CN111378858A - A kind of Mo-modified chromium carbide-nickel-chromium composite material and preparation method thereof - Google Patents

Abstract

The invention provides a Mo modified (Cr, Mo)₃C₂‑(Cr,Mo)₇C₃-a NiCr composite and a method for preparing the same, comprising: step 1, carrying out ball milling and mixing on Cr powder, C powder, Ni powder and Mo powder; step 2, carrying out compression molding on the mixed powder to obtain an original blank; step 3, sintering the original blank body under vacuum and no pressure, wherein the vacuum degree is 0.0001-0.1Pa during sintering, the sintering temperature is 1100-1500 ℃, and Mo modified (Cr, Mo) is obtained₃C₂‑(Cr,Mo)₇C₃-a NiCr composite material. The invention prepares novel (Cr, Mo)₃C₂‑(Cr,Mo)₇C₃The main mechanical property indexes of the-NiCr composite material are good, and the mechanical properties are obviously improved.

Description

A kind of Mo-modified chromium carbide-nickel-chromium composite material and preparation method thereof

technical field

The invention belongs to the field of structural functional materials, and relates to a Mo-modified chromium carbide-nickel-chromium composite material and a preparation method thereof.

Background technique

Chromium carbide-nickel composite material (composed of ceramic hard phase chromium carbide and metal binder phase nickel, wherein the mass percentage of ceramic hard phase is generally controlled between 70wt.%-90wt.%) has a series of excellent properties: 1 ) High temperature hardness, its Vickers hardness (HV) is greater than 2000HV at 1100 ℃; 2) The thermal expansion coefficient is significantly higher than other metal-ceramic composite materials and similar to steel, so it is especially suitable for the manufacture of various precision wear-resistant measuring tools, cutting tools and high temperature mold; 3) low density, its density is only about half of tungsten carbide cermet composite material, which is convenient for lightweight production in the industrial field; 4) high temperature oxidation resistance is good, and there is no change in heating at 1000 ° C for 2 hours. The polished sample is kept at 1100 °C for 24 hours without forming oxide scale on the surface; 5) Excellent wear resistance, due to the presence of hard chromium carbide skeleton phase, the room temperature hardness of chromium carbide-based cermet composites is about HRA88 or more, and The hardness and wear resistance of tungsten carbide cermet composite material YG8 are equivalent; 6) good corrosion resistance, excellent corrosion resistance in strong acid, strong alkali, seawater, petroleum industry and other corrosive media. Therefore, chromium carbide-nickel composite materials have broad application prospects in the fields of wear-resistant materials and corrosion-resistant materials.

In recent years, the Cr ₃ C ₂ -Ni cermets prepared by domestic and foreign researchers from Cr ₃ C ₂ powder and Ni powder have problems such as large Cr ₃ C ₂ particle size (about 20-30μm) and low flexural strength. , the lower mechanical properties limit its production applications.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a Mo-modified (Cr, Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material and a preparation method thereof. The prepared (Cr, Mo) ₃ C ₂ -( Cr,Mo) ₇ C ₃ -NiCr composite has good mechanical properties.

The present invention adopts following technical scheme to realize:

A preparation method of Mo-modified chromium carbide-nickel-chromium composite material, comprising the following steps:

In step 1, Cr powder, C powder, Ni powder and Mo powder are ball-milled and mixed to obtain a mixed powder; wherein, the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for Cr powder, The total mass of C powder and Ni powder is 10.7%, the mass of Ni powder is 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder is 0.5-1.5% of the total mass of Cr powder, C powder and Ni powder;

Step 2, molding the mixed powder to obtain the original body;

In step 3, vacuum pressureless sintering is performed on the original body, and the sintering temperature is 1100-1500° C. to obtain a Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material.

Preferably, in step 1, the ball milling jar used in the ball milling is an agate jar, the grinding balls are agate balls, the diameter of the agate balls is 1-5 mm, and the ball-to-material ratio used in the ball milling is (5-10):1, respectively.

Preferably, in step 1, the ball milling time is 1-15 hours.

