂₅ .

The preparation method of the shape memory alloy in this example is as follows: according to the stoichiometric ratio of Ni ₅₄ Fe _0.5 Mn ₂₀ Ga ₂₅ , put Ni, Fe, Mn and Ga elemental substances with a purity greater than 99.9% into an electric arc melting furnace, and vacuumize When it reaches below 4.5×10 ^-3 Pa, it is quickly filled with argon gas with a purity of 99.99% for melting, and the ingot is melted for 30 seconds under the condition of a current of 150A. During the melting process, the ingot is repeatedly smelted to ensure uniform alloy composition After three times, it was solid solution treated at 800°C and quenched to room temperature to obtain a magnetically controlled high damping shape memory alloy.

Example 4

A magnetic control high damping shape memory alloy, the chemical formula of the shape memory alloy is Ni ₅₂ Fe ₁ Mn ₂₀ Ga ₂₅ .

The preparation method of the shape memory alloy in this example is as follows: according to the stoichiometric ratio of Ni ₅₂ Fe ₁ Mn ₂₀ Ga ₂₅ , put Ni, Fe, Mn and Ga elemental substances with a purity greater than 99.9% into an arc melting furnace, and vacuumize When it reaches below 4.5×10 ^-3 Pa, it is quickly filled with argon gas with a purity of 99.99% for smelting, and smelted for 40 seconds under the condition of a current of 130A to obtain an ingot. After repeated smelting four times, it was subjected to solution treatment at 860°C and quenched to room temperature to obtain a magnetically controlled high damping shape memory alloy.

Example 5

A magnetic control high damping shape memory alloy, the chemical formula of the shape memory alloy is Ni ₅₀ Fe _1.5 Mn ₂₀ Ga ₂₅ .

The preparation method of the shape memory alloy in this example is as follows: according to the stoichiometric ratio of Ni ₅₀ Fe _1.5 Mn ₂₀ Ga ₂₅ , put Ni, Fe, Mn and Ga elemental substances with a purity greater than 99.9% into an electric arc melting furnace, and vacuumize When it reaches below 4.5×10 ^-3 Pa, it is quickly filled with argon gas with a purity of 99.99% for smelting. It is smelted for 90s under the condition of a current of 90A to obtain an ingot. Repeated smelting for six times, re-casting ingots and quenching to room temperature after solid solution treatment at 900°C to obtain a magnetically controlled high damping shape memory alloy.

The present invention carries out the damping test to the prepared Ni55-xFexMn20Ga25 sample and shows that when x=0, a high damping alloy sample (Q ^-1 ≥ 0.05) (as shown in Figure 1) with a wide temperature range of 150K-340K is obtained, which can be used For the preparation of damping devices; when 0<x≤2, the appearance of intermediate martensitic phase transformation due to Fe doping makes the sample have large magnetron damping characteristics in a wide temperature range of 215K-275K, such as x=2 When the frequency is 1Hz, the maximum value of the intermediate martensitic twin-type damping peak (IF _TBM ) reaches 0.0771 (as shown in Figure 2). When a 475Oe magnetic field is added, the internal friction value increases by about 20%. When the magnetic field is 900Oe, the internal friction value The increase is about 36% (as shown in FIG. 3 ), which can be used to prepare damping devices or magnetron damping devices. In short, the Ni55-xFexMn20Ga25 sample has low raw material price, simple preparation process, large magnetron damping effect in a wide temperature range, strong practical applicability and large-scale production.

Claims (5)

1. The application of a high damping shape memory alloy for the preparation of damping devices, the chemical formula of the high damping shape memory alloy is Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ , where 0≤x≤2. 2. The application according to claim 1, characterized in that 0<x≤2. 3. The application according to claim 1, characterized in that 0.5<x≤2. 4. The application according to claim 1, characterized in that, 0<x≤2, the damping device is a magnetron damping device. 5. The application according to claim 1, characterized in that the preparation method of the high damping shape memory alloy comprises the following steps: according to the stoichiometry of Ni _55-x Fe _x Mn ₂₀ Ga ₂₅ (0≤x≤2) For example, put Ni, Fe, Mn and Ga elemental substances into an electric arc melting furnace, vacuumize and fill with argon for melting, and melt under the condition of current of 90-150A to obtain ingots, and then repeatedly smelt the ingots for high temperature melting. Solution treatment and quenching to room temperature to obtain a magnetically controlled high damping shape memory alloy.