阅读说明：本技术 一种TiC/Ni复合材料的原位反应合成方法 (In-situ reaction synthesis method of TiC/Ni composite material ) 是由 齐倩 赵子燕 姚树玉 于 2021-01-18 设计创作，主要内容包括：本发明涉及一种TiC/Ni复合材料的原位反应合成方法,它是将原料Ni粉、Ti粉和石墨按比例混合均匀,冷压成型后制成坯体,然后控制加热速率对坯体进行氩气保护常压烧结或者真空烧结,在一定的温度下各组分之间进行放热化学反应,生成弥散分布的微观增强颗粒。主要用于航空航天、军事领域、交通运输工具、电子元器件、燃料电池连接体、陶瓷切削刀具材料等领域。本发明中将TiC/Ni复合材料的原位反应与致密化一步到位,不需要高能球磨和加压烧结等复杂过程,工艺方便简单,不受设备限制,成本低,可以有效解决现有原位反应合成高致密度TiC/Ni复合材料技术受到设备限制,工艺复杂、成本高等问题。(The invention relates to an in-situ reaction synthesis method of TiC/Ni composite material, which comprises the steps of uniformly mixing raw materials of Ni powder, Ti powder and graphite in proportion, carrying out cold press molding to prepare a blank, then controlling the heating rate to carry out argon protection normal pressure sintering or vacuum sintering on the blank, carrying out exothermic chemical reaction among all components at a certain temperature, and generating micro-reinforcing particles in dispersed distribution. The method is mainly used in the fields of aerospace, military, transportation, electronic components, fuel cell connectors, ceramic cutting tool materials and the like. According to the method, the in-situ reaction and densification of the TiC/Ni composite material are completed in one step, complex processes such as high-energy ball milling, pressure sintering and the like are not needed, the process is convenient and simple, the method is not limited by equipment, the cost is low, and the problems that the existing technology for synthesizing the high-density TiC/Ni composite material through the in-situ reaction is limited by the equipment, the process is complex, the cost is high and the like can be effectively solved.)

1. The in-situ reaction synthesis method of the TiC/Ni composite material is characterized in that raw materials of Ni powder, Ti powder and graphite are uniformly mixed according to a proportion, a blank is prepared after cold press molding, then the blank is subjected to argon protection normal pressure sintering or vacuum sintering by controlling the heating rate, and exothermic chemical reaction is carried out among all components at a certain temperature to generate micro-reinforcing particles which are dispersed and distributed; wherein Ti powder and graphite are taken according to an equimolar proportion, and the Ni content accounts for 0-100 wt% of the total mass of the system, not including the end value.

2. The in situ reaction synthesis method of TiC/Ni composite material according to claim 1, comprising the steps of:

the first step is as follows: preparation of a green body

Weighing Ni powder, Ti powder and graphite according to the designed mass percentage of each component, uniformly mixing the proportioned powder, and carrying out cold press molding on the powder to prepare a blank, wherein the Ni content accounts for 40-70 wt% of the total mass of the system;

the second step is that: heating the blank in a tubular furnace, wherein the sintering atmosphere adopts a normal-pressure argon protective atmosphere or a vacuum atmosphere, the in-situ reaction and material densification are completed in one step in the sintering process, and finally, the TiC/Ni composite material taking TiC as a reinforcing phase and dispersed in a matrix is synthesized; in the heating process, firstly, the temperature is required to be slowly raised when the temperature is lower than 1000 ℃ to ensure that Ti and graphite in the system slowly generate solid phase reaction to generate TiC, then the temperature is continuously raised to 1300-1400 ℃, a liquid phase appears, the dissolving-separating-out process of TiC in the Ni-Ti melt occurs, the porosity is reduced, and the sintering is finished.

3. The in situ reaction synthesis method of TiC/Ni composite material according to claim 2, wherein the slow temperature rise rate ranges from 0.5 to 3 ℃/min.

4. The TiC/Ni composite in-situ reaction synthesis method of claim 2, wherein the holding time at 1300-1400 ℃ is 120 min.

5. The in-situ reaction synthesis method of TiC/Ni composite material of claim 2, wherein the Ni powder has a particle size of 1-3 μm and a purity of not less than 99.9%; the particle size of the Ti powder is 1-3 mu m, and the purity is more than or equal to 99.9%; the particle size of the graphite powder is 1-5 mu m, and the purity is more than or equal to 99.9%.

6. The TiC/Ni composite in-situ reaction synthesis method of claim 2, wherein the mixing equipment adopted during the green body preparation is planetary ball milling at 300 rpm.

Technical Field

The invention belongs to the field of composite materials, and relates to an in-situ reaction synthesis technology of a TiC/Ni composite material; in particular to a compact TiC/Ni composite material which is prepared by taking Ni powder, Ti powder and graphite as raw materials through a pressureless reaction sintering method.

Background

The particle reinforced metal matrix composite has excellent performances of high specific strength, specific modulus, high temperature resistance, wear resistance, small thermal expansion coefficient, good dimensional stability and the like, and becomes an important component of the composite. The particle reinforced metal-based composite material has good toughness of metal and high wear resistance of ceramic, has incomparable excellent performance of single metal or ceramic material, and also has excellent fracture toughness and plasticity, is used as a cutting tool and a functional material, is widely applied to various industries, and has a non-wear promotion effect on the progress of the modern industrial production technology and the improvement of the production efficiency.

WC-Co has been used in many fields as the first cermet of research. However, the shortage of W and Co resources promotes the research and development of tungsten-free metal ceramics, and TiC metal ceramics are produced at the same time. The melting point of TiC is 3250 ℃, which is far higher than that of WC (2630 ℃), the wear resistance is good, the density is only 1/3 of WC, and the oxidation resistance is far higher than that of WC. TiC cermet is used to fill the gap between WC cermet and ceramic tool material and is suitable for high speed finishing tool. Since the toughness of TiC cermets was improved later, it was possible to not only finish the steel, but also semi-finish, rough and interrupted cut the steel and ductile cast iron. Through development, TiC metal ceramics can completely replace WC metal ceramics, and the application is in more and more extensive fields.

Nickel is a group VIII element and has a density of 8.9g/cm³The alloy has a melting point and a boiling point of 1455 ℃ and 2915 ℃, has excellent ductility, high melting point, good corrosion resistance, excellent oxidation resistance, good mechanical properties and excellent machining performance in cold and hot environments. Besides, the nickel alloy has excellent alloying performance, is stable in alloying performance, does not generate harmful phases, and increases operability for enhancing other properties of nickel.

TiC/Ni composite material prepared by introducing TiC into Ni-based alloy can realize pairingThe nickel-based alloy has the advantages of regulating and controlling the mechanical property, keeping higher conductivity and oxidation resistance, and being a composite material with good application prospect. The Luyilin powder is pure Ni powder or Ti powder₃AlC₂The powder is used as raw material, and Ti is synthesized by adopting a vacuum hot pressing sintering method comprising a post-extrusion process_0.65C/Ni based composite material. Zhangyuming, etc. utilizes quick forming technique and combustion synthesis technique, and adopts layered entity production method to successfully prepare TiC/Ni gradient functional composite material. At present, the research on the preparation and performance of the material at home and abroad is not few, but the preparation process is complicated, the requirements on conditions and equipment are strict, and the cost is high.The (Ti, Mo) C/Ni composite material is prepared by combining a high-energy ball milling technology with vacuum sintering and taking Ti, graphite, Mo and Ni powder as raw materials, and the process needs a high-energy ball milling process with high cost and is difficult to realize industrial production. Boutefnouche and the like prepare a Ti-C-Ni system by utilizing a self-propagating high-temperature synthesis method, the method has extremely high reaction speed, and the related physical and chemical phenomena are complex, so that the combustion process is difficult to optimize and the oxide composition and appearance influence of the combustion process is difficult to predict; although TiC/Ni can be prepared, more pores are left, a compact composite material is difficult to prepare, the reaction process is difficult to control, hot isostatic pressing or subsequent densification measures are required to be carried out simultaneously, the whole preparation process is complex and tedious, and the density of a finished product is not high. Tian et al prepared TiC/FeAl composites using plasma spray. The method needs a high-power laser to melt and deposit metal powder on a metal substrate, and forms a composite material after repeated multi-layer deposition, so that the method has high equipment cost and low energy conversion rate, and is difficult to realize large-scale popularization and use.

