CN113755729A

CN113755729A - Directionally solidified high-damping manganese-copper alloy material in strong magnetic field and preparation method thereof

Info

Publication number: CN113755729A
Application number: CN202110948710.7A
Authority: CN
Inventors: 田青超; 张思斌; 任忠鸣
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2021-08-18
Filing date: 2021-08-18
Publication date: 2021-12-07
Anticipated expiration: 2041-08-18
Also published as: CN113755729B

Abstract

The invention discloses a directional solidification high-damping manganese-copper alloy material under a strong magnetic field and a preparation method thereof, and relates to the technical field of a manganese-copper-based alloy preparation method with high damping performance. The invention includes raw material preparation and high damping manganese-copper alloy preparation. The raw material preparation includes the following steps: the proportion of alloy elements by weight percentage is: Mn: 70-75wt.%, Cu: 15-20wt.%, Ni: 6-10wt.%. %, Fe: 1.5‑2.5wt.% and other unavoidable impurities, then put the raw materials in a crucible and melt them in a vacuum induction melting furnace. The alloy of the invention combines the directional solidification process under a strong static magnetic field to obtain a single γ-phase structure with a (111) crystal plane preferential orientation, and the damping performance in the service temperature range of the alloy is significantly improved through the magnetic ordering of the antiferromagnetic phase transition. Further, the purpose of preparing a manganese-copper-based alloy with high damping performance is achieved. The damping alloy of the present invention has simple components, short preparation process flow, high production efficiency and low manufacturing cost.

Description

Directionally solidified high-damping manganese-copper alloy material in strong magnetic field and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation methods of high-damping manganese-copper-based alloys, and particularly relates to a directionally-solidified high-damping manganese-copper alloy material in a strong magnetic field and a preparation method thereof.

Background

The low-frequency noise with the frequency below 100 Hz is close to the natural frequency of human viscera, thus easily causing resonance and having the greatest harm to human health. The heart, lungs, spleen, kidneys, liver, etc. are irreversibly damaged by the influence of low frequency noise throughout the year. The Mn-Cu base damping alloy is adopted to design and manufacture the component, so that a vibration source can be blocked, and mechanical vibration energy is irreversibly converted into heat energy through an internal mechanism of the material to be consumed in the material, so that the vibration-damping noise-reducing component has good vibration-damping noise-reducing effect.

Patent CN201210491359.4 discloses a cast high-damping manganese-copper alloy material and a preparation method thereof, which are used for solving the technical problem of unstable damping performance of manganese-copper alloy, but because more rare earth and alkaline earth elements are added into the alloy, the alloy preparation process is complex and the cost is high. Patent CN201810335193.4 discloses a cast high-damping manganese-copper alloy material and a manufacturing method thereof, which utilizes the magnetic braking effect of a magnetic field to improve macrosegregation and refine a solidification dendritic structure, the damping material of the invention has compact structure, and the damping performance (Tan delta) can reach 0.049. Patent CN202110313373.4 discloses a method for preparing an ultrahigh damping Mn-Cu alloy by directional solidification, wherein the alloy has ultrahigh twin crystal relaxation internal loss (Tan delta >0.1) at a temperature of between 70 ℃ below zero and 20 ℃ below zero, the damping performance of the alloy is greatly improved, but the normal temperature damping performance is lower and is only 0.02 to 0.04. Patent CN202110552536.4 discloses a high-damping manganese-copper alloy in service in a wide temperature range and a preparation method thereof, wherein the alloy is prepared by directional solidification and then subjected to aging heat treatment, and the manufacturing process is complex.

It is well known that the transmission of vibrations and noise tends to be of a vectorial nature, i.e. directional. Generally speaking, for the ordinary directional solidification process of the alloy, with the increase of the drawing speed of the solidification process, the time required by the solidification of the alloy is greatly shortened, the production efficiency is greatly improved, but the (200) crystal orientation of the alloy is more and more dominant. However, the microstructure of the Mn-Cu-based alloy is mainly {011} twin crystal, and the relaxation motion of the twin boundary under the action of external force consumes the energy in the alloy, which is the main source of the high damping performance of the Mn-based alloy. Meanwhile, the damping capacity of the Mn-Cu-based alloy can also come from dislocation motion, and the dislocation slip plane of the Mn-Cu-based alloy is (111) and the slip direction is [110 ]. The (200) crystal orientation obtained with conventional directional solidification processes is extremely detrimental to both twins and dislocations. If we use the strong magnetic field to form (111) orientation which is beneficial to twin movement and dislocation slip by controlling the solidification process, the damping performance of the prepared alloy is greatly improved.

Further, the spin direction of the antiferromagnetic γ -Mn is along the c-axis, with spins parallel to each other in the c-plane and spins antiparallel to each other in the adjacent c-plane. The magnetic moments of different atomic planes in the unit cell are different, and the (111) plane has one eighth of remanent magnetic moment and the (200) plane have mutual cancellation. If the (111) crystal face orientation is dominant, the ordering of the magnetons can be induced through special alloying, so that the damping performance of the alloy is further improved.

Disclosure of Invention

The invention aims to provide a directionally solidified high-damping manganese-copper alloy material in a strong magnetic field and a preparation method thereof, which aim to solve the existing problems: the prior art has the defects of complex damping alloy components, longer preparation process flow and lower production efficiency in the damping alloy preparation process.

In order to solve the technical problems, the invention is realized by the following technical scheme:

the invention relates to a directionally solidified high-damping manganese-copper alloy material in a strong magnetic field and a preparation method thereof, and the method comprises the following steps of preparing raw materials and preparing high-damping manganese-copper alloy:

the alloy elements comprise the following components in percentage by weight: 70-75 wt% of Mn, 15-20 wt% of Cu, 6-10 wt% of Ni, 1.5-2.5 wt% of Fe and other inevitable impurities, then placing the raw materials in a crucible, placing the crucible in a vacuum induction melting furnace for melting, introducing argon protective atmosphere during melting, carrying out induction heating to 1250-.

The design principle of each chemical element of the directionally solidified high-damping manganese-copper alloy in the strong magnetic field is as follows:

mn: the main elements forming the gamma-Mn phase crystal lattice directly influence the antiferromagnet phase transition temperature and magnetic ordering. During solidification, a non-uniform nucleation core is firstly precipitated to form a dendritic Mn-rich area, when the Mn content is too high, the casting performance is easy to be deteriorated and the alloy becomes brittle, and when the Mn content is too low, the antiferromagnet phase change temperature is lowered, and the damping performance is poor; preferably, a content of 70-75 wt.% is used.

Cu: form solid solution together with Mn, form Cu-rich regions by aggregation among Mn-rich dendrites precipitated first during solidification, and preferably have a content of 15-20 wt.% in order to form single gamma-Mn in both Mn-rich and Cu-rich regions during solidification at high temperature.

Ni: the high-temperature melt is used as a high-melting-point element to adjust the viscosity of the high-temperature melt, can form a gamma phase with Mn, is completely dissolved in a Mn-Cu alloy lattice, is mainly gathered in a Cu-rich area, and mainly changes the orientation of a gamma phase solidification structure in the Cu-rich area under the action of a strong magnetic field, so that the magnetic ordering is influenced, the magnetic field adjusting and controlling effect is not obvious when the magnetic field is too low, the too high performance is poor, and the content is preferably 6-10 wt.%.

Fe: the high-temperature melt viscosity is adjusted by taking the high-melting-point element as a high-melting-point element, the high-temperature melt viscosity is completely dissolved in a gamma phase in Mn-Cu alloy and mainly gathers in a Mn-rich area, and the orientation of a solidification structure of the gamma phase in the Mn-rich area is changed under the action of a strong magnetic field, so that the magnetic ordering is influenced, the damping performance is deteriorated when the content of Fe is too high, the effect of magnetic field regulation and control is not obvious when the content of Fe is too low, and the content of 1.5-2.5 wt.% is preferably adopted.

