阅读说明：本技术 一种挤压模用碳氮化钛金属陶瓷材料及制备方法 (Titanium carbonitride cermet material for extrusion die and preparation method thereof ) 是由 刘毅 颜焰 于 2020-03-25 设计创作，主要内容包括：本发明提供了一种挤压模用碳氮化钛金属陶瓷材料及制备方法,解决了现有技术中挤压模消耗成本较高,缺少耐磨性好、高温硬度高、寿命长的挤压模材料的技术问题。其制备包括下述重量百分比的主料：硬质颗粒70%～95%,金属粘结相基体5%～30%；硬质颗粒和金属粘结相基体的重量百分比之和为100%；其中,所述金属粘结相基体中包括ⅧB铂族过渡金属元素粉末。本发明制得的挤压模用碳氮化钛金属陶瓷材料,具有耐磨性好、高温硬度高、摩擦系数低的优点,能够有效延长挤压模模具的使用寿命,提高加工效率降低加工成本。(The invention provides a titanium carbonitride cermet material for an extrusion die and a preparation method thereof, and solves the technical problems of higher consumption cost, lack of extrusion die materials with good wear resistance, high-temperature hardness and long service life of the extrusion die in the prior art. The preparation method comprises the following main materials in percentage by weight: 70-95% of hard particles and 5-30% of metal binding phase matrix; the sum of the weight percentages of the hard particles and the metal binding phase matrix is 100 percent; wherein the metal binding phase matrix comprises VIIIB platinum group transition metal element powder. The titanium carbonitride cermet material for the extrusion die has the advantages of good wear resistance, high-temperature hardness and low friction coefficient, and can effectively prolong the service life of the extrusion die, improve the processing efficiency and reduce the processing cost.)

1. A titanium carbonitride cermet material for an extrusion die is characterized in that: the preparation method comprises the following main materials in percentage by weight: 70-95% of hard particles and 5-30% of metal binding phase matrix; the sum of the weight percentages of the hard particles and the metal binding phase matrix is 100 percent; wherein the content of the first and second substances,

the metal binding phase matrix comprises VIIIB platinum group transition metal element powder.

2. The titanium carbonitride cermet material for an extrusion die of claim 1, wherein: the weight percentages of the main materials are respectively as follows: 80-90% of hard particles and 10-20% of metal binding phase matrix; the sum of the weight percentages of the hard particles and the matrix of the metallic binder phase is 100%.

3. The titanium carbonitride cermet material for an extrusion die of claim 2, wherein: the weight percentages of the main materials are respectively as follows: 85% of hard particles and 15% of metal binding phase matrix.

4. The titanium carbonitride cermet material for an extrusion die according to any one of claims 1 to 3, characterized in that: the preparation also comprises a ball milling medium, a carbon source and a forming agent; the carbon source is graphite or carbon black, and the adding amount of the carbon source is 0.1-1% of the total weight of the components for preparing the hard particles; the forming agent is paraffin, and the addition amount of the forming agent is 3-6% of the total weight of the hard particle component.

5. The titanium carbonitride cermet material for an extrusion die according to claim 4, wherein: the hard particles comprise titanium carbonitride powder, metal binder phase powder and carbide additive powder; the weight ratio of the titanium carbonitride powder to the metal binder phase powder to the carbide additive powder is (60-80): (6-12): (10-30).

6. The titanium carbonitride cermet material for an extrusion die according to claim 5, wherein: the carbide additive powder comprises tungsten carbide powder and molybdenum carbide powder, and the carbide additive powder also comprises at least one of niobium carbide powder and tantalum carbide powder; the tungsten carbide powder, the molybdenum carbide powder, the niobium carbide powder and the tantalum carbide powder are mixed according to the weight ratio of (5-30): (4-15): (0-5): (0-5).

7. The titanium carbonitride cermet material for an extrusion die according to claim 6, wherein: the metal binding phase powder comprises cobalt powder and nickel powder, and the weight ratio of the cobalt powder to the nickel powder is (0.5-1.2): 1.

8. the titanium carbonitride cermet material for an extrusion die of claim 7, wherein: the metal binding phase matrix comprises cobalt powder, nickel powder and VIIIB platinum group transition metal element powder; in the metal binding phase matrix, the weight ratio of the cobalt powder, the nickel powder and the VIIIB platinum group transition metal element powder is 1: 1: (0.05-0.3).

9. The method for preparing a titanium carbonitride cermet material for an extrusion die as set forth in any one of claims 1 to 8, characterized in that: the method comprises the following steps:

(1) preparing components for preparing hard particles and a metal binding phase matrix according to a ratio;

(2) preparing hard particles:

pouring the components for preparing the hard particles into a ball milling tank, simultaneously adding a carbon source, a forming agent and a ball milling medium for wet milling, and obtaining a mixture after ball milling; then drying the mixture and granulating to obtain granules; continuously carrying out degreasing and presintering on the obtained particles to obtain hard particles;

wherein the carbon source is graphite or carbon black, and the adding amount of the carbon source is 0.1-1% of the total weight of the hard particle preparation components; the forming agent is paraffin, and the addition amount of the forming agent is 3-6% of the total weight of the hard particle component;

(3) uniformly mixing the hard particles prepared in the step (2) with a metal binding phase matrix to obtain a mixture;

(4) pressing the mixture prepared in the step (3) to obtain a cold pressed blank;

(5) and (4) sintering the cold pressed compact prepared in the step (4) in vacuum or inert gas atmosphere, preserving heat for 1-3 h at 1400-1500 ℃, and cooling along with the furnace to obtain the titanium carbonitride cermet material for the extrusion die.

10. The method for preparing a titanium carbonitride cermet material for an extrusion die as set forth in claim 9, characterized in that: in the step (2), the particle size range of the obtained granules after granulation is 30-200 μm; the degreasing and presintering are vacuum degreasing or carrier gas degreasing, wherein the carrier gas degreasing adopts nitrogen or argon, and the degreasing and presintering are carried out at the sintering temperature of 700-900 ℃ for 1-2 h.

Technical Field

The invention relates to a titanium carbonitride cermet material, in particular to a titanium carbonitride cermet material for an extrusion die and a preparation method thereof.

Background

With the increasing industrial scale, the demand for parts in manufacturing industry is kept at a high level. The hot extrusion processing equipment is common, convenient to install and simple in flow, and meanwhile, the machining allowance of the machined workpiece obtained through the hot extrusion process is small, so that the material utilization rate is greatly increased. Therefore, the hot extrusion process is an advanced and mature pressure processing process, and can bring huge economic benefits when corresponding parts with proper shapes are produced in a large scale. The hot extrusion process is influenced by more factors due to high process temperature and severe working environment. The hot extrusion die is an extremely important accessory in the hot extrusion process, is subjected to continuous high temperature, continuous friction and extremely large cyclic stress during working, mainly has adhesive wear, abrasive wear and fatigue wear, is extremely easy to lose efficacy through forms such as wear, thermal fatigue, cracking, collapse and the like, and causes the service life of the hot extrusion die to be low and the hot extrusion die needs to be frequently replaced. Therefore, in the current hot extrusion large-scale production, the hot extrusion die has limited service life and frequent replacement, so that the capital investment is increased seriously, the production efficiency is reduced, and the search for a hot extrusion die material with excellent high-temperature performance and excellent wear resistance is imperative. In the hot extrusion process of the prior art, the hot extrusion die material is hot work alloy die steel, so that the problems of over-quick abrasion and the like occur. In the exploration process, a hard alloy and pure ceramic hot extrusion die is also considered, but the hard alloy material has poor chemical stability, the ceramic material has poor toughness and thermal shock resistance, and the hard alloy material is easy to crack in the use process, so that the service life of the hot extrusion die cannot be effectively prolonged.

Titanium carbonitride based cermet is a widely used new hard material, composed of titanium carbonitride hard phase, cobalt nickel binder phase and other carbide additives, has drawn extensive attention to its excellent high temperature mechanical properties, excellent wear resistance, high chemical inertness and low friction coefficient, and has excellent performance in high speed cutting, high precision machining, corrosion-resistant and high temperature-resistant parts. Titanium carbonitride base cermet is a material that is fit for hot extrusion die preparation, and its low coefficient of friction can significantly reduce the friction that receives, promotes product quality when reducing self wearing and tearing, and its higher chemical stability can reduce the adhesion wearing and tearing under the high temperature simultaneously, and excellent wear resistance can keep high life. However, the cermet material has the problems of high brittleness and poor toughness, and has small abrasion loss but high cracking risk in the current use process. In order to expand the application range of titanium carbonitride-based cermet, realize the practical application of a hot extrusion die and prolong the service life of the hot extrusion die, the toughness and thermal shock resistance of the cermet are also required to be improved.

The applicant has found that the prior art has at least the following technical problems:

Disclosure of Invention

The invention aims to provide a titanium carbonitride cermet material for an extrusion die and a preparation method thereof, and solves the technical problems that the extrusion die in the prior art is high in consumption cost, and lacks of extrusion die materials with good wear resistance, high-temperature hardness and long service life. The technical effects that can be produced by the preferred technical scheme in the technical schemes provided by the invention are described in detail in the following.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides a titanium carbonitride cermet material for an extrusion die, which is prepared from the following main materials in percentage by weight: 70-95% of hard particles and 5-30% of metal binding phase matrix; the sum of the weight percentages of the hard particles and the metal binding phase matrix is 100 percent; wherein the content of the first and second substances,

the metal binding phase matrix comprises VIIIB platinum group transition metal element powder.

Further, the weight percentages of the main materials are respectively as follows: 80-90% of hard particles and 10-20% of metal binding phase matrix; the sum of the weight percentages of the hard particles and the matrix of the metallic binder phase is 100%.

Further, the weight percentages of the main materials are respectively as follows: 85% of hard particles and 15% of metal binding phase matrix.

Further, the preparation also comprises a ball milling medium, a carbon source and a forming agent; the carbon source is graphite or carbon black, and the adding amount of the carbon source is 0.1-1% of the total weight of the components for preparing the hard particles; the forming agent is paraffin, and the addition amount of the forming agent is 3-6% of the total weight of the hard particle component.

Further, the hard particles include titanium carbonitride powder, metal binder phase powder, and carbide additive powder; the weight ratio of the titanium carbonitride powder to the metal binder phase powder to the carbide additive powder is (60-80): (6-12): (10-30).

Further, in the hard particles, the titanium carbonitride powder has a particle size of 0.5 to 4 μm, the metal binder phase powder has a particle size of 3 to 10 μm, and the carbide additive powder has a particle size of 1 to 8 μm.

Further, the carbide additive powder comprises tungsten carbide powder and molybdenum carbide powder, and the carbide additive powder also comprises at least one of niobium carbide powder and tantalum carbide powder; the tungsten carbide powder, the molybdenum carbide powder, the niobium carbide powder and the tantalum carbide powder are mixed according to the weight ratio of (5-30): (4-15): (0-5): (0-5).

Further, the metal binder phase powder comprises cobalt powder and nickel powder, and the weight ratio of the cobalt powder to the nickel powder is (0.5-1.2): 1.

further, the metal binding phase matrix comprises cobalt powder, nickel powder and VIIIB platinum group transition metal element powder; in the metal binding phase matrix, the weight ratio of the cobalt powder, the nickel powder and the VIIIB platinum group transition metal element powder is 1: 1: (0.05-0.3).

Further, the VIIIB platinum group transition metal element powder is any one or more of ruthenium powder, rhodium powder, palladium powder, osmium powder, iridium powder and platinum powder.

Furthermore, the particle size of the VIIIB platinum group transition metal element powder is 5-20 microns.

