Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Superhigh-temperature ceramic densification method based on defect regulation and control and superhigh-temperature ceramic

A technology of ultra-high temperature ceramics and densification, applied in the field of ultra-high temperature ceramics, can solve the problems of high raw material cost, low powder sintering activity, low defect concentration, etc., and achieve the effect of simplifying the sintering process

Pending Publication Date: 2022-06-07
GENERAL RESEARCH INSTITUTE FOR NONFERROUS METALS BEIJNG
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the self-propagating method, due to the high temperature rise / fall rate of the reaction, there is a high temperature gradient in the reaction environment, which causes the growing crystal to deflect or bend, causing a phase difference between adjacent crystal blocks and thermal stress of rapid cooling volume change, resulting in a large number of sites. Wrong, and then the powder defect concentration is high, the powder sintering activity is high, but the self-propagating reaction rate is too fast, the reaction is not complete, the product particle size is coarse, and the cost of raw materials is high, which is not conducive to industrial production
However, the sol-gel method and the carbothermal reduction method have slow reaction heating / cooling rates, sufficient time for grain nucleation and growth, and the synthesized ultra-high temperature ceramic powder has a low dislocation density, low defect concentration, and low sintering activity of the powder. It is difficult to obtain highly densified ceramics by conventional sintering methods

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Superhigh-temperature ceramic densification method based on defect regulation and control and superhigh-temperature ceramic
  • Superhigh-temperature ceramic densification method based on defect regulation and control and superhigh-temperature ceramic
  • Superhigh-temperature ceramic densification method based on defect regulation and control and superhigh-temperature ceramic

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0041] In the embodiment of the present invention, the various synthesis methods may include high-temperature self-propagation method, carbothermic reduction method, sol-gel method, hydrothermal / solvothermal method, plasma synthesis method, precursor synthesis method, etc.; The sintering method of the ultra-high temperature ceramic powder may include: hot pressing sintering, isostatic pressing sintering, hot isostatic pressing sintering, gas pressure sintering, microwave sintering, spark plasma sintering, and the like.

[0042]Usually, there are a large number of dislocations in the powder, and the amount of these dislocations is represented by the dislocation density, which is defined as the total length of the dislocation lines contained in a unit volume of crystal; One definition is: the number of dislocation lines passing through a unit cross-sectional area, also in units of 1 / square centimeter. Generally speaking, when the powder has a higher dislocation density, it can h...

Embodiment 1

[0066] Preparation of ZrB by Self-Propagation and Carbothermal Reduction 2 powder;

[0067] The powder obtained by the self-propagating method and the powder obtained by the carbothermic reduction method were respectively obtained by X-ray diffraction to obtain basic data such as diffraction curves and lattice parameters, and the dislocation density of the two powders was calculated by the CMWP-fit method, and the self-propagating method was calculated. ZrB prepared by 2 The powder dislocation density is 8.68×10 15 m -2 , ZrB prepared by carbothermal reduction method 2 The powder dislocation density is 6.49×10 11 m -2 ;

[0068] Mix the two powders, in which the self-propagating method ZrB 2 The proportion of powder is 25%, and the calculated and adjusted dislocation density of the powder is 2.67×10 15 m -2 ; The regulated powder is densified by hot pressing and sintering to obtain ZrB 2 ceramics.

[0069] According to the calculation results, the calculated ZrB 2 ...

Embodiment 2

[0071] Preparation of ZrB by self-propagating and sol-gel methods 2 powder;

[0072] The powder obtained by the self-propagating method and the powder obtained by the sol-gel method were respectively obtained by X-ray diffraction to obtain basic data such as diffraction curves and lattice parameters, and the dislocation density of the two powders was calculated by the CMWP-fit method, and the self-propagating method was obtained. Prepared ZrB 2 The powder dislocation density is 8.68×10 15 m -2 , ZrB prepared by carbothermal reduction method 2 The powder dislocation density is 6.49×10 11 m -2 ;

[0073] Mix the two powders, in which the self-propagating method ZrB 2 The proportion of powder is 50%, and the calculated and adjusted dislocation density of the powder is 5.41×10 15 m -2 , the regulated powder was densified by pressureless sintering to obtain ZrB 2 ceramics.

[0074] According to the calculation results, the calculated ZrB 2 Powder dislocation density, co...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides an ultra-high-temperature ceramic densification method based on defect regulation and control. The method comprises the following steps: preparing ultra-high-temperature ceramic powder corresponding to each synthesis method by adopting multiple synthesis methods; the dislocation density of the ultra-high-temperature ceramic powder is obtained through calculation; based on the dislocation density of the powder obtained through calculation, the mixing proportions of the ultrahigh-temperature ceramic powder obtained through multiple synthesis methods are determined; according to the mixing ratio, mixing the ultra-high temperature ceramics obtained by the multiple synthesis methods to regulate and control the defect concentration of the ultra-high temperature ceramic powder; sintering the mixed ultra-high-temperature ceramic powder to obtain ultra-high-temperature ceramic; according to the invention, the dislocation density is calculated, and the powder with different dislocation densities is utilized to regulate and control the powder defects, so that the ultrahigh-temperature ceramic with high density is prepared.

Description

technical field [0001] The invention relates to the field of ultra-high temperature ceramic preparation, in particular to a method for densifying ultra-high temperature ceramics based on defect control, and ultra-high temperature ceramics. Background technique [0002] Ultrahigh-Temperature Ceramics (UHTCs) mainly refers to a special material that can maintain chemical stability in high temperature environment (above 2000 ℃) and reactive atmosphere (such as atomic oxygen environment), usually including borides, carbides, Some high melting point transition metal compounds including oxides, and the multi-component composite ceramic materials composed of the above compounds are collectively referred to as ultra-high temperature ceramic materials. Among these high melting point transition metal compounds, TaC, ZrB 2 , HfB 2 , HfC, etc. have melting points exceeding 3000 °C, which makes them have great application potential under extreme high temperature conditions. However, t...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/58C04B35/622C04B35/626
CPCC04B35/58078C04B35/5805C04B35/622C04B35/62605C04B2235/77
Inventor 王星明刘宇阳白雪李小宁杨磊桂涛王星奇储茂友韩沧
Owner GENERAL RESEARCH INSTITUTE FOR NONFERROUS METALS BEIJNG
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com