阅读说明：本技术 一种合金强化的碳氮化钛基复合材料及其制备方法 (Alloy-reinforced titanium carbonitride-based composite material and preparation method thereof ) 是由 李淼鑫 邓莹 姜山 张艳华 陈巧旺 成小庆 廖广 张恒硕 皇甫浩霆 于 2020-07-22 设计创作，主要内容包括：一种合金强化的碳氮化钛基复合材料,其特征在于：由钛基基础材料和合金复合材料,其中钛基基础材料由TiCN、WC粉末组成,合金复合材料为β-Co、Cr、Ce、Nb、Zr组成的合金相复合粉末。本发明碳氮化钛基复合材料为球状形貌,界面结合度优异、结构晶面、晶粒均匀性好。本发明方法制备过程中有效抑制了Co和碳化物发生偏析,抑制了合金相发生团聚,制备的碳氮化钛基复合材料均匀性好、缺陷少。本发明制备的碳氮化钛基复合材料的抗弯强度平均达到3000MPa,断裂韧性平均可达到13MPa·m<Sup>1/2</Sup>。(An alloy-reinforced titanium carbonitride based composite material characterized by: the titanium-based composite material is composed of titanium-based base material and alloy composite material, wherein the titanium-based base material is composed of TiCN and WC powder, and the alloy composite material is alloy phase composite powder composed of beta-Co, Cr, Ce, Nb and Zr. The titanium carbonitride based composite material is spherical, and has excellent interface combination degree, structural crystal face and crystal grain uniformity. The method effectively inhibits segregation of Co and carbide and agglomeration of alloy phases in the preparation process, and the prepared titanium carbonitride-based composite material has good uniformity and few defects. The bending strength of the titanium carbonitride-based composite material prepared by the invention averagely reaches 3000MPa, and the fracture toughness averagely reaches13MPa·m 1/2 。)

1. An alloy-reinforced titanium carbonitride based composite material characterized by: the titanium-based composite material is composed of titanium-based base material and alloy composite material, wherein the titanium-based base material is composed of TiCN and WC powder, and the alloy composite material is alloy phase composite powder composed of beta-Co, Cr, Ce, Nb and Zr.

2. The alloy reinforced titanium carbonitride based composite material of claim 1 wherein: in the beta-Co, Cr, Ce, Nb and Zr alloy phase composite powder, the weight ratio of beta-Co: cr: ce: nb: the atomic ratio of Zr is 5-6: 1-2: 1-2: 0.5-1: 0.5 to 1.

3. The alloy reinforced titanium carbonitride based composite material of claim 1 wherein: the content of the alloy phase composite powder is 25-30 wt%, the content of TiCN powder in the titanium-based base material is 50-65 wt%, and the content of WC powder is 10-25 wt%.

4. A preparation method of an alloy reinforced titanium carbonitride based composite material is characterized by comprising the following steps: sequentially preparing alloy phase composite powder and titanium carbonitride based composite material, wherein the preparation of the alloy phase composite powder is performed according to the following steps of beta-Co: cr: ce: nb: the atomic ratio of Zr is 5-6: 1-2: 1-2: 0.5-1: weighing 0.5-1 parts of cobalt oxide powder, chromium oxide, cerium oxide, niobium oxide and zirconium oxide, mixing, sequentially carrying out mechanical force collision grinding, crushing, mixing, high-pressure spray drying and nitrogen hydrogenation reduction.

5. The method of preparing an alloy-reinforced titanium carbonitride based composite material as set forth in claim 4, characterized in that: the mechanical force collision grinding crushing mixing is to place the weighed oxide powder and TiCN balls into a stirring ball milling tank, add anhydrous ethanol according to the amount of 0.05-0.1L/kg, then perform mechanical force collision crushing mixing to form wet slurry, wherein the ball-material ratio is 3-5: 1, the stirring ball milling speed is 300-500 r/min, and the crushing mixing time is 36-48 h.

6. The method for preparing an alloy-reinforced titanium carbonitride based composite material as set forth in claim 4 or 5, characterized in that: and the high-pressure spray drying is to screen the mixed wet slurry to remove balls, atomize the slurry under the pressure of 2-15 MPa, and mix and dry the atomized slurry and hot air at the temperature of 60-80 ℃ to form the micro-nano alloy mixed powder.

7. The method for producing an alloy-reinforced titanium carbonitride based composite material as set forth in any one of claims 4 to 6, characterized by: and the nitrogen hydrogenation reduction is to react the alloy mixed powder at 400-500 ℃ for 120-180min in the atmosphere of mixed gas of nitrogen and hydrogen to generate beta-Co, Cr, Ce, Nb and Zr alloy phase composite powder, after the reaction is finished, the hydrogen is closed, and the alloy mixed powder is cooled to room temperature under the protection of nitrogen.

8. The method of preparing an alloy-reinforced titanium carbonitride based composite material as set forth in claim 4, characterized in that: the titanium carbonitride-based alloy material is prepared by mixing and ball-milling 25-30 wt% of alloy phase composite powder, 50-65 wt% of TiCN powder and 10-25 wt% of WC powder, performing high-pressure spray drying to obtain titanium carbonitride-based alloy powder, and then sequentially performing press forming and microwave sintering.

9. The method of preparing an alloy-reinforced titanium carbonitride based composite material as set forth in claim 8, characterized in that: in the microwave sintering, under the microwave frequency of 2.6GHz +/-30 MHz, the temperature of titanium-based alloy powder is raised to 450 ℃, the temperature is kept for 1-2h for dewaxing, then the temperature is raised to 1200-1300 ℃ in the solid phase sintering stage, and the temperature is kept for 60-120 min, so that the strengthening phase metal elements are fully diffused, and the matrix is effectively strengthened; then further heating to the sintering temperature of 1350-.

10. The preparation method of the alloy reinforced titanium carbonitride based composite material is characterized by comprising the following steps of:

preparation of alloy phase composite powder

(1) Weighing the following raw materials: according to the proportion of beta-Co: cr: ce: nb: the atomic ratio of Zr is 5-6: 1-2: 0.5-1: weighing corresponding cobalt oxide powder, chromium oxide, cerium oxide, niobium oxide and zirconium oxide (the purity of the oxide is more than 99%) 0.5-1;

(2) crushing and mixing by mechanical collision and grinding: putting the weighed oxide powder and TiCN balls into a stirring ball-milling tank, adding anhydrous ethanol according to the amount of 0.05-0.1L/kg, and then performing mechanical collision, crushing and mixing to form wet slurry, wherein the ball-material ratio is 3-5: 1, the stirring ball-milling speed is 300-500 r/min, and the crushing and mixing time is 36-48 h;

(3) high-pressure spray drying: sieving the mixed wet slurry to remove balls, atomizing the slurry under the pressure of 2-15 MPa, and mixing and drying the atomized slurry and hot air at the temperature of 60-80 ℃ to form micro-nano alloy mixed powder;

(4) and (3) nitrogen hydrogenation reduction reaction: reacting the alloy mixed powder for 120-180min at 400-500 ℃ in a mixed gas atmosphere with the flow ratio of nitrogen to hydrogen being 2:8 to generate beta-Co, Cr, Ce, Nb and Zr alloy phase composite powder, closing hydrogen after the reaction is finished, and cooling to room temperature under the protection of nitrogen;

preparation of titanium carbonitride based composite material

(1) Ball milling: mixing 25-30 wt% of alloy phase composite powder, 50-65 wt% of TiCN powder and 10-25 wt% of WC powder, performing ball milling, taking TiCN balls as a grinding body, adding absolute ethyl alcohol according to a ball-to-material ratio of 1: 3-5 and 0.2-0.3L/kg of material, adding paraffin accounting for 2-3% of the weight ratio of the raw materials, and performing high-speed ball milling to form wet slurry, wherein the ball milling speed is 200 and 300r/min, and the ball milling time is 36-48 h;

(2) high-pressure spray drying: screening the wet slurry to remove balls, atomizing the slurry under the pressure of 2-15 MPa, mixing the atomized slurry with hot air at the temperature of 60-80 ℃, and drying to form micro-nano alloy mixed powder;

(3) microwave sintering: under the microwave frequency of 2.6GHz +/-30 MHz, heating the titanium-based alloy powder to 450 ℃, preserving heat for 1-2h, then continuing heating to the sintering temperature of 1200-1300 ℃ in the solid phase sintering stage, preserving heat for 60-120 min, fully diffusing the strengthening phase metal elements, and effectively strengthening the matrix; then further heating to the sintering temperature of 1350-.

Technical Field

The invention belongs to the field of hard alloy materials in metal materials, and particularly relates to an alloy reinforced titanium carbonitride based composite material and a preparation method thereof.

Background

Titanium carbonitride based composite materials are the main materials for cutting tools. With the increasing development of various industries, the requirements and the demand of various products, especially in the fields of aerospace, aviation, automobiles and the like, on materials are higher and higher, and no matter the precision or the complexity, the traditional materials cannot meet the requirements of the fields, especially the demand of metal material cutting tools. The machining of metal materials cannot be completed without high-quality numerical control cutters, for example, the cutters are required to carry out cutting machining on various shaft and tooth parts of automobiles. The existing numerical control cutter material in the market of China has the defects of high brittleness, low strength and toughness, poor thermal shock resistance and the like, so that the working efficiency is reduced, and the quality of a product is influenced. Therefore, the research and development of high-end cutter materials with high hardness, high toughness and high thermal shock resistance have great significance for improving the competitiveness of cutters in China internationally and relieving import dependence of China on the high-end cutters. Therefore, the titanium carbonitride based composite material with good high temperature performance and super hardness is moved into the array of high-end cutting tool materials.

The titanium carbonitride based composite material is generally added with WC, although the titanium carbonitride based composite material has certain strength and toughness, the hard phase of the titanium carbonitride based composite material is a polycrystalline sintered material, and crystal grains are easy to grow in the calcining process, so that the brittleness and the toughness of the alloy material are increased and are insufficient. After long-term research and development, the performance of the current titanium carbonitride-based composite material is gradually improved, but the problem of low strength still generally exists. In recent years, a great deal of research is being carried out on strengthening and toughening methods, such as phase change strengthening, fiber toughening, fine grain strengthening, nano modification and the like. These methods have some effect, but they do not improve the strength of the material significantly. And the material still has a large amount of grain boundary defects, causes a large amount of dislocation and slippage, so that the interface bonding is poor, a large gap exists between the grain boundaries, and the uniformity of the grain size is poor.

Disclosure of Invention

The invention aims to provide an alloy reinforced titanium carbonitride based composite material.

The invention also aims to provide a preparation method of the alloy reinforced titanium carbonitride based composite material.

The purpose of the invention is realized by the following technical scheme:

an alloy-reinforced titanium carbonitride based composite material characterized by: the crystal structure of the titanium carbonitride-based composite material is a spherical structure and consists of a titanium-based base material and an alloy phase composite material, wherein the titanium-based base material consists of TiCN and WC powder, and the alloy composite material is alloy phase composite powder consisting of beta-Co, Cr, Ce, Nb and Zr.

Further, in the beta-Co, Cr, Ce, Nb and Zr alloy composite powder, the weight ratio of beta-Co: cr: ce: nb: the atomic ratio of Zr is 5-6: 1-2: 1-2: 0.5-1: 0.5 to 1.

Furthermore, the content of the alloy composite powder is 25-30 wt%, the content of TiCN powder is 50-65 wt% and the content of WC powder is 10-25 wt% in the titanium-based base material.

