CN102528052A - Preparation method for quickly quenched Fe-based metal grain with excellent wave absorbing property - Google Patents

Abstract

The invention provides a method for preparing fast-quenching Fe-based metal particles with wave-absorbing characteristics by using ultrasonic waves. The mass percentage of each metal element in the alloy is weighed and the corresponding metal is made into a magnetic metal alloy, and after smelting, stripping, and ball milling, it is obtained through ultrasonic dispersion treatment, which can improve the interface characteristics and distribute uniformly. Characteristics of Fe-based metal particulate materials. The present invention starts from the cavitation principle and mechanical effect of ultrasonic waves in liquids to obtain materials with uniform dispersion of rapidly quenched Fe-based metal particles. At the same time, when ultrasonic waves propagate in piezoelectric materials and magnetostrictive materials, due to the mechanical action of ultrasonic waves The induced electric polarization and induced magnetization are induced, thereby improving the wave-absorbing characteristics of the Fe-based metal particle material. The principle of the invention is correct, and the method is scientific. The bulk quenched Fe-based metal particle material with good wave-absorbing properties obtained by the invention has high practical value and wide application prospect.

Description

A Preparation Method of Rapidly Quenched Fe-Based Metal Particles with Good Wave Absorbing Properties

technical field

The invention relates to a metal particle material with wave-absorbing properties, especially a method for preparing a fast-quenched Fe-based metal particle material with good wave-absorbing properties. the

Background technique

With the development of modern science and technology, the impact of electromagnetic radiation on the environment is increasing. At airports, airplane flights are delayed due to electromagnetic wave interference; in hospitals, mobile phones often interfere with the normal work of various electronic medical instruments; in increasingly important stealth and electromagnetic compatibility (EMC) technologies, the role and status of electromagnetic wave absorbing materials It also appears very prominent, and has become a magic weapon and "secret weapon" for electronic countermeasures in modern military affairs. Therefore, controlling electromagnetic pollution and finding a material with excellent wave-absorbing properties have become a major topic in material science. the

Research on absorbing materials is not only of great significance in the military, but also plays a role in promoting the development of civilian electronics such as anti-jamming devices. Finding a new design method for materials with excellent wave-absorbing properties has always been the purpose of people's pursuit, but there is a problem of reflection of electromagnetic waves in wave-absorbing materials. Although people have studied a lot of electromagnetic wave absorbing materials so far, they still cannot achieve non-reflective absorption. They can only improve the wave-absorbing characteristics of materials as high as possible, so there is still a long way to go for practical applications. the

Contents of the invention

The object of the present invention is to provide a kind of method that prepares the fast-quenching Fe-based metal particle material with good wave-absorbing characteristic, the preparation method of this fast-quenching Fe-base metal particle material with good wave-absorbing characteristic is characterized in that Use the following steps:

(1) Preparation of Fe-based metal alloy: the proportion of high-purity iron rod (99.9wt%) is 65-70%, the proportion of neodymium block (99.9wt%) is 2-4%, and the proportion of analytical pure cobalt sheet (99.8wt%) 16-20%, and the proportion of analytically pure boron (99.8wt%) is 9-13%. According to the atomic percentage of each element in the alloy, the corresponding mass of metal is weighed, made into a magnetic metal alloy, and placed in a high-frequency induction Alloy ingots are obtained by smelting in a smelting furnace;

(2) Preparation of Fe-based metal thin strip: the magnetic metal alloy obtained in (1) is smelted in a vacuum quenching furnace and thrown away, the alloy ingot is put into a crucible, and the argon is filled to 0.05MP after vacuuming, and the molybdenum When the speed along the outer wheel is 20-40m/s, the alloy ingot is melted by the tungsten-cerium electrode after the high-voltage arc, and the molten solution is thrown into a thin strip by the high-speed rotating molybdenum wheel;

(3) Preparation of Fe-based metal particles: the thin strip obtained in (2) is first coarsely crushed with a pulverizer, and then finely ground by adding absolute ethanol with a planetary ball mill, the ball-to-material ratio is 10:1, and the rotating speed is 500r/min. Reverse once every 20 minutes, the ball milling time is 2 hours, and the abrasive after ball milling for 2 hours is dried in the shade;