Further, the preparation of the high-damping manganese-copper alloy comprises the following steps:

the method comprises the following steps: preparing a directional solidification furnace, wherein the upper half part of the furnace body is an alloy heating and melting area, the lower half part of the furnace body is a Ga-In-Sn cooling pool, the prepared cast manganese-copper-based alloy is placed into a hollow corundum tube, and the directional solidification is carried out on the alloy by using the directional solidification furnace;

step two: preparing a stable and constant strong magnetic field, and applying a stable and constant strong magnetic field with the magnetic field intensity of 1-10T outside the furnace body of the whole directional solidification furnace;

step three: sending the corundum tube filled with the manganese-copper-based alloy to a heating and melting area, and preserving heat for 10-30min when the alloy reaches the melting point of 1150-1250 ℃ or above so as to fully melt the alloy (the heating-melting process of the alloy is influenced by a stable and constant strong magnetic field);

step four: and (3) pulling the alloy downwards into a quenching bath at a pulling speed of 80-120 mu m/s (the solidification process of the alloy is influenced by a stable and constant strong magnetic field), so as to obtain the manganese-copper-based alloy directionally solidified by the strong magnetic field.

Because the affinity of Fe and Mn, Ni and Cu is stronger in a high-temperature melt state and are respectively distributed among Mn-rich dendritic crystal trunks and copper-rich dendrites, the growth orientation of the dendritic crystal is regulated and controlled under the action of a strong static magnetic field, so that (111) directionally solidified gamma-phase manganese-copper alloy with dominant orientation is obtained, Ni and Fe are ferromagnetic elements, Mn and Cu are paramagnetic elements, and after antiferromagnetic transformation, the Mn-rich dendritic crystal trunks and the copper-rich dendrites can be magnetically ordered due to the interaction of the ferromagnetic elements Ni and Fe, so that the damping performance is greatly improved.

Further, the high-damping manganese-copper alloy has a preferred orientation of a (111) crystal plane.

Furthermore, the damping performance Tan delta of the high-damping manganese-copper alloy is 0.061-0.123 when the high-damping manganese-copper alloy is used in a conventional service temperature range of-30 ℃.

Further, the directionally solidified high damping manganin alloy phase is composed into a single gamma phase.

The invention has the following beneficial effects:

1. the alloy of the invention combines a directional solidification process under a strong magnetostatic field to obtain a single gamma-phase structure with (111) crystal face preferred orientation, and the damping performance of the alloy within the service temperature range is remarkably improved through the magnetic ordering of the antiferromagnet phase change, thereby realizing the purpose of preparing the manganese-copper-based alloy with high damping performance.

2. The damping alloy disclosed by the invention is simple in component, short in preparation process flow and high in production efficiency.

3. The manganese-copper alloy prepared by the strong magnetic field directional solidification technology has obvious preferred orientation, and the damping performance of the alloy is greatly improved by antiferromagnetic ordering within the temperature range of normal temperature, so that the damping performance of the alloy is 1.5-3 times that of the existing alloy.

Of course, it is not necessary for any product in which the invention is practiced to achieve all of the above-described advantages at the same time.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is an XRD pattern of an example of the present invention and a comparative example;

FIG. 2 is a cross-sectional structural view of example 1 of the present invention;

FIG. 3 is a graph comparing the curves of internal friction with temperature for the examples of the present invention and the comparative examples;

FIG. 4 is a cross-sectional structural view of comparative example 1 of the present invention.

Detailed Description

The preparation method of the high damping manganese-copper alloy of the present invention is further described by the following specific embodiments.

The damping performance test of the alloys obtained in the examples and comparative examples was carried out by a DMA-Q800 type dynamic thermo-mechanical analyzer using a three-point bending mode to measure the damping performance (Tan. delta.) of the alloy, the test vibration frequency was 0.1Hz, and the strain amplitude was 2X 10^-5. The metallographic structure of the alloy was observed by a come card optical microscope of type DM 6000. The X-ray diffraction (XRD) pattern was performed on a Rigaku SmartLab type X-ray diffractometer, with the target Cu target and the scanning speed 4.5 deg./min.

Example 1: preparing a manganese-copper-based damping alloy of 75 wt.% of Mn to 15 wt.% of Cu to 7.5 wt.% of Ni to 2.5 wt.% of Fe in a vacuum furnace, carrying out heat preservation at an induction heating temperature of 1350 ℃ for 30min, and then casting and solidifying; heating the mother alloy material in a directional solidification furnace with 1T strong magnetic field to 1250 ℃ above, preserving heat for 10min to ensure that the alloy is fully melted and then directionally solidifying at the drawing speed of 100 mu m/s. The crystal face of the alloy (111) is in obvious preferred orientation, see figure 1; the metallographic structure is developed dendritic crystal, and the strong magnetic field stirs a liquid-solid front interface, so that the distribution of the dendritic crystal is relatively disordered, which is shown in the attached figure 2; maintains high damping performance at a normal use temperature range of-30 ℃ to 30 ℃, and has a Tan delta value of: 0.061-0.065, as shown in Table 1 and attached FIG. 3.

Example 2: preparing manganese-copper-based damping alloy of 70 wt.% of Mn, 20 wt.% of Cu, 6 wt.% of Ni and 1.5 wt.% of Fe in a vacuum furnace, and casting and solidifying after keeping the induction heating temperature of 1350 ℃ for 60 min; heating the mother alloy material in a directional solidification furnace with a 3T strong magnetic field to a temperature above 1150 ℃, preserving heat for 30min, fully melting the alloy, and performing directional solidification at a drawing speed of 80 mu m/s. The crystal face of the alloy (111) is in obvious preferred orientation; the metallographic structure is developed dendritic crystals which are arranged in a disordered way; maintains high damping performance at a normal use temperature range of-30 ℃ to 30 ℃, and has a Tan delta value of: 0.071-0.075 as shown in Table 1.

Example 3: preparing a manganese-copper-based damping alloy of 73 wt.% of Mn to 18 wt.% of Cu to 7 wt.% of Ni to 2 wt.% of Fe in a vacuum furnace, carrying out heat preservation at the induction heating temperature of 1350 ℃ for 40min, and then casting and solidifying; heating the mother alloy material in a directional solidification furnace with a strong magnetic field of 10T to a temperature of more than 1150 ℃, preserving heat for 20min, fully melting the alloy, and performing directional solidification at a drawing speed of 120 mu m/s. The crystal face of the alloy (111) is in obvious preferred orientation; the metallographic structure is developed dendritic crystals which are arranged in a disordered way; and maintains high damping performance at a normal use temperature range of-30 ℃ to 30 ℃, and the Tan delta value is as follows: 0.081-0.123, see table 1.

Example 4: preparing a manganese-copper-based damping alloy of 72 wt.% of Mn, 16 wt.% of Cu, 10 wt.% of Ni, 2 wt.% of Fe and 2.5 wt.% of Fe in a vacuum furnace, carrying out heat preservation at an induction heating temperature of 1450 ℃ for 50min, and then carrying out casting solidification; heating the mother alloy material in a directional solidification furnace with 8T strong magnetic field to 1250 ℃ or above, preserving heat for 30min to ensure that the alloy is fully melted and then directionally solidifying at the drawing speed of 100 mu m/s. The crystal face of the alloy (111) is in obvious preferred orientation; the metallographic structure is developed dendritic crystals which are arranged in a disordered way; and maintains high damping performance at a normal use temperature range of-30 ℃ to 30 ℃, and the Tan delta value is as follows: 0.075-0.118, see table 1.

Comparative example 1: preparing a manganese-copper-based damping alloy with the chemical components of Mn-20 wt.% Cu-5 wt.% Ni-2 wt.% Fe in a vacuum furnace, carrying out heat preservation at the induction heating temperature of 1350 ℃ for 30min, and then casting and solidifying; heating the mother alloy material in a directional solidification furnace to a temperature of over 1250 ℃, preserving heat for 30min, performing directional solidification at a drawing speed of 100 mu m/s after the alloy is fully melted, and applying no strong magnetic field in the whole process. Obtaining the common preferred orientation of the (200) crystal face, and the (111) crystal face has no preferred characteristic, and is shown in the attached figure 1; the metallographic structure is developed dendrites which are regularly arranged, and is shown in figure 4; the damping performance was significantly reduced at conventional service temperatures of-30 ℃ to 30 ℃ with Tan delta values of only 0.035-0.049, see table 1.

TABLE 1 comparison table of damping performance at-30 to 30 ℃ for examples of the present invention and comparative examples

As can be seen from the first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the first comparative embodiment, the weight percentages are as follows: 70-75 wt.% of Mn, 15-20 wt.% of Cu, 6-10 wt.% of Ni and 1.5-2.5 wt.% of Fe are placed in a crucible and placed in a vacuum induction melting furnace for melting, argon protective atmosphere is introduced during the melting, the alloy is inductively heated to 1250-; with the increase of the magnetic field strength, the damping performance is gradually improved, as in example two; when the aging heat treatment is not performed after the directional solidification, the damping performance is reduced by about 50% or more as in comparative example one.

The microstructure of the directionally solidified manganese-copper alloy with the (111) preferred orientation prepared in the high-intensity magnetic field is suitable for twin crystal movement and dislocation slippage, and the alloy has high damping performance in a conventional temperature range due to magnetic ordering caused by antiferromagnetic phase change, is 1.5-3 times that of the existing alloy, and has a very obvious performance improvement effect.

It is noted that the above list is only the specific embodiment of the present invention, and it is obvious that the chemical components and the preparation process of the strong magnetic field directional solidification related to the present invention are not limited to the above embodiments, and there are many similar variations. All modifications which would occur to one skilled in the art and which are, therefore, directly derived or suggested from the disclosure herein are deemed to be within the scope of the present invention.

One specific application of this embodiment is: alloy elements containing 70-75 wt% of Mn, 15-20 wt% of Cu, 6-10 wt% of Ni, 1.5-2.5 wt% of Fe and other impurities are placed In a crucible and placed In a vacuum induction melting furnace for melting, argon protective atmosphere is introduced during the melting, the alloy is inductively heated to 1250 ℃ - & lt 1450 & gt ℃ and is kept warm for 30-60min, so that a mother alloy ingot is obtained, then a directional solidification furnace is prepared, the upper half part of the furnace body is an alloy heating and melting area, the lower half part of the furnace body is a Ga-In-Sn cooling pool, the prepared cast manganese-state manganese-copper-based alloy is placed In a hollow corundum tube, the alloy is directionally solidified by using the directional solidification furnace, a stable high-magnetic field is prepared, a stable high-magnetic field with the magnetic field intensity of 1-10T is applied to the outside of the furnace body of the whole directional solidification furnace, the corundum tube filled with the manganese-copper-based alloy is sent to the heating and melting area, and when the alloy reaches the temperature of 1250 ℃ or above, keeping the temperature for 10-30min to fully melt the alloy (the heating-melting process of the alloy is influenced by a stable strong magnetic field), and then drawing the alloy downwards into a quenching tank at a drawing speed of 80-120 mu m/s (the solidification process of the alloy is influenced by the stable strong magnetic field) to obtain the directionally solidified manganin-based alloy by the strong magnetic field.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A directional solidification high damping manganese copper alloy material and its preparation method under the strong magnetic field, including raw materials preparation and high damping manganese copper alloy preparation, characterized by that: the preparation of the raw materials comprises the following steps:

2. The directionally solidified high-damping manganese-copper alloy material under the strong magnetic field and the preparation method thereof according to claim 1 are characterized in that: the preparation method of the high-damping manganese-copper alloy comprises the following steps:

3. The directionally solidified high-damping manganese-copper alloy material under the strong magnetic field and the preparation method thereof according to claim 1 are characterized in that: the high-damping manganese-copper alloy has a preferred orientation of a (111) crystal plane.

4. The directionally solidified high-damping manganese-copper alloy material under the strong magnetic field and the preparation method thereof according to claim 1 are characterized in that: the high-damping manganese-copper alloy is used in a conventional service temperature range of-30 ℃ and has the damping performance Tan delta of 0.061-0.123.

5. The directionally solidified high-damping manganese-copper alloy material under the strong magnetic field and the preparation method thereof according to claim 1 are characterized in that: the directionally solidified high damping manganese-copper alloy phase composition becomes a single gamma phase.