WO2022041516A1

WO2022041516A1 - Preparation method and application of noble metal element-containing powder material

Info

Publication number: WO2022041516A1
Application number: PCT/CN2020/130962
Authority: WO
Inventors: 赵远云; 刘丽
Original assignee: 赵远云
Priority date: 2020-08-27
Filing date: 2020-11-23
Publication date: 2022-03-03
Also published as: CN116056819A; CN112276106A

Abstract

A preparation method and application of a noble metal element-containing powder material. According to the preparation method, an initial alloy strip containing a matrix phase and a dispersed particle phase is obtained by means of solidification of an alloy melt, the matrix phase in the initial alloy strip is then removed, and at the same time, the dispersed particle phase containing a noble metal element is retained, thereby obtaining a noble metal element-containing powder material composed of the original dispersed particle phase. The preparation method is simple in process, can be used to prepare noble metal element-containing powder materials having various sizes such as nano-scale, sub-micron level, and micron-level, and has good prospects for application in the fields of catalytic materials, powder metallurgy, composite materials, wave-absorbing materials, sterilization materials, metal injection molding, 3D printing, coating and the like.

Description

A kind of preparation method of powder material containing noble metal element and application thereof

technical field

The invention relates to the technical field of micro-nano materials, in particular to a preparation method and application of a powder material containing noble metal elements.

Background technique

The preparation methods of ultrafine powder materials with micron, submicron and nanometer particle size are divided into solid phase method, liquid phase method and gas phase method from the state of matter. Among them, the solid phase method mainly includes mechanical pulverization method, ultrasonic pulverization method, thermal decomposition method, explosion method, etc. The liquid phase method mainly includes precipitation method, alkoxide method, carbonyl method, spray thermal drying method, freeze drying method, electrolysis method, Chemical condensation methods, etc., gas phase methods mainly include gas phase reaction method, plasma method, high temperature plasma method, evaporation method, chemical vapor deposition method, etc.

Although there are many methods for preparing ultrafine powder materials, each method has certain limitations. For example, the disadvantages of the liquid phase method are low yield, high cost and complex process; the disadvantage of the mechanical method is that it is difficult to classify after the powder material is prepared, and the purity, fineness and morphology of the product are difficult to guarantee; Electrode method and gas atomization method are the main methods for preparing high-performance metal and alloy powder at present, but the production efficiency is low, the yield is not high, and the energy consumption is relatively large; jet milling method and hydrogenation dehydrogenation method are suitable for large-scale industrialization production, but with strong selectivity to raw materials and alloys.

For noble metal powder materials, especially noble metal nano-powder materials, they are generally prepared by chemical reduction methods. However, the chemical reduction method is generally difficult to ensure the large-scale preparation of the product and also ensure that the particle size of the obtained noble metal nanopowder can be well controlled.

In addition, the impurity content of the powder material, especially the oxygen content, has a great influence on its performance. At present, the impurity content of metals or alloys is mainly controlled by controlling the purity and vacuum degree of raw materials, which is expensive. Therefore, it is of great significance to develop new preparation methods for high-purity powder materials.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a method for preparing a powder material containing noble metal elements with a simple process and easy operation to address the above problems.

A preparation method of a powder material containing noble metal elements, characterized in that, comprising the following steps:

Step S1, select the initial alloy raw material, and melt the initial alloy raw material according to the initial alloy composition ratio to obtain a uniform initial alloy melt containing the impurity element D; the average composition of the initial alloy melt is mainly Cu _a (M _x T _y ) ) _b D _d , wherein M includes at least one of noble metal elements Ir, Ru, Re, Os, Tc, Au, Pt, Pd, and Ag, and T includes W, Cr, Mo, V, Ta, Nb, Zr, At least one of Hf, Ti, Fe, D contains at least one of O, H, N, P, S, F, Cl, I, Br; and 60%≤a≤99.9%, 0.1%≤b≤ 40%, 0≤d≤5%; 0.1%≤x≤100%, 0%≤y≤99.9%; among them, a, b, d, and x, y represent the atomic percentage content of the corresponding constituent elements;

In step S2, the initial alloy melt is solidified into initial alloy strips; the solidified structure of the initial alloy strip includes a matrix phase and a dispersed particle phase; the melting point of the matrix phase is lower than that of the dispersed particle phase, and the The dispersed particle phase is coated in the matrix phase; during the solidification of the initial alloy melt, the impurity element D in the initial alloy melt is redistributed in the dispersed particle phase and the matrix phase, and is enriched in the matrix phase, so that the dispersed particle phase is purified;

The composition of the dispersed particle phase in the initial alloy strip is mainly (M _x T _y ) _x1 D _z1 , and the average composition of the matrix phase is mainly Cu _x2 D _z2 ; and 99%≤x1≤100%, 0≤z1≤1 %; 90%≤x2≤100%, 0≤z2≤10%; z1≤d≤z2, 2z1≤z2; x1, z1, x2, z2 represent the atomic percentage content of the corresponding constituent elements;

In step S3, the matrix phase in the initial alloy strip is removed, and the dispersed particle phase that cannot be removed at the same time in the process of removing the matrix phase is retained; High-purity target powder materials of precious metal elements.

In the step S1,

Further, the M includes at least one of noble metal elements Ir, Ru, Re, Os, Tc, Au, Pt, Pd, Ag, and the atomic percentage of elements such as Ir, Ru, Re, Os, Tc in M The content is higher than 50%;

Further, the M includes at least one of noble metal elements Ir, Ru, Re, Os, Tc, Au, Pt, Pd, Ag, and the atomic percentage of elements such as Ir, Ru, Re, Os, Tc in M The content is higher than 75%;

Preferably, the M contains at least one of noble metal elements Ir, Ru, Re, Os, Tc,

Further, the T includes at least one of W, Cr, Mo, V, Ta, Nb, Zr, Hf, Ti, Fe, and W, Cr, Mo, V, Ta, Nb and other elements in T The atomic percentage content is higher than 50%;

Further, the T includes at least one of W, Cr, Mo, V, Ta, Nb, Zr, Hf, Ti, Fe, and W, Cr, Mo, V, Ta, Nb and other elements in T The atomic percentage content is higher than 75%;

Preferably, the T includes at least one of W, Cr, Mo, V, Ta, and Nb;

Further, the source of the D impurity element in the initial alloy melt includes: impurities introduced from the initial alloy raw material, and impurities introduced from the atmosphere or the crucible during the smelting process. Among them, the impurities introduced into the atmosphere refer to impurities such as O, N, and H in the ambient atmosphere absorbed by the alloy melt.

Further, D is an impurity element and includes at least one of O, H, N, P, S, F, Cl, I, and Br; and the total content of these impurity elements is the content of D impurity elements;

Further, if the raw material is each element or master alloy containing impurity elements, it can be melted according to the proportion to prepare the initial alloy melt. If the supplied raw material is directly the alloy raw material corresponding to the composition of the initial alloy melt, it can be remelted to obtain the initial alloy melt.