(4) Put the abrasive obtained in (3) into a beaker and add an appropriate amount of absolute ethanol. After stirring well with a glass rod, put it into the center of the water tank of the ultrasonic equipment, where the water in the water tank is higher than the powder in the beaker. ;Turn on the ultrasonic equipment, set the ultrasonic frequency to 2.5-3.5GHz, and perform ultrasonic treatment on the abrasive for 20-40min;

(5) Put the abrasive obtained in (4) into an oven for drying and then sieve to obtain uniform Fe-based metal powder particles with a mesh size of 200-300 mesh. the

Advantages and effects of the present invention

The obtained Fe-based metal powder particle material in (5) is made into a standard measurement ring to measure its electromagnetic parameters, and after calculating the reflection loss through the line transmission theory, it is found that:

Both the magnetic loss μ″ and the magnetic permeability μ′ have a small decrease, but the reduction is not obvious; the dielectric loss ε″ and the dielectric constant ε′ have been significantly reduced, forming a better impedance matching condition, and the reflection loss is obtained It has been greatly improved, that is, the wave-absorbing characteristics of metal particle materials have been significantly improved. the

Compared with the prior art, the present invention proceeds from the cavitation principle and mechanical effect of ultrasonic waves in liquids to obtain materials with uniform dispersion of rapidly quenched Fe-based metal particles, while ultrasonic waves are used in piezoelectric materials and magnetostrictive materials. When propagating, due to the induced electric polarization and induced magnetization caused by the mechanical action of ultrasonic waves, the wave-absorbing characteristics of Fe-based metal particle materials are improved. The principle of the invention is correct, and the method is scientific. The bulk quenched Fe-based metal particle material with good wave-absorbing properties obtained by the invention has high practical value and wide application prospect. the

Description of drawings

Fig. 1A is the magnetic loss μ " characteristic figure of sample measured in embodiment 1 of the present invention

Fig. 1 B is the magnetic permeability μ ' characteristic diagram of the sample measured in embodiment 1 of the present invention

Fig. 1 C is the dielectric loss ε " characteristic figure of sample measured in embodiment 1 of the present invention

Fig. 1 D is the dielectric constant ε ' characteristic diagram of the sample measured in Example 1 of the present invention

Figure 1E is a reflection loss characteristic diagram of the sample measured in Example 1 of the present invention

Fig. 2 is the reflection loss characteristic diagram of sample measured in embodiment 2 of the present invention

Fig. 3 is the reflection loss characteristic figure of sample measured in embodiment 3 of the present invention

Detailed ways

In order to better understand the present invention, the following examples further illustrate the content of the present invention, the following examples are intended to illustrate the present invention rather than further limit the present invention, those skilled in the art make some non-essential according to the above-mentioned content of the present invention Improvements and adjustments all belong to the protection scope of the present invention. the

Example 1:

(1) The proportion of high-purity iron rod (99.9wt%) is 65-70%, the proportion of neodymium block (99.9wt%) is 2-4%, the proportion of analytical pure cobalt sheet (99.8wt%) is 16-20%, analytical pure The proportion of boron (99.8wt%) is 9-13%. Weigh the corresponding mass of metal according to the atomic percentage of each element in the alloy, make it into a magnetic metal alloy, and melt it in a high-frequency induction melting furnace to obtain an alloy ingot. , in order to ensure the uniformity of the ingredients, the melting was repeated twice. the

Melting strips are smelted in a vacuum quenching furnace. Put the alloy ingot into the crucible, under the state of vacuuming and filling with argon, the alloy ingot is melted by the high-voltage arc of the tungsten-cerium electrode, and the molten solution is thrown into a thin strip by the high-speed rotating molybdenum wheel. Then the obtained ribbons were roughly crushed with a pulverizer, then finely ground with anhydrous ethanol for 2 hours with a planetary ball mill, and then dried in the shade. Among them, the ratio of ball to material is 10:1, the speed is 500r/min, and the rotation is reversed every 20min. the

Pour the dried abrasive into a beaker and add an appropriate amount of absolute ethanol, then put it into the water tank of the ultrasonic equipment, turn on the ultrasonic wave, set the ultrasonic frequency to 2.5 GHz, and the ultrasonic time to 20 min. the

Finally, the ultrasonic abrasive is put into an oven, fully dried and sieved to obtain uniform Nd-Fe-Co-based metal powder particles with a mesh number of 200-300. the

The Nd-Fe-Co-based magnetic metal particles prepared above and the untreated Nd-Fe-Co-based magnetic metal particles (film thickness 1.5 mm) were calculated according to the line transmission theory and reflected by the comparison, as shown in Figure 1 As shown, found:

(1) After ultrasonic dispersion treatment, the magnetic loss μ" has a small decrease, and the decrease rate is less than 1-2%. 

(2) After the ultrasonic dispersion treatment, the magnetic permeability μ' has a small decrease, and the decrease rate is less than 1-2%. the

(3) After ultrasonic dispersion treatment, the dielectric loss ε″ has been greatly reduced. At 2 GHz, the dielectric loss has been reduced from 55 to 15 for the untreated sample, a drop of more than 50%. 

(4) After ultrasonic dispersion treatment, the dielectric constant ε' has been significantly reduced. At 2GHz, it has been reduced from 115 to 65 in the untreated sample, a decrease of more than 40%. the

(5) After ultrasonic dispersion treatment, the reflection loss dB has been greatly improved. The maximum reflection loss value before ultrasound is -6.5dB at 2.2GHz, and the maximum reflection loss after ultrasound is -11.4dB at 3.1GHz, which is relatively Compared with the untreated sample, the maximum reflection loss is increased by more than 90%. the

In summary, the Nd-Fe-Co-based magnetic metal particle material after ultrasonic dispersion treatment has better wave-absorbing characteristics than the Nd-Fe-Co-based magnetic metal particle material without ultrasonic dispersion treatment. the

Example 2:

The method for preparing the Nd-Fe-Co-based magnetic metal particle material in Example 1 is the same, but the ultrasonic frequency is set to 3.0 GHz, and the ultrasonic time is 30 min. The prepared Nd-Fe-Co-based magnetic metal particles and the untreated Nd-Fe-Co-based magnetic metal particles (film thickness 1.5 mm) were calculated and compared according to the line transmission theory through reflection loss (see Figure 2 ) Obtained the conclusion consistent with embodiment 1. the

Example 3:

The method for preparing the Nd-Fe-Co-based magnetic metal particle material is the same as that in Example 1, but the ultrasonic frequency is set to 3.5 GHz, and the ultrasonic time is 40 min. The prepared Nd-Fe-Co-based magnetic metal particles and the untreated Nd-Fe-Co-based magnetic metal particles (film thickness 1.5 mm) were calculated and compared according to the line transmission theory through reflection loss (see Figure 3 ) Obtained the conclusion consistent with embodiment 1. the

Claims (1)

1. A method for preparing a fast-quenching Fe-based metal particle with good wave-absorbing properties, characterized in that it adopts the following steps: The preparation of Fe-based metal alloy: the ratio of high-purity iron rod (99.9wt%) is 65-70%, the ratio of neodymium block (99.9wt%) is 2-4%, the ratio of analytical pure cobalt sheet (99.8wt%) is 16- 20%, the proportion of analytically pure boron (99.8wt%) is 9-13%, the corresponding mass of metal is weighed according to the atomic percentage of each element in the alloy, and it is made into a magnetic metal alloy, which is placed in a high-frequency induction melting furnace Smelting to obtain alloy ingots; The magnetic metal alloy obtained in (1) is smelted and thrown in a vacuum quenching furnace, and the alloy ingot is put into a crucible. After vacuuming, it is filled with argon to 0.05MP, and the speed along the outer edge of the molybdenum wheel is 20-40m/s. Next, the alloy ingot is melted by the high-voltage arc of the tungsten-cerium electrode, and the molten solution is thrown into a thin strip by the high-speed rotating molybdenum wheel; The thin ribbon obtained in (2) is first coarsely crushed with a pulverizer, and then finely ground with anhydrous ethanol with a planetary ball mill. The ball-to-material ratio is 10:1, the speed is 500r/min, reversed every 20min, and the ball milling time is 2h. Dry the abrasive after ball milling for 2 hours; Put the abrasive obtained in (3) into a beaker and add an appropriate amount of absolute ethanol. After fully stirring with a glass rod, put it into the center of the water tank of the ultrasonic equipment, where the water in the water tank is higher than the powder height in the beaker; turn on the ultrasonic wave equipment, and set the ultrasonic frequency to 2.5-3.5GHz, and ultrasonically treat the sample for 20-40min; The abrasive obtained in (4) is dried in an oven and then sieved to obtain uniform Fe-based metal powder particles with a mesh size of 200-300 mesh.

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