DE1106296B - Process for the production of hot-pressable aluminum nitride that is resistant to humid air - Google Patents

Process for the production of hot-pressable aluminum nitride that is resistant to humid air

Info

Publication number
DE1106296B
DE1106296B DED32179A DED0032179A DE1106296B DE 1106296 B DE1106296 B DE 1106296B DE D32179 A DED32179 A DE D32179A DE D0032179 A DED0032179 A DE D0032179A DE 1106296 B DE1106296 B DE 1106296B
Authority
DE
Germany
Prior art keywords
aluminum nitride
hot
nitrogen
production
pressable
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
DED32179A
Other languages
German (de)
Inventor
Fritz Frehn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deutsche Edelstahlwerke AG
Original Assignee
Deutsche Edelstahlwerke AG
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 NL259366D priority Critical patent/NL259366A/xx
Application filed by Deutsche Edelstahlwerke AG filed Critical Deutsche Edelstahlwerke AG
Priority to DED32179A priority patent/DE1106296B/en
Priority to GB3605660A priority patent/GB899398A/en
Priority to FR847291A priority patent/FR1279586A/en
Publication of DE1106296B publication Critical patent/DE1106296B/en
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/06—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron
    • C01B21/072—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron with aluminium
    • C01B21/0728—After-treatment, e.g. grinding, purification
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/581—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on aluminium nitride

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Ceramic Products (AREA)

Description

DEUTSCHESGERMAN

Bei der Herstellung von dichten Körpern aus Aluminiumnitrid, beispielsweise auf dem Sinterwege, stellen sich insofern Schwierigkeiten ein, als dieser Werkstoff dazu neigt, bei erhöhten Temperaturen in seine Elemente zu zerfallen, also thermisch zu dissoziieren. Die Folge hiervon ist, daß die hergestellten Körper stets eine mehr oder weniger große Menge von Aluminiumoxyd enthalten, welches durch Reaktion des infolge der thermischen Dissoziation frei gewordenen Aluminiums mit dem vorhandenen Luftsauerstoff entsteht. Wird die Sinterung im Vakuum oder unter Schutzgas durchgeführt, so tritt ebenfalls eine Dissoziation des Aluminiumnitrides ein, welche nun zu einem mehr oder weniger schnellen Verdampfen (Sublimieren) des Werkstoffes führt und den zurückbleibenden Körper infolge der starken Gasentwicklung porös werden läßt.In the production of dense bodies made of aluminum nitride, for example by sintering, difficulties arise insofar as this material tends to at elevated temperatures in to disintegrate its elements, i.e. to dissociate thermally. The consequence of this is that the manufactured Bodies always contain a more or less large amount of aluminum oxide, which is produced by reaction of the aluminum released as a result of thermal dissociation with the oxygen present in the air arises. If the sintering is carried out in a vacuum or under protective gas, one also occurs Dissociation of the aluminum nitride, which now leads to more or less rapid evaporation (Sublimation) of the material leads and the remaining body as a result of the strong gas development can become porous.

Versuche des Erfinders, käufliches oder nach den üblichen bekannten Verfahren hergestellte Aluminiumnitrid heiß zu pressen, schlugen fehl, da die Gasentwicklung so stark war, daß die aus Graphit hergestellten Heißpreßformen auseinandergetrieben wurden.Experiments by the inventor, aluminum nitride which is commercially available or produced by the customary known processes Pressing hot failed because the gas evolution was so strong that that of graphite produced hot press molds were driven apart.

Ein weiterer Nachteil, der sich der Verarbeitung von käuflichem oder auf die übliche Weise hergestellten Aluminiumnitrid insbesondere in technischem Ausmaß entgegengestellt, ist der, daß die Verbindung an der feuchten Luft hydrolysiert und auf diese Weise Aluminiumhydroxyd und Ammoniak gebildet wird. Ein Aufbewahren des frisch hergestellten Aluminiumnitrides über längere Zeit an der Luft ist daher nicht möglich.Another disadvantage, which is the processing of commercial or conventionally manufactured Opposed to aluminum nitride, in particular on a technical level, is that the compound hydrolyzed in humid air and in this way aluminum hydroxide and ammonia are formed. It is therefore not possible to keep the freshly produced aluminum nitride in the air for a long period of time possible.

Ziel der Erfindung ist, ein Verfahren zur Herstellung von lagerfähigem, an feuchter Luft nicht hydrolysierendem Aluminiumnitrid anzugeben, welches geeignet ist, etwa durch Heißpressen zu dichten Körpern verarbeitet zu werden.The aim of the invention is to provide a process for the production of storable, non-hydrolyzing in humid air Specify aluminum nitride, which is suitable, for example by hot pressing to form dense bodies to be processed.