There are many methods for synthesizing Ti-C-Ni system in the prior art, one of them is a method of pressure sintering by using TiC powder and Ni powder as raw materials, such as TiC-Ni hard alloy composite powder disclosed in Chinese patent application publication No. CN 109837447A and its application; for example, the patent publication No. CN 103468995B discloses a TiC-Ni-Mo hard alloy material for a wear-resisting plate and a manufacturing method thereof. Still another method is to directly use an in-situ reaction sintering method. Relevant to the present invention is the in-situ reactive sintering process.

Chinese patent application publication No. CN 104775046A discloses a TiC-Ni3Al composite material and a preparation method thereof, which is synthesized by taking Ti powder, Ni powder, Al powder, graphite powder and B powder as raw materials and adopting high-energy ball milling to induce self-propagating combustion reaction through air pressure sintering under the protection of argon. The defects of the technology are as follows: the method not only needs a high-energy ball milling process with high cost, but also adopts self-propagating combustion reaction with extremely high reaction speed and poor control on the appearance of the synthesized material, the density of the synthesized material is poor, and the synthesis process is more complicated by adopting 3-6MPa of pressure sintering at the later stage in order to improve the density.

Chinese patent publication No. CN101649398B discloses a method for synthesizing TiCx particle reinforced nickel-based composite material by in-situ reaction, which comprises the following three steps: the powder material consists of Ti, C, Al, Fe and Mo, wherein the weight ratio of Al powder: 8-12 wt.%, Fe powder: 12-15 wt.%, Mo powder: 3-5 wt.%, graphite C powder: 8-12 wt.%, and the balance of Ti powder, wherein the ratio of the weight of the Ti powder to the weight of the C powder in the powder needs to satisfy (5-6.7): 1. The second part is the preparation of the powder chip: rolling the Ni foil into a cylinder with the diameter of 16-25mm, and filling the mixed powder obtained after ball milling and mixing into the cylinder. The third part is a smelting and casting process: and preparing the TiCx/Ni composite material by using a vacuum intermediate frequency induction smelting furnace. This technique has the following drawbacks: firstly, the preparation process is complex, the preparation of mixed powder and the preparation of powder chips are divided into two parts to be prepared, secondly, the process condition requirement is higher, the preparation is carried out by utilizing a vacuum intermediate frequency induction smelting furnace, only the whole smelting and casting process step covers seven steps, the pressure and temperature are higher, and the prepared TiCx particle reinforced nickel-based composite density is lower.

Therefore, there is a need to develop an in-situ reaction synthesis technique which is low in cost, easy to operate, capable of realizing industrial production and excellent in material compactness maintenance.

Disclosure of Invention

Aiming at the problems of equipment limitation, complex process, high cost and the like in the existing TiC/Ni composite material sintering and pressurizing in-situ reaction synthesis technology, the invention provides an in-situ reaction synthesis method of a TiC/Ni composite material, which prepares a compact TiC/Ni composite material through pressureless reaction sintering.

In order to achieve the purpose, the in-situ reaction synthesis method of the TiC/Ni composite material comprises the steps of uniformly mixing Ni powder, Ti powder and graphite according to a certain proportion, carrying out cold press molding to prepare a blank, carrying out argon protection normal pressure sintering or vacuum sintering on the blank at a certain heating rate, carrying out exothermic chemical reaction among components at a certain temperature, and generating micro-reinforcing particles in dispersed distribution.

Specifically, the method comprises the following steps:

the first step is as follows: preparation of a green body

Weighing Ni powder, Ti powder and graphite according to the designed mass percentage of each component, uniformly mixing the proportioned powder, and carrying out cold press molding on the powder to prepare a blank, wherein the Ti powder and the graphite are taken according to an equimolar ratio, the Ni content accounts for 0-100 wt% of the total mass of the system, and the blank is not included, preferably 40-70 wt%.

