Joining method of SiC ceramic through combining nano-impregnated transient co-crystal phase with chemical vapor infiltration as well as prepared ceramic connector

A technology of chemical vapor infiltration and connection method, which is applied in the field of ceramic material connection, can solve the problems of brittleness and low impact toughness, weak thermal shock resistance, and difficult parts, and achieve the effect of consistent thermal expansion coefficient and promotion of densification

Inactive Publication Date: 2019-03-08
GUANGDONG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, due to the brittleness, low impact toughness and weak thermal shock resistance of ceramic materials, their processing performance is poor, and it is difficult to manufacture parts with large sizes and complex shapes. Therefore, it is necessary to use the connection technology between ceramics to produce complex shapes. parts
At present, in the connection method of SiC ceramics, the nano-impregnated transient eutectic phase has the highest shear strength, and has good corrosion resistance and neutron radiation resistance. However, when using nano-impregnated transient eutectic phase generally High temperature and high pressure, which is the cladding tube and the most critical protective cover for accident-tolerant fuel (the first layer of protective material used to wrap nuclear fuel in nuclear reactors. This material directly withstands all neutron radiation in nuclear reactors and is also the most critical shield). A fatal flaw for end plug connections

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] 1. Preparation: Nano-SiC powder, Al 2 o 3 and Y 2 o 3 As a connecting material, the SiC powder has a purity of 99% and a particle size of 10nm; Al 2 o 3 The purity is 99%, the particle size is 0.1μm; Y 2 o 3 The purity is 99%, the particle size is 0.1μm; SiC:Al 2 o 3 :Y 2 o 3 The mass percentage is 93wt%: 2wt%: 5wt%. The connecting material powder is mixed on a planetary ball mill for 8 hours according to the above ratio. The solvent is absolute ethanol. The mixed powder obtained after drying is spread in the middle of two polished SiC A sandwich structure is formed and then heat treated in a heat treatment furnace. The specific process parameters of the heat treatment are as follows: heat up to 1000°C at 20°C / min, keep it warm for 1h, connect the environment to vacuum, and then use polycarbosilane doped with 50wt% nano-silicon carbide at 1500°C for 0.5h for chemical vapor infiltration to obtain Connectors for SiC ceramics.

[0027] 2. Performance test: The ...

Embodiment 2

[0029] 1. Preparation: Nano-SiC powder, Al 2 o 3 and La 2 o 3 As a connecting material, the particle size of SiC is 100nm; Al 2 o 3 The particle size is 5μm; La 2 o 3 Particle size is 5μm; SiC:Al 2 o 3 :CeO 2 The mass percentage is 90wt%: 5wt%: 5wt%. Connect according to the method of Example 1, wherein the heat treatment process is: heat up to 1400°C at 20°C / min, keep it warm for 1h, connect the environment to Ar, and then use doping 80wt% SiC whiskers of polycarbosilane were subjected to chemical vapor infiltration at 1600°C for 4h to prepare SiC ceramic connectors.

[0030] 2. Performance test: The connection strength of the connected SiC ceramics in this example is 180MPa at room temperature, and 150MPa at a high temperature of 1600°C; the leakage rate at the connection reaches 1×10 -11 Pa·L / s.

Embodiment 3

[0032] 1. Preparation: Nano-SiC powder, Al 2 o 3 and Gd 2 o 3 As a connecting material, the particle size of SiC is 50nm; Al 2 o 3 The particle size is 10μm; Gd 2 o 3 Particle size is 10μm; SiC:Al 2 o 3 :Ho 2 o 3 The mass percentage is 90wt%: 5wt%: 5wt%. Connect according to the method of Example 1, wherein the heat treatment process is: heat up to 1200°C at 20°C / min, keep warm for 0.5h, connect the environment to vacuum, and then use doping 40 % SiC whiskers of polycarbosilane were subjected to chemical vapor infiltration at 1400°C for 4h to prepare SiC ceramic connectors.

[0033]2. Performance test: The connection strength of the connected SiC ceramics in this example is 200MPa at room temperature, and 180MPa at a high temperature of 1600°C; the leakage rate at the connection reaches 1×10 -13 Pa·L / s.

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Abstract

The invention belongs to the technical field of ceramic joining and discloses a joining method of SiC ceramic through combining a nano-impregnated transient co-crystal phase with chemical vapor infiltration as well as a prepared ceramic joining part. The method comprises the following steps: firstly, mixing SiC powder with Al2O3-Re2O3, adding a solvent and a ball milling medium for mixing and drying to obtain mixed powder; granulating the mixed powder and spreading the granulated powder between two pieces of polished SiC to form a sandwich structure; putting a sample with the sandwich structure into a heat treatment furnace, raising the temperature to 1000 to 1400 DEG C for heat treatment in a vacuum or protective atmosphere, adding organic carbon silane doped with filler and carrying outchemical vapor infiltration at 1300 to 1600 DEG C to obtain a joining part of the SiC ceramic. According to the joining method disclosed by the invention, low-temperature pressure-free joining of theSiC ceramic is realized by combining the nano-impregnated transient co-crystal phase with the chemical vapor infiltration and the leakage rate at the joint reaches 0 to 1*10<-10> Pa.L / s.

Description

technical field [0001] The invention belongs to the technical field of ceramic material connection, and more specifically relates to a method for connecting SiC ceramics realized by combining nano-impregnated transient eutectic phase (NITE phase) with chemical vapor infiltration (CVI) and a prepared ceramic connector. Background technique [0002] SiC ceramics generally have excellent characteristics such as high temperature resistance, high hardness, wear resistance, corrosion resistance, and high temperature strength. They are key materials for the development of new technologies in sectors such as automobiles, machinery, metallurgy, and aerospace. In addition, pure SiC materials can be used as accident-tolerant fuels in nuclear reactors because of their high thermal conductivity, resistance to neutron irradiation, and low neutron absorption cross-section. [0003] However, due to the brittleness, low impact toughness and weak thermal shock resistance of ceramic materials,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B37/00
CPCC04B37/003C04B2237/083C04B2237/365C04B2237/58
Inventor 郭伟明吴利翔朱林林牛文彬卫紫君林锐霖林华泰
Owner GUANGDONG UNIV OF TECH
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