Zur Herstellung von Aluminiumnitrid sind in der Literatur verschiedene Verfahren angegeben. Eines dieser Verfahren besteht darin, daß feingepulvertes Aluminiumoxyd mit Kohlenstoff gemischt und im Ammoniak- oder Stickstoff strom einer erhöhten Temperatur ausgesetzt wird. Hierbei tritt zunächst Reduktion des Aluminiumoxydes durch den vorhandenen Kohlenstoff ein, und das so gebildete Aluminiummetall reagiert mit dem vorhandenen Stickstoff zu Aluminiumnitrid. Bei Durchführung der Reaktion unter Ammoniak zerfällt dieser infolge der erhöhten Temperatur in seine Elemente und liefert so den zur Nitridbildung erforderlichen Stickstoff.Various processes are given in the literature for the production of aluminum nitride. One This method consists in that finely powdered aluminum oxide mixed with carbon and im Ammonia or nitrogen stream is exposed to an elevated temperature. Here, reduction occurs first of the aluminum oxide through the carbon present, and the aluminum metal thus formed reacts with the nitrogen present to form aluminum nitride. When performing the reaction below Ammonia breaks down into its elements as a result of the increased temperature and thus supplies the nitride formation required nitrogen.

Ein anderes Verfahren geht unmittelbar von Aluminiummetall aus, welches in feingepulverten Zustand im Stickstoff strom geglüht wird. Hierbei tritt unmittelbar eine Reaktion der beiden Elemente zu Verfahren zur HerstellungAnother method is based directly on aluminum metal, which is in a finely powdered state is annealed in a stream of nitrogen. The two elements react immediately Method of manufacture

von an feuchter Luft beständigemof resistant to humid air

heißpreßbarem Aluminiumnitridhot-pressable aluminum nitride

Anmelder:Applicant:

Deutsche EdelstahlwerkeGerman stainless steel works

Akti enges ells chaft,
Krefeld, Oberschlesienstr. 16Stock corporation,
Krefeld, Oberschlesienstr. 16

Fritz Frehn, Krefeld,
ist als Erfinder genannt wordenFritz Frehn, Krefeld,
has been named as the inventor

Aluminiumnitrid ein. Nach Ablauf der Reaktion wird die erhaltene Masse gemahlen und meist noch einmal unter Stickstoff bei Atmosphärendruck geglüht.Aluminum nitride. After the reaction has ended, the mass obtained is ground and usually again annealed under nitrogen at atmospheric pressure.

Versuche haben ergeben, daß beide Verfahren zu Reaktionsprodukten führen, die an feuchter Luft hydrolysieren und infolge der oben beschriebenen Sublimationserscheinungen sich sowohl der Sinterung wie auch dem Heißpressen widersetzen.Tests have shown that both processes lead to reaction products which hydrolyze in moist air and as a result of the above-described sublimation phenomena, both sintering and also oppose hot pressing.

Erfindungsgemäß wurde nun festgestellt, daß es möglich ist, auf die übliche Weise hergestelltes Aluminiumnitrid dadurch in einen Zustand zu versetzen, in dem es weder mit der Luftfeuchtigkeit reagiert, noch bei erhöhter Temperatur thermisch dissoziiert, daß das im Stickstoffstrom unter Atmosphärendruck ausgeglühte Aluminiumnitrid pulverisiert und in einer Stickstoff atmosphäre mit erniedrigtem Druck bei Temperaturen oberhalb 1600° C erneut geglüht wird. Als besonders vorteilhaft hat es sich erwiesen, diese zweite Glühung des Aluminiumnitrides bei einem Stickstoffdruck zwischen 10 und 50 mm Hg-Säule erfolgen zu lassen und hierbei in strömendem Stickstoff zu arbeiten.According to the invention it has now been found that it is possible to use aluminum nitride produced in the usual way to put it in a state in which it does not react with the humidity, still thermally dissociated at elevated temperature that that in a nitrogen stream under atmospheric pressure Annealed aluminum nitride is pulverized and placed in a nitrogen atmosphere at reduced pressure Temperatures above 1600 ° C is re-annealed. It has proven to be particularly advantageous to use this second annealing of the aluminum nitride at a nitrogen pressure between 10 and 50 mm Hg column to be done and to work here in flowing nitrogen.

Röntgenographische Untersuchungen haben gezeigt, daß das Aluminiumnitrid nach der ersten Glühung in Stickstoff unter Atmosphärendruck mehr oder weniger unscharfe Aluminiumnitridlinien zeigt. Erst nach der erfindungsgemäßen Behandlung ist die Intensität der Aluminiumnitridlinien im Röntgenogramm verstärkt, und die Linien erscheinen scharf und gut ausgebildet.Radiographic examinations have shown that the aluminum nitride after the first annealing in Nitrogen shows more or less fuzzy aluminum nitride lines under atmospheric pressure. Only after the treatment according to the invention, the intensity of the aluminum nitride lines in the roentgenogram is increased, and the lines appear sharp and well developed.

Versuche haben ergeben, daß das auf die erfindungsgemäße Art hergestellte Aluminiumnitrid beliebig lange an Luft mit normalem Feuchtigkeitsgehalt gelagert werden kann, ohne daß eine Hydrolyse, also Ammoniak- und Aluminiumhydroxydbildung, eintritt.Tests have shown that the aluminum nitride produced in the manner according to the invention is arbitrary can be stored for a long time in air with normal moisture content without hydrolysis, ie Ammonia and aluminum hydroxide formation occurs.

109 580/378109 580/378

Weiter hat es sich gezeigt, daß dieses Aluminiumnitrid ohne Schwierigkeiten in Graphitformen auf die übliche Weise heiß gepreßt werden kann, wobei Temperaturen von etwa 1800 bis 1900° C und Drücke von vorzugsweise mehr als 100 kg/cm2 angewandt werden. Die Dichte der so erzeugten Körper beträgt 3,2 g/cm3, entspricht also fast der theoretischen Dichte von Aluminiumnitrid, die in der Literatur mit 3,25 g/cm3 angegeben ist.It has also been shown that this aluminum nitride can be hot-pressed in graphite molds in the usual way without difficulty, temperatures of about 1800 to 1900 ° C. and pressures of preferably more than 100 kg / cm 2 being used. The density of the bodies produced in this way is 3.2 g / cm 3 , which almost corresponds to the theoretical density of aluminum nitride, which is given in the literature as 3.25 g / cm 3 .

Dementsprechend wird gemäß der vorliegenden Erfindung ein Verfahren zur Herstellung von Aluminiumnitrid vorgeschlagen, welches dadurch gekennzeichnet ist, daß das in an sich bekannter Weise hergestellte und unter Stickstoff von Atmosphärendruck ausgeglühte Aluminiumnitrid pulverisiert und in einer Stickstoffatmosphäre mit erniedrigtem Druck bei Temperaturen oberhalb 1600° C geglüht wird. Der so erzeugte Werkstoff kann anschließend wiederum pulverisiert und sodann durch Heißpressen zu dichten Formkörpern verarbeitet werden.Accordingly, according to the present invention, there is provided a method for producing aluminum nitride proposed, which is characterized in that in a known manner aluminum nitride produced and annealed under nitrogen at atmospheric pressure is pulverized and is annealed in a nitrogen atmosphere with reduced pressure at temperatures above 1600 ° C. Of the The material produced in this way can then be pulverized again and then sealed by hot pressing Moldings are processed.

Die aus dem erfindungsgemäß hergestellten Aluminiumnitrid erzeugten Körper weisen eine völlig glatte, porenfreie Oberfläche auf und werden selbst bei sehr hohen Temperaturen, etwa in der GrößenOrdnung von 1800° C und mehr, von den meisten Agenzien weder benetzt noch angegriffen. Sie eignen sich deshalb insbesondere zur Herstellung von Teilen, die mit hocherhitzten Werkstoffen in Berührung kommen und gegen diese chemisch physikalisch indifferent sein müssen.Those from the aluminum nitride produced according to the invention Bodies produced have a completely smooth, pore-free surface and are themselves at very high temperatures, of the order of 1800 ° C and more, of most Agents neither wetted nor attacked. They are therefore particularly suitable for the production of parts, that come into contact with highly heated materials and are chemically and physically indifferent to them must be.

Claims (3)

Patentansprüche:Patent claims: 1. Verfahren zur Herstellung von an feuchter ίο Luft beständigem, heißpreßbarem Aluminiumnitrid, dadurch gekennzeichnet, daß in an sich bekannter Weise hergestelltes und unter Stickstoff von Atmosphärendruck ausgeglühtes Aluminiumnitrid pulverisiert und in einer Stickstoffatmosphäre von erniedrigtem Druck bei Temperaturen oberhalb 1600° C erneut geglüht wird.1. Process for the production of hot-pressable aluminum nitride which is resistant to humid air, characterized in that it is produced in a manner known per se and under nitrogen Atmospheric pressure annealed aluminum nitride and pulverized in a nitrogen atmosphere is re-calcined under reduced pressure at temperatures above 1600 ° C. 2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die zweite Glühung des Aluminiumnitrides bei einem Stickstoffdruck zwischen 10 und 50 Torr erfolgt.2. The method according to claim 1, characterized in that the second annealing of the aluminum nitride takes place at a nitrogen pressure between 10 and 50 torr. 3. Verfahren nach Anspruch 1 und 2, dadurch gekennzeichnet, daß die zweite Glühung des Aluminiumnitrides bei erniedrigtem Stickstoffdruck in strömender SticWnifatmosphäre erfolgt.3. The method according to claim 1 and 2, characterized in that the second annealing of the aluminum nitride takes place at reduced nitrogen pressure in a flowing stitching atmosphere.
DED32179A 1959-12-22 1959-12-22 Process for the production of hot-pressable aluminum nitride that is resistant to humid air Pending DE1106296B (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NL259366D NL259366A (en) 1959-12-22
DED32179A DE1106296B (en) 1959-12-22 1959-12-22 Process for the production of hot-pressable aluminum nitride that is resistant to humid air
GB3605660A GB899398A (en) 1959-12-22 1960-10-20 A method of producing aluminium nitride which is stable when exposed to moist air, and the use of the same for producing dense compacts
FR847291A FR1279586A (en) 1959-12-22 1960-12-19 Manufacturing process of moisture resistant aluminum nitride and profiles obtained with this nitride

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DED32179A DE1106296B (en) 1959-12-22 1959-12-22 Process for the production of hot-pressable aluminum nitride that is resistant to humid air

Publications (1)

Publication Number Publication Date
DE1106296B true DE1106296B (en) 1961-05-10

Family

ID=7041212

Family Applications (1)

Application Number Title Priority Date Filing Date
DED32179A Pending DE1106296B (en) 1959-12-22 1959-12-22 Process for the production of hot-pressable aluminum nitride that is resistant to humid air

Country Status (3)

Country Link
DE (1) DE1106296B (en)
GB (1) GB899398A (en)
NL (1) NL259366A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3194635A (en) * 1961-07-18 1965-07-13 Norton Co Method for the production of aluminum refractory material
US5049367A (en) * 1988-10-05 1991-09-17 Sumitomo Chemical Co., Limited Aluminum nitride powder and process for preparation of the same
US5837633A (en) * 1995-11-02 1998-11-17 Agency Of Industrial Science And Technology Method for production of aluminum nitride sintered body and aluminum nitride powder

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3194635A (en) * 1961-07-18 1965-07-13 Norton Co Method for the production of aluminum refractory material
US5049367A (en) * 1988-10-05 1991-09-17 Sumitomo Chemical Co., Limited Aluminum nitride powder and process for preparation of the same
US5837633A (en) * 1995-11-02 1998-11-17 Agency Of Industrial Science And Technology Method for production of aluminum nitride sintered body and aluminum nitride powder

Also Published As

Publication number Publication date
GB899398A (en) 1962-06-20
NL259366A (en)

Similar Documents

Publication Publication Date Title
DE1483312B1 (en) PROCESS FOR THE PRODUCTION OF ADDITIVES CONTAINING VANADIUM FOR THE PRODUCTION OF STEEL
DE1122762B (en) Moisture-protected metal phosphide for pest control and process for its production
DE1104930B (en) Process for the production of hot-pressable stabilized boron nitride
DE1106296B (en) Process for the production of hot-pressable aluminum nitride that is resistant to humid air
DE1078927B (en) Carbon bodies, in particular graphite bodies for nuclear reactors, and processes for their manufacture
DE1102710B (en) Process for the production of powdery boron nitride
DE2118770A1 (en) Process for the production of a catalyst for the oxidation of carbon monoxide to carbon dioxide
DE2304731A1 (en) METHOD FOR MANUFACTURING SINTER CARBIDES AND THE PRODUCTS OBTAINED THEREOF
DE820134C (en) Process for removing hydrogen and / or oxygen from gas mixtures and means therefor
DE2848452A1 (en) METHOD FOR MANUFACTURING SILICON CARBIDE POWDER
DE3742667C2 (en)
DE4023561A1 (en) Foam glass mouldings mfr. - by prepn. of mixt. contg. water, finely ground glass and foaming agents, granulating and expanding
DE2439163C2 (en) Process for the production of stable ferrosilicon nitride
DE1267844B (en) Reduction of discoloration in the production of molded articles from polytetrafluoroethylene
DE1930486A1 (en) Process for the production of objects from beryllium oxide of high density
DE2930847C2 (en) Process for making a silicon carbide sintered product
DE2021952C3 (en) Process for the production of shaped bodies from boron nitride
AT36796B (en) Radioactive material and facility for its use.
DE4003457C1 (en)
DE2140762A1 (en) Process for the production of sintered bodies from boron nitride
DE2148707A1 (en) Ammonia oxidation catalyst - by decomposing cobalt carbonate pellets and sintering the resulting oxide
DE2021952B2 (en) METHOD FOR MANUFACTURING SHAPED BODIES FROM BORNITRIDE
DE1197439B (en) Process for the production of hot-pressable aluminum nitride which is resistant to humid air
DE1076016B (en) Process for the production of shaped boron nitride bodies
AT163162B (en) Process for the production of sintered steel bodies