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Hexagonal boron nitride-ytterbium silicon oxygen nitride ceramic matrix composite material and its in-situ preparation method

A technology of ytterbium silicon oxynitride ceramics and hexagonal boron nitride, which is applied in the field of hexagonal boron nitride-ytterbium silicon oxynitride ceramic matrix composite materials and their in-situ preparation, can solve the problems of poor mechanical properties and machinability of composite materials. The improvement effect is limited, the density of composite materials is reduced, etc., to achieve the effects of excellent mechanical properties, low cost, and good processability

Active Publication Date: 2021-01-08
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the application of ytterbium silicon oxynitride in hexagonal boron nitride has not been reported yet.
[0004] similar to Y 4 Si 2 o 7 N 2 -BN composite material, Patent 1: Publication No. CN 102351541 A and Patent 2: Publication No. CN 102432298 A The results show that the preferred content of boron nitride is 10-30vol.%. At this time, the composite material obtained has a higher Density (~95%) and good mechanical properties, but as the content of boron nitride continues to increase, the density of the composite material decreases significantly, and the mechanical properties are not good
due to Y 4 Si 2 o 7 N 2 The hardness itself is high (10.3±0.3GPa), and the introduction of a small amount of boron nitride has limited effect on improving the machinability of composite materials

Method used

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  • Hexagonal boron nitride-ytterbium silicon oxygen nitride ceramic matrix composite material and its in-situ preparation method
  • Hexagonal boron nitride-ytterbium silicon oxygen nitride ceramic matrix composite material and its in-situ preparation method

Examples

Experimental program
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Effect test

Embodiment 1

[0025] 16.74 grams of 5 micron hexagonal boron nitride powder (h-BN), 400 mesh ytterbium oxide (Yb 2 o 3 ) powder 20.66 grams, 400 mesh silicon oxide (SiO 2 ) powder 0.76 g, 400 mesh silicon nitride (Si 3 N 4 ) powder 1.84 g into a silicon nitride ball mill tank, ball milled with absolute ethanol as the medium for 12 hours, dried at 60°C for 12 hours, sieved through an 80-mesh sieve, and then put into a graphite mold coated with BN on the inner wall and cold-pressed Forming, the applied pressure is 10MPa, the pressure is maintained for 10 minutes, and then placed in a hot-press furnace for hot-pressing sintering, the heating rate is 5°C / min, and the pressure is gradually increased to 20MPa while the temperature is rising, and heated to 2000°C for 3 hours. The whole sintering process was carried out under the protection of nitrogen, and the obtained block samples were analyzed by X-ray diffraction as h-BN and Yb 4 Si 2 o 7 N 2 , no impurity phase is formed, see figure 1...

Embodiment 2

[0028] 14.33 grams of 10 micron hexagonal boron nitride powder (h-BN), 300 mesh ytterbium oxide (Yb 2 o 3 ) powder 27.25 grams, 300 mesh silicon oxide (SiO 2 ) powder 1.00 g, 300 mesh silicon nitride (Si 3 N 4 ) powder 2.43 grams into a silicon nitride tank, ball milled with absolute ethanol for 8 hours, dried at 60°C for 12 hours, sieved through an 80-mesh sieve, and then put into a graphite mold coated with BN on the inner wall and cold-pressed , the applied pressure is 15MPa, the pressure is maintained for 5 minutes, and then put into a hot-press furnace for hot-pressing sintering, the heating rate is 10°C / min, and the pressure is gradually increased to 30MPa while the temperature is rising, and heated to 1900°C for 2 hours. The whole sintering process was carried out under the protection of nitrogen, and the obtained block samples were analyzed by X-ray diffraction as h-BN and Yb 4 Si 2 o 7 N 2 , no impurity phase is formed, see figure 1 (b) curve in. In this exam...

Embodiment 3

[0032] 11.93 grams of 0.5 micron hexagonal boron nitride powder (h-BN), 200 mesh ytterbium oxide (Yb 2 o 3 ) powder 33.81 grams, 200 mesh silicon oxide (SiO 2 ) powder 1.26 grams, 200 mesh silicon nitride (Si 3 N 4 ) powder 3.01 g into a silicon nitride tank, ball milled with absolute ethanol for 24 hours, dried at 60°C for 12 hours, sieved through an 80-mesh sieve, and then put into a graphite mold coated with BN on the inner wall and cold-pressed , the applied pressure is 20MPa, keep the pressure for 1 minute and then put it into a hot-press furnace for hot-pressing sintering, the heating rate is 20°C / min, gradually increase the pressure to 40MPa while heating, heat to 1800°C and keep it for 1 hour. The whole sintering process was carried out under the protection of nitrogen, and the obtained block samples were analyzed by X-ray diffraction as h-BN and Yb 4 Si 2 o 7 N 2 , no impurity phase is formed, see figure 1 (c) curve in. In this example, h-BN and Yb 4 Si 2 o...

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Abstract

The invention belongs to the field of ceramic based composite material, and more specifically relates to a hexagonal boron nitride-ytterbium silicon oxygen nitrogen ceramic based composite material, and an in-suit preparation method thereof. According to the in-suit preparation method, hexagonal boron nitride powder, ytterbium oxide powder, silicon oxide powder, and silicon nitride powder are taken as raw materials, are subjected to physical mechanical mixing for 8 to 24h, are dried and sieved, are introduced into a graphite die with a BN-coated internal wall for cold press moulding at 10 to 20MPa for 1 to 10min, and are subjected to sintering in a hot press furnace at a protective atmosphere, wherein heating rate is controlled to be 5 to 20 DEG / min, sintering temperature is controlled tobe 1800 to 2000 DEG C, sintering time is controlled to be 1 to 3h, and sintering pressure is controlled to be 20 to 40MPa. The obtained hexagonal boron nitride-ytterbium silicon oxygen nitrogen ceramic based composite material is compact, and is high in boron nitride content, the volume fraction of the hexagonal boron nitride matrix phase ranges from 50 to 90%, the volume fraction of the ytterbiumsilicon oxygen nitrogen enhancing phase ranges from 10 to 50%, and the mechanical properties and machinable properties of the hexagonal boron nitride-ytterbium silicon oxygen nitrogen ceramic based composite material are excellent.

Description

technical field [0001] The invention relates to the field of ceramic matrix composite materials, in particular to a hexagonal boron nitride-ytterbium silicon oxygen nitride ceramic matrix composite material and an in-situ preparation method thereof. Background technique [0002] Among the many crystal forms of boron nitride, hexagonal boron nitride (h-BN) is the most stable. Hexagonal boron nitride has high thermal conductivity, low thermal expansion coefficient, good thermal shock resistance, low Dielectric constant and dielectric loss, reliable electrical insulation, excellent processability, non-wetting to most metals, non-toxic properties, etc., have been widely used in many fields. However, due to its special layered structure and poor sintering density, the strength and hardness of hexagonal boron nitride ceramics are relatively low, which limits their wider application as structural materials. [0003] Ytterbium Silicon Oxynitride (Yb 4 Si 2 o 7 N 2 ) has a high ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/5833C04B35/597C04B35/645
CPCC04B35/583C04B35/597C04B35/645C04B2235/3224C04B2235/3418C04B2235/3873C04B2235/5436C04B2235/5445C04B2235/656C04B2235/658C04B2235/80C04B2235/96
Inventor 陈继新陈娟娟康小录余水淋赵震王宣苗磊
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI