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

Method for preparing in-situ self-toughening alumina ceramics

A self-toughening technology for alumina ceramics, applied in the field of preparation of in-situ self-toughened alumina ceramics, can solve the problem of high cost and achieve simple and controllable equipment and processes

Inactive Publication Date: 2008-05-21
TSINGHUA UNIV
View PDF0 Cites 25 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The equipment and process are simple and controllable. The prepared ceramic products are composed of alumina containing long columnar and plate-like crystals, which solves the difficulties caused by the use of fibers and whiskers and carbon nanotubes in traditional processes (such as dispersion and high cost), as well as some defects in ceramic products caused by the introduction of additives, provide a new idea for the toughening of alumina ceramics

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
  • Method for preparing in-situ self-toughening alumina ceramics
  • Method for preparing in-situ self-toughening alumina ceramics

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Weigh the initial raw material 40g Al 2 o 3 and 0.004g Al powder into a nylon resin ball mill jar, use alumina balls with a purity of 99%, add polyethylene glycol with a mass fraction of alumina powder of 1‰ and 250mL alcohol, and perform wet ball milling in a high-energy ball mill for 8 hours . Put the mixture after high-energy ball milling into a 99% alumina ceramic crucible, dry it in an oven at 50°C to obtain a uniformly mixed powder, shape it with various molding methods, and sinter it at 1550°C in an ordinary sintering furnace under an air atmosphere. Hours, a single-phase alumina ceramic with in-situ growth of long columnar and plate-like crystals is obtained, and its typical structure is shown in Figure 1. It can be seen from Figure 1 that the prepared alumina ceramic grains have appeared plate-shaped crystals or long columnar crystals with an aspect ratio greater than 2.

Embodiment 2

[0028] Weigh the initial raw material 40g Al 2 o 3 and 0.02g Al powder into a nylon resin ball mill jar, use alumina balls with a purity of 99%, add polyethylene glycol with a mass fraction of alumina powder of 5‰ and 250mL alcohol, and perform wet ball milling in a high-energy ball mill for 10 hours . Put the mixture after high-energy ball milling into a 99% alumina ceramic crucible, and dry it in an oven at 50°C to obtain a uniformly mixed powder, which is formed by cold isostatic pressing and sintered at 1580°C in an ordinary sintering furnace under an air atmosphere. Hours, a single-phase alumina ceramic with in-situ growth of long columnar and plate-like crystals was obtained, and its typical structure is shown in Figure 2. It can be seen from Figure 2 that there are long columnar and plate-shaped crystals with a large area as shown by the arrows. These irregularly grown grains form a certain degree of interpenetrating network structure. The longest grain aspect ratio i...

Embodiment 3

[0030] Weigh the initial raw material 40g Al 2 o 3 and 0.04g Al powder into a nylon resin ball mill jar, use alumina grinding balls with a purity of 99%, add polyethylene glycol with a mass fraction of alumina powder 1% and 250mL alcohol, and perform wet ball milling in a high-energy ball mill for 12 hours . Put the mixture after high energy ball milling into a 99 alumina ceramic crucible, dry it in an oven at 50°C to obtain a uniformly mixed powder, shape it by injection molding, and sinter at 1560°C for 3 hours in an ordinary sintering furnace under an air atmosphere , to obtain single-phase alumina ceramics with in-situ growth of long columnar and plate-like crystals, the typical structure of which is shown in Figure 3. It can be seen from Figure 3 that there are long columnar and plate-like crystals with a large area. As shown by the arrows, these irregularly grown grains form a certain degree of interpenetrating network structure. The longest grain aspect ratio is great...

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
flexural strengthaaaaaaaaaa
Login to View More

Abstract

A method for preparing in-situ self-toughening alumina ceramics, which includes the following specific steps: the process is as follows: nano-aluminum powder and high-purity alumina powder are used as initial raw materials, mixed uniformly; the mixed slurry is dried and ground into powder body; the obtained powder is formed into a green body; the green body is directly sintered in an ordinary air sintering furnace to obtain a ceramic material. The advantage is that alumina ceramics with in-situ growth of long columnar and plate-like crystals can be prepared; this process is expected to retain the obvious toughening and reinforcing effect of traditional fibers and whiskers, and will directly solve the problem of fibers, whiskers and carbon The difficulties brought about by the use of nanotubes. It also has amorphous additives such as SiO2, TiO2, La2O3, and CAS (CaO-Al2O3-SiO2), which do not need to be added. The final alumina product only contains a single alumina phase, which has high density, high purity and high toughness. The advantages.

Description

technical field [0001] The invention relates to the technical field of preparation of ceramic materials, and in particular provides a preparation method of in-situ self-toughening alumina ceramics. Background technique [0002] Alumina ceramic materials have excellent mechanical and electrical properties, and low manufacturing cost, and are currently the most widely used advanced ceramic materials. Alumina precision ceramic materials with a bending strength of 700-1000Mpa can be prepared by using high-purity submicron alumina ultrafine powder. However, the fracture toughness of this material is very low, usually only 3-4Mpa m 1 / 2 . Therefore, improving the fracture toughness of alumina ceramics has always been the goal that ceramic material workers expect and strive for. [0003] There are generally four methods for ceramic toughening: dispersion toughening, phase transformation toughening, fiber and whisker toughening, and the recently developed carbon nanotube toughenin...

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): C04B35/10C04B35/622
Inventor 谢志鹏张新霓黄勇
Owner TSINGHUA UNIV
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