A preparation method of high-strength and high-toughness boron carbide-based ceramic material and ceramic material thereof

Abstract

The invention discloses a preparation method of a high-strength and high-toughness boron carbide-based ceramic material and the ceramic material thereof, comprising: refining boron carbide coarse powder through high-energy ball milling, pickling, water washing, and drying to obtain boron carbide fine powder; The dual-phase alloy pre-alloy powder prepared by the gas atomization method is smelted by gas atomization and sieved to obtain the dual-phase alloy metal powder; weigh boron carbide powder, dual-phase alloy powder, and yttrium powder according to the volume fraction of 94.95-98.95 vol.%: 1~5vol.%: 0.05vol.% mixing, ball milling, drying; sintering under the protection of vacuum or inert gas by hot pressing sintering or discharge plasma sintering and other sintering methods, cooling and grinding to obtain the high strength High-toughness boron carbide-based ceramic material; the density of the ceramic material of the present invention is 2.57-2.73g / m 3 , the flexural strength is greater than 450MPa, the micro-Vickers hardness is greater than 30Gpa, and the fracture toughness is greater than 4.5Mpa m 1 / 2 .

Description

technical field

[0001] The invention belongs to the technical field of ceramic materials, and in particular relates to a preparation method of a high-strength and high-toughness boron carbide-based ceramic material and the ceramic material. Background technique

[0002] Boron carbide ceramic materials are widely used in friction materials, bearings, bulletproof materials, etc. However, boron carbide also has many disadvantages, such as high sintering temperature, poor toughness, and low strength, which hinder the further expansion of the application range of boron carbide. Boron carbide itself has a very high melting point, around 2450°C. Boron carbide is mainly bonded by strong covalent bonds, has a low self-diffusion coefficient, and is difficult to sinter. The relative density of pressureless sintered boron carbide is only 98% at 2350°C for three hours, and it still cannot be sintered fully dense.

[0003] Boron carbide has very high hardness, second only to diamond and...

Examples

preparation example Construction

[0032] The present invention uses industrially produced boron carbide coarse powder as a preparation method for preparing high-strength and high-toughness boron carbide-based ceramics, and the specific steps include:

[0033] step one:

[0034] Take industrial boron carbide coarse powder, put it into a stirring ball mill tank, and use deionized water as a ball milling medium for high-speed ball milling. The specific steps of high-speed ball milling: put boron carbide coarse powder into a stirring ball mill tank, use iron balls, and the ball-to-material ratio is (8~15):1, preferably 12:1, ball milling for 48~72h, preferably 72h, rotating speed 300~600r / min, preferably 450r / min. After ball milling, hot pickling and water washing are carried out to obtain a mixed slurry of boron carbide and deionized water, and the slurry is placed in a blast drying oven for low-temperature drying to obtain boron carbide micropowder. The boron carbide fine powder has a purity of 99.9%.

[0035]...

Embodiment 1

[0049] Take 200g of boron carbide coarse powder with a particle size greater than 10 μm, pickle and wash with water after high-speed ball milling for 72 hours. The specific steps of the high-speed ball milling are: put the boron carbide coarse powder into a stirring ball mill tank, use iron balls, and the ball-to-material ratio is 12: 1. Ball milling for 72 hours at a speed of 450r / min. Putting it in a blast drying oven for low-temperature drying to obtain boron carbide micropowder with an average particle diameter of 5 μm and a purity greater than 99%. Dual-phase alloy MnCoCrFe pre-alloyed powder prepared by gas atomization method: the molar ratio is Mn: Co: Cr: Fe = 3: 1: 1: 5. After smelting, use nitrogen gas atomization to make powder, and sieve 150 mesh to obtain dual phase Alloy metal powder. Weigh 95.95vol.% of boron carbide fine powder, 4vol.% of dual-phase alloy metal powder and 0.05vol.% of rare earth metal yttrium powder. The average particle size of the yttrium po...

