CN115974557B - ZrSi-Ti-based alloy 3 SiC 2 High-toughness composite ceramic as well as preparation method and application thereof - Google Patents

Abstract

ZrSi-Ti-based alloy ₃ SiC ₂ High-toughness composite ceramic, and a preparation method and application thereof. The application belongs to the field of complex phase ceramic materials. The application aims to solve the technical problem that the existing titanium carbide-silicon carbide composite ceramic cannot achieve both sinterability and excellent fracture toughness. The composite ceramic of the application is made of TiC _x Phase, siC phase, (Zr, ti) C _x Solid solution phase ZrSi phase, ti ₃ SiC ₂ Phase composition. The method comprises the following steps: step 1: mixing TiC powder, si powder and ZrC powder to obtain mixed powder, adding absolute ethyl alcohol for ultrasonic treatment, ball-milling and mixing under the protection of inert gas, drying and sieving to obtain ceramic powder; step 2: hot-pressing and sintering the ceramic powder to obtain ZrSi-Ti-based ceramic powder ₃ SiC ₂ Is a high-toughness composite ceramic. The application relates to a ZrSi-Ti-based alloy ₃ SiC ₂ The high-toughness composite ceramic is used for preparing cutters, molds and aerospace materials.

Description

A kind of high-toughness composite ceramics based on ZrSi-Ti3SiC2 and its preparation method and application

technical field

The invention belongs to the field of composite ceramic materials, and in particular relates to a high-toughness composite ceramic based on ZrSi-Ti ₃ SiC ₂ and its preparation method and application.

Background technique

Titanium carbide (TiC) has excellent comprehensive properties such as high melting point, high hardness, and good chemical stability, but a single TiC material has insufficient wear resistance, extremely low electrical conductivity, and a large thermal expansion coefficient, which cannot meet certain requirements in industrial production. Specific requirements (e.g. machinery manufacturing, aerospace, etc.). If TiC can be combined with other rigid inert particles to make up for the performance shortcomings of TiC itself, the application range of TiC will be expanded.

The combination of TiC and SiC can solve the problem of insufficient performance of TiC itself, and can realize the complementarity of the properties of the two materials. However, due to its covalent bond coordination characteristics and low self-diffusion coefficient, the sintering and fracture toughness of composite ceramics are poor, making it widely used in superhard tool materials, microelectronic materials, nuclear energy storage materials and coating materials, etc. Further widespread use of the field is limited.

In recent years, many efforts have been made to improve the sinterability of titanium carbide-silicon composite ceramics. The Chinese invention patent with the publication number CN102390999A discloses a liquid phase sintered SiC-TiC composite ceramic and its preparation method. It consists of 15-50wt% titanium carbide, 40-80wt% silicon carbide, 5-10wt% sintering aids Al ₂ O ₃ and Y ₂ O ₃ , and is obtained by batching, pulping, molding, drying, and sintering. The room temperature flexural strength of SiC-TiC composite ceramics is increased to 580Mpa, and the fracture toughness is increased to 7.8MPa·m ^1/2 . However, the introduction of additives with different or greatly different properties at the same time will damage the inherent properties of the material, resulting in unsatisfactory microstructure and properties of sintered materials. Therefore, how to reduce the sintering temperature of ceramics while ensuring high density of ceramics, especially how to ensure the toughness is an urgent problem to be solved.

Contents of the invention

The purpose of the present invention is to solve the technical problem that the existing titanium carbide-silicon carbide composite ceramics cannot take into account both sinterability and excellent fracture toughness, and to provide a high-toughness composite ceramic based on ZrSi-Ti ₃ SiC ₂ and its preparation method and application .

A high-toughness composite ceramic based on ZrSi-Ti ₃ SiC ₂ of the present invention is composed of TiC _x phase, SiC phase, (Zr,Ti)C _x solid solution phase, Ti ₃ SiC ₂ phase and ZrSi phase.

It is further defined that the high-toughness composite ceramics based on ZrSi-Ti ₃ SiC ₂ (based on a total mole percentage of 100%) consists of 40-60% TiC powder, 20-40% Si powder and 10% by molar content. -30% ZrC powder prepared.

Further defined, the particle size of TiC powder, Si powder and ZrC powder is 1-3 μm.

A kind of preparation method based on ZrSi-Ti ₃ SiC ₂ high-toughness composite ceramics of the present invention is carried out according to the following steps:

Step 1: Mix TiC powder, Si powder and ZrC powder to obtain a mixed powder, add absolute ethanol for ultrasonic treatment, and then ball mill the mixture under the protection of an inert gas, dry, and sieve to obtain ceramic powder;

Step 2: hot pressing and sintering the ceramic powder to obtain a high-toughness composite ceramic based on ZrSi-Ti ₃ SiC ₂ .

It is further defined that the volume ratio of the mass of the mixed powder to absolute ethanol in step 1 is 25g: (10-15)mL.

Further defined, the frequency of the ultrasound in step 1 is 30-40 kHz, and the time is 10-30 min.

It is further defined that in step 1, the ball-to-material ratio is (5-50):1, the ball milling speed is 200-300rpm, and the ball milling time is 5-30h.

Further defined, in step 1, the drying temperature is 50-70° C., and the drying time is 1-5 hours.

To further define, pass through a 200-mesh sieve in step 1.

It is further defined that the hot pressing sintering process in step 2: first raise the temperature to 500-700°C at a heating rate of 20-40°C/min, then raise the temperature to 1300-1600°C at a heating rate of 15-25°C/min, and at 1300 Keep warm at -1600°C for 0.5-3h, then cool down to room temperature at a rate of 10-30°C/min, pressurize when the temperature rises to 500-700°C, pressurize to 20MPa-60MPa, and keep the pressure at this pressure to The heat preservation is over.

A high-toughness composite ceramic based on ZrSi-Ti ₃ SiC ₂ of the present invention is used to prepare cutting tools, molds and aerospace materials.

The remarkable effect that the present invention has compared with prior art:

The present invention significantly reduces the sintering temperature by introducing ZrC powder and optimizing the proportion of raw material powder. At the same time, it ensures that the composite ceramic final product has excellent mechanical properties. The specific advantages are as follows:

1) The present invention aims to form two new phases of ZrSi phase and Ti ₃ SiC ₂ phase in the composite ceramics by regulating the formula and process of the composite ceramics. The Ti ₃ SiC ₂ phase is dispersed among other phases, and the different thermal expansion coefficients of the phases enable the cracks to deflect between the interfaces of different ceramic phases during the fracture process, thereby greatly improving the fracture toughness of the composite ceramics.

2) The composite ceramics prepared by the present invention are composed of TiCx, SiC, (Zr, Ti)Cx solid solution, Ti ₃ SiC ₂ phase, ZrSi and other phases. Through the solid solution strengthening mechanism, the hardness and strength of the composite ceramics are effectively improved, forming The Ti ₃ SiC ₂ phase can enhance the machinability of the composite and advance its further wider application.

Description of drawings

Fig. 1 is the XRD schematic diagram of the composite ceramics that embodiment 3 prepares;

Fig. 2 is the cross-sectional SEM schematic diagram of the composite ceramics prepared in Example 3;

FIG. 3 is an SEM schematic diagram of crack growth of the composite ceramic prepared in Example 3. FIG.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are all conventional materials, reagents, methods and instruments in this field unless otherwise specified, and those skilled in the art can obtain them through commercial channels.

The terms "comprising", "comprising", "having", "containing" or any other variations thereof used in the following embodiments are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or device comprising listed elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to such composition, step, method, article, or device. elements.

When amounts, concentrations, or other values or parameters are expressed in terms of ranges, preferred ranges, or ranges bounded by a series of upper preferred values and lower preferred values, it is to be understood that any range upper or preferred value combined with any lower range limit is specifically disclosed. All ranges formed by any pairing of values or preferred values, whether or not such ranges are individually disclosed. For example, when the range "1 to 5" is disclosed, the recited range should be construed to include the ranges "1 to 4," "1 to 3," "1 to 2," "1 to 2, and 4 to 5" , "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, that range is intended to include its endpoints and all integers and fractions within the range. Throughout the specification and claims of this application, range limitations may be combined and/or interchanged, unless otherwise stated such ranges include all subranges contained therebetween.

The indefinite articles "a" and "an" preceding an element or component of the present invention do not limit the quantity requirement (ie, the number of occurrences) of the element or component. Thus "a" or "an" should be read to include one or at least one, and elements or components in the singular also include the plural unless it is clear that the number only refers to the singular.

Embodiment 1: The preparation method of a kind of high-strength, high-hardness and toughness composite ceramics of this embodiment is carried out according to the following steps:

Step 1: 10% zirconium carbide powder (particle size is 1-3 μm), 54% titanium carbide powder (particle size is 1-3 μm) and 36% silicon powder (particle size is 1-3 μm) by mole percentage ) in a polyethylene mixing tank to obtain 25g of mixed powder, add 10mL of absolute ethanol, ultrasonically treat at 35kHz for 10min, then add Si ₃ N ₄ grinding balls, and place the mixing tank on a rolling ball feeder , under the protection of an inert gas, ball milled the mixture, the ball to material ratio was 40:1, the ball milling speed was 250r/min, ball milled for 24h, and then rotary evaporated to remove absolute ethanol, and then placed in an oven at 60°C for 2h, passed 200 mesh sieves to obtain ceramic powder;

Step 2: Carry out hot pressing sintering of the ceramic powder, first raise the temperature to 600°C at a heating rate of 30°C/min, then raise the temperature to 1400°C at a heating rate of 20°C/min, and keep it at 1400°C for 1 hour, then heat it at 20°C The rate of ℃/min is lowered to room temperature, and the pressure is increased when the temperature is raised to 600 ℃, and the pressure is increased to 30MPa, and the pressure is maintained at this pressure until the end of the heat preservation, and a high-strength, high-hardness and toughness composite ceramic is obtained.

Embodiment 2: The preparation method of a kind of high-strength, high-hardness and toughness composite ceramics of this embodiment is carried out according to the following steps:

Step 1: 10% zirconium carbide powder (particle size is 1-3 μm), 54% titanium carbide powder (particle size is 1-3 μm) and 36% silicon powder (particle size is 1-3 μm) by mole percentage ) in a polyethylene mixing tank to obtain 25g of mixed powder, add 10mL of absolute ethanol, ultrasonically treat at 35kHz for 10min, then add Si ₃ N ₄ grinding balls, and place the mixing tank on a rolling ball feeder , under the protection of an inert gas, ball milled the mixture, the ball to material ratio was 40:1, the ball milling speed was 250r/min, ball milled for 24h, and then rotary evaporated to remove absolute ethanol, and then placed in an oven at 60°C for 2h, passed 200 mesh sieves to obtain ceramic powder;

Step 2: Carry out hot pressing sintering of the ceramic powder, first raise the temperature to 600°C at a heating rate of 30°C/min, then raise the temperature to 1500°C at a heating rate of 20°C/min, and keep it at 1500°C for 1 hour, then heat it at 20°C The rate of ℃/min is lowered to room temperature, and the pressure is increased when the temperature is raised to 600 ℃, and the pressure is increased to 30MPa, and the pressure is maintained at this pressure until the end of the heat preservation, and a high-strength, high-hardness and toughness composite ceramic is obtained.

Embodiment 3: The preparation method of a kind of high-strength, high-hardness and toughness composite ceramics of this embodiment is carried out according to the following steps:

Step 1: 10% zirconium carbide powder (particle size is 1-3 μm), 54% titanium carbide powder (particle size is 1-3 μm) and 36% silicon powder (particle size is 1-3 μm) by mole percentage ) in a polyethylene mixing tank to obtain 25g of mixed powder, add 10mL of absolute ethanol, ultrasonically treat at 35kHz for 10min, then add Si ₃ N ₄ grinding balls, and place the mixing tank on a rolling ball feeder , under the protection of an inert gas, ball milled the mixture, the ball to material ratio was 40:1, the ball milling speed was 250r/min, ball milled for 24h, and then rotary evaporated to remove absolute ethanol, and then placed in an oven at 60°C for 2h, passed 200 mesh sieves to obtain ceramic powder;

Step 2: Carry out hot pressing sintering of the ceramic powder, first raise the temperature to 600°C at a heating rate of 30°C/min, then raise the temperature to 1600°C at a heating rate of 20°C/min, and keep it at 1600°C for 1 hour, then heat it at 20°C The rate of ℃/min is lowered to room temperature, and the pressure is increased when the temperature is raised to 600 ℃, and the pressure is increased to 30MPa, and the pressure is maintained at this pressure until the end of the heat preservation, and a high-strength, high-hardness and toughness composite ceramic is obtained.

The obtained high-strength, high-hardness and toughness composite ceramics were tested by XRD, and the test results are shown in Figure 1. It can be seen from Figure 1 that the sintered product consists of TiC _x phase, SiC phase, (Zr, Ti) C _x solid solution phase, ZrSi phase, and Ti ₃ SiC ₂ phase.

The SEM test was carried out on the fracture surface of the obtained high-strength, high-hardness and toughness composite ceramics, and the test results are shown in Fig. 2 . It can be seen from Figure 2 that the grains of each phase obtained by reaction sintering are fine and dispersed, and the composite ceramics are densely sintered. The existence of layered Ti ₃ SiC ₂ and the mode of transgranular fracture all improve the strength of the material.

The SEM test was carried out on the crack growth of the obtained high-strength, high-hardness and toughness composite ceramics, and the test results are shown in Figure 3. It can be seen from Figure 3 that there are obvious bridging and deflection during the crack propagation process, which has a good effect on the toughening of the material.

Embodiment 4: The preparation method of a kind of high-strength, high-hardness and toughness composite ceramics of this embodiment is carried out according to the following steps:

Step 1: 30% zirconium carbide powder (particle size is 1-3 μm), 42% titanium carbide powder (particle size is 1-3 μm) and 28% silicon powder (particle size is 1-3 μm) by mole percentage ) in a polyethylene mixing tank to obtain 25g of mixed powder, add 10mL of absolute ethanol, ultrasonically treat at 35kHz for 10min, then add Si ₃ N ₄ grinding balls, and place the mixing tank on a rolling ball feeder , under the protection of an inert gas, ball milled the mixture, the ball to material ratio was 40:1, the ball milling speed was 250r/min, ball milled for 24h, and then rotary evaporated to remove absolute ethanol, and then placed in an oven at 60°C for 2h, passed 200 mesh sieves to obtain ceramic powder;

Step 2: Carry out hot pressing sintering of the ceramic powder, first raise the temperature to 600°C at a heating rate of 30°C/min, then raise the temperature to 1400°C at a heating rate of 20°C/min, and keep it at 1400°C for 1 hour, then heat it at 20°C The rate of ℃/min is lowered to room temperature, and the pressure is increased when the temperature is raised to 600 ℃, and the pressure is increased to 30MPa, and the pressure is maintained at this pressure until the end of the heat preservation, and a high-strength, high-hardness and toughness composite ceramic is obtained.

Embodiment 5: The preparation method of a kind of high-strength, high-hardness and toughness composite ceramics of this embodiment is carried out according to the following steps:

Step 1: 30% zirconium carbide powder (particle size is 1-3 μm), 42% titanium carbide powder (particle size is 1-3 μm) and 28% silicon powder (particle size is 1-3 μm) by mole percentage ) in a polyethylene mixing tank to obtain 25g of mixed powder, add 10mL of absolute ethanol, ultrasonically treat at 35kHz for 10min, then add Si ₃ N ₄ grinding balls, and place the mixing tank on a rolling ball feeder , under the protection of an inert gas, ball milled the mixture, the ball to material ratio was 40:1, the ball milling speed was 250r/min, ball milled for 24 hours, and then rotary evaporated to remove absolute ethanol, and then placed in an oven at 60 ° C for 2 hours, passed 200 mesh sieves to obtain ceramic powder;

Step 2: Carry out hot pressing sintering of the ceramic powder, first raise the temperature to 600°C at a heating rate of 30°C/min, then raise the temperature to 1500°C at a heating rate of 20°C/min, and keep it at 1500°C for 1 hour, then heat it at 20°C The rate of ℃/min is lowered to room temperature, and the pressure is increased when the temperature is raised to 600 ℃, and the pressure is increased to 30MPa, and the pressure is maintained at this pressure until the end of the heat preservation, and a high-strength, high-hardness and toughness composite ceramic is obtained.

