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Silicon nitride-based composite ceramic material and SPS preparation technology thereof

A composite ceramic and silicon nitride-based technology, which is applied in the field of silicon nitride-based composite ceramic materials and its SPS preparation process, can solve the problems of imperfect SPS preparation process, mechanical properties to be improved, and fewer composite ceramic systems, and achieve excellent Effects of mechanical properties and microstructure, shortening of sintering time, and improvement of hardness

Inactive Publication Date: 2018-08-28
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In summary, the current Si 3 N 4 Spark plasma sintering of base ceramics is still based on single-phase Si 3 N 4 Based on the preparation of Si 3 N 4 There are few composite ceramic systems, the SPS preparation process is not perfect, the density is low and the mechanical properties need to be improved

Method used

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  • Silicon nitride-based composite ceramic material and SPS preparation technology thereof
  • Silicon nitride-based composite ceramic material and SPS preparation technology thereof

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Embodiment 1

[0023] A silicon nitride-based composite ceramic material and its SPS preparation process, specifically: by mass percentage α-Si 3 N 4 80%, MgSiN 2 2.25%, Y 2 o 3 5.25%, CeO 2 1.5%, Co 1%, WC 10% for batching, the prepared mixed powder with absolute ethanol as the medium, silicon nitride balls as grinding balls, put them into a polyurethane ball mill tank for ball milling for 48 hours, the ball-to-material ratio is 7 : 1; dry and grind after ball milling, and pass through a 100-mesh sieve, put the sieved powder in a circular graphite mold with an inner diameter of 20mm for pre-compression, the pressure is 10MPa, and hold the pressure for 2 minutes; Put the felt graphite mold into the chamber of the spark plasma sintering system, evacuate the furnace chamber into a vacuum state, and then pour in a certain amount of argon gas; apply a pressure of 50MPa, turn on the sintering button to heat, and heat up at a rate of 100°C / min Heat the sample to 1650°C, keep it warm for 6 ...

Embodiment 2

[0025] A silicon nitride-based composite ceramic material and its SPS preparation process, specifically: by mass percentage α-Si 3 N 4 70%, MgSiN 2 2.25%, Y 2 o 3 5.25%, CeO 21.5%, Co 1%, WC 20% for batching, the prepared mixed powder with absolute ethanol as the medium, silicon nitride balls as grinding balls, put them into a polyurethane ball mill tank for ball milling for 48 hours, the ball-to-material ratio is 7 : 1; dry and grind after ball milling, and pass through a 100-mesh sieve, put the sieved powder in a circular graphite mold with an internal diameter of 20mm for pre-compression, the pressure is 10MPa, and hold the pressure for 2 minutes; Put the graphite mold of the felt into the chamber of the spark plasma sintering system, evacuate the furnace chamber into a vacuum state, and then pour in a certain amount of argon gas; apply a pressure of 50MPa, turn on the sintering button to heat, and heat up at a rate of 100°C / min Heat the sample to 1650°C, keep it war...

Embodiment 3

[0027] A silicon nitride-based composite ceramic material and its SPS preparation process, specifically: by mass percentage α-Si 3 N 4 60%, MgSiN 2 2.25%, Y 2 o 3 5.25%, CeO 2 1.5%, Co 1%, WC 30% for batching, the prepared mixed powder with absolute ethanol as the medium, silicon nitride balls as grinding balls, put them into a polyurethane ball mill tank for ball milling for 48 hours, the ball-to-material ratio is 7 : 1; dry and grind after ball milling, and pass through a 100-mesh sieve, put the sieved powder in a circular graphite mold with an internal diameter of 20mm for pre-compression, the pressure is 10MPa, and hold the pressure for 2 minutes; Put the graphite mold of the felt into the chamber of the spark plasma sintering system, evacuate the furnace chamber into a vacuum state, and then pour in a certain amount of argon gas; apply a pressure of 50MPa, turn on the sintering button to heat, and heat up at a rate of 100°C / min Heat the sample to 1650°C, keep it w...

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Abstract

The invention discloses a silicon nitride-based composite ceramic material and an SPS preparation technology thereof. The silicon nitride-based composite ceramic material is prepared from, by mass, 60-80% of alpha-Si3N4, 2.25% of MgSiN2, 5.25% of Y2O3, 1.5% of CeO2, 1% of Co and 10-30% of WC or 10-30% of Ti(C,N) or 10-30% of TiC. According to the material, the silicon nitride-based composite ceramic material is prepared by selecting a proper second phase, optimizing the content of the second phase and using a discharge plasma sintering technology at a high temperature increase speed during short sintering time. The silicon nitride-based composite ceramic material prepared through the method is relatively high in density and excellent in mechanical property, the Vickers hardness of a samplewith the optimal comprehensive performance reaches 17.66 GPa, the fracture toughness reaches 7.01 MPa.ml / 2, the fracture toughness is increased by 14.41-41.37% compared with that of a reported silicon nitride-based composite ceramic material obtained through spark plasma sintering, and the hardness is increased by 37.71% compared with the literature 1.

Description

technical field [0001] The invention belongs to the technical field of discharge plasma sintering materials, and relates to a silicon nitride-based composite ceramic material and an SPS preparation process thereof. Background technique [0002] Silicon nitride ceramics are one of the most potential engineering structural materials. This material has excellent properties such as high specific strength, high specific modulus, high temperature resistance, wear resistance, oxidation resistance and creep resistance. Because of its excellent properties, Si 3 N 4 Ceramics also show its unique application value in demanding working environments, such as engine parts, cutting tools, bearings, heat exchangers, piston pumps, etc. However, Si 3 N 4 The inherent high brittleness and poor thermal shock resistance of ceramics limit their wide application in the field of high-speed machining. Therefore, in Si 3 N 4 Adding a suitable second phase to the matrix to make it suitable for ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/584C04B35/622C04B35/64
CPCC04B35/584C04B35/622C04B35/64C04B2235/3225C04B2235/3229C04B2235/3843C04B2235/3847C04B2235/3852C04B2235/3856C04B2235/3878C04B2235/3886C04B2235/3891C04B2235/405C04B2235/6562C04B2235/6567C04B2235/658C04B2235/666C04B2235/96
Inventor 汪振华曹丽燕刘奎殷增斌袁军堂
Owner NANJING UNIV OF SCI & TECH