Multi-morphology microstructure SiC-TiB 2 -Ti 3 SiC 2 Reinforced composite ceramics and its preparation method and application

Abstract

Multi-morphology microstructure SiC-TiB2-Ti3SiC2 reinforced composite ceramics and its preparation method and application. The present invention belongs to the field of ultra-high temperature composite ceramic materials and their preparation. The purpose of the present invention is to solve the technical problem that the flexural strength and fracture toughness of existing sub-group titanium carbide composite ceramics cannot be further improved. The method of the present invention: Mix TiC, TiSi2, sub-group titanium boride and TiH2 powders, and then alternately perform ultrasonic and ball milling to obtain a composite powder. After sintering, the composite ceramics can be obtained. The present invention generates nano-scale equiaxed SiC by in-situ reaction, which can play a role in pinning grain boundaries, inhibit grain growth, and significantly improve the comprehensive mechanical properties of the material. The in-situ generation of plate-like (Ti,Zr)B2 and layered Ti3SiC2 grain structures causes cracks to deflect or bridge during propagation, thereby greatly improving the strength and toughness of sub-group titanium carbide ceramics.

Description

Technical Field

[0001] The present invention belongs to the field of ultra-high temperature composite ceramic materials and their preparation, and particularly relates to a multi-morphology microstructure SiC-TiB 2 -Ti 3 SiC 2 reinforced composite ceramic and its preparation method and application. Background Art

[0002] The high melting point (>3000 °C), high hardness (>20 GPa), good thermal shock resistance and other excellent comprehensive properties of titanium subgroup carbides (TiC, ZrC, HfC) have received extensive attention in the fields of high temperature and extreme mechanical applications. For example, they are applied to the new thermal protection system and sharp leading edge components of hypersonic aircraft, and machine tools in the machinery industry. However, the sintering of titanium subgroup carbide ceramic materials is difficult, and the poor flexural strength and fracture toughness limit the practical application of titanium subgroup carbides. In recent years, many efforts have been made to improve the sinterability of titanium subgroup carbides (TiC, ZrC, HfC), but introducing different additives will damage the inherent properties of the materials, and the obtained microstructure and properties of the sintered materials are still often not ideal, and there are also problems such as high self-sintering temperature. Summary of the Invention

[0003] The purpose of the present invention is to solve the technical problem that the flexural strength and fracture toughness of the existing titanium subgroup carbide composite ceramics cannot be further improved, and to provide a multi-morphology microstructure SiC-TiB 2 -Ti 3 SiC 2 reinforced composite ceramic and its preparation method and application.

[0004] One of the purposes of the present invention is to provide a preparation method of a multi-morphology microstructure SiC-TiB 2 -Ti 3 SiC 2 reinforced composite ceramic, and the preparation method is carried out according to the following steps:

[0005] Mix TiC, TiSi 2 , titanium subgroup boride and TiH 2 powders, and then alternately perform ultrasonic and ball milling to obtain a composite powder. After sintering, a multi-morphology microstructure SiC-TiB 2 -Ti 3 SiC 2 reinforced composite ceramic can be obtained.

[0006] Preferably, the titanium subgroup boride is zirconium boride, hafnium boride or niobium boride.

[0007] Preferably, the molar content of borides of the titanium subgroup in the composite powder is 5-30%, the molar content of TiC is 50-75%, and the molar content of TiSi 2 is 5-16%, and the molar content of TiH 2 is 0-5%.

[0008] Preferably, ultrasonic treatment and ball milling are each alternately carried out 6-20 times.

[0009] More preferably, the ultrasonic frequency is 30-50 kHz and the time is 20-40 min.

[0010] More preferably, the ball milling medium is anhydrous ethanol, the ball-to-material ratio is (5-50):1, and the single ball milling time is 0.5-1 h.

[0011] Preferably, before sintering, the ball milling medium in the composite powder is removed first and then dried.

[0012] Preferably, sintering is carried out by plasma discharge sintering or hot pressing sintering. After heating to 1400-1600 °C, it is kept warm, and pressure is applied when heating to 600-800 °C, and the pressure is 20-60 MPa.

[0013] More preferably, during plasma discharge sintering, the heating rate is 50-350 °C / min, the holding time is 5-25 min, and the cooling rate is 320 °C / min.

[0014] More preferably, during hot pressing sintering, it is first heated to 600 °C-800 °C at a rate of 20-40 °C / min, then heated to 1400 °C-1600 °C at a rate of 10-30 °C / min, and kept warm at 1400 °C-1600 °C for 1-2 h, and then cooled to room temperature at a rate of 30 °C / min.

[0015] The second object of the present invention is to provide a multi-morphology microstructure SiC-TiB prepared by the above method 2 -Ti 3 SiC 2 reinforced composite ceramic, and the ceramic includes equiaxed SiC, plate-like (Ti,Zr)B 2 and layered Ti 3 SiC 2 tissue.

[0016] Preferably, the flexural strength of the ceramic is as high as 725 Mpa, and the fracture toughness is as high as 7.12 MPa·m 1 / 2 .

[0017] The third object of the present invention is to provide a multi-morphology microstructure SiC-TiB prepared by the above method 2 -Ti 3 SiC 2Application of Reinforced Composite Ceramics in High-Temperature Environments

[0018] The remarkable effects of the present invention compared with the prior art are as follows:

[0019] The preparation method of the present invention comprehensively improves the material properties by optimizing the sintering process, adjusting the proportion of raw material powders, and adding sintering aids. Compared with the traditional sintering process, the method of the present invention has the following beneficial effects:

[0020] (1) Through all-round ultrasonic ball milling, the present invention can effectively reduce the particle size of the composite powder. At the same time, by alternating ultrasonic and ball milling, the uniformity of the composite powder is improved, and a composite ceramic with refined and uniform structure is obtained. (2) In the present invention, in-situ reactions occur between titanium disilicide powder and titanium carbide powder (2TiSi 2 +7TiC=3Ti 3 SiC 2 +SiC), in-situ reactions and solid solution processes occur between titanium subgroup boride powder and titanium carbide powder (ZrB 2 / HfB 2 / NbB 2 +TiC=ZrC / HfC / NbC+TiB 2 →(Zr,Ti)C / (Hf,Ti)C / (Nb,Ti)C+(Ti,Zr)B 2 ). At the same time, a small amount of TiH 2 undergoes a dehydrogenation reaction during the sintering process ((Zr,Ti)C / (Hf,Ti)C / (Nb,Ti)C+zTiH 2 =(Zr,Ti)C x / (Hf,Ti)C x / (Nb,Ti)C x +zH 2 ↑) to generate vacancies to promote material densification. On the other hand, the melting temperature of TiSi 2 is low (1487 °C), which promotes the low-temperature full densification of the composite ceramic. Moreover, low-temperature sintering ensures that the grain size of the material is uniformly fine. In addition, the in-situ generated grain boundaries are clear and the grain boundary bonding force is strong, obtaining a fully densified composite ceramic at low temperature. (3) The present invention uses a low-temperature in-situ reaction method to prepare a multi-morphology microstructure SiC-TiB 2 -Ti 3 SiC 2 composite toughened titanium subgroup carbide composite ceramic material with (Ti,Zr)C x , (Zr,Ti)C x , SiC, (Ti,Zr)B 2 , Ti 3 SiC 2, phase compositions such as ZrSi, etc., in-situ generate nanoscale equiaxed SiC, which can play a role in pinning grain boundaries, inhibiting grain growth, and significantly improving the comprehensive mechanical properties of the material. In-situ generate lath-shaped (Ti,Zr)B 2 and layered Ti 3 SiC 2 The grain structure causes cracks to deflect or bridge during propagation, thereby greatly improving the strength and toughness of the sub-group titanium carbide ceramics. Moreover, compared with the powder of the final phase formed by direct sintering, the in-situ reaction preparation of the composite material can reduce production costs and has high practical value. (4) The method of the present invention can provide good ideas for the preparation of other cermets and improve the preparation performance of cermets. Description of the Drawings

[0021] Figure 1 It is the XRD schematic diagram of the composite ceramic prepared in Specific Example 9;

[0022] Figure 2 It is the SEM schematic diagram of the composite ceramic prepared in Specific Example 9;

[0023] Figure 3 It is the SEM schematic diagram of the crack propagation of the composite ceramic prepared in Specific Example 9. Detailed Embodiments

[0024] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified. The materials, reagents, methods and instruments used, unless otherwise specified, are all conventional materials, reagents, methods and instruments in the art, and those skilled in the art can obtain them through commercial channels.

[0026] In the mechanical test analysis of the following embodiments: Use specimens with dimensions of 4×3×36mm 3 and measure the flexural strength through a three-point bending experiment on an Instron-1186 machine with a span of 30mm and a indenter speed of 0.5mm / min.

[0027] The Vickers hardness of the ceramic materials obtained by the Vickers indentation experiment in the following embodiments is tested, and the test conditions are measured under an external load of 9.8N with a dwell time of 10s.

[0028] Example 1

[0029] (1) By molar percentage, 10% zirconium diboride, 74% titanium carbide, 16% titanium disilicide powder, Si 3N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.2% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0030] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1400°C at 20°C / min, kept at 1400°C for 1 h, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0031] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 532±13MPa and the fracture toughness was 6.32±0.21MPa·m 1 / 2 , Vickers hardness is 15.2±1.2GPa.

[0032] Example 2

[0033] (1) According to molar percentage, 10% zirconium diboride, 74% titanium carbide, 16% titanium disilicide powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=3.1% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0034] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1400°C at 130°C / min, kept at 1400°C for 15 min, then cooled to room temperature at 320°C / min, pressurized to 50 MPa when the temperature is raised to 700°C, and maintained at this pressure until the insulation is completed. The ceramic material of this embodiment can be obtained by demolding.

[0035] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 502±13MPa and the fracture toughness was 5.68±0.13MPa·m 1 / 2 , Vickers hardness is 13.3±1.5GPa.

[0036] Example 3

[0037] (1) According to molar percentage, 10% zirconium diboride, 74% titanium carbide, 16% titanium disilicide powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=4.2% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0038] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1500°C at 20°C / min, kept at 1500°C for 1 h, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0039] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 678±14MPa and the fracture toughness was 6.81±0.13MPa·m 1 / 2 , Vickers hardness is 27±0.5GPa.

[0040] Example 4

[0041] (1) According to molar percentage, 10% zirconium diboride, 74% titanium carbide, 16% titanium disilicide powder, Si3N4 grinding balls and anhydrous ethanol were placed in a mixing tank and mixed into a slurry. The mixture was placed in an ultrasonicator and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 4.0% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve and collected for standby use.

[0042] (2) Place the powder in a graphite mold coated with a release agent, put it into a plasma discharge sintering furnace, heat it to 1500 °C at a rate of 130 °C / min, hold it at 1500 °C for 15 min, then cool it to room temperature at a rate of 320 °C / min. Apply pressure when heating to 700 °C, increase the pressure to 50 MPa, hold the pressure until the heat preservation ends, and demold to obtain the ceramic material of this example.

[0043] Mechanical test analysis was carried out on the composite ceramic material. The results show that the flexural strength at room temperature is 631 ± 18 MPa, and the fracture toughness is 6.69 ± 0.08 MPa·m 1 / 2 and the Vickers hardness is 23 ± 2.7 GPa.

[0044] Example 5

[0045] (1) According to the molar percentage, put 10% zirconium diboride, 74% titanium carbide, 16% titanium disilicide powder, Si 3 N 4 grinding balls and absolute ethanol into the mixing tank to mix into a slurry, place it in an ultrasonic device, disperse it ultrasonically at 40 KHz for 20 min, place the mixing tank on an all-round planetary high-energy ball mill, the ball-to-material ratio is 40:1, the ball milling speed is 250 r / min, alternate ultrasonic and ball milling 20 times each, the single ball milling time is 1 h, obtain a composite powder with a particle size of 0.15 - 0.20 μm and a uniformity RSD = 4.5%, use rotary evaporation to remove the absolute ethanol in the mixed powder slurry in a vacuum drying oven, and continue to dry it in the oven at 60 °C for 2 h. Mix the obtained dry and uniform powder, sieve it through a 200-mesh sieve, collect it, and set it aside.

[0046] (2) Place the powder in a graphite mold coated with a release agent, put it into a hot press sintering furnace, heat it to 700 °C at a rate of 30 °C / min, then continue to heat it to 1600 °C at a rate of 20 °C / min, hold it at 1600 °C for 1 h, then cool it at a rate of 30 °C / min, start to apply pressure to 30 MPa at 700 °C until the heat preservation ends, and demold to obtain the ceramic material of this example.

[0047] Mechanical test analysis was carried out on the composite ceramic material. The results show that the flexural strength at room temperature is 652 ± 16 MPa, and the fracture toughness is 6.72 ± 0.10 MPa·m 1 / 2 and the Vickers hardness is 25.8 ± 2.7 GPa.

[0048] Example 6

[0049] (1) According to the molar percentage, put 10% zirconium diboride, 74% titanium carbide, 16% titanium disilicide powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=3.8% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0050] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1600°C at 130°C / min, kept at 1600°C for 15 min, then cooled to room temperature at 320°C / min, and pressurized to 50 MPa when the temperature is raised to 700°C. The pressure is maintained at this pressure until the insulation ends, and the ceramic material of this embodiment is obtained by demolding.

[0051] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 636±15MPa and the fracture toughness was 6.63±0.12MPa·m 1 / 2 , Vickers hardness is 24±1GPa.

[0052] Example 7

[0053] (1) According to molar percentage, 9.5% zirconium diboride, 70.3% titanium carbide, 15.2% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.9% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0054] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1400°C at 20°C / min, kept at 1400°C for 1 hour, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0055] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 541±15MPa and the fracture toughness was 6.38±0.15MPa·m 1 / 2 , Vickers hardness is 15.9±1.3GPa.

[0056] Example 8

[0057] (1) According to molar percentage, 9.5% zirconium diboride, 70.3% titanium carbide, 15.2% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=4.0% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0058] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1400°C at 130°C / min, kept at 1400°C for 15 min, then cooled to room temperature at 320°C / min, pressurized to 50 MPa when the temperature is raised to 700°C, and maintained at this pressure until the insulation is completed. The ceramic material of this embodiment can be obtained by demolding.

[0059] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 512±31MPa and the fracture toughness was 5.70±0.09MPa·m 1 / 2 , Vickers hardness is 13.7±0.08GPa.

[0060] Example 9

[0061] (1) According to molar percentage, 9.5% zirconium diboride, 70.3% titanium carbide, 15.2% titanium disilicide, 5% titanium hydride powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=4.1% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0062] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1500°C at 20°C / min, kept at 1500°C for 1 h, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0063] The ceramic material of Example 9 was subjected to XRD test, and the test results are as follows: Figure 1 As shown, from Figure 1 It can be seen that the ceramic material is composed of (Ti, Zr)C x 、(Zr,Ti)C x 、SiC、(Ti,Zr)B 2 、Ti 3 SiC 2 , ZrSi and other phases.

[0064] The surface of the ceramic material of Example 9 was tested by SEM, and the test results are as follows: Figure 2 As shown. Figure 2 Quantitative calculation of the energy spectrum shows that the dark fine structure is SiC, and the gray lath is (Ti,Zr)B 2 , the black phase is Ti 3 SiC 2 .

[0065] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 725±21MPa and the fracture toughness was 7.12±0.16MPa·m 1 / 2 , Vickers hardness is 27±0.7GPa, the SEM diagram of crack extension of the composite ceramic is shown in Figure 3 Example 10

[0066] (1) According to molar percentage, 9.5% zirconium diboride, 70.3% titanium carbide, 15.2% titanium disilicide, 5% titanium hydride powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 5.2% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0067] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, and heated to 1500°C at 130°C / min, then kept at 1500°C for 15 min, then cooled to room temperature at 320°C / min, and pressurized to 50 MPa when the temperature is raised to 700°C. The pressure is maintained at this pressure until the insulation ends, and the ceramic material of this embodiment is obtained by demolding.

[0068] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 689±25MPa and the fracture toughness was 7±0.12MPa·m 1 / 2 , Vickers hardness is 26±1.4GPa.

[0069] Embodiment 11

[0070] (1) According to molar percentage, 9.5% zirconium diboride, 70.3% titanium carbide, 15.2% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=4.9% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0071] (2) Place the powder in a graphite mold coated with a release agent, put it into a hot pressing sintering furnace, heat it to 700 °C at a rate of 30 °C / min, then continue to heat it to 1600 °C at a rate of 20 °C / min, hold it at 1600 °C for 1 h, and then cool it at a rate of 30 °C / min. Start pressurizing to 30 MPa at 700 °C until the holding ends, and then demold to obtain the ceramic material of this example. Perform mechanical property test and analysis on the composite ceramic material. The results show that the flexural strength at room temperature is 668 ± 23 MPa, the fracture toughness is 6.77 ± 0.10 MPa·m 1 / 2 , and the Vickers hardness is 27 ± 1.6 GPa.

[0072] Example 12

[0073] (1) According to the molar percentage, put 9.5% zirconium diboride, 70.3% titanium carbide, 15.2% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 grinding balls and absolute ethanol into a mixing tank to mix into a slurry, place it in an ultrasonic device, disperse it ultrasonically at 40 KHz for 20 min, place the mixing tank on an all-round planetary high-energy ball mill, with a ball-to-material ratio of 40:1 and a ball milling speed of 250 r / min, alternate ultrasonic treatment and ball milling 20 times each, with a single ball milling time of 1 h, to obtain a composite powder with a particle size of 0.15 - 0.20 μm and a uniformity RSD = 3.0%. Use rotary evaporation to remove the absolute ethanol in the mixed powder slurry in a vacuum drying oven, and continue to dry it in an oven at 60 °C for 2 h. Mix the obtained dry and uniform powder, pass it through a 200-mesh sieve, collect it, and set it aside.

[0074] (2) Place the powder in a graphite mold coated with a release agent, put it into a plasma discharge sintering furnace, heat it to 1600 °C at a rate of 130 °C / min, then hold it at 1600 °C for 15 min, and then cool it to room temperature at a rate of 320 °C / min. Start pressurizing when heating to 700 °C, pressurize to 50 MPa, and hold the pressure until the holding ends, and then demold to obtain the ceramic material of this example.

[0075] Perform mechanical property test and analysis on the composite ceramic material. The results show that the flexural strength at room temperature is 659 ± 9 MPa, the fracture toughness is 6.69 ± 0.18 MPa·m 1 / 2 , and the Vickers hardness is 26.9 ± 2.0 GPa.

[0076] Example 13

[0077] (1) According to the molar percentage, put 20% zirconium diboride, 68% titanium carbide, 12% titanium disilicide powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.2% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0078] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1400°C at 20°C / min, kept at 1400°C for 1 hour, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0079] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 510±17MPa and the fracture toughness was 5.28±1.73MPa·m 1 / 2 , Vickers hardness is 20.8±1.2GPa.

[0080] Embodiment 14

[0081] (1) According to molar percentage, 20% zirconium diboride, 68% titanium carbide, 12% titanium disilicide powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.9% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0082] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1400°C at 130°C / min, kept at 1400°C for 15 min, then cooled to room temperature at 320°C / min, pressurized to 50 MPa when the temperature is raised to 700°C, and maintained at this pressure until the insulation is completed. The ceramic material of this embodiment can be obtained by demolding.

[0083] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 502±8MPa and the fracture toughness was 5.22±0.18MPa·m 1 / 2 , Vickers hardness is 19.8±1.7GPa.

[0084] Embodiment 15

[0085] (1) According to molar percentage, 20% zirconium diboride, 68% titanium carbide, 12% titanium disilicide powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 5.8% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0086] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1500°C at 20°C / min, kept at 1500°C for 1 h, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0087] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 559±23MPa and the fracture toughness was 6.49±0.26MPa·m 1 / 2 , Vickers hardness is 23.3±0.9GPa.

[0088] Example 16

[0089] (1) According to molar percentage, 20% zirconium diboride, 68% titanium carbide, 12% titanium disilicide powder, Si 3 N 4The grinding balls and absolute ethanol are put into a mixing tank to be mixed into a slurry, which is placed in an ultrasonic device and ultrasonically dispersed at 40 KHz for 20 min. Then the mixing tank is placed on an all-round planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball-milling rotation speed of 250 r / min. Ultrasonic treatment and ball milling are alternately carried out 20 times each, and the single ball-milling time is 1 h to obtain a composite powder with a particle size of 0.15 - 0.20 μm and a uniformity RSD = 5.1%. The absolute ethanol in the mixed powder slurry is removed by rotary evaporation in a vacuum drying oven, and it is further dried in an oven at 60 °C for 2 h. The obtained dried and uniform powder is mixed and passed through a 200-mesh sieve and then collected for use.

[0090] (2) The powder is placed in a graphite mold coated with a release agent and put into a plasma discharge sintering furnace. It is heated to 1500 °C at a rate of 130 °C / min, held at 1500 °C for 15 min, and then cooled to room temperature at a rate of 320 °C / min. Pressure is applied when the temperature is raised to 700 °C and the pressure is increased to 50 MPa. The pressure is maintained at this value until the heat preservation ends, and then the mold is removed to obtain the ceramic material of this example. Mechanical test analysis is carried out on the composite ceramic material. The results show that the flexural strength at room temperature is 537 ± 24 MPa, the fracture toughness is 6.36 ± 0.34 MPa·m 1 / 2 , and the Vickers hardness is 24.8 ± 1.9 GPa.

[0091] Example 17

[0092] (1) By molar percentage, 20% zirconium diboride, 68% titanium carbide, 12% titanium disilicide powder, Si 3 N 4 The grinding balls and absolute ethanol are put into a mixing tank to be mixed into a slurry, which is placed in an ultrasonic device and ultrasonically dispersed at 40 KHz for 20 min. Then the mixing tank is placed on an all-round planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball-milling rotation speed of 250 r / min. Ultrasonic treatment and ball milling are alternately carried out 20 times each, and the single ball-milling time is 1 h to obtain a composite powder with a particle size of 0.15 - 0.20 μm and a uniformity RSD = 5.2%. The absolute ethanol in the mixed powder slurry is removed by rotary evaporation in a vacuum drying oven, and it is further dried in an oven at 60 °C for 2 h. The obtained dried and uniform powder is mixed and passed through a 200-mesh sieve and then collected for use.

[0093] (2) The powder is placed in a graphite mold coated with a release agent and put into a hot-pressing sintering furnace. It is heated to 700 °C at a rate of 30 °C / min and then continued to be heated to 1600 °C at a rate of 20 °C / min. It is held at 1600 °C for 1 h and then cooled at a rate of 30 °C / min. Pressure is applied starting from 700 °C until the pressure reaches 30 MPa and is maintained until the heat preservation ends, and then the mold is removed to obtain the ceramic material of this example.

[0094] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 612±29MPa and the fracture toughness was 6.68±0.16MPa·m 1 / 2 , Vickers hardness is 27.7±1.6GPa.

[0095] Embodiment 18

[0096] (1) According to molar percentage, 20% zirconium diboride, 68% titanium carbide, 12% titanium disilicide powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=4.1% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0097] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1600°C at 130°C / min, kept at 1600°C for 15 min, then cooled to room temperature at 320°C / min, and pressurized to 50 MPa when the temperature is raised to 700°C. The pressure is maintained at this pressure until the insulation ends, and the ceramic material of this embodiment is obtained by demolding.

[0098] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 600±38MPa and the fracture toughness was 6.61±0.23MPa·m 1 / 2 , Vickers hardness is 27.8±1.8GPa.

[0099] Embodiment 19

[0100] (1) According to molar percentage, 19% zirconium diboride, 64.6% titanium carbide, 11.4% titanium disilicide, 5% titanium hydride powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=2.9% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0101] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1400°C at 20°C / min, kept at 1400°C for 1 hour, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0102] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 523±17MPa and the fracture toughness was 5.31±0.15MPa·m 1 / 2 , Vickers hardness is 21.2±1.2GPa.

[0103] Embodiment 20

[0104] (1) According to molar percentage, 19% zirconium diboride, 64.6% titanium carbide, 11.4% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=3.4% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0105] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1400°C at 130°C / min, kept at 1400°C for 15 min, then cooled to room temperature at 320°C / min, pressurized to 50 MPa when the temperature is raised to 700°C, and maintained at this pressure until the insulation is completed. The ceramic material of this embodiment can be obtained by demolding.

[0106] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 512±27MPa and the fracture toughness was 5.26±0.22MPa·m 1 / 2 , Vickers hardness is 20.1±1.3GPa.

[0107] Embodiment 21

[0108] (1) According to molar percentage, 19% zirconium diboride, 64.6% titanium carbide, 11.4% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each alternately, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=4.8% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0109] (2) Place the powder in a graphite mold coated with a release agent, put it into a hot pressing sintering furnace, heat it to 700°C at 30°C / min, then continue to heat it to 1500°C at 20°C / min, keep it at 1500°C for 1h, then cool it down at 30°C / min, pressurize it to 30MPa at 700°C until the end of the heat preservation, and demold it to obtain the ceramic material of this embodiment. Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 572±33MPa and the fracture toughness was 6.58±0.18MPa·m 1 / 2 , Vickers hardness is 26.4±0.3GPa.

[0110] Embodiment 22

[0111] (1) According to molar percentage, 19% zirconium diboride, 64.6% titanium carbide, 11.4% titanium disilicide, 5% titanium hydride powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=3.1% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0112] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, and heated to 1500°C at 130°C / min, then kept at 1500°C for 15 min, then cooled to room temperature at 320°C / min, and pressurized to 50 MPa when the temperature is raised to 700°C. The pressure is maintained at this pressure until the insulation ends, and the ceramic material of this embodiment is obtained by demolding.

[0113] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 552±41MPa and the fracture toughness was 6.39±0.21MPa·m 1 / 2 , Vickers hardness is 25.4±1.8GPa.

[0114] Embodiment 23

[0115] (1) According to molar percentage, 19% zirconium diboride, 64.6% titanium carbide, 11.4% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=5.7% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0116] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1600°C at 20°C / min, kept at 1600°C for 1 h, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0117] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 654±34MPa and the fracture toughness was 6.74±0.18MPa·m 1 / 2 , Vickers hardness is 24.4±1.2GPa.

[0118] Embodiment 24

[0119] (1) According to molar percentage, 19% zirconium diboride, 64.6% titanium carbide, 11.4% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.3% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0120] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1600°C at 130°C / min, kept at 1600°C for 15 min, then cooled to room temperature at 320°C / min, and pressurized to 50 MPa when the temperature is raised to 700°C. The pressure is maintained at this pressure until the insulation ends, and the ceramic material of this embodiment is obtained by demolding.

[0121] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 622±27MPa and the fracture toughness was 6.69±0.17MPa·m 1 / 2 , Vickers hardness is 26.1±1.2GPa.

[0122] Embodiment 25

[0123] (1) According to molar percentage, 30% zirconium diboride, 62% titanium carbide, 8% titanium disilicide powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed alternately for 20 times, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.7% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0124] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1400°C at 20°C / min, kept at 1400°C for 1 hour, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0125] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 542±25MPa and the fracture toughness was 5.46±0.16 MPa·m 1 / 2 , Vickers hardness is 21.2±1.3GPa.

[0126] Embodiment 26

[0127] (1) According to molar percentage, 30% zirconium diboride, 62% titanium carbide, 8% titanium disilicide powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each alternately, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=4.8% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0128] (2) Place the powder in a graphite mold coated with a release agent, put it into a plasma discharge sintering furnace, heat it to 1400 °C at a rate of 130 °C / min, hold it at 1400 °C for 15 min, then cool it to room temperature at a rate of 320 °C / min. Apply pressure when heating to 700 °C, increase the pressure to 50 MPa, and hold the pressure until the heat preservation ends. Demold to obtain the ceramic material of this embodiment. Conduct mechanical property tests and analyses on the composite ceramic material. The results show that the flexural strength at room temperature is 537 ± 32 MPa, the fracture toughness is 5.42 ± 0.23 MPa·m 1 / 2 , and the Vickers hardness is 20.6 ± 1.9 GPa.

[0129] Example 27

[0130] (1) By molar percentage, put 30% zirconium diboride, 62% titanium carbide, 8% titanium disilicide powder, Si 3 N 4 grinding balls and absolute ethanol into a mixing tank to mix into a slurry. Place it in an ultrasonic device and ultrasonically disperse it for 20 min at 40 KHz. Place the mixing tank on an all-round planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250 r / min. Alternately perform ultrasonic treatment and ball milling 20 times each, with a single ball milling time of 1 h to obtain a composite powder with a particle size of 0.15 - 0.20 μm and a uniformity RSD = 4.0%. Use rotary evaporation in a vacuum drying oven to remove the absolute ethanol in the mixed powder slurry, and continue to dry it in an oven at 60 °C for 2 h. Mix the obtained dry and uniform powder, pass it through a 200-mesh sieve, collect it, and set it aside for use.

[0131] (2) Place the powder in a graphite mold coated with a release agent, put it into a hot press sintering furnace, heat it to 700 °C at a rate of 30 °C / min, then continue to heat it to 1500 °C at a rate of 20 °C / min, hold it at 1500 °C for 1 h, then cool it at a rate of 30 °C / min. Start applying pressure to 30 MPa at 700 °C until the heat preservation ends. Demold to obtain the ceramic material of this embodiment.

[0132] Conduct mechanical property tests and analyses on the composite ceramic material. The results show that the flexural strength at room temperature is 612 ± 37 MPa, the fracture toughness is 6.72 ± 0.08 MPa·m 1 / 2 , and the Vickers hardness is 25.3 ± 1.3 GPa.

[0133] Example 28

[0134] (1) By molar percentage, put 30% zirconium diboride, 62% titanium carbide, 8% titanium disilicide powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 5.6% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0135] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, and heated to 1500°C at 130°C / min, then kept at 1500°C for 15 min, then cooled to room temperature at 320°C / min, and pressurized to 50 MPa when the temperature is raised to 700°C. The pressure is maintained at this pressure until the insulation ends, and the ceramic material of this embodiment is obtained by demolding.

[0136] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 602±20MPa and the fracture toughness was 6.63±0.18MPa·m 1 / 2 , Vickers hardness is 24.4±1.5GPa.

[0137] Embodiment 29

[0138] (1) According to molar percentage, 30% zirconium diboride, 62% titanium carbide, 8% titanium disilicide powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=3.1% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0139] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1600°C at 20°C / min, kept at 1600°C for 1 h, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0140] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 662±39MPa and the fracture toughness was 6.52±0.11 MPa·m 1 / 2 , Vickers hardness is 26.8±1.2GPa.

[0141] Embodiment 30

[0142] (1) According to molar percentage, 30% zirconium diboride, 62% titanium carbide, 8% titanium disilicide powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each alternately, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 4.7% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0143] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1600°C at 130°C / min, kept at 1600°C for 15 min, then cooled to room temperature at 320°C / min, and pressurized to 50 MPa when the temperature is raised to 700°C. The pressure is maintained at this pressure until the insulation ends, and the ceramic material of this embodiment is obtained by demolding.

[0144] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 621±39MPa and the fracture toughness was 6.48±0.14MPa·m 1 / 2 , Vickers hardness is 28.8±1.5GPa.

[0145] Embodiment 31

[0146] (1) According to molar percentage, 28.5% zirconium diboride, 58.9% titanium carbide, 7.6% titanium disilicide, 5% titanium hydride powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.2% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0147] (2) Place the powder in a graphite mold coated with a release agent, put it into a hot pressing sintering furnace, heat it to 700°C at 30°C / min, then continue to heat it to 1400°C at 20°C / min, keep it at 1400°C for 1h, then cool it down at 30°C / min, pressurize it to 30MPa at 700°C until the end of the heat preservation, and demold it to obtain the ceramic material of this embodiment. Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 572±29MPa and the fracture toughness was 5.53±0.12 MPa·m 1 / 2 , Vickers hardness is 23.3±1.8GPa.

[0148] Embodiment 32

[0149] (1) According to molar percentage, 28.5% zirconium diboride, 58.9% titanium carbide, 7.6% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were placed in a mixing tank and mixed into a slurry, which was placed in an ultrasonicator and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=4.6% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0150] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, heated to 1400°C at 130°C / min, kept at 1400°C for 15 min, then cooled to room temperature at 320°C / min, pressurized to 50 MPa when the temperature is raised to 700°C, and maintained at this pressure until the insulation is completed. The ceramic material of this embodiment can be obtained by demolding.

[0151] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 561±28MPa and the fracture toughness was 5.48±0.12MPa·m 1 / 2 , Vickers hardness is 22.2±1.3GPa.

[0152] Embodiment 33

[0153] (1) According to molar percentage, 28.5% zirconium diboride, 58.9% titanium carbide, 7.6% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed alternately for 20 times, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.7% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0154] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1500°C at 20°C / min, kept at 1500°C for 1 h, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0155] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength was 642±43MPa and the fracture toughness was 6.89±0.09 MPa·m at room temperature. 1 / 2 , Vickers hardness is 27.8±1.4GPa.

[0156] Embodiment 34

[0157] (1) According to molar percentage, 28.5% zirconium diboride, 58.9% titanium carbide, 7.6% titanium disilicide, 5% titanium hydride powder, Si 3 N 4Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=2.9% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0158] (2) The powder is placed in a graphite mold coated with a release agent, placed in a plasma discharge sintering furnace, and heated to 1500°C at 130°C / min, then kept at 1500°C for 15 min, then cooled to room temperature at 320°C / min, and pressurized to 50 MPa when the temperature is raised to 700°C. The pressure is maintained at this pressure until the insulation ends, and the ceramic material of this embodiment is obtained by demolding.

[0159] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 621±18MPa and the fracture toughness was 6.78±0.06MPa·m 1 / 2 , Vickers hardness is 28.2±1.5GPa.

[0160] Embodiment 35

[0161] (1) According to molar percentage, 28.5% zirconium diboride, 58.9% titanium carbide, 7.6% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity RSD of 3.6% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0162] (2) The powder is placed in a graphite mold coated with a release agent, placed in a hot pressing sintering furnace, and heated to 700°C at 30°C / min, then heated to 1600°C at 20°C / min, kept at 1600°C for 1 h, then cooled at 30°C / min, and pressurized to 30 MPa at 700°C until the end of the insulation. The ceramic material of this embodiment can be obtained by demolding.

[0163] Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 592±34MPa and the fracture toughness was 6.68±0.12 MPa·m 1 / 2 , Vickers hardness is 27.2±1.8GPa.

[0164] Embodiment 36

[0165] (1) According to molar percentage, 28.5% zirconium diboride, 58.9% titanium carbide, 7.6% titanium disilicide, 5% titanium hydride powder, Si 3 N 4 Grinding balls and anhydrous ethanol were mixed into a mixing tank to form a slurry, placed in an ultrasonicator, and ultrasonically dispersed at 40KHz for 20 minutes. The mixing tank was placed on an omnidirectional planetary high-energy ball mill with a ball-to-material ratio of 40:1 and a ball milling speed of 250r / min. Ultrasonication and ball milling were performed 20 times each, and the single ball milling time was 1 hour. A composite powder with a particle size of 0.15-0.20μm and a uniformity of RSD=5.4% was obtained. The anhydrous ethanol in the mixed powder slurry was removed by rotary evaporation in a vacuum drying oven, and the mixture was dried in an oven at 60°C for 2 hours. The obtained dry uniform powder was mixed and passed through a 200-mesh sieve, then collected and set aside.

[0166] (2) Place the powder in a graphite mold coated with a release agent, put it into a plasma discharge sintering furnace, heat it to 1600°C at 130°C / min, keep it at 1600°C for 15 minutes, then cool it to room temperature at 320°C / min, pressurize it when it is heated to 700°C, pressurize it to 50MPa, keep it at this pressure until the end of the insulation, and demold it to obtain the ceramic material of this embodiment. Mechanical testing and analysis of the composite ceramic material showed that the flexural strength at room temperature was 576±56MPa and the fracture toughness was 6.53±0.11MPa·m 1 / 2 , Vickers hardness is 28.8±1.3GPa.

[0167] The above are only preferred specific embodiments of the present invention, which are all different implementations based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. Preparation method of a multi-morphology microstructure SiC-TiB 2 -Ti 3 SiC 2 reinforced composite ceramic It is characterized in that it is carried out according to the following steps: Mix TiC, TiSi 2 , boride and TiH 2 powders, and then perform ultrasonic treatment and ball milling alternately to obtain a composite powder. After sintering, a multi-morphology microstructure SiC-TiB 2 -Ti 3 SiC 2 reinforced composite ceramic can be obtained; wherein the boride is zirconium boride, hafnium boride or niobium boride, the molar content of the boride in the composite powder is 5-30%, the molar content of TiC is 50-75%, and the molar content of TiSi 2 is 5-16%, and the molar content of TiH 2 is 0-5%.

2. The method according to claim 1, it is characterized in that ultrasound and ball milling are each alternately carried out 6 to 20 times.

3. The method according to claim 2, it is characterized in that the ultrasound frequency is 30 to 50 kHz, the time is 20 to 40 min, and the single ball milling time is 0.5 - 1 h.

4. The method according to claim 1, it is characterized in that sintering is carried out by plasma discharge sintering or hot press sintering, heated to 1400 - 1600 °C and then held, pressurization starts when heated to 600 - 800 °C, and the pressure is 20 - 60 MPa.

5. The method according to claim 4, it is characterized in that during plasma discharge sintering, the heating rate is 50 - 350 °C / min, the holding time is 5 - 25 min, and the cooling rate is 320 °C / min; during hot press sintering, first heat to 600 °C - 800 °C at a rate of 20 - 40 °C / min, then heat to 1400 °C - 1600 °C at a rate of 10 - 30 °C / min, and hold at 1400 °C - 1600 °C for 1 - 2 h, and then cool to room temperature at a rate of 30 °C / min.

6. The multi-morphological microstructure SiC-TiB 2 -Ti 3 SiC 2 reinforced composite ceramic prepared by the method according to any one of claims 1-5 it is characterized in that It includes equiaxed SiC, lath-shaped (Ti,Zr)B 2 and lamellar Ti 3 SiC 2 structures.

7. The composite ceramic according to claim 6, it is characterized in that Its flexural strength is as high as 725 MPa, and its fracture toughness is as high as 7.12 MPa·m 1 / 2 .

8. The multi-morphological microstructure SiC-TiB 2 -Ti 3 SiC 2 prepared by the method according to any one of claims 1-5, and the application of the SiC reinforced composite ceramic in a high-temperature environment.

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