CN108251622B - A kind of heat treatment method of FeGa base high damping alloy - Google Patents

Abstract

The invention discloses a heat treatment method for a FeGa-based high damping alloy. The method eliminates defects inside the material through pretreatment, and then heats it to 800°C at a heating rate of 120°C/h, keeps it warm for 1h, and then heats it up to 800°C at a rate of 120°C/h. Cool the furnace to 580-660°C and keep it warm for 0.5h, so that the internal temperature of the material is uniform, and the orderly and disorderly transformation phase transition is fully carried out, and finally quenched. Compared with the existing heat treatment process, this process can greatly improve the intrinsic damping performance of the material at low amplitude (≤120×10 ^‑6 ), and the damping value is increased by 1.5‑3 times compared with the original sample; compared with the traditional heat treated Fe The damping value of high-base damping materials is increased by 2-3.5 times. At the same time, the advantage of this process is that the entire heat treatment process is carried out below the recrystallization temperature, which greatly improves the damping performance of the material and hardly damages the mechanical properties of the material.

Description

A kind of heat treatment method of FeGa base high damping alloy

technical field

The invention relates to the technical field of heat treatment of high damping alloys, in particular to a heat treatment method for FeGa-based high damping alloys.

Background technique

In recent years, FeGa-based alloys have received widespread attention as a new generation of magnetostrictive materials. When magnetostrictive materials are subjected to external magnetic fields and stress fields, the internal magnetic domains will rotate accordingly, which can cause energy loss in the process. , thus becoming the source of high damping performance. Traditional Fe-based high-damping materials such as FeCr-based, FeAl-based, and FeMo-based alloys mainly increase the grain size and reduce internal stress through high-temperature heat preservation and furnace cooling, which is beneficial to the rotation and migration of magnetic domains. The damping performance of alloys is improved, such as FeCr-based alloys. At present, the optimal heat treatment method to obtain high damping performance is to hold at 1100 ° C for 1 hour and cool in a furnace. At present, the heat treatment process of FeGa-based alloys is mainly focused on improving its magnetostrictive properties, and it was found that holding at 1000 ° C for 1 hour and quenching can significantly improve the magnetostrictive properties. However, neither high temperature insulation and furnace cooling nor high temperature quenching can significantly improve the damping performance of FeGa-based alloys, and it does not have obvious advantages over other Fe-based alloys. On the contrary, at the recrystallization temperature The high-temperature heat treatment above leads to a significant decrease in the mechanical properties of the FeGa-based alloy, which limits its application range. Therefore, it is very important to broaden the application range of FeGa-based alloys by designing the heat treatment process of FeGa-based alloys from a new perspective to greatly improve their damping properties without compromising the mechanical properties (no recrystallization).

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a heat treatment method for FeGa-based high damping alloys to solve the technical problem that the existing heat treatment process cannot significantly improve the damping performance of FeGa-based alloys.

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

The invention provides a heat treatment method for FeGa-based high damping alloy, comprising:

Step 1: Alternate cooling and heating of the FeGa-based alloy material for several times, then keep it at 800°C for 1 hour or more; or directly keep the FeGa-based alloy material at 800°C for more than 6 hours; The temperature is controlled at 800°C, and the internal defects and internal stress of the material can be eliminated to the greatest extent without exceeding the recrystallization temperature;

Step 2: Slowly cool the material treated in step 1 to the temperature zone where short-range ordered phase exists at 580-660°C, and keep it warm for more than 0.5h to ensure that the orderly and disordered reaction inside the material is fully carried out, and then perform quenching treatment immediately; through rapid Quenching can keep the high-temperature short-range ordered phase as much as possible, and ensure the qualitative improvement of the damping performance of the treated sample.

In the alternating cycle of cold and heat in the first step, heating the FeGa-based alloy material to 800° C. and then cooling down to room temperature constitutes a cycle.

In the heating and cooling process of step 1, the heating and cooling process is carried out at a rate of 120° C./h, which can ensure that the temperature of the alloy sample is uniform throughout the treatment process.

In the alternating cooling and heating cycle mode of step 1, the more the number of heating and cooling cycles, the greater the reduction of the internal stress of the material, and the better the final damping performance of the corresponding material, but it will basically reach saturation after 5 cycles. Therefore, the The number of heating and cooling cycles is preferably 3-5 times.

In the continuous heat preservation process of step 1, the longer the continuous heat preservation time at 800°C, the greater the reduction in the internal stress of the material, and the better the final damping performance of the corresponding material, but it is necessary to pay attention to preventing the recrystallization of grains during this process Growth behavior, therefore, the 800°C continuous holding time is preferably 6h, which can ensure no recrystallization growth behavior and reduce the internal stress of the material to an ideal state.

