Zirconium dioxide short fiber and basic magnesium sulfate whisker composite enhanced magnesia-based crucible and preparation method thereof

A technology of magnesium sulfate whiskers and zirconium dioxide, which is used in magnesium oxide-based crucibles and their preparation, smelting of magnesium and its alloys, and composite reinforced magnesium oxide-based crucibles with zirconium dioxide short fibers and basic magnesium sulfate whiskers. In the field of preparation, it can solve the problems of reducing the sintering temperature of magnesia ceramics, increasing the emission of gaseous fluoride, increasing the lattice distortion of the magnesia matrix, and achieving the effects of improving the density and mechanical properties, optimizing the mixing uniformity and the uniform wall thickness of the crucible.

Active Publication Date: 2018-08-24
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
View PDF9 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Chinese patent document CN103030407B (a kind of preparation method of high-strength, high-density, high-purity magnesia crucible), Chinese patent document CN1011306B (pure magnesia foam ceramic filter and its preparation process) etc. use pure magnesia as raw material to prepare magnesia Ceramics, because MgO has a high melting point and thermal expansion coefficient (13.5×10 -6 /°C) is high, therefore, it leads to difficult sintering (sintering temperature is not lower than 0.8 times its melting point) and poor thermal shock resistance, which limits the application and development of MgO ceramics
add V 2 o 5 In powder form, MgO will react with V at 1190°C 2 o 5 form an approximate composition of Mg 3 V 2 o 8 The liquid phase promotes sintering and can significantly reduce the sintering temperature of MgO foam ceramics, but V 2 o 5 Harmful to the respiratory system and skin during use, and has strict restrictions on operation
with V 2 o 5 Similarly, cobalt oxide is also a good low-temperature sintering aid, but its application is limited as a highly toxic substance and rare resource
Add fluorite (melting point 1423 ℃) and magnesium fluoride ( Melting point 1248°C), the solid solution of fluoride not only increases the lattice distortion of the matrix magnesium oxide during the sintering process, but also easily forms a low melting point liquid phase, thereby reducing the sintering temperature of the magnesia ceramics; however, during the sintering process F in fluoride is combined with Si, Al, Fe, Ca, and most of them (about 70% in ceramic tile production) volatilize in gaseous form, which not only corrodes the green body itself and damages the quality of sintered ceramics, but more s

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
  • Zirconium dioxide short fiber and basic magnesium sulfate whisker composite enhanced magnesia-based crucible and preparation method thereof
  • Zirconium dioxide short fiber and basic magnesium sulfate whisker composite enhanced magnesia-based crucible and preparation method thereof
  • Zirconium dioxide short fiber and basic magnesium sulfate whisker composite enhanced magnesia-based crucible and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] According to the mass percentage of nano-lanthanum oxide in the ceramic powder is 1%, zirconia short fiber is 0.5%, basic magnesium sulfate whisker is 1%, and the rest is the proportion of fused magnesia, the nanometer particle size is 60nm Lanthanum oxide, commercial zirconium dioxide short fibers (diameter 7 μm-10 μm, length 2 mm-3 mm), commercial magnesium basic sulfate whiskers (diameter about 1 μm, length 50 μm-100 μm) and particle size 250 mesh ( Middle diameter d 50Mix and prepare ceramic powder with fused magnesia powder (58 μm); mix and prepare rheological agent according to the mass ratio of urea-formaldehyde resin and hydroxyethyl cellulose at a ratio of 1:4.

[0057] According to mass percentage, 15% of nano-alumina sol with a solid content of 20% (select a commercial nano-alumina sol with a nearly neutral pH value, the same below), 0.8% of rheological agent, and the rest are ceramic powders for batching. First, add the fused magnesia powder into the ball m...

Embodiment 2

[0062] According to the ratio of nanometer lanthanum oxide to the mass percentage of ceramic powder as 3%, zirconium dioxide short fiber as 1%, basic magnesium sulfate whisker as 2%, and the rest as fused magnesia, the nanometer with a particle size of 30nm Lanthanum oxide, commercial zirconia short fibers (diameter 7μm-10μm, length 2mm-3mm), commercial magnesium basic sulfate whiskers (diameter about 1μm, length 50μm-100μm) and particle size 500 mesh ( Middle diameter d 50 Mix and prepare ceramic powder with fused magnesia powder (25 μm); mix and prepare rheological agent according to the mass ratio of urea-formaldehyde resin and hydroxypropyl cellulose at a ratio of 1:4.