Further, the average particle size of the beta-Co, Cr, Ce, Nb, Zr alloy phase composite powder is 100 to 500 nm.

Further, the titanium-based alloy powder has an average particle size of 200 to 600 nm.

The preparation method of the alloy reinforced titanium carbonitride based composite material is characterized by comprising the following steps of: the preparation method comprises the steps of preparing alloy phase composite powder and preparing a titanium carbonitride-based composite material in sequence, wherein the alloy phase composite powder is prepared by mixing cobalt oxide powder, chromium oxide, cerium oxide, niobium oxide and zirconium oxide serving as raw materials, then sequentially performing mechanical force collision grinding crushing mixing, high-pressure spray drying and nitrogen hydrogenation reduction.

Further, the above cobalt oxide powder, chromium oxide, cerium oxide, niobium oxide, and zirconium oxide are mixed in accordance with the ratio of β -Co: cr: ce: nb: the atomic ratio of Zr is 5-6: 1-2: 1-2: 0.5-1: 0.5-1 weight percent.

Further, the above mentioned mechanical force collision grinding crushing mixing is that the weighed oxide powder and TiCN ball are put into a stirring ball milling tank together, absolute ethyl alcohol is added according to the amount of 0.05-0.1L/kg, then mechanical force collision crushing mixing is carried out to form wet slurry, the ball-material ratio is 3-5: 1, the stirring ball milling speed is 300-500 r/min, and the crushing mixing time is 36-48 h.

Further, the high-pressure spray drying is to screen the mixed wet slurry to remove balls, atomize the slurry under the pressure of 2-15 MPa, and mix and dry the atomized slurry and hot air at the temperature of 60-80 ℃ to form the micro-nano alloy mixed powder.

Further, the nitrogen hydrogenation reduction is to react the alloy mixed powder in a mixed gas atmosphere of nitrogen and hydrogen at 400-500 ℃ for 120-180min to generate beta-Co, Cr, Ce, Nb and Zr alloy phase composite powder, after the reaction is finished, the hydrogen is closed, and the alloy mixed powder is cooled to room temperature under the protection of nitrogen.

Further, the flow ratio of the nitrogen to the hydrogen is 2:8, and the flow rate of the mixed gas is 500-600 mL/min.

Due to the performance difference of all metal elements, the alloy is subjected to segregation in the preparation process to form aggregates, the dispersibility is poor, and the size of metal particles is uncontrollable. According to the invention, a method of mechanical force collision grinding, crushing, mixing, high-pressure spray drying and nitrogen hydrogenation reduction is adopted, and the alloy oxide mixed powder with high internal energy and uniform dispersion is obtained in the mixing process, so that the time and temperature of nitrogen hydrogenation reduction are shortened, and the growth of powder particles in the reduction process is effectively inhibited; the high-pressure spray drying treatment is adopted, spherical micro-nano-grade powder is effectively formed at low temperature quickly, and the fluidity of the alloy in the matrix is increased, so that the dispersion uniformity of the alloy material in the matrix is improved, meanwhile, the high-pressure spray drying effectively prevents the powder from being oxidized, and the oxygen content of the finally prepared alloy phase composite powder is reduced; in addition, after the alloy phase composite powder is spheroidized, the interface energy of the alloy phase is reduced, so that the binding force of the alloy material is reduced, the component segregation is well prevented, and the aim of inhibiting the agglomeration of the alloy powder is fulfilled. The steps are combined with nitrogen-hydrogen reduction reaction to form micro-nano beta-Co, Cr, Ce, Nb and Zr alloy phase composite powder with high dispersibility and low oxygen content, and nitrogen attached to the surface of the prepared alloy powder is beneficial to subsequent solid solution to enter a matrix material to form a gap solid solution.

The Co that is typically produced is typically a mixed phase Co composed of beta-Co (face centered cubic structure) and alpha-Co (body centered cubic structure). The cobalt oxide in the invention has enough internal energy stored by high-energy collision and grinding, effectively overcomes martensite phase transformation in the subsequent nitrogen hydrogenation reduction reaction process, generates beta-phase cobalt (beta-Co) with a single-phase face-centered cubic structure under the nitrogen-hydrogen reduction, and inhibits the conversion of the beta-Co to the alpha-Co. The single-phase face-centered cubic structure beta-Co has 12 slip systems, has the same structure with the matrix TiCN, high matching degree and structural advantages, and is effectively strengthened as a bonding phase, thereby improving the toughness of the matrix.

Further, the titanium carbonitride-based alloy material is prepared by mixing and ball-milling 25-30 wt% of alloy phase composite powder, 50-65 wt% of TiCN powder and 10-25 wt% of WC powder, performing high-pressure spray drying to obtain titanium carbonitride-based alloy powder, and then sequentially performing press forming and microwave sintering.

Further, the mixed ball milling is to mix beta-Co, Cr, Ce, Nb and Zr alloy phase composite powder, TiCN powder and WC powder, put the mixture into a ball mill, add absolute ethyl alcohol into the mixture according to the ball-to-material ratio of 0.2-0.3L/kg by taking TiCN balls as a grinding body and adding paraffin accounting for 2-3% of the weight ratio of the raw materials according to the ball-to-material ratio of 1: 3-5, and then perform high-speed ball milling to form wet slurry, wherein the ball milling speed is 200 and 300r/min, and the ball milling time is 36-48 h.

Further, the high-pressure spray drying is to screen the wet slurry to remove balls, atomize the slurry under the pressure of 2-15 MPa, and mix and dry the atomized slurry and hot air at the temperature of 60-80 ℃ to form the micro-nano alloy mixed powder.

The traditional heating drying is generally carried out at the temperature of more than 100 ℃, the drying time is long, the normal-pressure atomization drying temperature is about 100 ℃, the high-pressure atomization combination and hot air mixing drying are adopted, the hot air temperature is 60-80 ℃, the drying temperature is reduced, meanwhile, the high-dispersion micro-nano alloy mixed powder is dried in a very short time, the spherical powder is obtained at a fast low temperature, and the size uniformity of the powder is improved.

Further, in the microwave sintering, under the microwave frequency of 2.6GHz +/-30 MHz, the temperature of the titanium-based alloy powder is raised to 450 ℃, the temperature is kept for 1-2h for dewaxing, then the temperature is raised continuously to 1200-1300 ℃ of the sintering temperature in the solid phase sintering stage, and the temperature is kept for 60-120 min, so that the strengthening phase metal elements are fully diffused, and the matrix is effectively strengthened; then further heating to the sintering temperature of 1350-.

Most specifically, the preparation method of the alloy reinforced titanium carbonitride based composite material is characterized by comprising the following steps of:

preparation of alloy phase composite powder

(1) Weighing the following raw materials: according to the proportion of beta-Co: cr: ce: nb: the atomic ratio of Zr is 5-6: 1-2: 0.5-1: weighing corresponding cobalt oxide powder, chromium oxide, cerium oxide, niobium oxide and zirconium oxide (the purity of the oxide is more than 99%) 0.5-1;

(2) crushing and mixing by mechanical collision and grinding: putting the weighed oxide powder and TiCN balls into a stirring ball-milling tank, adding anhydrous ethanol according to the amount of 0.05-0.1L/kg, and then performing mechanical collision, crushing and mixing to form wet slurry, wherein the ball-material ratio is 3-5: 1, the stirring ball-milling speed is 300-500 r/min, and the crushing and mixing time is 36-48 h;

(3) high-pressure spray drying: sieving the mixed wet slurry to remove balls, atomizing the slurry under the pressure of 2-15 MPa, and mixing and drying the atomized slurry and hot air at the temperature of 60-80 ℃ to form micro-nano alloy mixed powder;