Further, the combination of Cu and M and Cu and T in the average composition of the initial alloy melt in the step S1 is extremely important. Intermetallic compounds are not formed between them. In this way, the two-phase separation of the Cu-based matrix phase and the M and T-based particle phases during the solidification of the initial alloy melt can be achieved, which is beneficial to the subsequent preparation of M and T-based powder materials containing noble metal elements .

Further, 59.9%≤a≤99.8%, 0.1%≤b≤40%, 0<d≤5%;

In the step S2,

Further, the initial alloy strip does not contain an intermetallic compound composed of Cu and M;

Further, the initial alloy strip does not contain an intermetallic compound composed of Cu and T;

Further, when M contains at least one of Au, Pt, Pd, and Ag, it exists in a solid-solution manner in a dispersed particle phase whose main component is (M _x T _y ) _x1 D _z1 , and the The dispersed particle phase whose main component is (M _x T _y ) _x1 D _z1 also contains at least one of Ir, Ru, Re, Os, and Tc all belonging to M;

Further, when T contains at least one of Zr, Hf, Ti, and Fe, it is present in a solid solution in a dispersed particle phase whose main component is (M _x T _y ) _x1 D _z1 , and the The dispersed particle phase whose main component is (M _x T _y ) _x1 D _z1 also contains at least one of W, Cr, Mo, V, Ta, and Nb all belonging to T;

Further, the dispersed particle phase containing noble metal elements whose composition is mainly (M _x T _y ) _x1 D _z1 does not contain Cu element;

Further, the method of solidification of the alloy melt includes strip method and continuous casting method; generally, thinner initial alloy strip can be obtained by strip method; thicker alloy strip can be obtained by continuous casting method .

Whether it is the thin alloy strip obtained by the stripping method or the thick alloy strip obtained by the continuous casting method, the morphology of the alloy ingot obtained by the ordinary casting method is completely different. The alloy ingot obtained by the ordinary casting method is average in size. There is no obvious difference in length, width and thickness.

Further, the thickness of the initial alloy strips ranges from 5 μm to 10 mm; further, the thickness of the initial alloy strips ranges from 5 μm to 5 mm; preferably, the thickness of the initial alloy strips ranges from 5 μm to 1 mm ; As a further preference, the thickness of the initial alloy strip ranges from 5 μm to 200 μm; as a further preference, the thickness of the initial alloy strip ranges from 5 μm to 20 μm.

It should be noted that when the thickness of the initial alloy strip is in the order of millimeters, it can also be referred to as an alloy sheet.

Further, the width of the cross section of the initial alloy strip is more than 2 times its thickness; further, the length of the initial alloy strip is more than 10 times its thickness; The length is more than 50 times its thickness; preferably, the length of the initial alloy strip is more than 100 times its thickness;

Further, the solidification rate of the initial alloy melt is 1K/s～10 ⁷ K/s;

Further, the particle size of the dispersed particle phase is related to the solidification rate of the initial alloy melt; in general, the particle size of the dispersed particle phase has a negative correlation with the solidification rate of the initial alloy melt, that is, the initial alloy melt. The higher the solidification rate of the melt, the smaller the particle size of the dispersed particle phase.

Further, the particle size range of the disperse particle phase is 2nm～3mm; further, the particle size range of the disperse particle phase is 2nm～500μm; preferably, the particle size range of the disperse particle phase is 2nm～ 99 μm; as a further preference, the particle size range of the dispersed particle phase is 2 nm to 5 μm; as a further preference, the particle diameter of the dispersed particle phase is in the range of 2 nm to 200 nm; as a further preference, the particle diameter of the dispersed particle phase The range is 2nm to 100nm.

Further, when the solidification rate of the initial alloy melt is 10 ⁵ K/s to 10 ⁷ K/s, dispersed particles with particle diameters mainly in nanoscale can be obtained.

Further, when the solidification rate of the initial alloy melt is 10 ⁴ K/s to 10 ⁵ K/s, dispersed particles with particle diameters mainly in the submicron scale can be obtained.

Further, when the solidification rate of the initial alloy melt is 10 ² K/s˜10 ⁴ K/s, dispersed particles with a particle size mainly in the micron scale can be obtained.

Further, when the solidification rate of the initial alloy melt is 1K/s˜10 ² K/s, dispersed particles with a particle size mainly in the millimeter scale can be obtained.

Further, the particle shape of the dispersed particle phase is not limited, and may include at least one of dendritic, spherical, nearly spherical, square, pie, and rod-shaped; when the particle shape is rod-shaped, the Size refers to the diameter dimension of the cross-section of the rod.

Further, when the dispersed particles are of nanometer or submicron scale, spherical or nearly spherical particles are obtained with high probability; when the dispersed particles are of micrometer scale and above, dendritic particles are obtained with high probability.

Further, the dispersed particle phase solidifies and precipitates from the initial alloy melt. According to the nucleation and growth theory, whether it is a nearly spherical nanoparticle that has just nucleated and grown, or a fully grown micron-scale or millimeter-scale tree branch. The crystal grains all have a fixed orientation relationship in their crystal growth, so that the precipitated single grains are mainly composed of a single crystal.

When the volume percentage of the dispersed particles in the entire initial alloy strip is relatively high, in the process of endogenous precipitation of single crystal particles, it is not excluded that two or more particles merge. If two or more single crystal particles are only softly agglomerated, adsorbed to each other, or connected together by only a few parts, and are not sufficiently combined into one particle through normal grain boundaries as in polycrystalline materials, they are still two single crystal particles. . Its characteristic is that after the matrix phase is removed in the subsequent process, these single crystal particles can be easily separated by techniques including ultrasonic dispersion treatment and jet milling. For polycrystalline materials of normal ductile metals or alloys, it is difficult to separate the grain boundaries by techniques including ultrasonic dispersion treatment and jet milling.

Preferably, the number of single crystal particles in the dispersed particles in the initial alloy strip accounts for not less than 60% of the total number of dispersed particles.

As a further preference, the number of single crystal particles in the dispersed particles accounts for not less than 90% of the total number of dispersed particles.

Further, for a certain initial alloy strip, the volume percentage content of the dispersed particle phase in the initial alloy strip can be determined by the corresponding initial alloy melt composition, dispersed particle phase composition, and matrix phase composition, Combined with element atomic weight, density parameters and other calculations to determine.

Further, the volume percentage of the dispersed particle phase in its corresponding initial alloy strip is not higher than 50%.

Further, 99%≤x1<100%, 0<z1≤1%; 90%≤x2<100%, 0<z2≤10%; z1<d<z2, 2z1<z2;

Further, z1<d<z2, and 3z1<z2, that is, the D impurity content in the dispersed particle phase is lower than the D impurity content in the initial alloy melt, and the D impurity content in the dispersed particle phase is 3%. times are still lower than the D impurity content in the matrix phase;

Further, 99.5%≤x1<100%, 0<z1≤0.5%;

Further, 99.8%≤x1<100%, 0<z1≤0.2%;

In the step S3,

Further, the method for removing the matrix phase in the alloy strip includes acid reaction removal;

Because Cu can generally be removed by corrosion with a relatively concentrated and high-temperature hydrochloric acid aqueous solution, while M and T elements generally do not react with a relatively concentrated and high-temperature hydrochloric acid aqueous solution. Even if M contains elements (such as Fe) that can react with concentrated hydrochloric acid alone, when it is solid-dissolved in inert M or T, it is protected by inert M or T and cannot react with concentrated hydrochloric acid. Therefore, the matrix phase in the alloy ribbons can be removed by etching with a relatively concentrated and high temperature aqueous hydrochloric acid solution, while retaining the dispersed particle phase.

Further, the concentration of the hydrochloric acid aqueous solution contained in the acid reaction removal method is 2 mol/L to 12 mol/L.

Further, the acid reaction removal method includes the reaction temperature of the hydrochloric acid aqueous solution and the alloy strip being 0°C to 100°C.

Further, since the target powder material is the disperse particle phase dropped from the initial alloy ribbon, the composition and particle size of the target powder material are all equivalent to the composition and particle size of the corresponding disperse particle phase.

Further, the particle size range of the target powder material containing noble metal elements is 2 nm to 3 mm; preferably, the particle size range of the target powder material containing noble metal elements is 2 nm to 500 μm; The particle size range of the target powder material containing noble metal elements is 2 nm to 99 μm; as a further preference, the particle size range of the target powder material containing noble metal elements is 2 nm to 5 μm; The particle size range of the target powder material of the noble metal element is 2 nm to 200 nm; as a further preference, the particle size range of the target powder material containing the noble metal element is 2 nm to 100 nm.

Further, after the initial alloy strip is reacted with the acid solution, the dispersed particles are separated from the initial alloy strip, which is cleaned and dried to obtain the target powder material containing precious metal elements.

Further, the composition of the target powder material containing noble metal elements is mainly (M _x T _y ) _x1 D _z1 ;

Further, the target powder material containing noble metal elements whose composition is mainly (M _x T _y ) _x1 D _z1 does not contain Cu element;

Preferably, the composition of the target powder material containing noble metal elements is (M _x T _y ) _x1 D _z1 ;

Further, the atomic percentage content of D impurity element in the target powder material containing noble metal element is not more than 1%;

Preferably, the atomic percentage content of D impurity element in the target powder material containing noble metal element is not more than 0.5%;

Preferably, the atomic percentage content of D impurity element in the target powder material containing noble metal element is not more than 0.2%;

Further, the following step is performed after the step S3: after sieving the target powder material containing noble metal elements, selecting the target powder material containing noble metal elements with a particle size range of 5 μm to 200 μm for plasma spheroidization processing to obtain spherical powder materials containing precious metal elements;

Further, the particle size range of the spherical powder material containing noble metal elements is 5 μm˜200 μm.

The present invention also relates to the target powder material containing noble metal elements obtained by the above preparation method or the spherical powder material containing noble metal elements in catalytic materials, powder metallurgy, composite materials, wave absorbing materials, sterilization materials, metal injection molding, 3D materials Printing, coating applications.

Further, the application of the spherical powder material containing noble metal elements obtained by the above preparation method in the field of metal powder 3D printing is characterized in that the particle size range of the spherical powder material containing noble metal elements is 10μm～200μm.

Further, the application of the target powder material containing noble metal elements or the spherical powder material containing noble metal elements obtained by the above preparation method in metal injection molding and powder metallurgy, characterized in that the particle size range is 0.1 μm ~200 μm.

Further, the application of the target powder material containing noble metal elements obtained by the above preparation method in coatings and catalysts is characterized in that the particle size of the powder material ranges from 2 nm to 5 μm.

The invention also relates to an alloy strip, which is characterized in that it includes endogenous powder and a coating body; the solidified structure of the alloy strip includes a matrix phase and a dispersed particle phase, and the matrix phase is the coating body, and the dispersed particles The phase is the endogenous powder; the melting point of the coating body is lower than the endogenous powder, and the endogenous powder is coated in the coating body;

The composition of the endogenous powder in the initial alloy strip is mainly (M _x T _y ) _x1 D _z1 , and the average composition of the clad is mainly Cu _x2 D _z2 ; and 99%≤x1≤100%, 0≤z1≤ 1%; 90%≤x2≤100%, 0≤z2≤10%; z1≤d≤z2, 2z1≤z2; x1, z1, x2, z2 respectively represent the atomic percentage content of the corresponding constituent elements;

Preferably, further, 99%≤x1<100%, 0<z1≤1%; 90%≤x2<100%, 0<z2≤10%; z1<d<z2, 2z1<z2;

Further, z1<d<z2, and 3z1<z2,

Preferably, 99.5%≤x1<100%, 0<z1≤0.5%;

As a further preference, 99.8%≤x1<100%, 0<z1≤0.2%;

Further, the M contains at least one of the noble metal elements Ir, Ru, Re, Os, Tc, Au, Pt, Pd, and Ag; preferably, the M contains the noble metal elements Ir, Ru, Re, Os, Tc , at least one of Au, Pt, Pd, Ag, and the atomic percentage content of Ir, Ru, Re, Os, Tc and other elements in M is higher than 50%; as a further preference, the M contains noble metal elements Ir, At least one of Ru, Re, Os, Tc;

Further, the T includes at least one of W, Cr, Mo, V, Ta, Nb, Zr, Hf, Ti, and Fe; preferably, the T includes W, Cr, Mo, V, Ta, Nb , at least one of Zr, Hf, Ti, Fe, and the atomic percentage content of elements such as W, Cr, Mo, V, Ta, Nb in T is higher than 50%; as a further preference, the T contains W, At least one of Cr, Mo, V, Ta, Nb;

Wherein, the D is an impurity element and includes at least one of O, H, N, P, S, F, Cl, I, and Br; and the total content of these impurity elements is the content of D impurity elements;

Further, the endogenous powder in the alloy strip whose main component is (M _x T _y ) _x1 D _z1 does not contain Cu element;

Preferably, the composition of the endogenous powder in the initial alloy strip is (M _x T _y ) _x1 D _z1 , and the average composition of the cladding body is Cu _x2 D _z2 ;

Further, the thickness of the alloy strip is in the range of 5 μm to 10 mm; preferably, the thickness of the alloy strip is in the range of 5 μm to 5 mm; preferably, the thickness of the alloy strip is in the range of 5 μm to 1 mm; as a further Preferably, the thickness of the alloy strip is in the range of 5 μm to 200 μm; as a further preference, the thickness of the alloy strip is in the range of 5 μm to 20 μm.

Further, the width of the cross section of the alloy strip is more than 2 times its thickness; further, the length of the initial alloy strip is more than 10 times its thickness; preferably, the length of the initial alloy strip is more than 50 times its thickness; preferably, the length of the initial alloy strip is more than 100 times its thickness.

Further, the particle size range of the endogenous powder is 2nm～3mm; preferably, the particle size range of the endogenous powder is 2nm～500μm; preferably, the particle size range of the endogenous powder is 2nm～99μm ; As a further preference, the particle size range of the endogenous powder is 2nm～10μm; As a further preference, the particle diameter range of the endogenous powder is 2nm～1μm; As a further preference, the particle size range of the endogenous powder It is 2nm～200nm; as a further preference, the particle size range of the endogenous powder is 2nm～100nm.