In the second step, the slow cooling rate is lower than 120° C./h. The slower the cooling rate, the more uniform the heating inside the material, and the more sufficient the order-disorder reaction.

In the second step, the temperature is lowered to the temperature range (580-660° C.) where the short-range ordered phase exists by means of continuous or stepwise cooling.

In the second step, the quenching method is water quenching or oil quenching.

Compared with the prior art, the present invention has the following advantages:

① High damping: The alloy sample treated by this method has a greatly improved damping performance in the low amplitude range (20-120×10 ^-6 ) and 1Hz: Compared with the original sample, the damping value is increased by 1.5-3 times ; Compared with the traditional heat-treated Fe-based high-damping material, the damping value is increased by 2-3.5 times;

②Wide temperature range: The damping value remains stable at -85°C-160°C and basically does not change with temperature; it has a wider application range than other non-Fe-based high damping materials.

③ During the whole heat treatment process, the sample did not recrystallize, and the mechanical properties of the material did not decrease.

④The internal friction value of the FeGa-based sample quenched at 580°C can reach 0.031 at the amplitude of 30×10 ^-6 and 1 Hz.

Description of drawings

Fig. 1 is a schematic diagram of heat treatment process based on embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of heat treatment process based on embodiment 2 of the present invention;

Fig. 3 is a schematic diagram of heat treatment process based on embodiment 3 of the present invention;

Fig. 4 is a comparative schematic diagram of the internal friction of the FeGa alloy quenched in the quenching temperature range of the present invention and quenched outside the range;

Fig. 5 is a comparative schematic diagram of FeGa alloy processed by the method of the present invention and FeGa not processed by the method of the present invention, and a classic FeCrAl high damping material under low amplitude internal friction;

Fig. 6 is -85-300 ℃ internal friction-temperature curve of the FeGa alloy processed by the method of the present invention;

Fig. 7 is a schematic diagram showing the comparison of the yield strength of the FeGa alloy processed by the method of the present invention and the FeGa alloy not processed by the method of the present invention.

Detailed ways

The technical solution of this patent will be further described in detail below in conjunction with specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, but the protection scope of this patent is not limited to the following embodiments.

Example 1

This embodiment provides a heat treatment method for a wide temperature range and high damping FeGa-based alloy, as shown in Figure 1, comprising the following steps:

(1) Pretreatment: Place the alloy sample in a tubular heat treatment furnace, heat it up to 800°C at a heating rate of 120°C/h under a protective atmosphere of argon, hold it for 1 hour, and then cool it at a rate of 120°C/h Cool to room temperature with the furnace, a total of 4 cycles;

(2) Heat treatment: In a tubular heat treatment furnace, under a protective atmosphere of Ar gas, heat to 800°C at a heating rate of 120°C/h, and hold for 1h;

(3) Furnace cooling treatment: cooling treatment is carried out by heating the alloy sample, the cooling rate is 90°C/h, and the temperature is kept at 750°C, 700°C, 680°C, 660°C, and 640°C for 0.5h during the cooling process;

(4) Quenching treatment: Rapidly perform water quenching treatment on the sample kept at 640° C. for 0.5 h, and cool to room temperature.

Example 2

This embodiment provides a heat treatment method for a wide temperature range and high damping FeGa-based alloy, as shown in Figure 2, comprising the following steps:

(1) Pretreatment and heat treatment: place the alloy sample in a tubular heat treatment furnace, and heat it to 800°C at a heating rate of 120°C/h under the protective atmosphere of argon, and keep it for 6h;

(2) Furnace cooling treatment: conduct cooling treatment on the alloy sample through heating treatment, the cooling rate is 90°C/h, when the temperature drops to 620°C, keep it for 1h;

(3) Quenching treatment: the sample kept at 620° C. for 1 hour was quickly subjected to water quenching treatment, and cooled to room temperature.

Example 3

This embodiment provides a heat treatment method for a FeGa-based high damping alloy, as shown in Figure 3, comprising the following steps:

(1) Pretreatment The temperature of the FeGa-based alloy material is first raised to 800°C at a rate of 120°C/h by means of alternating cold and heat cycles, and after holding for 1 hour, it is then lowered to room temperature with the furnace at a rate of 120°C/h. cycle, a total of 4 cycles to reduce the internal stress of the material;

(2) Heat treatment: In a tubular heat treatment furnace, under a protective atmosphere of Ar gas, heat to 800°C at a heating rate of 120°C/h, and hold for 1h;

(3) Furnace cooling treatment: the heat-treated alloy sample is cooled to a certain temperature of 450-750°C at a rate of 90°C/h, and kept for 0.5h.