Embodiment 6: The preparation method of a kind of high-strength, high-hardness and toughness composite ceramics of this embodiment is carried out according to the following steps:

Step 1: 30% zirconium carbide powder (particle size is 1-3 μm), 42% titanium carbide powder (particle size is 1-3 μm) and 28% silicon powder (particle size is 1-3 μm) by mole percentage ) in a polyethylene mixing tank to obtain 25g of mixed powder, add 10mL of absolute ethanol, ultrasonically treat at 35kHz for 10min, then add Si ₃ N ₄ grinding balls, and place the mixing tank on a rolling ball feeder , under the protection of an inert gas, ball milled the mixture, the ball to material ratio was 40:1, the ball milling speed was 250r/min, ball milled for 24h, and then rotary evaporated to remove absolute ethanol, and then placed in an oven at 60°C for 2h, passed 200 mesh sieves to obtain ceramic powder;

Step 2: Carry out hot pressing sintering of the ceramic powder, first raise the temperature to 600°C at a heating rate of 30°C/min, then raise the temperature to 1600°C at a heating rate of 20°C/min, and keep it at 1600°C for 1 hour, then heat it at 20°C The rate of ℃/min is lowered to room temperature, and the pressure is increased when the temperature is raised to 600 ℃, and the pressure is increased to 30MPa, and the pressure is maintained at this pressure until the end of the heat preservation, and a high-strength, high-hardness and toughness composite ceramic is obtained.

Comparative example 1: the preparation method of a kind of composite ceramics of this embodiment is carried out according to the following steps:

Step 1: Mix 60% of titanium carbide powder (with a particle size of 1-3 μm) and 40% of silicon powder (with a particle size of 1-3 μm) in a polyethylene mixing tank by mole percentage to obtain 25 g of mixed powder , add 10mL of absolute ethanol, ultrasonic treatment at 35kHz for 10min, then add Si ₃ N ₄ grinding balls, and place the mixing tank on a rolling ball machine, and ball mill the mixture under the protection of inert gas, the ball-to-material ratio is 40 : 1. The ball milling speed is 250r/min, ball milling for 24 hours, then rotary steamed to remove absolute ethanol, then placed in an oven and dried at 60°C for 2 hours, and passed through a 200-mesh sieve to obtain ceramic powder;

Step 2: Carry out hot pressing sintering of the ceramic powder, first raise the temperature to 600°C at a heating rate of 30°C/min, then raise the temperature to 1400°C at a heating rate of 20°C/min, and keep it at 1400°C for 1 hour, then heat it at 20°C The rate of °C/min is lowered to room temperature, and the pressure is increased when the temperature is raised to 600 °C, and the pressure is increased to 30 MPa, and the pressure is maintained at this pressure until the end of the heat preservation to obtain titanium carbide-silicon carbide ceramics.

Comparative example 2: the preparation method of a kind of composite ceramics of this embodiment is carried out according to the following steps:

Step 1: Mix 60% of titanium carbide powder (with a particle size of 1-3 μm) and 40% of zirconium carbide (with a particle size of 1-3 μm) in a polyethylene mixing tank by mole percentage to obtain 25 g of mixed powder , add 10mL of absolute ethanol, ultrasonic treatment at 35kHz for 10min, then add Si ₃ N ₄ grinding balls, and place the mixing tank on a rolling ball machine, and ball mill the mixture under the protection of inert gas, the ball-to-material ratio is 40 : 1. The ball milling speed is 250r/min, ball milling for 24 hours, then rotary steamed to remove absolute ethanol, then placed in an oven and dried at 60°C for 2 hours, and passed through a 200-mesh sieve to obtain ceramic powder;

Step 2: Carry out hot pressing sintering of the ceramic powder, first raise the temperature to 600°C at a heating rate of 30°C/min, then raise the temperature to 1400°C at a heating rate of 20°C/min, and keep it at 1400°C for 1 hour, then heat it at 20°C The rate of ℃/min is lowered to room temperature, and the pressure is increased when the temperature is raised to 600 ℃, and the pressure is increased to 30MPa, and the pressure is maintained at this pressure until the end of the heat preservation, and titanium carbide-zirconium carbide ceramics are obtained.

Detection test:

(1) Carry out mechanical test analysis on the composite ceramics of Examples 1-6 and the ceramics of Comparative Examples 1-2, using a sample with a size of 2 × 4 × 25mm ³ at a span of 20mm and an indenter speed of 0.5mm /min on the Instron-1186 machine, the bending strength was measured by a three-point bending test, and the results are shown in Table 1.

(2) The hardness test was carried out on the composite ceramics of Examples 1-6 and the ceramics of Comparative Examples 1-2, and the Vickers hardness was measured under an external load of 9.8N using a Vickers indentation test, and the residence time was 10s. The results are shown in Table 1.

The sample performance test data of table 1 embodiment 1-6, comparative example 1-2

Bending strength (MPa) Vickers Hardness (GPa) Fracture toughness (MPa·m ^1/2 ) Example 1 606±8 17.6±1.3 6.4±0.2 Example 2 580±34 20.2±1.2 6.7±0.3 Example 3 548±38 25.7±1.5 5.5±0.5 Example 4 500±45 20.6±1.7 4.6±0.5 Example 5 540±44 24.4±0.8 5.6±0.4 Example 6 577±34 23.8± 1.2 5.1±0.2 Comparative example 1 501±63 13.9±0.8 4.0±0.8 Comparative example 2 313±21 16.1±0.9 3.5±0.8

The above are only preferred specific implementations of the present invention. These specific implementations are all based on different implementations under the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field Within the technical scope disclosed in the present invention, any changes or substitutions that can be easily conceived by a skilled person shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (9)

1. ZrSi-Ti-based alloy ₃ SiC ₂ Is characterized in that the high-toughness composite ceramic consists of TiC _x Phase, siC phase, (Zr, ti) C _x Solid solution phase, zrSi phase, ti ₃ SiC ₂ The phase composition is prepared from 54% of TiC powder, 36% of Si powder and 10% of ZrC powder by mol content.

2. A ZrSi-Ti based alloy according to claim 1 ₃ SiC ₂ The high-toughness composite ceramic is characterized in that the granularity of TiC powder, si powder and ZrC powder is 1-3 mu m.

3. ZrSi-Ti based according to any one of claims 1-2 ₃ SiC ₂ The preparation method of the high-toughness composite ceramic is characterized by comprising the following steps:

step 1: mixing TiC powder, si powder and ZrC powder to obtain mixed powder, adding absolute ethyl alcohol for ultrasonic treatment, ball-milling and mixing under the protection of inert gas, drying and sieving to obtain ceramic powder;

step 2: hot-pressing and sintering the ceramic powder to obtain a baseIn ZrSi-Ti ₃ SiC ₂ Is a high-toughness composite ceramic.

4. The method according to claim 3, wherein the volume ratio of the mass of the mixed powder to the absolute ethanol in the step 1 is 25g: (10-15) mL.

5. A method according to claim 3, wherein the ultrasound in step 1 has a frequency of 30-40kHz for a period of 10-30min.

6. A method according to claim 3, wherein the ball to material ratio in step 1 is (5-50): 1, the ball milling rotating speed is 200-300rpm, and the ball milling time is 5-30h.

7. A method according to claim 3, wherein in step 1 the drying temperature is 50-70 ℃ and the time is 1-5h, and the drying is carried out by sieving with a 200 mesh sieve.

8. A method according to claim 3, characterized in that the hot-press sintering process in step 2: heating to 500-700 ℃ at a heating rate of 20-40 ℃/min, heating to 1300-1600 ℃ at a heating rate of 15-25 ℃/min, preserving heat at 1300-1600 ℃ for 0.5-3h, cooling to room temperature at a heating rate of 10-30 ℃/min, pressurizing to 20-60 MPa when heating to 500-700 ℃, and maintaining the pressure at the pressure until the heat preservation is finished.

9. ZrSi-Ti based according to any one of claims 1-2 ₃ SiC ₂ The high-toughness composite ceramic is used for preparing cutters, molds and aerospace materials.