The second step is that: heating the blank in a tubular furnace, wherein the sintering atmosphere adopts a normal-pressure argon protective atmosphere or a vacuum atmosphere, the in-situ reaction and material densification are completed in one step in the sintering process, and finally, the TiC/Ni composite material taking TiC as a reinforcing phase and dispersed in a matrix is synthesized; in the heating process, firstly, the temperature is required to be slowly raised when the temperature is lower than 1000 ℃ to ensure that Ti and graphite in the system slowly generate solid phase reaction to generate TiC, then the temperature is continuously raised to 1300-1400 ℃, a liquid phase appears, the 'dissolving-separating out' process of the TiC in the Ni-Ti melt is generated, the porosity is reduced, and the sintering is completed, so that the non-pressureless reaction sintering TiC/Ni composite material is prepared.

Further: the slow heating rate range is as follows: 0.5-3 ℃/min;

further: the heat preservation time is 120min at 1300-1400 ℃.

Further: the particle size of the Ni powder is 1-3 mu m, and the purity is more than or equal to 99.9%; the particle size of the Ti powder is 1-3 mu m, and the purity is more than or equal to 99.9%; the particle size of the graphite powder is 1-5 mu m, and the purity is more than or equal to 99.9%.

Further: in order to improve the formability of the powder, a small amount of binder, such as phenolic resin, polyvinyl butyral (PVB), polyvinyl alcohol ester (PVA), etc., needs to be added into the green body, and the binder used herein is 3 wt.% of PVB alcoholic solution.

Further: the mixing equipment adopted during the preparation of the green body is planetary ball milling with 300 r/min, and the ball milling solvent is 3 wt.% of PVB alcoholic solution; the adopted pressing method is a dry pressing method, mixed powder is filled into a die with a specified size, a certain pressure (for example, 4-6 MPa) is applied to form the powder, and the powder is further subjected to cold isostatic pressing after forming to prepare a blank.

The advantages of the present invention are illustrated below based on the reaction mechanism:

in the invention, at the stage of pressureless reaction sintering at low temperature (less than 1000 ℃), the temperature is slowly raised, Ti and graphite are subjected to solid-phase reaction to form TiC with irregular morphology through diffusion under the protection of argon atmosphere or under vacuum atmosphere, and Ni and Ti are subjected to solid-phase reaction to form NiTi₂NiTi and Ni₃And in the stage, the reaction rate is controlled by reducing the temperature rise rate, so that the phenomenon that the reaction speed is too high, the heat release amount is large, and the porosity is increased due to the expansion phenomenon is avoided, and the smooth proceeding of the later densification is ensured. As the temperature rises and exceeds the melting point or eutectic point of intermetallic chemicals, a Ni-Ti liquid phase appears to promote the dissolution and diffusion of C in Ni, meanwhile, TiC generated at the earlier stage is dissolved in the Ni-Ti liquid phase, and TiC with a regular shape is precipitated after reaching the TiC saturation point. Compared with the in-situ synthesis technology of other TiC/Ni composite materials, the technology does not need additional high-energy ball milling technology and pressure sintering equipment, has simple process, easy operation, low energy consumption and low consumption, and is more suitable for the batch production of the composite materials.

2. The invention adopts a slow heating rate mode in the initial stage of calcination, titanium carbide is generated in the slow process, the explosion-like reaction like self-propagating combustion reaction cannot suddenly form fire balls, and the porosity of the system is not large in the solid phase reaction stage, so that normal-pressure argon atmosphere or vacuum atmosphere sintering can be realized only when liquid phase appears in the later stage.

3. The Ni powder has the purity of more than 99.9 percent and the particle size of 1 mu m; the Ti powder has the purity of over 99.9 percent and the grain diameter of 1 mu m; the graphite powder has the purity of more than 99.9 percent and the particle size of 1-5 mu m. Thus, the particles have a large specific surface area, and the in-situ reaction is promoted. The Ni content range in the blank is not limited, and can be adjusted according to the performance requirement of a required sample.