[0063] According to mass percentage, 25% of nano-alumina sol with a solid content of 25%, 1.5% of rheological agent, and the rest are ceramic powder for batching. First, add the fused magnesia powder into the ball mill tank according to the ratio, prepare nano-aluminum sol, rheological agent and appropria...

Embodiment 3

[0068] According to the mass percentage of nano-lanthanum oxide in ceramic powder is 2%, zirconium dioxide short fiber is 0.7%, basic magnesium sulfate whisker is 1.5%, and the rest is electric fused magnesia, the particle size is 45nm nano Lanthanum oxide, commercial zirconia short fibers (diameter 7μm-10μm, length 2mm-3mm), commercial magnesium basic sulfate whiskers (diameter about 1μm, length 50μm-100μm) and particle size 325 mesh ( Middle diameter d 50 Mix and prepare ceramic powder with fused magnesia powder (45 μm); mix and prepare rheological agent according to the mass ratio of urea-formaldehyde resin and hydroxyethyl cellulose at a ratio of 1:4.

[0069] According to mass percentage, 20% of nano-alumina sol with a solid content of 22%, 1% of rheological agent, and the rest are ceramic powder for batching. First, add the fused magnesia powder into the ball mill tank according to the ratio, prepare nano-aluminum sol, rheological agent and appropriate amount of deioniz...

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 sizeaaaaaaaaaa
Diameteraaaaaaaaaa
Lengthaaaaaaaaaa
Login to view more

Abstract

The invention discloses a preparation method of a zirconium dioxide short fiber and basic magnesium sulfate whisker composite enhanced magnesia-based crucible which can be sintered at the low temperature and has excellent chemical stability and thermal shock resistance. The method comprises steps as follows: (1) 15%-25% of nano aluminum sol, 0.8%-1.5% of a rheological agent and the balance of fused magnesia ceramic powder containing nano lanthanum oxide, zirconium dioxide short fiber and basic magnesium sulfate whisker are prepared in percentage by mass, deionized water is added, the mixture is subjected to ball milling and mixed uniformly, then, vacuum exhausting is performed, and ceramic slurry with the solid content of 70%-80% is prepared; (2) a crucible biscuit is prepared; (3) the dried biscuit is put in a sintering furnace to be sintered at the high temperature and then cooled with the furnace, and a magnesia-based crucible blank is obtained; (4) the magnesia-based crucible blankis subjected to vacuum impregnation treatment in aluminum sol, then, surface polishing treatment is performed, high-temperature secondary sintering is performed after drying, a product is cooled withthe furnace to the room temperature, and the magnesia-based crucible is obtained.

Description

technical field [0001] The invention relates to a magnesia-based crucible and a preparation method thereof, in particular to a magnesia-based crucible reinforced by composites of zirconia short fibers and basic magnesium sulfate whiskers and a preparation method thereof, belonging to the field of metal materials and metallurgy. The magnesium oxide-based crucible prepared by the invention is particularly suitable for smelting magnesium and its alloys. Background technique [0002] In recent years, the demand for lightweight has led to the rapid development of the application of magnesium alloys and aluminum alloys. Whether it is wrought magnesium, aluminum alloys or cast magnesium, aluminum alloys, the production is inseparable from casting equipment. The chemical properties of magnesium are lively, and it is easy to react with oxygen, nitrogen and water vapor. It is easy to be oxidized and burned during the melting and refining process, and the product remaining in the magne...

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
IPC IPC(8): C04B35/043C04B35/622C04B35/64C04B35/80C04B35/81
CPCC04B35/803C04B35/043C04B35/622C04B35/64C04B2235/3217C04B2235/3227C04B2235/5236C04B2235/5276C04B2235/616C04B2235/6562C04B2235/661
Inventor 刘子利刘希琴刘思雨
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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