CN111745155B - Low-melting cladding alloy powder and preparation method thereof, and iron-based diamond matrix - Google Patents

Abstract

The invention relates to the technical field of diamond tool matrix, in particular to low-melting cladding alloy powder, a preparation method thereof and an iron-based diamond matrix. The low-melting cladding alloy powder is of a core-shell structure, a shell layer comprises any one of Sn and Bi, and a core layer comprises FeCuNi prealloy. The preparation method of the low-melting cladding alloy powder comprises the following steps: under the action of a dispersing agent, ball-milling the mixture of Sn powder or Bi powder and FeCuNi prealloying powder, drying and screening. In the low-melting cladding alloy powder, in the sintering process of a matrix, a liquid phase formed by Sn or Bi and Cu on the surface of FeCuNi particles can form a Cu-Sn or Cu-Bi alloy liquid phase, and the Cu-Sn or Cu-Bi alloy liquid phase is rapidly diffused along the surface layer of the FeCuNi particles and permeates into gaps of the FeCuNi particles; improved tissue homogeneity, improved strength, etc.

Description

Low-melting cladding alloy powder and preparation method thereof, and iron-based diamond matrix

technical field

The invention relates to the technical field of diamond tool matrix, in particular to a low-melting clad alloy powder and a preparation method thereof, and an iron-based diamond matrix.

Background technique

The matrix system of diamond tools can be divided into Co-based, Cu-based, Fe-based, Ni-based and so on according to the main components of its base metal. Co-based matrix has good low-temperature bonding properties, high temperature resistance, good wettability to diamond and low erosiveness; good wear performance, high flexural strength, and easy alloying with other elements, but Co is a scarce strategic resource ,expensive. The Cu-based matrix is cheap and has high cutting edge, but low hardness and strength; Ni-based has good ductility, toughness and oxidation resistance, but its overall performance is worse than that of Co-based, the material price is higher than that of iron-based, and the overall cost performance is not high. Fe-based matrix has good wettability and suitable mechanical properties, low crack tendency and low price. Fe-based Co has always been the development trend of diamond tools, but Fe-based matrix diamond tools have problems in the manufacturing process. High sintering temperature, narrow controllable process range, easy thermal erosion of diamond, weak holding force, and easy burning of the matrix.

In the preparation of traditional iron-based matrix, Cu powder, Sn powder and Ni powder are added to Fe powder, and then sintered after mixing. During the sintering process, Sn first begins to melt at a lower temperature (231°C) to form a liquid phase, which contacts and dissolves the Cu in the particle system under the action of pre-sintering pressure to form a continuous Cu-Sn alloy liquid Mutually. However, due to the poor wettability between the Cu-Sn alloy liquid phase and the Fe particles and the uneven distribution of the two in the system, most of the Cu-Sn liquid phase cannot penetrate into the cracks of the Fe particles. It forms effective bonding, so a large number of Fe particles in the system contact each other under the action of sintering pressure and form a weak solid-phase sintering. In this system, although the liquid phase is generated, the liquid phase cannot effectively wet and bond the solid particles. This sintering method causes the inhomogeneity of the sample structure and affects the sintering effect and tool performance. . Therefore, it is an urgent technical problem to develop an iron-based diamond matrix that can improve the microstructure uniformity and bonding strength of the sintered body.

In view of this, the present invention is proposed.

SUMMARY OF THE INVENTION

The first object of the present invention is to provide low-melting cladding alloy powder to solve the technical problems in the prior art, such as poor uniformity of composition and structure.

The second object of the present invention is to provide low-melting cladding alloy powder, the preparation method is simple to operate and the conditions are mild.

The third object of the present invention is to provide an iron-based diamond matrix, the iron-based diamond matrix has uniform distribution of components and structure, and avoids the occurrence of component segregation.

The fourth object of the present invention is to provide a method for preparing an iron-based diamond matrix, which has no chemical process, does not pollute the environment, and can form an effective bond to make the distribution of the tissue structure more uniform.

The low melting cladding alloy powder has a core-shell structure, the shell layer includes any one of Sn and Bi, and the core layer includes FeCuNi pre-alloy.

The core-shell structure refers to a structure formed by covering the surface of the core-layer material with the shell-layer material.

When the low-melting cladding alloy powder of the present invention is used to prepare a carcass, during the sintering process of the carcass, due to the special core-shell structure, the liquid phase formed by Sn or Bi can form Cu-Sn with Cu on the surface of FeCuNi particles. or Cu-Bi alloy liquid phase, and rapidly diffused along the surface of FeCuNi particles and penetrated into the gaps of FeCuNi particles. Finally, the Cu-Sn or Cu-Bi alloy can form a continuous network structure, which wraps and binds FeCuNi particles, and the framework phase FeCuNi is granular and tightly bound in the network. The formation of this structure makes the bonding agent The distribution of components and tissue structure is more uniform, avoiding the occurrence of component segregation. In addition, during the preparation of the carcass, there are the same elements as other elements in the carcass, and according to the principle of similarity and compatibility, it has better affinity and is easy to combine with each other.

In a specific embodiment of the present invention, the mass ratio of the shell layer and the core layer is 1:(5-15), preferably 1:(8-10), more preferably 1:9.

As in different embodiments, the mass ratio of the shell layer and the core layer may be 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1 : 12, 1: 13, 1: 14, 1: 15, etc.

In a specific embodiment of the present invention, the particle size of the low-melting cladding alloy powder is 45-150 μm.

In a specific embodiment of the present invention, the FeCuNi pre-alloy includes Fe64%-65%, Cu 28%-29% and Ni 6.5%-7.5% by weight percentage, preferably Fe64.5%, Cu 28.5% % and Ni7%.

The present invention also provides a method for preparing the above-mentioned low-melting cladding alloy powder, comprising the following steps:

Under the action of a dispersant, the mixture of Sn powder or Bi powder and FeCuNi pre-alloyed powder is ball-milled and then dried.

In a specific embodiment of the present invention, after the drying treatment, screening is also included. Screening is carried out according to the actual required particle size to obtain the low-melting cladding alloy powder with the core-shell structure of the required particle size.

Among them, the purity of the raw materials Sn powder and Bi powder is ≥99.9%.

In a specific embodiment of the present invention, the average particle size of the Sn powder or Bi powder is less than or equal to 45 μm; the average particle size of the FeCuNi pre-alloyed powder is 75-150 μm.

Wherein, Sn powder or Bi powder and FeCuNi pre-alloyed powder are mixed in a mass ratio of 1:(5-15), preferably 1:(8-10), more preferably 1:9.

In a specific embodiment of the present invention, the conditions of the ball mill include: the rotational speed of the ball mill is 300-500r/min, the ball-milling time is 20-40h, and the ball-to-material ratio of the ball mill is (18-22 ):1. Preferably, the conditions of the ball milling include: the rotational speed of the ball mill is 400 r/min, the time of the ball milling is 20-40 hours, and the ball-to-material ratio of the ball mill is 20:1. Further, the medium of the ball milling is agate balls.

In practice, the ball milling process can be performed in an agate jar, such as an agate ball milling jar.

In a specific embodiment of the present invention, the drying is carried out under vacuum conditions. Further, the drying temperature is 100-120° C., and the drying time is ≥2h. Specifically, the vacuum degree of the vacuum condition is -0.1MPa or the vacuum degree is higher than -0.1MPa. Oxidation of the powder is prevented by applying vacuum conditions.

In a specific embodiment of the present invention, the dispersing agent includes ethanol and/or acetone. By adding a dispersant, the sphericity of the prepared low-melting clad alloy powder with a core-shell structure is improved, and powder adhesion is avoided.

In a specific embodiment of the present invention, the added amount of the dispersant is 3% to 5% of the mass of the mixture.

When the added amount of the dispersant is within the above range, the adhesion of the powder can be avoided, the uniformity of the powder dispersion can be ensured, and the sphericity of the low melting cladding alloy powder can be further improved.

The present invention also provides an iron-based diamond matrix, which is mainly prepared from the following components by weight percentage:

Fe 35%～45%, Cu 15%～20%, Sn 5%～10%, Ni 3%～5% and low melting cladding alloy powder 25%～35%;

Wherein, the low-melting cladding alloy powder is any one of the aforementioned low-melting cladding alloy powders.

