Preparation method for high-strength and high-porosity porous silicon nitride ceramics

A silicon nitride ceramic, high-porosity technology, applied in ceramic products, applications, household appliances, etc., can solve the problems of irregular pore structure and low strength

Active Publication Date: 2019-02-12
NAT INST CORP OF ADDITIVE MFG XIAN
View PDF9 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The porosity of the porous silicon nitride ceramics obtained by the above methods is all below 60%, the pore structure is irregular and the strength is low.

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
  • Preparation method for high-strength and high-porosity porous silicon nitride ceramics
  • Preparation method for high-strength and high-porosity porous silicon nitride ceramics
  • Preparation method for high-strength and high-porosity porous silicon nitride ceramics

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0049] The invention discloses a method for preparing porous silicon nitride ceramics with high strength and high porosity, see figure 1 It is a specific flow chart of the preparation method of the invention, and the preparation method specifically includes the following steps:

[0050] Step 1, Prepare Water-Based Slurry

[0051] (1) Mixed α-Si 3 N 4 Raw material powder and rare earth oxide powder to obtain mixed powder A, rare earth oxide includes Y 2 o 3 , La 2 o 3 and Ce 2 o 3 etc.; in terms of mass percentage, the α-Si in mixed powder A 3 N 4 The proportion of raw material powder is 94%-97%, the proportion of rare earth oxide powder is 3-6%, and the sum of the two is 100%; the mixed powder A is placed in the ball mill tank;

[0052] (2) Weigh 0.1%-0.5% of the dispersant of mixed powder A mass, disperse the dispersant in deionized water at 50°C-70°C, and prepare a dispersant solution with a mass fraction of 0.5%-1.5%; Select any one of sodium carboxymethylcellulo...

Embodiment 1

[0084] Step 1, Prepare Water-Based Slurry

[0085] (1) Mixed α-Si 3 N 4 Raw material powder and Y 2 o 3 powder to obtain mixed powder A, in which α-Si 3 N 4 The mass ratio of raw material powder is 95%, Y 2 o 3 The proportion of powder is 5%, and the mixed powder A is placed in a ball mill jar;

[0086] (2) Weigh 0.3% CMC of the mass of the mixed powder A as a dispersant, disperse the CMC in 60° C. deionized water, prepare a CMC solution with a mass fraction of 1%, and add the dispersant aqueous solution to the ball mill tank;

[0087] (3) Adjust the pH value of deionized water to 10.5 with concentrated ammonia water to make an alkaline solution; add the alkaline solution with a pH value of 10.5 into the ball milling tank until the mass fraction of mixed powder A in the ball milling tank is 50 %, stir evenly to prepare slurry C;

[0088] (4) Add defoamer glycerol dropwise in slurry C, the addition of glycerol is 0.05% of the mass of mixed powder A, and water-based slu...

Embodiment 2

[0095] Adjust the amount of pore-forming agent added in step 2 in Example 1, specifically adding 40% soluble starch by volume of mixed powder A to stale slurry E, and the rest of the steps are the same as in Example 1.

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
particle diameteraaaaaaaaaa
particle diameteraaaaaaaaaa
densityaaaaaaaaaa
Login to view more

Abstract

The invention discloses a preparation method for high-strength and high-porosity porous silicon nitride ceramics. According to the method, a sintering aid and a dispersant aqueous solution are sequentially added into Alpha-Si3N4 raw material powder, a defoaming agent is added after pH is regulated, so that water-based slurry is obtained, and by optimizing the sequence of adding each substance, each substance can play a role to the max. On the other hand, the water-based slurry is ball-milled and aged, so that the flowability of the slurry can be increased, soluble starch, polymethyl methacrylate (PMMA) and stearic acid, of which the micromorphologies are all spherical, are chosen as pore-forming agent, and while serving as the pore-forming agent, the spherical pore-forming agent can play the role of increasing the flowability of the slurry. In addition, slip casting can also break through the limitation of conventional compression molding on dies, and meets the shape complexity and diversity of porous ceramic parts.

Description

【Technical field】 [0001] The invention belongs to the technical field of engineering preparation of porous silicon nitride materials, and relates to a method for preparing porous silicon nitride ceramics with high strength and high porosity. 【Background technique】 [0002] Due to their complex crystal structure and the absence of free electrons, inorganic non-metallic materials have stronger covalent bonds and ionic bonds than pure covalent bonds and metal bonds, so these materials have high melting point, high hardness, corrosion resistance and wear resistance ,high strength. Inorganic non-metallic materials can be divided into cement, glass, refractory materials and ceramics. Among them, ceramics are divided into narrow sense and broad sense. The former is the collective name of pottery and porcelain, which are generally used in daily life, art, building hygiene and other fields, while the latter is "inorganic non-metallic solid materials", which are divided into oxide ce...

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): C04B35/584C04B35/622C04B38/06
CPCC04B35/584C04B35/622C04B38/0645C04B38/067C04B2235/6022C04B2235/6567C04B2235/658C04B2235/66C04B2235/77C04B2235/96
Inventor 潘欢满积友鲍崇高宋索成王克杰赵纪元卢秉恒
Owner NAT INST CORP OF ADDITIVE MFG XIAN
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