4. The invention takes Ni powder, Ti powder and graphite powder with low cost as raw materials, adopts a non-pressurized reaction sintering method, uses a common tube furnace, and prepares the material with relative density of more than 90 percent and obvious densification effect, thereby being an in-situ reaction synthesis technology with simple process, low cost and capability of realizing industrialized production. The problems of equipment limitation, complex process and high cost in the existing TiC/Ni composite material in-situ reaction synthesis technology are effectively solved, and technical support is provided for the wide application and the industrialized production of the TiC/Ni composite material. The composite material can be used as cutting tools, wear-resistant parts, fuel cell connectors and the like.

For a long time, the person skilled in the art has created an inertial thinking that: if the density of the material is required to be improved, the pressing and sintering are one way, which leads to high cost of in-situ synthesis of the TiC/Ni composite material with higher density. On the premise of not increasing the calcining temperature, the invention changes the reaction mechanism by controlling the heating rate and does not pressurize and sinter, thereby realizing the preparation of the TiC/Ni composite material with high density at low cost and having outstanding substantive characteristics and remarkable progress.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below.

FIG. 1(a), FIG. 1(b), FIG. 1(c) are phase analysis graphs of TiC/Ni composite materials with nickel contents of 60 wt%, 40 wt%, 70 wt%, respectively, before and after sintering densification in examples prepared by the method of the present invention;

FIG. 2 is a micro-topography picture of TiC/Ni composite material with nickel content of 60 wt%, 40 wt% and 70 wt% respectively before and after sintering in the example prepared by the method of the present invention; wherein FIG. 2(a) is a micro-topography analysis diagram of a green body before sintering, and FIG. 2(b) is a micro-topography picture of a sintered TiC/Ni composite material with a nickel content of 60 wt% in the example; FIG. 2(c) is a picture of the microstructure of the sintered TiC/Ni composite material with 40 wt% Ni in the example; FIG. 2(d) is a microstructure picture of the sintered TiC/Ni composite material with a nickel content of 70 wt% in the example.

FIG. 3 is a graph of the relative density of TiC/Ni composites having nickel contents of 60 wt%, 40 wt% and 70 wt%, respectively, as a function of sintering temperature for examples prepared by the method of the present invention.

FIG. 4(a) is an appearance of the green body of the present invention before calcination; FIG. 4(b) is a graph showing the appearance of the green body shown in FIG. 4(a) after calcination by the method of the present invention while controlling the temperature increase rate at 5 ℃/min.

Detailed Description

The present invention is further described below in conjunction with the following embodiments, which are intended to illustrate and not to limit the present invention.

The present invention will be described in detail by way of examples. It is also to be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the invention, and that modifications and variations of the invention described herein are possible in light of the above teachings and may be acquired from practice of the invention. The specific process parameters and the like of the following examples are also only one example of suitable ranges, i.e., those skilled in the art can select the appropriate ranges through the description herein, and are not limited to the specific values exemplified below. In the embodiment, the doping amount of Ti powder and graphite powder is always equal molar ratio no matter how much Ni powder is doped.

The first embodiment is as follows: taking the mass fraction of Ni as 60 wt% of the total system as an example

Preparation of mixed powder: ni powder (purity is more than or equal to 99.9 percent and granularity is 1-3 mu m); ti powder (purity is more than or equal to 99.9 percent and granularity is 1-3 mu m); graphite powder (the purity is more than or equal to 99.9 percent and the granularity is 1-5 mu m), and the three kinds of powder and 3 wt.% of PVB are uniformly mixed by a planetary ball mill by taking ethanol as a solvent;

preparing a blank: putting the mixed powder into a cylindrical die with the diameter of 13.00mm, applying the pressure of 4-6MPa to prepare a cylindrical tabletting sample with the diameter of 13.00mm, and carrying out cold isostatic pressing on the sample to prepare a blank.

③ no-pressurization reaction sintering: and placing the blank obtained in the second step into a tubular furnace, introducing normal-pressure argon for atmosphere protection, slowly heating at the heating rate of 1 ℃/min, and preserving the temperature for 120min when the temperature in the furnace rises to 1300 ℃ to obtain the TiC/Ni composite material taking TiC as a reinforcing phase and dispersed in a nickel matrix.

The phase analysis chart of TiC/Ni composite material with 60 wt% nickel content before and after calcination as prepared in example one is shown in FIG. 1(a), and the micro-topography analysis chart before and after calcination is shown in FIGS. 2(a) and 2 (b).

As can be seen from the comparison of the phase analysis before and after sintering in FIG. 1(a), the phase composition of the TiC/Ni composite material after sintering only consists of two phases of TiC and Ni, and no residual Ti and graphite exist, which indicates that the TiC is generated by the reaction between graphite and Ti by the normal pressure argon atmosphere reaction sintering method, and the TiC/Ni composite material is successfully prepared. From fig. 2(a) and 2(b), it can be seen that the microstructure of the green body is changed before and after sintering, the reinforced particles after sintering are all TiC particles generated by in-situ reaction, the mass fraction of the reinforced particles in the composite material is high, no graphite particles are found, the TiC particles are uniformly distributed in the metal matrix and present a face-centered cubic structure, and the interface between the particles and the matrix is clean, tightly combined and free of agglomeration.

As can be seen from fig. 3, when the mass fraction of Ni is 60 wt.%, the relative density of the TiC/Ni composite material prepared reaches 91.20% at 1300 ℃, and reaches 97.30% at 1400 ℃, and the densification effect of the TiC/Ni composite material prepared at this time is obvious.

Example two: taking the mass fraction of Ni as 40 wt% of the total system as an example

Preparation of mixed powder: ni powder (purity is more than or equal to 99.9 percent and granularity is 1-3 mu m); ti powder (purity is more than or equal to 99.9 percent and granularity is 1-3 mu m); graphite powder (the purity is more than or equal to 99.9 percent and the granularity is 1-5 mu m), and the three kinds of powder and 3 wt.% of PVB are uniformly mixed by a planetary ball mill by taking ethanol as a solvent;

preparing a blank: putting the mixed powder into a cylindrical die with the diameter of 13.00mm, applying the pressure of 4-6MPa to prepare a cylindrical tabletting sample with the diameter of 13.00mm, and carrying out cold isostatic pressing on the sample to prepare a blank.

③ no-pressurization reaction sintering: and placing the blank obtained in the second step into a tubular furnace, introducing normal-pressure argon for atmosphere protection, slowly heating at the heating rate of 1 ℃/min, and preserving the temperature for 120min when the temperature in the furnace rises to 1300 ℃ to obtain the TiC/Ni composite material taking TiC as a reinforcing phase and dispersed in a nickel matrix.

The phase analysis chart of TiC/Ni composite material with 40 wt% nickel content before and after calcination as prepared in example two is shown in FIG. 1(b), and the micro-morphology analysis after calcination is shown in FIG. 2(a) and FIG. 2 (c).

As can be seen from the comparison of the phase analysis before and after sintering in FIG. 1(b), the phase composition of the TiC/Ni composite material after sintering only consists of two phases of TiC and Ni, and no residual Ti and graphite exist, which indicates that the TiC is generated by the reaction between graphite and Ti by the normal pressure argon atmosphere reaction sintering method, and the TiC/Ni composite material is successfully prepared. At this time, the relative content and peak value of TiC after sintering are obviously larger than that of Ni because of the smaller content of Ni. From fig. 2(c), it can be seen that the microstructure of the sintered green body is changed, the sintered reinforcing particles are all TiC particles generated by in-situ reaction, the mass fraction of the TiC particles in the composite material is high, no graphite particles are found, the TiC particles are uniformly distributed in the metal matrix and present a face-centered cubic structure, and the interface between the particles and the matrix is clean, tightly bonded and free of agglomeration.

As can be seen from fig. 3, when the mass fraction of Ni is 40 wt.%, the density of the prepared TiC/Ni composite material is lower at 1200 ℃ and 1300 ℃, and when the temperature rises, the relative density reaches 91.30% at 1400 ℃, and the densification effect of the prepared TiC/Ni composite material is obvious.

Example 3: taking the mass fraction of Ni as 70 wt% of the total system as an example

Preparation of mixed powder: ni powder (purity is more than or equal to 99.9 percent and granularity is 1-3 mu m); ti powder (purity is more than or equal to 99.9 percent and granularity is 1-3 mu m); graphite powder (the purity is more than or equal to 99.9 percent and the granularity is 1-5 mu m), and the three kinds of powder and 3 wt.% of PVB are uniformly mixed by a planetary ball mill by taking ethanol as a solvent;

preparing a blank: putting the mixed powder into a cylindrical die with the diameter of 13.00mm, applying the pressure of 4-6MPa to prepare a cylindrical tabletting sample with the diameter of 13.00mm, and carrying out cold isostatic pressing on the sample to prepare a blank.

③ no-pressurization reaction sintering: and placing the blank obtained in the second step into a tubular furnace, introducing normal-pressure argon for atmosphere protection, slowly heating at the heating rate of 1 ℃/min, and preserving the temperature for 120min when the temperature in the furnace rises to 1300 ℃ to obtain the TiC/Ni composite material taking TiC as a reinforcing phase and dispersed in a nickel matrix.

The phase analysis chart before and after calcination of the TiC/Ni composite material with 70 wt% nickel content prepared in example three is shown in FIG. 1(c), and the micro-topography analysis chart after calcination is shown in FIG. 2(a) and FIG. 2 (d).

As can be seen from the comparison of the phase analysis before and after sintering in FIG. 1(c), the phase composition of the TiC/Ni composite material after sintering only consists of two phases of TiC and Ni, and no residual Ti and graphite exist, which indicates that the TiC is generated by the reaction between graphite and Ti by the normal pressure argon atmosphere reaction sintering method, and the TiC/Ni composite material is successfully prepared. Wherein, because of the higher Ni content, the relative Ni content in the sample before and after sintering is higher than that of TiC. From fig. 2(d), it can be seen that the microstructure of the green body is changed before and after sintering, the reinforced particles after sintering are all TiC particles generated by in-situ reaction, the mass fraction of the TiC particles in the composite material is high, no graphite particles are found, the TiC particles are uniformly distributed in the metal matrix and present a face-centered cubic structure, and the interface between the particles and the matrix is clean, tightly bonded and free of agglomeration.

As can be seen from fig. 3, when the mass fraction of Ni is 70 wt.%, the relative density of the TiC/Ni composite material prepared reaches 93.64% at 1400 ℃, and the densification effect of the TiC/Ni composite material prepared at this time is obvious.

In order to prove the importance of the invention in controlling the heating rate, the blank shown in fig. 4(a) manufactured by the invention is controlled to have the heating rate of 5 ℃/min on the premise of not changing other parameters, the appearance diagram of the TiC/Ni composite material prepared by the method is shown in fig. 4(b), and comparison of the blank and the blank in fig. 4(a) and 4(b) shows that the height of the calcined blank is obviously increased when the heating rate is 5 ℃/min compared with that before calcination, because the heating rate is too fast, the reaction between phases is violent, the expansion phenomenon occurs, the porosity is increased, and the material is not dense. This shows that it is important to control the temperature rise rate of the present invention to be 0.5-3 deg.C/min.

In addition, only the mass fractions of Ni accounting for 40%, 60% and 70% of the system are taken in the embodiment of the invention, theoretically, the Ni content range in the system is unlimited, and the densified TiC/Ni composite material can be prepared according to the method of the invention as long as the Ni content is taken within the range of 0-100, and as for the Ni content, the skilled person can completely deduce through designing the performance of the product and based on the professional knowledge of the person without innovative labor. Therefore, the above embodiments are not intended to limit the present invention, and the scope of the present invention is defined by the appended claims, and any modifications made thereto are within the scope of the present invention.