Further, the shape of the endogenous powder includes at least one of dendritic shape, spherical shape, nearly spherical shape, square shape, cake shape, and rod shape.

Further, the number of single crystal particles in the endogenous powder in the alloy strip accounts for not less than 60% of the total number of endogenous powders.

Further, the volume percentage of the endogenous powder in the alloy strip does not exceed 50%.

Further, the alloy strip is prepared by step S1 and step S2 in the above-mentioned method for preparing a powder material containing a noble metal element.

It should be noted that M, T or D in the solution of the present invention may also contain other elements or impurity elements other than those listed above. As long as the introduction of these elements or the changes in their contents do not cause a "qualitative change" in the solidification process and law of the initial alloy, it does not affect the realization of the above technical solutions of the present invention.

Specifically, the result that the initial alloy solidification process and law does not undergo "qualitative change" means that when the M, T or D contains other elements or impurity elements other than those listed above, the following 1)- 3) The listed factual processes and laws still exist:

1) The initial alloy strip does not contain intermetallic compounds mainly composed of Cu and M, or Cu and T;

2) The solidified structure of the initial alloy strip includes a matrix phase and a dispersed particle phase; the melting point of the matrix phase is lower than that of the dispersed particle phase, and the dispersed particle phase is coated in the matrix phase;

3) When the D impurity content in the initial alloy melt is not 0, the D impurity content in the dispersed particle phase is lower than the D impurity content in the initial alloy melt, and the D impurity content in the dispersed particle phase is less than 2 times is still lower than the D impurity content in the matrix phase.

The technical scheme of the present invention has the following beneficial effects:

First, through ingenious alloy design, phase separation occurs when the initial alloy melt is solidified, so that endogenous particles of a certain particle size target composition can be formed during the solidification of the initial alloy melt and can be separated by subsequent processes. Generally speaking, nano-metal particles can be easily prepared by bottom-up chemical methods, such as chemical reduction, but when the size of the particles increases to hundreds of nanometers or even micrometers, it is difficult to prepare them. Metal particles of tens of microns or hundreds of microns can be easily prepared by top-down physical methods, such as atomization, ball milling, etc., but when the size of the particles is reduced to hundreds of nanometers to several microns, It is also difficult to prepare. The technical scheme of the present invention can easily prepare nano-, sub-micron, micron, and even millimeter-scale target metal powder particles according to the different cooling rates in the solidification process of the initial alloy strip, which overcomes the above technical difficulties and has extremely high performance. Earth advantage.

Secondly, the high-purity target powder materials were obtained from low-purity raw materials, and a new way was pointed out for the preparation of high-purity powder materials from low-purity raw materials, which was of positive significance. The improvement of the purity of the target powder material of the present invention is mainly achieved through the following three mechanisms: 1) The "absorption" effect of the main element Cu of the relative active matrix on the impurity elements of the initial alloy melt. Since Cu in the alloy is a low melting point element, it has a stronger affinity with the impurity element D during the melting and solidification of the alloy melt, which can make the impurity element D in the initial alloy melt enter more In the matrix phase composed of Cu element; 2) During the nucleation and growth of the endogenously precipitated dispersed particle phase, the impurity element D will be discharged into the remaining melt. As long as the endogenous precipitation of the dispersed particle phase is not later than the matrix phase in the solidification process, its impurities will be enriched in the last part of the melt that solidifies, that is, the part of the melt that is mainly composed of the main elements of the matrix phase and solidifies to form the matrix phase. . 3) Due to the existence of the matrix phase, the impurities related to the crucible entering the melt due to the interaction between the crucible and the melt during the smelting process are generally concentrated in the matrix phase, thereby further ensuring the purity of the dispersed particle phase, which makes the smelting process. The requirements for the crucible in the process are further reduced, which greatly reduces the production cost.

Third, the target metal powder mainly composed of single crystal particles can be obtained. Compared with polycrystalline powders, single crystal powders can achieve many significant and beneficial effects. During the solidification of the initial alloy melt, each endogenous dispersed particle grows and grows according to a specific atomic arrangement after nucleation from a certain position in the melt. By controlling the volume percentage of the dispersed particle phase in the initial alloy strip to not exceed 50%, it is difficult to merge and grow between individual endogenous particles under the condition that each endogenous particle can be dispersed and distributed. Therefore, most of the dispersed and distributed particle phases finally obtained are single crystal phases. Even if the size of dendrite particles is as large as tens of microns or millimeters, the growth direction of each secondary dendrite maintains a certain phase relationship with the growth direction of the main dendrite, which is still a single crystal particle. For polycrystalline materials, the grain boundaries generally contain impurity elements discharged from the grain during solidification, so it is difficult to obtain high-purity polycrystalline powder materials. When the target metal powder is mainly composed of single crystal particles, its purity must be guaranteed. Moreover, the atoms on the surface of the single crystal particles have specific arrangements, such as (111) plane arrangement, which will endow the target metal powder with special mechanical, physical and chemical properties, thereby producing beneficial effects.

Fourth, the alloy strip composed of the endogenous powder and the coating body (matrix phase) creatively utilizes the in-situ generated matrix phase to wrap the endogenous powder, thereby maintaining the high purity and high activity of the endogenous powder. Specifically, metal or alloy powders prepared by traditional chemical methods or physical methods, especially nano-powders with extremely large specific surface areas, are easily oxidized naturally and face the problem of difficulty in powder preservation. In order to solve this problem, after the alloy strip composed of endogenous metal powder and cladding body (matrix phase) is prepared in the technical solution of the present invention, the cladding body can not be removed in a hurry, but the cladding can be directly used. The body protects the endogenous metal powder from natural oxidation. This alloy strip composed of endogenous metal powder and cladding can be directly used as raw material for downstream production, so it has the potential to become a special product. When the downstream production needs to use high-purity powder, according to the characteristics of the next process, you can choose a suitable time and release the endogenous metal powder from the coating in the alloy strip under a suitable environment, and then as far as possible In a short time, the released endogenous powder enters the next production process, so that the chance of endogenous metal powder being contaminated by impurities such as oxygen is greatly reduced. For example, when the endogenous metal powder is nano-powder, the endogenous metal powder can be compounded with the resin at the same time as the endogenous metal powder is released from the cladding or immediately afterward, thereby preparing the resin-based composite material with the addition of endogenous metal powder with high activity.

Fifth, the solid alloy obtained by solidification in the step S2 is in the shape of a strip, which ensures the uniformity of the product shape and the feasibility of mass production. When the alloy strip is a thin alloy strip, it can be prepared by the stripping method. As long as the flow rate of the alloy melt flowing to the rotating roll is kept constant and the rotation speed of the rotating roll is fixed, an alloy thin strip with a uniform thickness can be obtained, and the preparation process It can be carried out continuously, which is beneficial to large-scale production. When the alloy strip is a thick alloy strip, it can be prepared by a mature continuous casting method. The principle of continuous casting is similar to that of the strip method, and a continuous and uniform thick strip can also be obtained through the melt. The preparation process can also It is carried out continuously, which is beneficial to large-scale production. When the thickness of the alloy strip is uniform, the cooling rate is also relatively uniform, and the particle size of the obtained dispersed particles is relatively uniform. In contrast, if the solid alloy obtained by solidification is in the shape of an ingot, according to common sense, the ingot has no uniform thickness, and no obvious length and endpoints, which generally leads to difficulty in dissipating heat from the internal melt, and it is easy to obtain abnormally large internal melts. Green particles, this is only necessary when the large endogenous particles simply need to be collected and purified. Moreover, it is difficult to continuously produce ordinary ingots. Therefore, the present invention obtains alloy strips by solidification, which is suitable for subsequent preparation of powder materials by "dephase method".