Preferably, in step 1, the purity and particle size of Cr powder are: 99.9% and ≤20 μm; the purity and particle size of C powder are: 99.9% and ≤1 μm; the purity and particle size of Ni powder are: 99.9% and ≤5 μm; Mo The powder purity and particle size are: 99.9% and ≤5μm, respectively.

Preferably, in step 2, the pressure used for compression molding is 200-500 MPa.

Preferably, in step 3, the sintering time is 1-4h.

Preferably, the heating rate during sintering is 5°C-10°C/min.

Preferably, the degree of vacuum during sintering is 0.0001-0.1 Pa.

The Mo-modified chromium carbide-nickel-chromium composite material obtained by the preparation method.

Compared with the prior art, the present invention has the following beneficial technical effects:

The chromium carbide-nickel-chromium composite material prepared by doping the alloy element Mo in the present invention not only has a Cr ₃ C ₂ phase, but also produces a Cr ₇ C ₃ phase, and is compatible with the chromium carbide-nickel composite material not doped with Mo. Compared with the ceramic phase, the particle size is significantly reduced. Based on the theory of diffusion thermodynamics, the doping of Mo element will promote the interdiffusion of Ni and Cr. Part of the Cr atoms replaced by Ni atoms and Mo atoms diffuses into Ni to form NiCr phase, and the other part of Cr atoms increases the interdiffusion of Cr and C. At the initial ratio, a phase transformation of the Cr ₇ C ₃ phase occurs, resulting in the Cr ₇ C ₃ phase. Since the mechanical properties of the Cr ₇ C ₃ phase are better than those of the Cr ₃ C ₂ phase, and the particle size of the ceramic phase is reduced, the final prepared (Cr,Mo) ₃ C ₂ -(Cr,Mo) ₇ C ₃ -NiCr The mechanical properties such as flexural strength and hardness of composite materials have been significantly improved. The preparation method of the invention is simple, and provides a new technology with low cost, stable process and easy industrialization for preparing high-performance (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material.

The Mo-modified (Cr, Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material prepared in the present invention has high density and good main mechanical properties, and is suitable for high temperature oxidation, high temperature wear and the like. Harsh conditions.

Description of drawings

Fig. 1 is the XRD analysis results of the (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material of Example 1-3 and the material of the comparative example; (a) Examples 1-3 and (b) ) for the comparison.

Figure 2 is the structure diagram of the composite material of the present invention; (a) without Mo added, (b) with 0.5 wt.% Mo, (c) with 1.0 wt. % Mo and (d) with 1.5 wt. % Mo.

Detailed ways

The present invention will be further described in detail below in conjunction with specific embodiments, which are to explain rather than limit the present invention.

The preparation method of the Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material according to the present invention comprises the following steps:

Step 1, select Cr powder, C powder, Ni powder and Mo powder as raw materials, among which, the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for the total mass of Cr powder, C powder and Ni powder. The mass of Ni powder accounts for 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder accounts for 0.5-1.5% of the total mass of Cr powder, C powder and Ni powder. The Cr powder, C powder, Ni powder and Mo powder were weighed and put into the agate ball mill jar. The grinding balls were agate balls (1-5mm in diameter), and the ratio of balls to material was (5-10):1.

Step 2, put the agate ball mill into the planetary ball mill and turn it on. The ball milling time is 1-15 hours. After the ball milling is completed, it will be cooled to room temperature together with the ball mill, and the ball mill will be opened. The mixed powder is filled into a metal mold and molded under 200-500MPa.

Step 3, put the molded body into a graphite mold and put it into a vacuum pressureless sintering furnace for sintering, the vacuum degree during sintering is 0.0001-0.1Pa; the heating rate of the sintering furnace is: 5 ℃-10 ℃ / minutes; sintering temperature is: 1100-1500 ℃ (holding time is 1-4h), after the sintering is completed, it will be cooled together with the sintering furnace.

The purity and particle size of Cr powder are: 99.9% and ≤20μm;

The purity and particle size of C powder are: 99.9% and ≤1μm;

The purity and particle size of Ni powder are: 99.9% and ≤5μm;

The purity and particle size of Mo powder are: 99.9% and ≤5μm, respectively.