(4) Quenching treatment: quickly oil quench the sample kept for 0.5h, and cool it to room temperature.

The damping performance of the material processed in this embodiment is evaluated, wherein: the damping performance characterization of the FeGa-based alloy sample under different processing methods is measured by using a multi-functional inverted torsion pendulum internal friction instrument; The sample is subjected to torsional deformation; the stress and strain sensors are used to collect the force and vibration curves of the material in real time; the internal friction value is obtained by calculating the amplitude ratio of the stress and strain and the lag angle between the two; the damping performance of the material is affected by the internal friction value (Q ^-1 ) Conduct evaluation; the evaluation of damping performance is mainly concentrated in the low amplitude range (≤120×10 ^-6 ) and 1Hz. The damping performance is obtained by comparing the internal friction value, and the specific damping power is P=2πQ ^-1 .

The result is shown in Figure 4-7, where:

Figure 4 is a schematic diagram of the internal friction comparison of FeGa alloy materials at different quenching temperatures. It can be seen from the figure that under the condition of the amplitude of 30×10 ^-6 and 1 Hz, in the range of quenching temperature 580-660°C (short-range ordered phase exists The damping performance of the sample quenched in the temperature range) is significantly higher than that on both sides of the temperature range. Among them, the internal friction value of the FeGa-based sample quenched at 580°C can reach 0.031.

Figure 5 is a schematic diagram of the comparison of internal friction of FeGa alloy materials under low amplitude under different treatment methods. It can be seen from the figure that in the range of low amplitude (20-120×10 ^-6 ) and 1 Hz, the samples treated by the present invention (The quenching temperature is 580°C, the same below) Compared with the original sample, the damping value is increased by 1.5-3 times, and compared with the traditional heat-treated Fe-based high-damping material, the damping value is increased by 2-3.5 times; among them, at 20×10 ^-6 , 1Hz Under the conditions, the damping properties of the samples processed by the present invention are respectively 2.25 and 4.5 times that of FeGa not processed by the present invention and the classic Fe-based high damping material;

Figure 6 is the internal friction-temperature curve of the FeGa alloy treated by the present invention at -85-300°C. It can be seen from the figure that the damping value of the sample treated by the present invention remains stable at -85°C-160°C, and basically does not change with temperature. ;

Figure 7 is a schematic diagram of the comparison of the yield strength of FeGa alloy materials under different treatment methods. It can be seen from the figure that during the entire heat treatment process, the sample did not recrystallize and the mechanical properties of the material did not decrease;

The preferred implementation of this patent has been described in detail above, but this patent is not limited to the above-mentioned implementation. Within the scope of knowledge of those of ordinary skill in the art, various implementations can be made without departing from the purpose of this patent. kind of change.

Claims (6)

1. a kind of heat treatment method of FeGa base high-damping alloy characterized by comprising

Step 1: after FeGa base alloy material hot and cold alternation is recycled several times, in 800 DEG C of heat preservation 1h or more；Alternatively, directly By FeGa base alloy material in 800 DEG C of continuous heat preservation 6h or more；The hot and cold alternation circulation is heated to FeGa base alloy material Then it is a circulation that 800 DEG C are cooled to room temperature again；

Step 2: step 1 treated material is reduced the temperature into short distance by way of continuous cooling or staged cooling There are warm areas for ordered phase, are quenched immediately after keeping the temperature 0.5h or more, and it is 580-660 that the shortrange order, which mutually has warm area, ℃。

2. a kind of heat treatment method of FeGa base high-damping alloy according to claim 1, which is characterized in that the step One heating temperature-fall period is carried out with the rate of 120 DEG C/h.

3. a kind of heat treatment method of FeGa base high-damping alloy according to claim 1, which is characterized in that the step One hot and cold alternation cycle-index is 3-5 times.

4. a kind of heat treatment method of FeGa base high-damping alloy according to claim 1, which is characterized in that the step One continuous soaking time is 6h.

5. a kind of heat treatment method of FeGa base high-damping alloy according to claim 1, which is characterized in that the step Two slow cooling rates are lower than 120 DEG C/h.

6. a kind of heat treatment method of FeGa base high-damping alloy according to claim 1, which is characterized in that the step In two, the method for quenching treatment is that Water Quenching or oil quenching are handled.