(4) and (3) nitrogen hydrogenation reduction reaction: the nitrogen hydrogenation reduction is to react the alloy mixed powder at 400-500 ℃ for 120-180min in a mixed gas atmosphere with the flow ratio of nitrogen to hydrogen being 2:8 to generate beta-Co, Cr, Ce, Nb and Zr alloy phase composite powder, after the reaction is finished, the hydrogen is closed, and the alloy mixed powder is cooled to room temperature under the protection of nitrogen;

preparation of titanium carbonitride based composite material

(1) Ball milling: mixing 25-30 wt% of alloy phase composite powder, 50-65 wt% of TiCN powder and 10-25 wt% of WC powder, performing ball milling, taking TiCN balls as a grinding body, adding absolute ethyl alcohol according to a ball-to-material ratio of 1: 3-5 and 0.2-0.3L/kg of material, adding paraffin accounting for 2-3% of the weight ratio of the raw materials, and performing high-speed ball milling to form wet slurry, wherein the ball milling speed is 200 and 300r/min, and the ball milling time is 36-48 h;

(2) high-pressure spray drying: screening the wet slurry to remove balls, atomizing the slurry under the pressure of 2-15 MPa, mixing the atomized slurry with hot air at the temperature of 60-80 ℃, and drying to form micro-nano alloy mixed powder;

(3) microwave sintering: under the microwave frequency of 2.6GHz +/-30 MHz, heating the titanium-based alloy powder to 450 ℃, preserving heat for 1-2h for dewaxing, then continuously heating to the sintering temperature of 1200-1300 ℃ in the solid phase sintering stage, and preserving heat for 60-120 min to fully diffuse the strengthening phase metal elements and effectively strengthen the matrix; then further heating to the sintering temperature of 1350-.

According to the invention, the micro-nano spherical bonding wetting phase powder with excellent dispersibility and low oxygen content is prepared, and the TiCN, WC and composite alloy powder are subjected to ball milling, high-pressure spray drying and subsequent combination of specific high-temperature sintering measures, so that the bonding phase and the wetting phase are uniformly dispersed in a matrix, and the segregation of Co and carbide is inhibited, thereby effectively controlling the generation of defect sources and improving the comprehensive performance of the ceramic body. In the high-temperature sintering process, Ce, Nb and Zr are fully diffused and effectively dissolved into gaps of the matrix to form a gap solid solution with the matrix, so that the solid solution strengthening effect is achieved, the crystal boundary is purified, the phase interface is improved, the phase interface of the matrix phase and the binder phase can be remarkably wetted, and the bonding strength of the interface is improved. Finally, the invention improves the integral strength of the alloy through the coordination of binding phase strengthening, solid solution strengthening, grain refining and phase interface improvement.

The invention has the following beneficial effects:

(1) the titanium carbonitride based composite material is spherical, and has excellent interface combination degree, structural crystal face and crystal grain uniformity.

(2) The method effectively inhibits segregation of Co and carbide and agglomeration of alloy phases in the preparation process, and the prepared titanium carbonitride-based composite material has good uniformity and few defects.

(3) The invention achieves the multi-party common strengthening effects of strengthening a bonding phase, refining crystal grains, strengthening solid solution, purifying crystal boundaries and improving a phase interface by taking beta-Co, Cr, Ce, Nb and Zr as alloy phases, realizes the multi-component strengthening of the titanium carbonitride-based composite material, and improves the overall strength and toughness of the alloy, so that the bending strength of the titanium carbonitride-based composite material prepared by the invention can reach 3000MPa on average, and the fracture toughness can reach 13 MPa.m.^1/2。

Drawings

FIG. 1: SEM (scanning electron microscope) image (figure 1a) and energy spectrum (figure 1b) of the alloy phase powder prepared by the invention.

FIG. 2: the transmission electron microscope image of the titanium carbonitride based composite material prepared by the invention.

Detailed Description

The present invention is described in detail below by way of examples, it should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and those skilled in the art can make some insubstantial modifications and adaptations of the present invention based on the above-mentioned disclosure.