Specific embodiments of the present invention are described below:

Example 1:

First, the raw materials are Cr powder (purity and particle size: 99.9% and ≤20μm, respectively), C powder (purity and particle size: 99.9% and ≤1μm, respectively), Ni powder (purity and particle size: 99.9% and ≤5μm, respectively. ) and Mo powder (purity and particle size: 99.9% and ≤5μm, respectively), of which the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for the total mass of Cr powder, C powder and Ni powder. The mass of Ni powder accounts for 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder accounts for 0.5% of the total mass of Cr powder, C powder and Ni powder. After weighing, put it into an agate ball mill jar, the grinding balls are agate balls (diameter 1mm), and the ball-to-material ratio is 10:1.

Then, put the agate ball milling jar into the planetary ball mill and turn it on. After 13 hours of ball milling, the jar is cooled to room temperature together with the jar, and the jar is opened to fill the ball mill powder into the metal mold, and press-molded at 200 MPa;

Finally, put the molded green body into a graphite mold and put it into a vacuum sintering furnace for pressureless sintering. The vacuum degree during sintering is 10 ^-4 Pa; the heating rate of the sintering furnace is 5°C/min; the sintering temperature is : 1300 ℃ (holding time is 1h), after the sintering is completed, it will be cooled together with the sintering furnace.

The Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material prepared in this example has a porosity of 1.11%, a hardness of 86.9 HRA, a flexural strength of 1210 MPa, and a fracture toughness of 1210 MPa. up to 14.1MPa·m ^1/2 . Wherein, the volume percentage of Cr ₃ C ₂ and Cr ₇ C ₃ in the ceramic phase is 3:5.

Example 2:

First, the raw materials are Cr powder (purity and particle size: 99.9% and ≤20μm, respectively), C powder (purity and particle size: 99.9% and ≤1μm, respectively), Ni powder (purity and particle size: 99.9% and ≤5μm, respectively. ) and Mo powder (purity and particle size: 99.9% and ≤5μm, respectively), of which the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for the total mass of Cr powder, C powder and Ni powder. The mass of Ni powder accounts for 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder accounts for 1.0% of the total mass of Cr powder, C powder and Ni powder. After weighing, put it into an agate ball mill jar, the grinding balls are agate balls (diameter 1mm), and the ball-to-material ratio is 10:1.

Then, put the agate ball milling jar into the planetary ball mill and turn it on. After 13 hours of ball milling, the jar is cooled to room temperature together with the jar, and the jar is opened to fill the ball mill powder into the metal mold, and press-molded at 200 MPa;

Finally, put the molded green body into a graphite mold and put it into a vacuum sintering furnace for pressureless sintering. The vacuum degree during sintering is 10 ^-4 Pa; the heating rate of the sintering furnace is 5°C/min; the sintering temperature is : 1300 ℃ (holding time is 1h), after the sintering is completed, it will be cooled together with the sintering furnace.

The Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite prepared in this example has a porosity of 0.92%, a hardness of 88.5HRA, a flexural strength of 1290 MPa, and a fracture toughness of 1290 MPa. up to 15.6MPa·m ^1/2 . Wherein, the volume percentage of Cr ₃ C ₂ and Cr ₇ C ₃ in the ceramic phase is 1:3.

Example 3:

First, the raw materials are Cr powder (purity and particle size: 99.9% and ≤20μm, respectively), C powder (purity and particle size: 99.9% and ≤1μm, respectively), Ni powder (purity and particle size: 99.9% and ≤5μm, respectively. ) and Mo powder (purity and particle size: 99.9% and ≤5μm, respectively), of which the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for the total mass of Cr powder, C powder and Ni powder. The mass of Ni powder accounts for 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder accounts for 1.5% of the total mass of Cr powder, C powder and Ni powder. After weighing, put it into an agate ball mill jar, the grinding balls are agate balls (diameter 1mm), and the ball-to-material ratio is 10:1.

Then, put the agate ball milling jar into the planetary ball mill and turn it on. After 13 hours of ball milling, the jar is cooled to room temperature together with the jar, and the jar is opened to fill the ball mill powder into the metal mold, and press-molded at 200 MPa;

Finally, put the molded green body into a graphite mold and put it into a vacuum sintering furnace for pressureless sintering. The vacuum degree during sintering is 10 ^-4 Pa; the heating rate of the sintering furnace is 5°C/min; the sintering temperature is : 1300 ℃ (holding time is 1h), after the sintering is completed, it will be cooled together with the sintering furnace.

The Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite prepared in this example has a porosity of 0.88%, a hardness of 88.8 HRA, a flexural strength of 1300 MPa, and a fracture toughness of 1300 MPa. up to 15.8MPa·m ^1/2 . Wherein, the volume percentage of Cr ₃ C ₂ and Cr ₇ C ₃ in the ceramic phase is 1:4.

Example 4:

First, the raw materials are Cr powder (purity and particle size: 99.9% and ≤20μm, respectively), C powder (purity and particle size: 99.9% and ≤1μm, respectively), Ni powder (purity and particle size: 99.9% and ≤5μm, respectively. ) and Mo powder (purity and particle size: 99.9% and ≤5μm, respectively), of which the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for the total mass of Cr powder, C powder and Ni powder. The mass of Ni powder accounts for 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder accounts for 1.5% of the total mass of Cr powder, C powder and Ni powder. After weighing, put it into an agate ball mill jar, the grinding balls are agate balls (diameter 1mm), and the ball-to-material ratio is 5:1.

Then, put the agate ball milling jar into the planetary ball mill and turn it on. After 1 hour of ball milling, the jar is cooled to room temperature together with the jar body, and the jar body is opened to fill the ball mill powder into the metal mold, which is molded under 200MPa;

Finally, put the molded body into a graphite mold and put it into a vacuum sintering furnace for pressureless sintering. The vacuum degree during sintering is 0.1Pa; the heating rate of the sintering furnace is: 5°C/min; the sintering temperature is: 1100 ℃ (holding time is 1h), after the sintering is completed, it will be cooled together with the sintering furnace.

The Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite prepared in this example has a porosity of 3.46%, a hardness of 81.2 HRA, a flexural strength of 720 MPa, and a fracture toughness of 720 MPa. up to 7.4MPa·m ^1/2 . Wherein, the volume percentage of Cr ₃ C ₂ and Cr ₇ C ₃ in the ceramic phase is 1:5.

Example 5:

First, the raw materials are Cr powder (purity and particle size: 99.9% and ≤20μm, respectively), C powder (purity and particle size: 99.9% and ≤1μm, respectively), Ni powder (purity and particle size: 99.9% and ≤5μm, respectively. ) and Mo powder (purity and particle size: 99.9% and ≤5μm, respectively), of which the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for the total mass of Cr powder, C powder and Ni powder. The mass of Ni powder accounts for 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder accounts for 1.5% of the total mass of Cr powder, C powder and Ni powder. After weighing, put it into an agate ball mill jar, the grinding ball is agate ball (diameter 5mm), and the ratio of ball to material is 10:1.

Then, put the agate ball milling jar into the planetary ball mill and turn it on. After 15 hours of ball milling, the jar is cooled to room temperature together with the jar body, and the jar body is opened to fill the ball mill powder into the metal mold, which is molded under 500MPa;

Finally, put the molded green body into a graphite mold and put it into a vacuum sintering furnace together for pressureless sintering, and the vacuum degree during sintering is 10 ^-4 Pa; the heating rate of the sintering furnace is: 10°C/min; the sintering temperature is : 1500 ℃ (holding time is 4h), after the sintering is completed, it will be cooled together with the sintering furnace.

The Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material prepared in this example has a porosity of 1.02%, a hardness of 86.5 HRA, a flexural strength of 1120 MPa, and a fracture toughness of 1120 MPa. up to 12.3MPa·m ^1/2 . Wherein, the volume percentage of Cr ₃ C ₂ and Cr ₇ C ₃ in the ceramic phase is 2:5.

Example 6:

First, the raw materials are Cr powder (purity and particle size: 99.9% and ≤20μm, respectively), C powder (purity and particle size: 99.9% and ≤1μm, respectively), Ni powder (purity and particle size: 99.9% and ≤5μm, respectively. ) and Mo powder (purity and particle size: 99.9% and ≤5μm, respectively), of which the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for the total mass of Cr powder, C powder and Ni powder. The mass of Ni powder accounts for 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder accounts for 1.5% of the total mass of Cr powder, C powder and Ni powder. After weighing, put it into an agate ball mill jar, the grinding balls are agate balls (diameter 3mm), and the ball-to-material ratio is 8:1.

Then, put the agate ball milling jar into the planetary ball mill and turn it on. After 10 hours of ball milling, the jar is cooled to room temperature together with the jar, and the jar is opened to fill the ball mill powder into the metal mold, which is molded under 300MPa;

Finally, put the molded body into a graphite mold and put it into a vacuum sintering furnace together for pressureless sintering, the vacuum degree during sintering is 10 ^-3 Pa; the heating rate of the sintering furnace is: 8°C/min; the sintering temperature is : 1300 ℃ (holding time is 2h), after the sintering is completed, it will be cooled together with the sintering furnace.

The Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material prepared in this example has a porosity of 0.91%, a hardness of 88.2 HRA, a flexural strength of 1270 MPa, and a fracture toughness of 1270 MPa. up to 15.4MPa·m ^1/2 . Wherein, the volume percentage of Cr ₃ C ₂ and Cr ₇ C ₃ in the ceramic phase is 3:8.

Comparative ratio:

First, the raw materials are Cr powder (purity and particle size: 99.9% and ≤20μm, respectively), C powder (purity and particle size: 99.9% and ≤1μm, respectively) and Ni powder (purity and particle size: 99.9% and ≤5μm, respectively ), in which the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, the mass of C powder accounts for 10.7% of the total mass of Cr powder, C powder and Ni powder, and the mass of Ni powder accounts for Cr powder, C powder and Ni powder. 20% of the total mass of the powder is weighed and put into an agate ball mill jar. The grinding balls are agate balls (diameter 1mm), and the ball-to-material ratio is 10:1.

Then, put the agate ball milling jar into the planetary ball mill and turn it on. After 13 hours of ball milling, the jar is cooled to room temperature together with the jar, and the jar is opened to fill the ball mill powder into the metal mold, and press-molded at 200 MPa;

Finally, put the molded green body into a graphite mold and put it into a vacuum sintering furnace for pressureless sintering. The vacuum degree during sintering is 10 ^-4 Pa; the heating rate of the sintering furnace is 5°C/min; the sintering temperature is : 1300 ℃ (holding time is 1h), after the sintering is completed, it will be cooled together with the sintering furnace.

The Cr ₃ C ₂ -Ni composite material without Mo added in this comparative example has a porosity of 1.44%, a hardness of 85.4 HRA, a flexural strength of 1040 MPa, and a fracture toughness of 13.2 MPa·m ^1/2 . Among them, all the ceramic phases are Cr ₃ C ₂ and do not contain Cr ₇ C ₃ .

The XRD patterns of the materials prepared in Examples 1-3 and Comparative Examples are shown in Figure 1. It can be seen from the peaks of the XRD patterns that the materials obtained by adding Mo in Example 1-3 include (Cr, Mo) ₃ C ₂ , ( Cr, Mo) ₇ C ₃ and NiCr three phases, while the material prepared without adding Mo in the comparative example has only two phases of Cr ₃ C ₂ and Ni.

The comparative example is a Cr ₃ C ₂ -Ni composite material prepared without adding Mo, using Cr powder, C powder and Ni powder for sintering, under the conditions of ball milling time of 13h, sintering temperature of 1300°C, and holding time of 1h, the microstructure after sintering is shown in the figure. As shown in 2(a), Cr ₇ C ₃ is not contained in the structure, the gray portion is Cr ₃ C ₂ , and the white portion is Ni. Examples 1-3 of the present invention were prepared by using Cr powder, C powder, Ni powder and Mo powder with different contents under the conditions of ball milling for 13 hours, molding pressure of 200 MPa, sintering temperature of 1300 °C, and holding time of 1 hour. A new Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material was obtained, as shown in (b), (c) and (d) in Figure 2, the black part is (Cr,Mo) ₃ C ₂ , the gray part is (Cr, Mo) ₇ C ₃ , and the white part is NiCr. It can be seen from the comparison that the particle size of the ceramic phase obtained by adding Mo in Examples 1-3 is significantly reduced compared to the comparative example. Compared with Cr ₃ C ₂ , the newly formed Cr ₇ C ₃ has more excellent hardness and strength, and the particle size of the ceramic phase is reduced, so (Cr,Mo) ₃ C ₂ -(Cr,Mo) ₇ C ₃ -NiCr The mechanical properties of the composites are more excellent, and the main mechanical properties are good, as shown in Table 1.

Table 1 Comparative Example and Example Mechanical Properties Contrast Value

Compared with the comparative example, the particle size of the ceramic phase in the Mo-modified (Cr,Mo) ₃ C ₂ -(Cr,Mo) ₇ C ₃ -NiCr composites was significantly reduced, and the newly formed particles were significantly smaller than those of Cr ₃ C ₂ . Cr ₇ C ₃ has more excellent hardness and strength, so the mechanical properties of the (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material are obviously improved, and the production cycle of the invention is short and the process is relatively simple.

At the same time, the present invention improves the microstructure of the composite material by adding Mo powder with different contents, and controls the microstructure ratio of the ceramic phase Cr ₃ C ₂ and Cr ₇ C ₃ by adjusting the content of the Mo powder added, thereby effectively reducing the size of the ceramic particles and improving the mechanical properties. performance. By comparing Examples 1-3, it can be seen that with the increase of Mo addition, the proportion of Cr ₇ C ₃ in the ceramic phase increases, and the mechanical properties also increase. ratio is significantly reduced.

Claims (9)

1. a preparation method of Mo-modified chromium carbide-nickel-chromium composite material, is characterized in that, comprises the following steps: In step 1, Cr powder, C powder, Ni powder and Mo powder are ball-milled and mixed to obtain a mixed powder; wherein, the mass of Cr powder accounts for 69.3% of the total mass of Cr powder, C powder and Ni powder, and the mass of C powder accounts for Cr powder, The total mass of C powder and Ni powder is 10.7%, the mass of Ni powder is 20% of the total mass of Cr powder, C powder and Ni powder, and the mass of Mo powder is 0.5-1.5% of the total mass of Cr powder, C powder and Ni powder; Step 2, molding the mixed powder to obtain the original body; In step 3, vacuum pressureless sintering is performed on the original body, and the sintering temperature is 1100-1500° C. to obtain a Mo-modified (Cr,Mo) ₃ C ₂ -(Cr, Mo) ₇ C ₃ -NiCr composite material. 2. the preparation method of the chromium carbide-nickel-chromium composite material of Mo modification according to claim 1, is characterized in that, in step 1, the ball mill tank that ball mill adopts is agate tank, and grinding ball is agate ball, and agate ball diameter 1-5mm, the ball-to-material ratio used in the ball mill is (5-10): 1, respectively. 3. The preparation method of Mo-modified chromium carbide-nickel-chromium composite material according to claim 1, wherein in step 1, the ball milling time is 1-15 hours. 4. The preparation method of Mo-modified chromium carbide-nickel-chromium composite material according to claim 1, is characterized in that, in step 1, Cr powder purity and particle size are respectively: 99.9% and≤20μm; C powder purity and The particle size is: 99.9% and ≤1μm; the purity and particle size of Ni powder are: 99.9% and ≤5μm; the purity and particle size of Mo powder are: 99.9% and ≤5μm, respectively. 5. The preparation method of Mo-modified chromium carbide-nickel-chromium composite material according to claim 1, characterized in that, in step 2, the pressure used in the compression molding is 200-500MPa. 6. The preparation method of Mo-modified chromium carbide-nickel-chromium composite material according to claim 1, wherein in step 3, the sintering time is 1-4h. 7 . The preparation method of Mo-modified chromium carbide-nickel-chromium composite material according to claim 1 , wherein the heating rate during sintering is: 5° C.-10° C./min. 8 . 8 . The preparation method of Mo-modified chromium carbide-nickel-chromium composite material according to claim 1 , wherein the degree of vacuum during sintering is 0.0001-0.1 Pa. 9 . 9. The Mo-modified chromium carbide-nickel-chromium composite material obtained by the preparation method according to any one of claims 1-8.

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