The invention provides a preparation method of titanium carbonitride cermet material for an extrusion die, which comprises the following steps:

(1) preparing components for preparing hard particles and a metal binding phase matrix according to a ratio;

(2) preparing hard particles:

pouring the components for preparing the hard particles into a ball milling tank, simultaneously adding a carbon source, a forming agent and a ball milling medium for wet milling, and obtaining a mixture after ball milling; then drying the mixture and granulating to obtain granules; continuously carrying out degreasing and presintering on the obtained particles to obtain hard particles;

the carbon source is graphite or carbon black, the adding amount of the carbon source is 0.1-1% of the total weight of the hard particle component, the additionally added carbon source is mainly used for deoxidation and carbon supplement, different carbon amounts are added according to different working conditions, and the amorphous carbon black serving as the carbon source has higher reaction activity; the forming agent is paraffin, and the addition amount of the forming agent is 3-6% of the total weight of the hard particle component;

(3) uniformly mixing the hard particles prepared in the step (2) with a metal binding phase matrix to obtain a mixture;

(4) pressing the mixture prepared in the step (3) to obtain a cold pressed blank;

(5) and (4) sintering the cold pressed compact prepared in the step (4) in vacuum or inert gas atmosphere, preserving heat for 1-3 h at 1400-1500 ℃, and cooling along with the furnace to obtain the titanium carbonitride cermet material for the extrusion die.

Further, in the step (2), the added ball milling medium is alcohol, and the ball milling time is 40-70 h.

Further, in the step (2), the granulation is performed by a method of rubbing and screening granulation or spray granulation.

Further, in the step (2), the particle size of the granules obtained after granulation is in the range of 30 to 200 μm.

Further, in the step (2), the particle size of the granules obtained after granulation is in the range of 50 to 150 μm. In granulation, too small a granulation particle leads to excessive penetration of the binder phase into the hard particles during sintering, and thus, excellent wear resistance cannot be obtained, and too large a granulation particle leads to failure of uniform distribution of the binder phase on a small scale, and deterioration of material toughness.

Further, in the step (2), the degreasing and pre-sintering are performed by vacuum degreasing or carrier gas degreasing, wherein the carrier gas degreasing adopts nitrogen or argon, and the degreasing and pre-sintering are performed by keeping the sintering temperature at 700-900 ℃ for 1-2 h. The degreasing pre-sintering temperature is controlled so that the hard particles have certain particle strength and do not influence subsequent pressing, the high degreasing pre-sintering temperature can cause high particle strength and poor pressing performance, and the low degreasing pre-sintering temperature can cause low particle strength and dispersion in subsequent mixing.

Further, in the step (3), the hard particles and the metal binder phase matrix are uniformly mixed by a V-shaped mixer, and during mixing, an inert protective atmosphere is introduced, wherein the inert protective atmosphere is argon or nitrogen, and the mixing time is 12-48 hours. The V-shaped mixer adopts a non-crushing mixing mode.

Furthermore, in the step (4), the pressing mode of the cold pressed blank is mould pressing or cold isostatic pressing, and the pressing pressure is 120MPa to 250 MPa.

Further, in the step (4), the pressing mode of the cold pressed blank is cold isostatic pressing, and the pressing pressure is 180-150 MPa. In cold isostatic pressing, the green compact shrinks more uniformly in all directions, the hard particles still keep a sphere-like shape, and the cold isostatic pressing mode is preferred because the deformation in the horizontal direction is small, the orientation of the crushed hard particle material exists, and the material performance is different.

Further, in the step (5), in the sintering process, when a vacuum atmosphere is adopted, the air pressure is 0.001 Pa-0.1 Pa; when an inert gas atmosphere is adopted, the inert gas is nitrogen, and the air pressure is 20-300 Pa.

According to the titanium carbonitride cermet material for the hot extrusion die and the preparation method thereof, the titanium carbonitride cermet material for the hot extrusion die, which is prepared by the binder phase strengthening technology, changes the traditional cermet homogeneous design concept, is different from the traditional cermet homogeneous characteristic, hundred micron-sized homogeneous cermet hard particles are prepared firstly, and then the pre-sintered hard particles are adhered by a pure metal binder phase, and a metal binder phase matrix with larger size exists among the hard particles, so that the energy in crack propagation can be effectively absorbed, and the toughness of the material is greatly improved; in addition, the same important thing is that the VIII-group transition metal element is added into the metal bonding phase matrix to carry out solid solution strengthening on the metal bonding phase matrix, so that the strength and toughness of the hard particles and the large-scale metal bonding phase matrix are greatly improved, the toughness and high-temperature performance of the material are further improved, finally, the high-temperature performance and thermal shock performance of the metal ceramic material are greatly improved while certain hardness (HRA 89-92) and wear resistance are kept, the application range of the metal ceramic material is widened, the service life of a hot extrusion die is prolonged, and the processing cost of reducing the processing efficiency is indirectly improved.

Based on the technical scheme, the embodiment of the invention can at least produce the following technical effects:

(1) the titanium carbonitride cermet material for the extrusion die has a unique brand new organization structure and mainly comprises hundred micron-sized large wear-resistant hard particles and a large-scale metal bonding phase matrix; because the components of the metal binder phase powder in the hard particles are similar to those of the large-scale metal binder phase matrix, the metal binder phase matrix can diffuse into the hard particles due to concentration difference in the sintering process, so that the large-scale metal binder phase matrix and the hard particles have excellent bonding strength, and the stability in the application process can be ensured; moreover, the existence of the large-scale metal binder phase matrix can effectively absorb crack propagation energy and inhibit crack propagation, and the hard particles can provide excellent wear resistance; due to the existence of the structure, the prepared titanium carbonitride cermet material for the extrusion die can inhibit crack propagation while ensuring the wear resistance, thereby effectively improving the toughness and the thermal shock property of the material;

(2) according to the titanium carbonitride cermet material for the extrusion die and the preparation method thereof, the prepared titanium carbonitride cermet material for the extrusion die improves the toughness and the thermal shock property of the material under the combined action of a brand-new organization structure and a VIII-group transition metal element reinforced binder phase, keeps the unique hardness and the wear resistance of the cermet, is a cermet material designed for hot extrusion working conditions, and has the advantages of good wear resistance, high-temperature hardness and low friction coefficient compared with the existing hot extrusion die material, the titanium carbonitride cermet material for the extrusion die has the advantages of good wear resistance, high-temperature hardness and low friction coefficient, the service life of an extrusion die can be effectively prolonged, the processing efficiency is improved, and the processing cost is reduced; on the other hand, the addition of the VIII group transition metal element can also improve the wettability of the binding phase and the hard phase, improve the interface strength and improve the toughness of the material.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

First, examples and comparative examples

Titanium carbonitride cermet materials for extrusion dies were prepared in examples 1 to 9, and cermet materials were prepared in comparative examples 1 to 3:

1. main materials:

the composition table (in weight percent) for making the hard particles is shown in table 1 below; the composition of the matrix of the metal binder phase (in parts by weight) is shown in table 2 below; the main material tables (in weight percent) for preparing the titanium carbonitride cermet material for the extrusion die and for preparing the cermet material are shown in table 3 below:

TABLE 1 EXAMPLES AND COMPARATIVE EXAMPLES A TABLE OF COMPONENTS (in weight percent) FOR PREPARING HARD PARTICLES

TABLE 2 composition of matrix of metallic binder phase for examples and comparative examples (in parts by weight)

TABLE 3 Main materials Table for examples and comparative examples (in weight percent)

Description of the particle size of the main material powder:

in the hard particles: the grain diameter of the titanium carbonitride powder is 0.5-4 mu m, the grain diameter of the metal binding phase powder is 3-10 mu m, and the grain diameter of the carbide additive powder is 1-8 mu m;

in the matrix of the metal binding phase: the particle size of the VIIIB platinum group transition metal element powder is 5-20 mu m; the particle size of the cobalt powder is 3-10 μm; the particle size of the nickel powder is 3-10 mu m.

2. The preparation method comprises the following steps: