A kind of ultra-high porosity and low body shrinkage y 2 sio 5 Preparation method of porous ceramics

A technology of porous ceramics and porosity, which is applied in the field of preparation of ultra-high porosity and low body shrinkage Y2SiO5 porous ceramics, which can solve the problem of difficult preparation of porous ceramics, low porosity of porous materials, and total body shrinkage Large and other problems, to achieve the effect of good appearance, short preparation cycle and low body shrinkage

Active Publication Date: 2020-09-18
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
View PDF9 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the large amount of moisture contained in the low-solid content slurry will cause serious deformation or even cracking and large shrinkage (10-20%) of the green body during demoulding and drying (direct demoulding and drying at room temperature), which seriously affects the The regularity and integrity of the appearance of the green body and the porosity of the green body make it difficult to prepare porous ceramics with a complete appearance and high porosity
In addition, although there are reports in the literature that the use of freeze-drying techniques to prepare Y 2 SiO 5 Porous ceramics, but on the one hand, they do not use foaming technology, relying solely on the amount of solvent (that is, low solid content) to control the porosity, so the total amount of solvent used is very large (80-95%), making the demoulding and drying of the billet The overall volume shrinkage is relatively large (1.52–10.67%), thereby reducing the sample porosity; on the other hand, they used Y 2 SiO 5 Cooked powder, and cooked powder is highly active during high-temperature sintering, resulting in a large sintering line shrinkage of the sample, resulting in a low porosity of the final porous material

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
  • A kind of ultra-high porosity and low body shrinkage y <sub>2</sub> sio <sub>5</sub> Preparation method of porous ceramics
  • A kind of ultra-high porosity and low body shrinkage y <sub>2</sub> sio <sub>5</sub> Preparation method of porous ceramics
  • A kind of ultra-high porosity and low body shrinkage y <sub>2</sub> sio <sub>5</sub> Preparation method of porous ceramics

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] In this embodiment, first weigh 40 g of deionized water and 0.5 g of dispersant polyacetimide, and add Y 2 o 3 and SiO 2 (Molar ratio 1:2) mixed powder 30g, stirred for 1.5 hours to form a slurry;

[0024] Then above-mentioned ceramic slurry is placed in the water bath of 50 ℃, adds foaming agent sodium lauryl sulfate 1g, stirs rapidly (stirring rate is 2000rpm) and foams for 10 minutes, then adds gelling agent gelatin 3g and glycerine Alcohol 1g, continue rapid stirring (stirring rate is 2000rpm) injection molding after 20 minutes;

[0025] Put the solidified ceramic foam body and mold into a freezer at -20°C for 24 hours of low-temperature freezing, then dry it in a vacuum room temperature environment for 24 hours, then demould the body, and then dry it in an oven at 60°C for 24 hours ;

[0026] Finally, high-temperature reaction sintering was carried out in a muffle furnace at 1500 °C for 3.5 hours to prepare Y with ultra-high porosity, low density and low therma...

Embodiment 2

[0029] In the present embodiment, first weigh 60 g of deionized water and 1.5 g of dispersant ammonium citrate, and add Y 2 o 3 and SiO 2 (Molar ratio 1:2) mixed powder 50g, stirred for 3 hours to form a slurry;

[0030] Then above-mentioned ceramic slurry is placed in the water bath of 40 ℃, adds foaming agent sodium dodecyl sulfonate 3g, stirs rapidly (stirring speed is 1800rpm) and foams for 25 minutes, then adds gelling agent gelatin 6g and poly Ethylene glycol 3g, continue rapid stirring (stirring rate is 1800rpm) after 40 minutes injection molding;

[0031] Put the solidified ceramic foam body and mold into a freezer at -40°C for 12 hours of low-temperature freezing, and then dry it at room temperature in vacuum for 36 hours, then demould the body, and then dry it in an oven at 80°C for 12 hours ;

[0032] Finally, high-temperature reaction sintering was carried out in a muffle furnace at 1600 °C for 1 hour to prepare Y with ultra-high porosity, low density and low t...

Embodiment 3

[0035] In this example, first weigh 50 g of deionized water and 1 g of dispersant stearic acid, and add Y 2 o 3 and SiO 2 (Molar ratio 1:2) mixed powder 40g, stirred for 2 hours to form a slurry;

[0036] Then above-mentioned ceramic slurry is placed in the water bath of 45 ℃, adds foaming agent sodium dodecyl sulfonate 2g, stirs rapidly (stirring speed is 1600rpm) and foams for 20 minutes, then adds gelling agent gelatin 4.5g and Polyethylene glycol 2g, continue rapid stirring (stirring rate is 1600rpm) injection molding after 30 minutes;

[0037] Put the solidified ceramic foam body and mold into a freezer at -30°C for 18 hours of low-temperature freezing, and then dry it in a vacuum room temperature environment for 30 hours, then demould the body, and then dry it in an oven at 70°C for 20 hours ;

[0038] Finally, high-temperature reaction sintering was carried out in a muffle furnace at 1550 °C for 2 hours to prepare Y with ultra-high porosity, low density and low ther...

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

PropertyMeasurementUnit
densityaaaaaaaaaa
thermal resistanceaaaaaaaaaa
densityaaaaaaaaaa
Login to view more

Abstract

The invention relates to the field of thermal protection materials, particularly to a preparation method of an Y2SiO5 porous ceramic with characteristics of ultra-high porosity and low billet shrinkage rate. The preparation method comprises: using yttrium oxide powder and silicon oxide powder as reactants, using water as a dispersion medium, adding a dispersing agent, and continuously stirring toprepare a ceramic slurry; heating the slurry; adding a foaming agent, rapidly and mechanically stirring, and foaming; adding gelatin and a surfactant; injecting into a mold, carrying out low-temperature freezing, carrying out vacuum drying, demolding the billet, and drying in an oven; and carrying out high temperature sintering to prepare the Y2SiO5 porous ceramic. According to the present invention, with the preparation method, the difficulty of high billet shrinkage rate or severe deformation during the demolding drying can be solved, and the Y2SiO5 porous ceramic with characteristics of ultra-high porosity, low density, low thermal conductivity and high-temperature resistance is synthesized, and has wide application prospects in the field of heat protection materials; and the preparation method has advantages of low cost and high operability, can prepare the porous material with the ultra-high porosity through the novel and simple production process, and has broad industrial production prospect.

Description

technical field [0001] The invention relates to the field of heat protection materials, specifically a kind of ultra-high porosity and low green body shrinkage Y 2 SiO 5 Preparation methods of porous ceramics. Background technique [0002] With the rapid development of the aerospace industry, higher and higher requirements are put forward for thermal insulation materials, and thermal insulation materials are facing great opportunities and challenges. Y 2 SiO 5 Porous ceramics emerged as a new type of high-temperature insulation material, which has many excellent properties, such as: low density (1.65 ~ 1.28g / cm 3 ), high compressive strength (3.34~16.51MPa) and low thermal conductivity (0.07~0.22W / (m K)) (R.B.Zhang, et al.Mater. Design. (Materials and Design Journal) 2013(46 ):746-750). In addition, it also has the advantages of good thermal shock resistance, excellent thermal stability, and good high-temperature mechanical properties, and is very suitable for use in 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 Patents(China)
IPC IPC(8): C04B38/10C04B35/16
CPCC04B35/16C04B38/10C04B2235/3225C04B2235/6022C04B2235/606
Inventor 王京阳吴贞孙鲁超潘晶晶
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap