WO2002081397A2 - Method for producing mullite - Google Patents

Method for producing mullite Download PDF

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Publication number
WO2002081397A2
WO2002081397A2 PCT/DE2002/001273 DE0201273W WO02081397A2 WO 2002081397 A2 WO2002081397 A2 WO 2002081397A2 DE 0201273 W DE0201273 W DE 0201273W WO 02081397 A2 WO02081397 A2 WO 02081397A2
Authority
WO
WIPO (PCT)
Prior art keywords
precursor
characterized
mullite
verfaliren
sio
Prior art date
Application number
PCT/DE2002/001273
Other languages
German (de)
French (fr)
Inventor
Hans Schmidt
Hans-Joachim Kleebe
Günter Ziegler
Original Assignee
Universität Bayreuth
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to DE2001117470 priority Critical patent/DE10117470A1/en
Priority to DE10117470.5 priority
Application filed by Universität Bayreuth filed Critical Universität Bayreuth
Publication of WO2002081397A2 publication Critical patent/WO2002081397A2/en

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Classifications

    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C1/00Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels
    • C03C1/02Pretreated ingredients
    • C03C1/026Pelletisation or prereacting of powdered raw materials
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C17/00Surface treatment of glass, not in the form of fibres or filaments, by coating
    • C03C17/22Surface treatment of glass, not in the form of fibres or filaments, by coating with other inorganic material
    • C03C17/23Oxides
    • C03C17/25Oxides by deposition from the liquid phase
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/16Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silicates other than clay
    • C04B35/18Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silicates other than clay rich in aluminium oxide
    • C04B35/185Mullite 3Al2O3-2SiO2
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C2217/00Coatings on glass
    • C03C2217/20Materials for coating a single layer on glass
    • C03C2217/21Oxides
    • C03C2217/213SiO2
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C2217/00Coatings on glass
    • C03C2217/20Materials for coating a single layer on glass
    • C03C2217/21Oxides
    • C03C2217/214Al2O3
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C2217/00Coatings on glass
    • C03C2217/20Materials for coating a single layer on glass
    • C03C2217/21Oxides
    • C03C2217/23Mixtures
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C2218/00Methods for coating glass
    • C03C2218/10Deposition methods
    • C03C2218/11Deposition methods from solutions or suspensions

Abstract

Mullite is mainly produced from Al2O3 powder and SiO2 powder by sintering. Powder ceramic methods or casting techniques are employed for shaping. In order to enable complex shaping, a method is disclosed whereby SiO2 is sintered together with an Al2O3 precursor. The Al2O3 precursor can exist in a liquid, pasty or soluble form and SiO2 can be used as a shaped body which is obtained by means of known thermal hyalotechnic shaping processes. This enables the production or second casting of components having complicated geometrical structures and expands the range of use of said materials for structural and functional purposes such as in microsystem technology and electronic components.

Description

A process for producing mullite and Mullitbauteil

The invention relates to a process for the preparation of mullite and a Mullitbauteil.

Among aluminum silicates are meant compounds having different proportions of Al 2 O 3 and siue. 2 Aliuniniuinsilikate represent limiting cases of aluminum salts. In particular, the invention relates to minerals in which aluminum and silicon lattice sites occupied. These compounds are called aluminum silicates such. As zeolites, feldspars, Inosilika- te, andalusite, Sillimariit, kyanite and mullite. Reference shall be mainly due to the mullite whose composition as a series with increasing Al 2 θ3: Si0 2 - can be expressed money. Most multi- lite have compositions of 3 A1 2 0 3 • 2 SiC "2 to 2 Al 2 O 3 • Si0. Mullite has a Defektstniktiir, which can be regarded as a disordered Sillimanitstraktur, lacking in the 19% of bridging oxygens between the [A10 4] "and [SiO 4]" tetrahedra.

Natural mullite is present only in non-significant amount and therefore mullite is produced synthetically. These raw materials are used for the production of ceramic components. Structural and nimble tional applications are also in the field of high-performance ceramic materials. However, mullite in refractory materials, glass ceramics and as Trägeπnaterial for catalysts for afterburning of Autoab- gases to be found. In addition, mullite is the essential crystalline component of bone china, and causes, with its feinfilzigen crystalline aggregation th the strength of the porcelain ceramic body. Firebricks are therefore refractory applications so useful, the higher their mullite is.

To prepare Mullitbauteile, the raw materials have alumina and silica are brought into a predetermined ratio to react together. It is known durchzufxihren the formation of the mullite in-situ during the production of a ceramic component by so-called Reaktionssintera. From the state of the art production methods are known, according to which Al 2 θ3 powder having Si0 2 powder and Al 2 θ3 powder with SiC> 2 -Precursoren be implemented by powder ceramic Fonngebimgsveifahren to mullite. The preparation of synthetic mullite is carried out by reacting Reaktandengemischen and hybrids powder, powder from the sol-gel method or powder of Cofällungen of salt solutions. These methods of preparation lead to certain possibilities of shaping the powder over the route (z. B. slip casting, pressing technique) or Gießtecliniken of fluids (eg., Gel-casting).

The use of powdered starting materials, or a powdered starting material for the higher mass part (Al 2 O 3) and a liquid precursor for the lower mass part (Si0 2) is disadvantageous, since in both cases for the manufacture of the components ren only powdered ceramic Expiry come into question , However, powder Ceramic process lead to simple geometries at most large Sc maybe thick. Extremely thin-walled parts in the micrometer range with any geometry can either not at all or only at very high costs are produced.

The invention is zugmnde the task of producing a Verfaliren Aliuniniumsilikaten, preferably mullite, propose that allows to enable complicated or complex shapes. Weiterliin like to present an Mullitbauteil that is easily manufactured in complex shapes.

This object is achieved with a likaten Verfaliren for producing Aluminiumsi-, preferably mullite, dissolved in the silicon dioxide (Si0 2) is subjected together with an ABC VPrecursor a sintering process.

The use of an Al 2 θ 3 -Precursors leads to liquid, pasty or soluble precursor for the mass moderately higher A ^ CVAnteil which allows molding dispensing with expensive and limiting the Foπngebung ceramic powder Verfaliren (powder technology). By underlying the invention manufacturing process complicated or complex shapes, as they can be made with the glass processing (fused silica, silicon dioxide) are suitable for the production of multi- suffered rush.

The invention is based on the insight that is to provide a method for the in-situ production of mullite by using not necessarily piüverförmiger starting materials, in which, starting from the basic shape of a without powder produced Fonnkörpers over melting SiCvGlas with liquid or soluble Al 2 0 3 -Precursoren a mullite body can be produced. Sintering referred ün proper sense only physico-chemical reactions in the American then range from about 10% (calculated in ° C) below the SMP of the respective substances. However, the conversion of the precursor is carried out in Al 2 θ 3 precursors and then ultimately in the Al 2 O 3 at much lower temperatures.

it when silica is used as Fonnkörper is advantageous. Overall ometrisch complex Strakturen obtained for example by then African treatment of amorphous silica in Fonn a solid base body, can be converted into Mullitteile way. Here, the vorgefonnte silica body is coated with a liquid or soluble Al 2 θ 3 -Precursor. Subsequently, the coated Grand body is a hydrolysis and / or Wännebe andlung in AI 2 converted O3 and in-situ formed Al 2 O 3 is converted into mullite during the reaction-sintering process with the SiO 2 base material, so that Si0 2 - Fonnkörper abgefonnt as Mullitbauteil can be. The invention thus permits the production Mullitfomikörper with complicated or complex geometry.

The novel method Bera t on the replacement of pulverfönnigen raw materials by the use of suitable liquid, paste or soluble Al 2 θ 3 -Precursoren for the mass moderately higher in the mullite Al 2 θ3 content and the use of Si0 2 in Fonn of a vitreous material, for the can be used the known and generally applied Fonngebungsverfahren such as melting at relatively low temperatures, for producing also complicated or complex geometries. In this case, provides a variant of the method, that prior to sintering, an amorphous Si0 2 -Foπrιkörper is doped with a liquid A Os precursor or coated. This ennöglicht the arbitrary shaping of a component by melting glass as a raw material of the SiO 2 component in the mullite producing thin Mullitschichten by ex fonnen a Si0 2 -Trägerkörpers by the application of a previously calculated Neten mass of liquid, paste-like or dissolved precursor for the Al 2 O 3 - content in the mullite and the subsequent reaction sintering as well as the relatively low Sclimelztemperatur of the forming raw material Si0 2 relative to the raw material α-Al 2 03 (mp 2045 ° C.). The method is thus ennöglicht it already to use known techniques of glass melting for Fonngebung the later Mullitbauteils or carrier component, although the raw material α-Al 2 03 is not fusible under Noraialbedingungen.

In addition, two -Fonnkörper can be embedded in a pasty AbCVPrecursor even before sintering SiO.

When Al 2 C> 3 -Precursor especially organoaluminum Verbindun- suitable gene. Possible Al 2 0 3 -Precursoren are Al (-OR) 3, A1 (NR) 3, Al-R 3. R ste t represent straight, branched, saturated or unsaturated hydrocarbon radicals having 1 to 20 carbon atoms. Alkyl groups which may be optionally branched and optionally unsaturated are preferred. More preferred are methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and tert-butyl, more preferably ethyl and propyl. Preferred precursors are malkoholat Ethylaluminiu- and Propylaluminiumalkoholat. These precursors can 3 precursors are converted by hydrolysis and / or heat treatment in oxide Al 2 O.

The production or Abfonnung of components with more complicated or complex geometry extends the application range for Almiiiniumsilikate and particularly for mullite strakturelle and fiinktionelle applications such. As the field of Mikrosystemteclinik and electronics components.

The basis of the invention hegende object is achieved component with a mullite having a glass body made of SiC and a surface area of ​​mullite.

The process of the invention is explained in reference to the appended figures. It shows

Figure 1 is a ball made of amorphous SiO 2 which has been coated with a liquid Ai 2 θ3 precursor to Abfonnung,

Figure 2 is a ball made of amorphous SiO 2, in a pasty sen AJ.2 θ3 precursor was embedded and

Figure 3 is an enlargement of a Aussclrnitts from FIG. 2

The figures show Ausfülrrangsbeispiele from different experiments. The ball made of amorphous Si0 2 shown in Figure 1 was coated initially with a liquid Al 2 θ 3 -Precursor to Abfonnung. The subsequent treatment of the coated ball thennisc e resulted in situ formation of Al 2 O 3 from the precursor, and then at higher temperatures to form a thin mullite layer of about 10 microns on the SiO 2 base material.

The bullet shown in Figures 2 and 3 of amorphous SiO 2 was first embedded in a pasty Al 2 θ 3 -Precursor and treated thennisch. The African then treatment resulted in situ formation of Al 2 O 3 from the precursor, and then at higher temperatures to Umwand- ing at least a portion of the SiO 2 -Grandkörpers to mullite (reaction-sintering).

The SiO 2 -Grandkörper can be manufactured with conventional thermal treatment method of glass. The solid SiO 2 is doped or with liquid, pasty or soluble precursors of Al 2 O 3 coated. The Al 2 O 3 - component of the mullite is produced from a precursor subscriptions by hydrolysis or decomposition before or during then African Auflieizvorgang for reaction sintering. As Bos precursor known and commercially available aluminum-organic compounds such suitable. B. Alumini nalkoholate, which are known from the sol-gel technology and can be used directly as a liquid. The precursor may be vennischt or with fine A ^ Os powders into a paste dissolved in appropriate solvents. As for conventional reactant mixtures of mullite the process of reaction sintering is carried out by a defined eizprozess on. By choosing the experimental parameters the formation of mullite can be controlled.

The base body made of SiO 2 can be formed as hollow or solid part, for example kugelfönnig, rod fönnig, rölirenfönnig, fibrous, plättchenföraiig, dense or porous and. He is endowed with a rule aluminiiunorgani- connection superficial or by infiltration of open porosity. The subsequent conversion to mullite takes place by hydrolysis of the Al 2 θ -Precursors to Al (OH) 3 and subsequent heat treatment for conversion to Al 2 O 3, then the wälirend African densification (sintering cycle). Al 2 θ 3 -Precursoren can be hydrolyzed with water and thus in Al hydroxides (precursors) are converted (Al (OH) 3, AIO (OH)). These precursors, or alternatively directly the precursors are converted wälirend the heat treatment (up to 800 ° C) by loss of water and / or the organic fraction over various modifications of Al 2 O 3 (up to 1100 ° C) ultimately between 1100 ° C and in α- A1 2 0 3 (coboundary) to 1200 ° C. Between 1200 ° C and 1600 ° C α- A1 2 0 3 reacts with Si0 2 to mullite.

In a Ausführangsbeispiel porous, was placed over glass bubbles gefonntes SiC> 2 in a solution of Al-alcoholate. The hydrolysis reaction is completed by portionwise addition of water. The organometallic compound in Al 2 O 3 is mngewandelt a heat treatment to 800 ° C in air and at temperatures of 1400-1600 ° C, the conversion to mullite takes place.

Claims

claims:
1. Verfaliren for the production of aluminum silicates, preferably mullite is subjected to a sintering in which teφrozess SiO 2 together with an Al 2 θ3 precursor.
2. Verfaliren addressed by 1, characterized in that an Al 2 θ 3 -Precursor used in liquid, paste or soluble form.
3, Verfaliren according to any one of the preceding claims, characterized in that the SiO 2 is used as Fonnköφer.
4. Verfaliren according to claim 3, characterized in that the SiO 2 - Fonnköφer is produced by African then processing of Si0 2 glass.
5. Verfaliren addressed to 4, characterized in that the Si0 2 - Foraiköφer is prepared by melting of Si0 2 glass.
6. Verfaliren according to any one of the preceding claims, characterized in that 2 -Fonnköφer is doped with a liquid precursor or BOS-coated prior to sintering, a amoφher SiO.
7. The method according to any one of the preceding claims, characterized in that a SiO 2 -Fonnköφer in a paste-like Al 2 O 3 - is embedded precursor.
8. Verfaliren according to any one of the preceding claims, characterized in that an Al 2 θ3 from the precursor is produced by hydrolysis of 2 θ 3 Al precursor.
9. Verfaliren according to any one of claims 1 to 7, characterized gekennzeich- advised that Al from the Al 2 θ 3 -Precursor generated by decomposition then African 2 θ 3 precursor.
10. Verfaliren according to any one of the preceding claims, characterized in that are used as Al 2 0 3 -Precursor AI-organic compounds.
11. The method according to any one of the preceding claims, characterized in that are used malkoholate as Al 2 0 -Precursor ethyl or Propylaluminiu-.
12. Mullitbauteil with a Glasköφer of Si0 2 and a surface area of mullite.
PCT/DE2002/001273 2001-04-06 2002-04-08 Method for producing mullite WO2002081397A2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE2001117470 DE10117470A1 (en) 2001-04-06 2001-04-06 A process for producing mullite and Mullitbauteil
DE10117470.5 2001-04-06

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2002191464 DE10291464D2 (en) 2001-04-06 2002-04-08 A process for Hersstellung of mullite and Mullitbauteil

Publications (1)

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WO2002081397A2 true WO2002081397A2 (en) 2002-10-17

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WO (1) WO2002081397A2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2078705A1 (en) * 2008-01-08 2009-07-15 Guardian Industries Corp. Method of making a temperable antiglare coating, and resulting products containing the same

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5079064A (en) * 1990-04-30 1992-01-07 E. I. Du Pont De Nemours And Company Thermal shock resistant ceramic honeycomb structures of cordierite, mullite and corundum
WO1992009541A1 (en) * 1990-12-03 1992-06-11 Manville Corporation Method of producing mullite materials

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2078705A1 (en) * 2008-01-08 2009-07-15 Guardian Industries Corp. Method of making a temperable antiglare coating, and resulting products containing the same
US8114472B2 (en) 2008-01-08 2012-02-14 Guardian Industries Corp. Method of making a temperable antiglare coating, and resulting products containing the same

Also Published As

Publication number Publication date
DE10117470A1 (en) 2002-10-17
DE10291464D2 (en) 2004-04-15

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