As in different embodiments, in the iron-based diamond matrix, the amount of the component Fe may be 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44% , 45%, etc.; the amount of component Cu can be 15%, 16%, 17%, 18%, 19%, 20%, etc.; the amount of component Sn can be 5%, 6%, 7%, 8 %, 9%, 10%, etc.; the amount of component Ni can be 3%, 3.5%, 4%, 4.5%, 5%, etc.; the amount of component low-melting cladding alloy powder can be 25%, 26% %, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, etc.

In a preferred embodiment of the present invention, the iron-based diamond matrix is mainly prepared from the following components by weight percentage:

Fe 38%-43%, Cu 15%-19%, Sn 7%-9%, Ni 3%-4% and low melting cladding alloy powder 28%-32%.

In a further preferred embodiment of the present invention, the iron-based diamond matrix is mainly prepared from the following components by weight percentage:

Fe 40.7%, Cu 17.5%, Sn 8%, Ni 3.8% and low cladding alloy powder 30%.

The preparation method of above-mentioned iron-based diamond matrix comprises the steps:

The elemental powders of Fe, Cu, Sn and Ni are uniformly mixed with the low-melting cladding alloy powders in proportion, and hot-pressed sintering is performed.

Specifically, the uniformly mixed material can be placed in a mold, and then hot-pressed and sintered. For the mold, a suitable mold can be selected according to the shape requirements of the actual carcass.

In a specific embodiment of the present invention, the mixing is performed by a vacuum mixer, and the mixing time is ≥2h. Further, the vacuum mixer can use a V-type vacuum mixer, but is not limited to this.

In a specific embodiment of the present invention, the hot pressing sintering is performed under vacuum conditions. Further, the vacuum degree of the vacuum condition is -0.1MPa or the vacuum degree is higher than -0.1MPa. Oxidation is prevented by applying vacuum conditions.

In a specific embodiment of the present invention, the temperature of the hot-pressing sintering is 700-750° C., the pressure of the hot-pressing sintering is 18-22 MPa, and the heat-holding and pressure-holding time of the hot-pressing sintering is 5-10 minutes; preferably The temperature of the hot-pressing sintering is 750° C., the pressure of the hot-pressing sintering is 20 MPa, and the heat-holding and pressure-holding time of the hot-pressing sintering is 5-10 minutes.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The present invention adopts specific low-melting cladding alloy powder for the preparation of the carcass, which overcomes the fact that the traditional carcass preparation uses Fe, Cu, Sn, Ni elemental powder, and most of the Cu-Sn liquid phase formed is impermeable The Fe particles enter into the cracks to form an effective bond, which causes the inhomogeneity of the sample structure and the problem of poor tool performance;

(2) In the low-melting cladding alloy powder of the present invention, during the sintering process of the carcass, thanks to the special core-shell structure, the liquid phase formed by Sn or Bi can form Cu-Sn, Cu with the Cu on the surface of FeCuNi particles -Bi alloy liquid phase, and rapidly diffuses along the surface of FeCuNi particles, penetrates into the gaps of FeCuNi particles; forms a continuous network structure, wraps and bonds FeCuNi particles, and the skeleton phase FeCuNi is granular and tightly adhered in the network junction, so that the distribution of components and tissue structure is more uniform, and the occurrence of component segregation is avoided;

(3) The preparation method of the low-melting clad alloy powder of the present invention belongs to a physical preparation method, without the risk of environmental pollution caused by chemical processes, the shell has a good coating effect on the core, and the powder shape is nearly spherical.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

Figure 1 is a schematic diagram of the sintering process reaction; wherein, (a) is a schematic diagram of the sintering process reaction of elemental powder, and (b) is a schematic diagram of the sintering process reaction of low-melting clad alloy powder;

2 is a scanning element distribution diagram of the low-melting cladding alloy powder prepared in Example 1 of the present invention;

3 is a scanning element distribution diagram of the low-melting cladding alloy powder prepared in Example 2 of the present invention;

4 is a microstructure diagram of different matrixes; wherein, (a) is the cobalt-based matrix of Comparative Example 1, (b) is the iron-based diamond matrix of Example 3, and (c) is the iron of Example 4. base diamond matrix.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments, It is only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. If the specific conditions are not indicated in the examples, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used without the manufacturer's indication are conventional products that can be purchased from the market.

Example 1

This embodiment provides a low-melting cladding alloy powder, which has a core-shell structure, the shell layer is Sn, and the core layer is FeCuNi pre-alloy. The mass ratio of the shell layer and the core layer is 1:9. The low-melting cladding alloy powder whose shell layer is Sn and the core layer is FeCuNi pre-alloyed is abbreviated as FeCuNi-Sn low-melting cladding alloy powder.

The preparation method of FeCuNi-Sn low-melting cladding alloy powder in this embodiment includes the following steps:

(1) The Sn powder with an average particle size of less than 45 μm (purity ≥ 99.9%) and the FeCuNi pre-alloy with an average particle size of 75 to 150 μm are mixed into the agate tank at a mass ratio of 1:9, and the agate tank contains Agate ball, the ratio of ball to material is 20:1, add absolute ethanol (the amount of absolute ethanol added is 3% of the total mass of Sn powder and pre-alloy), start ball milling, the speed is 400r/min, and the ball milling time is 20h.

(2) Place the ball-milled material in step (1) for drying in a vacuum drying oven, the vacuum degree reaches -0.1MPa or higher, the drying temperature is 120°C, and the drying holding time is 2h.

(3) The powder obtained in step (2) is placed in a standard vibrating sieve for particle size screening to obtain FeCuNi-Sn core-shell structure low-melting clad alloy powder with a desired particle size of 50-150 μm.

Among them, the FeCuNi pre-alloy includes the following components by weight percentage: Fe 64.5%, Cu 28.5% and Ni 7%.

Example 2

This embodiment provides a low-melting cladding alloy powder, which has a core-shell structure, the shell layer is Bi, and the core layer is FeCuNi pre-alloy. The mass ratio of the shell layer and the core layer is 1:9. The low-melting cladding alloy powder whose shell layer is Bi and the core layer is FeCuNi pre-alloyed is abbreviated as FeCuNi-Bi low-melting cladding alloy powder.

The preparation method of FeCuNi-Bi low-melting cladding alloy powder in this embodiment includes the following steps:

(1) Mix Bi powder with an average particle size of less than 45 μm (purity ≥ 99.9%) and FeCuNi pre-alloy with an average particle size of 75 to 150 μm into the agate tank in a mass ratio of 1:9. Agate ball, the ratio of ball to material is 20:1, add absolute ethanol (the amount of absolute ethanol added is 3% of the total mass of Bi powder and pre-alloy), start ball milling, the speed is 400r/min, and the ball milling time is 20h.

(2) Place the ball-milled material in step (1) for drying in a vacuum drying oven, the vacuum degree reaches -0.1MPa or higher, the drying temperature is 120°C, and the drying holding time is 2h.

(3) The powder obtained in step (2) is placed on a standard vibrating sieve for particle size screening to obtain FeCuNi-Bi low-melting cladding alloy powder with a core-shell structure with a desired particle size of 50-150 μm.

Among them, the FeCuNi pre-alloy includes the following components by weight percentage: Fe 64.5%, Cu 28.5% and Ni 7%.

Example 3

The present embodiment provides a diamond matrix, which is mainly prepared from the following components in percent by weight:

Fe 40.7%, Cu 17.5%, Sn 8%, Ni 3.8% and low-cladding alloy powder 30%; wherein, the low-cladding alloy powder is the low-cladding alloy powder FeCuNi- Sn.

The preparation method of the diamond matrix of the present embodiment comprises the following steps:

(1) Weigh Fe elemental powder, Cu elemental powder, Sn elemental powder, Ni elemental powder and FeCuNi-Sn powder according to the mass ratio of 40.7%, 17.5%, 8%, 3.8% and 30%, and then mix them in vacuum Mixing in the machine for 2h;

(2) loading the mixed material in step (1) into a preset mold, and sintering by vacuum hot-pressing sintering to obtain an iron-based diamond matrix; the conditions for vacuum hot-pressing sintering include: the vacuum degree reaches -0.1MPa or higher vacuum degree, the temperature of hot-pressing sintering is 750℃, the pressure of hot-pressing sintering is 20MPa, and the holding time of hot-pressing sintering is 5min.

Wherein, the mold is selected according to the shape of the actual target carcass.

Example 4

The present embodiment provides a diamond matrix, which is mainly prepared from the following components in percent by weight:

Fe 40.7%, Cu 17.5%, Sn 8%, Ni 3.8% and low-cladding alloy powder 30%; wherein, the low-cladding alloy powder is the low-cladding alloy powder FeCuNi- Bi.

The preparation method of the diamond matrix of the present embodiment comprises the following steps:

(1) Weigh Fe elemental powder, Cu elemental powder, Sn elemental powder, Ni elemental powder and FeCuNi-Bi powder according to the mass ratio of 40.7%, 17.5%, 8%, 3.8% and 30%, and then mix them in vacuum Mixing in the machine for 2h;

(2) loading the mixed material in step (1) into a preset mold, and sintering by vacuum hot-pressing sintering to obtain an iron-based diamond matrix; the conditions for vacuum hot-pressing sintering include: the vacuum degree reaches -0.1MPa or higher vacuum degree, the temperature of hot-pressing sintering is 750℃, the pressure of hot-pressing sintering is 20MPa, and the holding time of hot-pressing sintering is 5min.

Wherein, the mold is selected according to the shape of the actual target carcass.

Comparative Example 1

Comparative Example 1 is a cobalt-based matrix, prepared from the following components in percent by mass:

Fe 36%, Cu 26%, Sn 8% and Co 30%.

The preparation method of cobalt-based matrix comprises the following steps:

(1) Weigh Fe elemental powder, Cu elemental powder, Sn elemental powder and Co elemental powder according to the mass ratio of 36%, 26%, 8% and 30%, and then mix them in a vacuum mixer for 2h;

(2) loading the mixed material in step (1) into a preset mold, and sintering by vacuum hot-pressing sintering to obtain a cobalt-based matrix; the conditions for vacuum hot-pressing sintering include: the degree of vacuum reaches- The vacuum degree of 0.1MPa or higher, the temperature of hot pressing sintering is 750℃, the pressure of hot pressing sintering is 20MPa, and the holding time of hot pressing sintering is 5min.

Experimental example 1

In order to illustrate the difference between the low-melting cladding alloy powder of the present invention and the existing elemental powder sintering process, as shown in Figure 1, (a) is a schematic diagram of the sintering process of the elemental powder, and (b) is the low-melting cladding alloy powder. Schematic diagram of the sintering process reaction. It can be seen from the figure that, taking the low-cladding alloy powder FeCuNi-Sn of the present invention as an example, during the sintering process of the carcass, thanks to the special core-shell structure, the liquid phase formed by Sn can interact with the Cu on the surface of FeCuNi particles. The Cu-Sn alloy liquid phase is formed, and it diffuses rapidly along the surface of FeCuNi particles and penetrates into the gaps of FeCuNi particles; a continuous network structure is formed, which wraps and bonds FeCuNi particles, and the skeleton phase FeCuNi is granular and tightly packed in the network. Tight bonding makes the distribution of components and structure more uniform and avoids the occurrence of component segregation.

Experimental example 2

In order to further verify the core-shell structure of the low-cladding alloy powder of the present invention, the low-cladding alloy powder FeCuNi-Sn and the low-cladding alloy powder FeCuNi-Bi prepared in Example 1 and Example 2 were scanned for elements The analysis is shown in Figures 2 and 3, respectively. It can be seen from the figure that Sn and Bi elements wrap the surface of FeCuNi alloy particles.

Experimental example 3

In order to illustrate the properties of the iron-based diamond matrix of the present invention, the properties of the matrix prepared in Examples 3 and 4 were compared with the cobalt-based matrix of Comparative Example 1. The performance test results are shown in Table 1.

Table 1 Performance test results of different carcasses

It can be seen from Table 1 that the performance of the iron-based diamond matrix of the present invention is equivalent to that of the commonly used cobalt-based matrix, and does not contain cobalt. 4 is a microstructure diagram of different matrixes; wherein, (a) is the cobalt-based matrix of Comparative Example 1, (b) is the iron-based diamond matrix of Example 3, and (c) is the iron of Example 4. base diamond matrix. It can be seen from the figure that the overall structure of the carcass of the present invention is more uniform and the density is also improved.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (18)

1. The iron-based diamond matrix is characterized by being mainly prepared from the following components in percentage by weight:

35-45% of Fe, 15-20% of Cu, 5-10% of Sn, 3-5% of Ni and 25-35% of low-melting cladding alloy powder; the low-melting cladding alloy powder is of a core-shell structure, a shell layer comprises any one of Sn and Bi, and a core layer comprises FeCuNi prealloy; the mass ratio of the shell layer to the nuclear layer is 1: 5-15.

2. The iron-based diamond matrix of claim 1, wherein the shell layer and the core layer are present at a mass ratio of 1: 8 to 10.

3. The iron-based diamond matrix of claim 1, wherein the shell layer and the core layer are present at a mass ratio of 1: 9.

4. The iron-based diamond matrix according to any one of claims 1 to 3, wherein the low-melting cladding alloy powder has a particle size of 45 to 150 μm.

5. The iron-based diamond matrix of claim 1, wherein the FeCuNi prealloy comprises, in weight percent, Fe 64-65%, Cu 28-29%, and Ni6.5-7.5%.

6. The iron-based diamond matrix according to claim 1, wherein the method of preparing the low-melting cladding alloy powder comprises the steps of:

under the action of a dispersing agent, ball milling treatment is carried out on a mixture of Sn powder and FeCuNi prealloying powder or Bi powder and FeCuNi prealloying powder, and then drying treatment is carried out.

7. The iron-based diamond matrix according to claim 6, wherein screening is performed after the drying process.

8. The iron-based diamond matrix according to claim 6, wherein the average grain size of the Sn or Bi powder is 45 μm or less; the average particle size of the FeCuNi prealloying powder is 75-150 mu m.

9. The iron-based diamond matrix of claim 6, wherein the ball milling conditions include: the rotation speed of ball milling is 300-500 r/min, the ball milling time is 20-40 h, and the ball-to-material ratio of ball milling is (18-22): 1.

10. The iron-based diamond matrix according to claim 9, wherein the rotation speed of the ball milling is 400r/min, the ball milling time is 20-40 h, and the ball-to-material ratio of the ball milling is 20: 1.

11. The iron-based diamond matrix according to claim 6, wherein the drying process is performed under vacuum conditions;

the drying temperature is 100-120 ℃, and the drying time is more than or equal to 2 h.

12. The iron-based diamond matrix of claim 11, wherein the vacuum condition is at a vacuum level of-0.1 MPa or at a vacuum level greater than-0.1 MPa.

13. The iron-based diamond matrix of claim 6, wherein the dispersant comprises ethanol and/or acetone.

14. The iron-based diamond matrix according to claim 13, wherein the dispersant is added in an amount of 3% to 5% by mass of the mixture.

15. The method for preparing an iron-based diamond matrix according to any one of claims 1 to 14, wherein the elemental powders of Fe, Cu, Sn and Ni and the low-melting coating alloy powder are uniformly mixed in proportion and subjected to hot-pressing sintering.

16. The method of making an iron-based diamond matrix according to claim 15, wherein the hot press sintering is performed under vacuum conditions.

17. The method of making an iron-based diamond matrix according to claim 16, wherein the vacuum condition is at a vacuum level of-0.1 MPa or at a vacuum level higher than-0.1 MPa.

18. The method for preparing the iron-based diamond matrix according to claim 15, wherein the temperature of the hot-pressing sintering is 700-750 ℃, the pressure of the hot-pressing sintering is 18-22 MPa, and the holding time and pressure maintaining time of the hot-pressing sintering are 5-10 min.

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