Therefore, the preparation method of the present invention has the characteristics of simple process, easy operation and low cost, and can prepare a variety of high-purity powder materials containing noble metal elements including nano-scale, sub-micron-scale and micro-scale. Metallurgy, composite materials, wave absorbing materials, sterilization materials, metal injection molding, 3D printing, coatings and other fields have good application prospects.

As an alternative solution, the present invention also provides a method for preparing metal powder, which comprises the following steps:

Step 1: Select an initial alloy with a composition of Cu _a M _b T _c , M is selected from at least one of Ir, Ru, Re, Os, Tc, T is selected from W, Cr, Mo, V, Ta, Nb, Zr , at least one of Hf, Ti, Fe; a, b, c represent the atomic percentage content of the corresponding constituent elements, and 50%≤a≤99.9%, 0.1%≤b≤50%, 0≤c≤49.9%, a+b+c=100%; the initial alloy raw material is melted according to the initial alloy composition ratio to obtain a uniform alloy melt, and then the alloy melt is solidified into a Cu _a M _b T _c master alloy by rapid solidification technology; The solidification structure of the Cu _a M _b T _c master alloy is composed of a matrix phase composed of Cu and a dispersed particle phase composed of MT, and the melting point of the MT dispersed particle phase is higher than that of the Cu matrix phase; preferably, 0.2%≤b≤ 50%, c=0, a+b+c=100%;

Step 2: The Cu matrix phase in the Cu _a M _b T _c master alloy is removed by the acid solution reaction, while retaining the MT dispersed particle phase that does not react with the acid solution, that is, the target metal composed of the MT dispersed particle phase is obtained. powder.

Through the above technical solution, the preparation of ultrafine metal powder can be realized. The higher the solidification rate of the master alloy melt, the smaller the dispersed particle phase in the obtained master alloy solidified structure. Therefore, the present invention can obtain nano-scale, sub-micron-scale and micro-scale dispersed particle phases by controlling the size of the solidification rate, and then obtain the target metal powder with the corresponding particle size by removing the Cu matrix phase, which greatly reduces the ultra-fine particle size. Manufacturing cost of metal powder.

Further, the rapid solidification technology includes the alloy melt metal rolling strip method, and the solidification rate of the alloy melt is 100K/s˜1×10 ⁷ K/s.

Further, the rapid solidification technology includes an alloy melt atomization pulverization method, and the solidification rate of the alloy melt is 50K/s˜5×10 ⁵ K/s.

Further, for the initial alloy composition, when the solidification rate is higher than 5×10 ⁴ K/s, a nanoscale (2nm～200nm) dispersed particle phase can be obtained; when the solidification rate is 1×10 ³ K/s～ At 5×10 ⁴ K/s, submicron (200nm～1000nm) dispersed particles can be obtained; when the solidification rate is lower than 1×10 ³ K/s, micron (>1μm) dispersed particles can be obtained .

Further, the Cu _a M _b T _c master alloy has at least one dimension in the three-dimensional dimension direction ranging from 5 μm to 500 μm. When the strip-shaped master alloy is prepared by the metal roll stripping method, the thickness of the master alloy strip is in the range of 5 μm to 500 μm; when the powdered master alloy is prepared by the melt atomization powder milling technology, the thickness of the master alloy strip is specified. The diameter range of 5μm ~ 500μm;

Further, the atomization and pulverization technology includes at least one of gas atomization, water atomization, water vapor-combined atomization, and vacuum atomization.

Further, the shape of the dispersed particle phase in the solidified structure of the master alloy includes at least one of dendritic, spherical, nearly spherical, square, cake, and rod, and the particle size ranges from 2 nm to 100 μm.

Further, the acid solution includes at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, acetic acid, and oxalic acid. The ratio of the acid and the concentration of the acid are to ensure that the Cu matrix can be removed by reaction, and the M-T dispersed particle phase does not react with the acid. Since the MT dispersed particle phase is mainly composed of extremely acid-resistant elements, and Cu can react significantly with some acids, such as 2 mol/L hydrochloric acid aqueous solution with a concentration higher than 2 mol/L, it can be determined according to the specific composition and ratio of the master alloy. The acid solution ratio and concentration are designed to remove the Cu matrix phase while retaining the MT dispersed particle phase. When Fe is contained in M-T, it is difficult for Fe to react with acid to be removed due to the protective effect of extremely acid-resistant M-type or other T-type elements. Therefore, it is also feasible to prepare M-T metal powders containing Fe.

Further, the particle size range of the target metal powder composed of the dispersed particle phase is 2 nm˜100 μm.

Further, the shape of the target metal powder includes at least one of dendritic shape, spherical shape, nearly spherical shape, square shape, pie shape, and rod shape.

Describe the technical characteristics of the present invention in further detail below:

First, the present invention can obtain nano-scale, sub-micron-scale, and micro-scale dispersed particle phases by controlling the size of the melt solidification rate, and then obtain the target metal powder with the corresponding particle size by removing the matrix phase, which greatly reduces the superfluous particle size. Preparation cost of fine metal powder.

Secondly, when the MT in the Cu _a M _b T _c alloy is a combination of multiple elements, the resulting dispersed particle phase is also composed of multiple elements, which makes it easier to prepare the target alloy powder composed of the dispersed particle phase. It is simple and feasible, and greatly expands the composition range and application field of the target alloy powder.

Therefore, the preparation method invented by this alternative solution has the characteristics of simple process, easy operation and low cost, and can prepare various metal powders including nano-scale, sub-micron and micro-scale, and is used in the fields of catalysis, powder metallurgy, composite materials, etc. Has a very good application prospect.

detailed description

Hereinafter, the preparation method of the high-purity metal powder will be further described by the following specific examples.

Example 1

The present embodiment provides a preparation method of nano Ru powder, and the preparation method comprises the following steps:

The alloy with the atomic ratio formula of Cu ₉₀ Ru ₁₀ was selected, and the raw materials were weighed according to the formula. After the initial alloy raw materials were melted uniformly, Cu ₉₀ with a thickness of 15 μm was prepared by the copper roller stripping technique at a solidification rate of 10 ⁶ K/s. Ru ₁₀ master alloy strip. The solidified structure of the alloy strip is composed of a matrix phase with a composition of Cu and a large amount of dispersed particles with a composition of Ru, wherein the shape of the Ru particles is nearly spherical, and the particle size ranges from 3 nm to 150 nm.

The Cu matrix in the master alloy strip is removed by the reaction of 6 mol/L hydrochloric acid aqueous solution, so that the Ru particles in the master alloy strip that are difficult to react with the hydrochloric acid aqueous solution of this concentration are detached, that is, nano Ru powder is obtained, and its particle size is in the range of 3nm～150nm.

Example 2

The alloy with the atomic ratio formula of Cu ₉₅ Ru ₅ is selected, and the raw materials are weighed according to the formula. After the initial alloy raw material is melted uniformly, the alloy melt is prepared into granules at a solidification rate of 5×10 ⁴ K/s by gas atomization technology. Cu ₉₅ Ru ₅ master alloy powder with diameters ranging from 5 μm to 100 μm. The solidification structure of the master alloy powder is composed of a matrix phase with a composition of Cu and a large amount of dispersed particles with a composition of Ru, wherein the shape of the Ru dispersed particles is nearly spherical, and the particle size ranges from 50nm to 200nm.

The Cu matrix in the master alloy powder is removed by the reaction of 6 mol/L hydrochloric acid aqueous solution, so that the Ru particles in the master alloy powder that are difficult to react with the hydrochloric acid aqueous solution of this concentration are detached, that is, nano Ru powder is obtained, and its particle size ranges from 50 nm to 50 nm. 200nm.

Example 3

The present embodiment provides a preparation method of submicron Ir-Nb powder, and the preparation method comprises the following steps:

The alloy with the atomic ratio formula of Cu ₇₀ Ir ₁₅ Nb ₁₅ is selected, the raw materials are weighed according to the formula, and after the initial alloy raw material is melted uniformly, the alloy melt is prepared into granules at a solidification rate of 10 ⁴ K/s by gas atomization technology Ir ₅₀ Nb ₅₀ master alloy powder with diameters ranging from 10 μm to 150 μm. The solidification structure of the master alloy powder is composed of a matrix phase with a composition of Cu and a large number of dispersed particle phases with a composition of Ir ₅₀ Nb ₅₀ , wherein the shape of the Ir ₅₀ Nb ₅₀ dispersed particles is nearly spherical, and the particle size ranges from 50nm to 1000nm.

The Cu matrix in the master alloy powder is removed by the reaction of the 6 mol/L hydrochloric acid aqueous solution, so that the Ir ₅₀ Nb ₅₀ particles in the master alloy powder that are difficult to react with the aqueous hydrochloric acid solution of this concentration are separated out, that is, the submicron Ir ₅₀ Nb ₅₀ powder is obtained. The particle size ranges from 50nm to 1000nm.

Example 4

This embodiment provides a preparation method of nano Ru-Ir-Os-Fe powder, and the preparation method includes the following steps:

An alloy whose atomic ratio formula is Cu ₉₀ Ru _2.5 Ir _2.5 Os _2.5 Fe _2.5 is selected, and the raw materials are weighed according to the formula. After the initial alloy raw material is melted uniformly, it is prepared by copper roller stripping technology at a solidification rate of 10 ⁶ K/s. Cu ₉₀ Ru _2.5 Ir _2.5 Os _2.5 Fe _2.5 master alloy strips with a thickness of 15 μm. The solidification structure of the alloy strip is composed of a matrix phase with a composition of Cu and a large amount of dispersed particles with a composition of Ru ₂₅ Ir ₂₅ Os ₂₅ Fe ₂₅ , wherein the shape of the Ru ₂₅ Ir ₂₅ Os ₂₅ Fe ₂₅ particles is nearly spherical, and the particle size is The size range is from 3nm to 150nm.

The Cu matrix in the master alloy strip is reacted and removed by a 5 mol/L hydrochloric acid aqueous solution, so that the Ru ₂₅ Ir ₂₅ Os ₂₅ Fe ₂₅ particles in the master alloy strip that are difficult to react with the aqueous hydrochloric acid solution of this concentration are separated out, that is, nano Ru ₂₅ is obtained. The Ir ₂₅ Os ₂₅ Fe ₂₅ powder has a particle size range of 3nm to 150nm.

Example 5

The present embodiment provides a preparation method of submicron W-Re powder, and the preparation method comprises the following steps:

The alloy with the atomic ratio formula of Cu ₉₀ W ₅ Re ₅ was selected, and the raw materials were weighed according to the formula. After the initial alloy raw materials were melted uniformly, the copper roller stripping technique was used to prepare the alloy with a thickness of 150 μm at a solidification rate of 10 ⁴ K/s. Cu ₉₀ W ₅ Re ₅ master alloy strip. The solidification structure of the alloy strip is composed of a matrix phase with a composition of Cu and a large amount of dispersed particles with a composition of W ₅₀ Re ₅₀ , wherein the shape of the Ru ₂₅ Ir ₂₅ Os ₂₅ Fe ₂₅ particles is nearly spherical, and the particle size range is 50 nm. ~1000nm.

The Cu matrix in the master alloy strip is removed by the reaction of 6 mol/L hydrochloric acid aqueous solution, so that the W ₅₀ Re ₅₀ particles in the master alloy strip that are difficult to react with the hydrochloric acid aqueous solution of this concentration are detached, that is, sub-micron W ₅₀ Re ₅₀ powder is obtained. , and its particle size ranges from 50 nm to 1000 nm.

Example 6

The present embodiment provides a preparation method of micron Ir-Ta-Nb-V powder, and the preparation method comprises the following steps:

The alloy whose atomic ratio formula is Cu ₈₀ Ir ₅ Ta ₅ Nb ₅ V ₅ is selected, and the raw materials are weighed according to the formula. After the initial alloy raw material is melted uniformly, it is prepared into a thickness of 500 μm Cu ₈₀ Ir ₅ Ta ₅ Nb ₅ V ₅ master alloy strip. The solidification structure of the alloy strip is composed of a matrix phase with a composition of Cu and a large amount of dispersed particles with a composition of Ir ₂₅ Ta ₂₅ Nb ₂₅ V ₂₅ , wherein the shape of the Ir ₂₅ Ta ₂₅ Nb ₂₅ V ₂₅ particles is dendritic, and the particle size is dendritic. The size ranges from 1 μm to 50 μm.

The Cu matrix in the master alloy strip is reacted and removed by a 6 mol/L hydrochloric acid aqueous solution, so that the Ir ₂₅ Ta ₂₅ Nb ₂₅ V ₂₅ particles in the master alloy strip that are difficult to react with the aqueous hydrochloric acid solution of this concentration are detached, and the micron Ir ₂₅ is obtained. Ta ₂₅ Nb ₂₅ V ₂₅ powder has a particle size range of 1 μm to 50 μm.

Example 7

This embodiment provides a preparation method of nano-Ir-Ta-Nb-Cr-Zr powder, and the preparation method includes the following steps:

An alloy whose atomic ratio formula is Cu ₇₅ Ir ₆ Ta ₆ Nb ₆ Cr ₆ Zr ₁ is selected, the raw materials are weighed according to the formula, and the initial alloy raw materials are melted uniformly, and the solidification rate of 10 ⁶ K/s is carried out by the copper roller stripping technique. A Cu ₇₅ Ir ₆ Ta ₆ Nb ₆ Cr ₆ Zr ₁ master alloy strip with a thickness of 15 μm was prepared. The solidification structure of the alloy strip is composed of a matrix phase with a composition of Cu and a large number of dispersed particles with a composition of Ir ₂₄ Ta ₂₄ Nb ₂₄ Cr ₂₄ Zr ₄ , wherein the shape of the Ir ₂₄ Ta ₂₄ Nb ₂₄ Cr ₂₄ Zr ₄ particles is nearly Spherical, with particle size ranging from 3nm to 150nm.

The Cu matrix in the master alloy strip is removed by the reaction of 5 mol/L hydrochloric acid aqueous solution, so that the Ir ₂₄ Ta ₂₄ Nb ₂₄ Cr ₂₄ Zr ₄ particles in the master alloy strip that are difficult to react with the hydrochloric acid aqueous solution of this concentration are detached, and the nanometer particles are obtained. The Ir ₂₄ Ta ₂₄ Nb ₂₄ Cr ₂₄ Zr ₄ powder has a particle size range of 3nm to 150nm.

Example 8

The present embodiment provides a preparation method of nano-Ir-Nb powder, and the preparation method comprises the following steps:

Select D (including O, H, N, P, S, F, Cl, Br, I) impurity elements with atomic percentage content of 0.2at.%, 0.5at.%, 0.5at.% Cu, Ir and Nb respectively The raw material is melted according to the molar ratio of Cu:Ir:Nb about 70:15:15 to obtain a homogeneous initial alloy melt whose atomic percentage composition is mainly Cu _69.9 Ir _14.9 Nb _14.9 D _0.3 .

The initial alloy melt was prepared into Cu _69.9 Ir _14.9 Nb _14.9 D _0.3 alloy ribbons with a thickness of ˜20 μm by copper roll stripping technique at a solidification rate of about ˜10 ⁶ K/s. The solidification structure of the alloy strip is composed of a matrix phase whose atomic percentage composition is mainly Cu _99.6 D _0.4 and a large amount of dispersed particle phase whose composition is mainly Ir _49.97 Nb _49.97 D _0.06 . The Ir _49.97 Nb _49.97 D _0.06 dispersed particles are nearly spherical in shape, and their particle size ranges from 10 nm to 150 nm. The volume percentage of Ir _49.97 Nb _49.97 D _0.06 dispersed particles in the alloy strip is about 37%;

Through 4 mol/L hydrochloric acid aqueous solution at 40 ℃ and Cu _69.9 Ir _14.9 Nb _14.9 D _0.3 alloy strips, the Cu matrix in the alloy strips is corroded and removed, so as to obtain Ir _49.97 Nb _49.97 D _0.06 dispersed particles, the particle size of which is The range is 10nm to 150nm. And the total content of O, H, N, P, S, F, Cl, Br, and I in the nano Ir _49.97 Nb _49.97 D _0.06 is 0.06 at.%.

Example 9

The present embodiment provides a preparation method of nano-Ir-Pt powder, and the preparation method comprises the following steps:

Select D (including O, H, N, P, S, F, Cl, Br, I) impurity elements with atomic percentage content of 0.2at.%, 0.5at.%, 0.5at.% Cu, Ir and Pt respectively The raw material is melted according to the molar ratio of Cu:Ir:Pt about 70:20:10 to obtain a homogeneous initial alloy melt whose atomic percentage composition is mainly Cu _69.85 Ir _19.9 Pt _9.95 D _0.3 .

The initial alloy melt was prepared into Cu _69.85 Ir _19.9 Pt _9.95 D _0.3 alloy strips with a thickness of ~20 μm by copper roll stripping technique at a solidification rate of about ~10 ⁶ K/s. The solidification structure of the alloy strip is composed of a matrix phase whose atomic percentage is mainly Cu _99.6 D _0.4 and a large amount of which is a dispersed particle phase which is mainly Ir _66.62 Pt _33.31 D _0.07 . The Ir _66.62 Pt _33.31 D _0.07 dispersed particles are nearly spherical in shape, and their particle size ranges from 10 nm to 150 nm. The volume percentage of Ir _66.62 Pt _33.31 D _0.07 dispersed particles in the alloy strip is about 34%;

Through 4 mol/L hydrochloric acid aqueous solution at 40 ℃ and Cu _69.85 Ir _19.9 Pt _9.95 D _0.3 alloy strip, the Cu matrix in the alloy strip is corroded and removed, so as to obtain Ir _66.62 Pt _33.31 D _0.07 dispersed particles, the particle size of which is The range is 10nm to 150nm. And the total content of O, H, N, P, S, F, Cl, Br, and I in the nano Ir _66.62 Pt _33.31 D _0.07 is 0.07 at.%.

Example 10

Select D (including O, H, N, P, S, F, Cl, Br, I) impurity elements with atomic percentage content of 0.2at.%, 0.5at.%, 0.5at.% Cu, Ir and Nb respectively Raw material, wherein the Ir raw material also contains 2 at.% Rh. The raw materials were melted in a ratio of about 70:15:15 in the molar ratio of Cu:Ir:Nb to obtain a homogeneous initial alloy melt with a composition of Cu _69.9 (Ir ₉₈ Rh ₂ ) _14.9 Nb _14.9 D _0.3 in atomic percentage.

The initial alloy melt was prepared into Cu _69.9 (Ir ₉₈ Rh ₂ ) _14.9 Nb _14.9 D _0.3 alloy ribbons with a thickness of ˜20 μm by copper roll stripping technique at a solidification rate of about ˜10 ⁶ K/s. The solidification structure of the alloy strip is composed of a matrix phase whose atomic percentage composition is mainly Cu _99.6 D _0.4 and a large amount of dispersed particle phase whose composition is mainly (Ir ₉₈ Rh ₂ ) _49.97 Nb _49.97 D _0.06 . The shape of the (Ir ₉₈ Rh ₂ ) _49.97 Nb _49.97 D _0.06 dispersed particles is nearly spherical, and the particle size ranges from 10 nm to 150 nm. The volume percentage of (Ir ₉₈ Rh ₂ ) _49.97 Nb _49.97 D _0.06 dispersed particles in the alloy strip is about 37%; moreover, the introduction of a small amount of Rh in the alloy melt did not lead to the formation of Cu in the initial alloy strip. It is an intermetallic compound composed of Rh; and it does not affect the structural characteristics of the matrix phase and the dispersed particle phase in the alloy strip, nor does it affect the law of reducing the impurity content in the dispersed particle phase.

By 4 mol/L hydrochloric acid aqueous solution at 40 ℃ and Cu _69.9 (Ir ₉₈ Rh ₂ ) _14.9 Nb _14.9 D _0.3 alloy strips, the Cu matrix in the alloy strips was etched away, thereby obtaining (Ir ₉₈ Rh ₂ ) _49.97 Nb _49.97 D _0.06 disperse particles with a particle size range of 10nm to 150nm. And the total content of O, H, N, P, S, F, Cl, Br, and I in nano (Ir ₉₈ Rh ₂ ) _49.97 Nb _49.97 D _0.06 is 0.06 at.%.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

A preparation method of a powder material containing noble metal elements, characterized in that, comprising the following steps:

In step 1, the initial alloy raw material is selected, and the initial alloy raw material is melted according to the initial alloy composition ratio to obtain a uniform initial alloy melt containing impurity element D; the average composition of the initial alloy melt is mainly Cu a (M x T y ) ) b D d , wherein M includes at least one of noble metal elements Ir, Ru, Re, Os, Tc, Au, Pt, Pd, and Ag, and T includes W, Cr, Mo, V, Ta, Nb, Zr, At least one of Hf, Ti, Fe, D contains at least one of O, H, N, P, S, F, Cl, I, Br; and 60%≤a≤99.9%, 0.1%≤b≤ 40%, 0≤d≤5%; 0.1%≤x≤100%, 0%≤y≤99.9%; among them, a, b, d, and x, y represent the atomic percentage content of the corresponding constituent elements;

In step 2, the initial alloy melt is solidified into an initial alloy strip; the solidified structure of the initial alloy strip includes a matrix phase and a dispersed particle phase; the melting point of the matrix phase is lower than that of the dispersed particle phase, and the The dispersed particle phase is coated in the matrix phase; during the solidification of the initial alloy melt, the impurity element D in the initial alloy melt is redistributed in the dispersed particle phase and the matrix phase, and is enriched in the matrix phase, so that the dispersed particle phase is purified;

The composition of the dispersed particle phase in the initial alloy strip is mainly (M x T y ) x1 D z1 , and the average composition of the matrix phase is mainly Cu x2 D z2 ; and 99%≤x1≤100%, 0≤z1≤1 %; 90%≤x2≤100%, 0≤z2≤10%; z1≤d≤z2, 2z1≤z2; x1, z1, x2, z2 represent the atomic percentage content of the corresponding constituent elements;

In step 3, the matrix phase in the initial alloy strip is removed, and the dispersed particle phase that cannot be removed at the same time in the process of removing the matrix phase is retained; High-purity target powder materials of precious metal elements.
The method for preparing a powder material containing noble metal elements according to claim 1, wherein the source of D impurity element in the initial alloy melt comprises: impurities introduced from the initial alloy raw material, impurities introduced from the atmosphere or crucible during the smelting process .
The method for preparing a powder material containing a noble metal element according to claim 1, wherein the M contains at least one of the noble metal elements Ir, Ru, Re, Os, Tc, Au, Pt, Pd, and Ag , and the atomic percentage content of Ir, Ru, Re, Os, Tc and other elements in M is higher than 50%; the T includes W, Cr, Mo, V, Ta, Nb, Zr, Hf, Ti, Fe At least one, and the atomic percentage content of W, Cr, Mo, V, Ta, Nb and other elements in T is higher than 50%.
The method for preparing a powder material containing a noble metal element according to claim 1, wherein the initial alloy strip does not contain an intermetallic compound composed of Cu and M, nor does it contain an intermetallic compound composed of Cu and T. intermetallic compounds.
The method for preparing a powder material containing noble metal elements according to claim 1, wherein the number of single crystal particles of dispersed particles in the initial alloy strip accounts for not less than 60% of the total number of dispersed particles .
The method for preparing a powder material containing noble metal elements according to claim 1, wherein the method for removing the matrix phase in the alloy strip comprises acid reaction removal.
The method for preparing a powder material containing a noble metal element according to claim 1, wherein the particle size range of the target powder material containing a noble metal element is 2 nm to 3 mm.
The method for preparing a powder material containing noble metal elements according to claim 1, characterized in that after step 3, the following step is further performed: after sieving the target powder material containing noble metal elements, selecting particles Plasma spheroidization is performed on powder materials with a diameter ranging from 5 μm to 200 μm to obtain spherical powder materials containing noble metal elements.
The target powder material containing noble metal elements or the spherical powder material containing noble metal elements according to any one of claims 1-8 is used in catalytic materials, powder metallurgy, composite materials, wave absorbing materials, bactericidal materials, magnetic materials , metal injection molding, 3D printing, coating applications.
An alloy strip is characterized in that it includes endogenous powder and a coating body; the solidification structure of the alloy strip includes a matrix phase and a dispersed particle phase, the matrix phase is the coating body, and the dispersed particle phase is the endogenous powder; the melting point of the coating body is lower than the melting point of the endogenous powder, and the endogenous powder is coated in the coating body; the composition of the endogenous powder in the initial alloy strip is mainly is (M x T y ) x1 D z1 , the average composition of the clad is mainly Cu x2 D z2 ; and 99%≤x1≤100%, 0≤z1≤1%; 90%≤x2≤100%, 0≤ z2≤10%; z1≤d≤z2, 2z1≤z2; x1, z1, x2, z2 respectively represent the atomic percentage content of the corresponding constituent elements; wherein, the M includes Ir, Ru, Re, Os, Tc, Au, At least one of Pt, Pd, Ag; T includes at least one of W, Cr, Mo, V, Ta, Nb, Zr, Hf, Ti, Fe; D includes O, H, N, P, S, At least one of F, Cl, I, and Br.
A preparation method of metal powder is characterized in that, comprises the following steps:

Step 1: Select an initial alloy with a composition of Cu a M b D c , M is selected from at least one of Ir, Ru, Re, Os, Tc, D is selected from W, Cr, Mo, V, Ta, Nb, Zr , at least one of Hf, Ti, Fe; a, b, c represent the atomic percentage content of the corresponding constituent elements, and 50%≤a≤99.9%, 0.1%≤b≤50%, 0≤c≤49.9%, a+b+c=100%; the initial alloy raw material is melted according to the initial alloy composition ratio to obtain a uniform alloy melt, and then the alloy melt is solidified into a Cu a M b D c master alloy by rapid solidification technology; The solidification structure of Cu a M b D c master alloy is composed of a matrix phase with Cu composition and a dispersed particle phase with MD composition, and the melting point of the MD dispersed particle phase is higher than that of the Cu matrix phase;

Step 2: The Cu matrix phase in the Cu a M b D c master alloy is removed by the acid solution reaction, while the MD dispersed particle phase that does not react with the acid solution is retained, that is, the target metal composed of the MD dispersed particle phase is obtained. powder.
The method for preparing metal powder according to claim 11, wherein the rapid solidification technology comprises an alloy melt metal roll stripping method, and the solidification rate of the alloy melt is 100K/s～1×10 7 K/s.
The method for preparing metal powder according to claim 11, wherein the rapid solidification technology comprises an alloy melt atomization powder making method, and the solidification rate of the alloy melt is 50K/s～5×10 5 K/s.
The method for preparing metal powder according to claim 11, wherein the Cu a M b D c master alloy has at least one dimension in the three-dimensional dimension direction ranging from 5 μm to 500 μm.
The method for preparing metal powder according to claim 11, wherein the shape of the dispersed particle phase in the solidified structure of the master alloy comprises at least one of dendritic, spherical, nearly spherical, square, pie, and rod shapes. One, and its particle size ranges from 2 nm to 100 μm.
The method for preparing metal powder according to claim 11, wherein the acid solution comprises at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, acetic acid, and oxalic acid.
The method for preparing metal powder according to claim 11, wherein the target metal powder composed of dispersed particle phases has a particle size range of 2 nm to 100 μm; the shape of the target metal powder includes dendritic, spherical, , at least one of nearly spherical shape, square shape, pie shape and rod shape.