Embodiment 2

[0053] Take 200g of boron carbide coarse powder with a particle size greater than 10μm, high-speed ball milling for 72 hours, hot pickling, water washing, high-speed ball milling specific steps: put boron carbide coarse powder into a stirring ball mill tank, use iron balls, the ball-to-material ratio is 12:1 , ball milled for 72 hours, rotating speed 450r / min, placed in a blast drying oven for low-temperature drying, to obtain boron carbide powder with an average particle size of 5 μm and a purity greater than 99%. Two-phase alloy MnCoCrFe pre-alloyed powder prepared by gas atomization method: the molar ratio of metals with a fixed molar mass ratio is Mn: Co: Cr: Fe = 3: 1: 1: 5, and nitrogen gas atomization is used to make powder after smelting. Sieve through 150 mesh. Weigh 95.95vol.% boron carbide fine powder, 4vol.% dual-phase alloy powder and 0.05vol.% rare earth metal yttrium powder, mix ball mill for 3 hours, dry and grind to obtain mixed powder, the mass ratio of ball ...

technical field

[0001] The invention belongs to the technical field of ceramic materials, and in particular relates to a preparation method of a high-strength and high-toughness boron carbide-based ceramic material and the ceramic material. Background technique

[0002] Boron carbide ceramic materials are widely used in friction materials, bearings, bulletproof materials, etc. However, boron carbide also has many disadvantages, such as high sintering temperature, poor toughness, and low strength, which hinder the further expansion of the application range of boron carbide. Boron carbide itself has a very high melting point, around 2450°C. Boron carbide is mainly bonded by strong covalent bonds, has a low self-diffusion coefficient, and is difficult to sinter. The relative density of pressureless sintered boron carbide is only 98% at 2350°C for three hours, and it still cannot be sintered fully dense.

[0003] Boron carbide has very high hardness, second only to diamond and...

Examples

preparation example Construction

[0032] The present invention uses industrially produced boron carbide coarse powder as a preparation method for preparing high-strength and high-toughness boron carbide-based ceramics, and the specific steps include:

[0033] step one:

[0034] Take industrial boron carbide coarse powder, put it into a stirring ball mill tank, and use deionized water as a ball milling medium for high-speed ball milling. The specific steps of high-speed ball milling: put boron carbide coarse powder into a stirring ball mill tank, use iron balls, and the ball-to-material ratio is (8~15):1, preferably 12:1, ball milling for 48~72h, preferably 72h, rotating speed 300~600r / min, preferably 450r / min. After ball milling, hot pickling and water washing are carried out to obtain a mixed slurry of boron carbide and deionized water, and the slurry is placed in a blast drying oven for low-temperature drying to obtain boron carbide micropowder. The boron carbide fine powder has a purity of 99.9%.

[0035]...

Embodiment 1

[0049] Take 200g of boron carbide coarse powder with a particle size greater than 10 μm, pickle and wash with water after high-speed ball milling for 72 hours. The specific steps of the high-speed ball milling are: put the boron carbide coarse powder into a stirring ball mill tank, use iron balls, and the ball-to-material ratio is 12: 1. Ball milling for 72 hours at a speed of 450r / min. Putting it in a blast drying oven for low-temperature drying to obtain boron carbide micropowder with an average particle diameter of 5 μm and a purity greater than 99%. Dual-phase alloy MnCoCrFe pre-alloyed powder prepared by gas atomization method: the molar ratio is Mn: Co: Cr: Fe = 3: 1: 1: 5. After smelting, use nitrogen gas atomization to make powder, and sieve 150 mesh to obtain dual phase Alloy metal powder. Weigh 95.95vol.% of boron carbide fine powder, 4vol.% of dual-phase alloy metal powder and 0.05vol.% of rare earth metal yttrium powder. The average particle size of the yttrium po...

Embodiment 2

[0053] Take 200g of boron carbide coarse powder with a particle size greater than 10μm, high-speed ball milling for 72 hours, hot pickling, water washing, high-speed ball milling specific steps: put boron carbide coarse powder into a stirring ball mill tank, use iron balls, the ball-to-material ratio is 12:1 , ball milled for 72 hours, rotating speed 450r / min, placed in a blast drying oven for low-temperature drying, to obtain boron carbide powder with an average particle size of 5 μm and a purity greater than 99%. Two-phase alloy MnCoCrFe pre-alloyed powder prepared by gas atomization method: the molar ratio of metals with a fixed molar mass ratio is Mn: Co: Cr: Fe = 3: 1: 1: 5, and nitrogen gas atomization is used to make powder after smelting. Sieve through 150 mesh. Weigh 95.95vol.% boron carbide fine powder, 4vol.% dual-phase alloy powder and 0.05vol.% rare earth metal yttrium powder, mix ball mill for 3 hours, dry and grind to obtain mixed powder, the mass ratio of ball ...

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