DE715926C - Process for the production of electrically insulating and gas-tight bodies from aluminum oxide - Google Patents
Process for the production of electrically insulating and gas-tight bodies from aluminum oxideInfo
- Publication number
- DE715926C DE715926C DES124860D DES0124860D DE715926C DE 715926 C DE715926 C DE 715926C DE S124860 D DES124860 D DE S124860D DE S0124860 D DES0124860 D DE S0124860D DE 715926 C DE715926 C DE 715926C
- Authority
- DE
- Germany
- Prior art keywords
- aluminum oxide
- gas
- electrically insulating
- production
- bodies
- 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.)
- Expired
Links
Landscapes
- Spark Plugs (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Insulating Bodies (AREA)
Description
Verfahren zum Herstellen von elektrisch isolierenden und gasdichten Körpern aus Aluminiumoxyd Körper aus Aluminiumoxyd formt man vielfach durch Gießen in Gipsformen. Dabei zeit sich aber, daß die Körper oftmals fehle Risse haben. Dies ist offenbar darauf zurückzuführen, daß die Masse im Innern des Körpers unter anderen Bedingungen erstarrt als an der Berührungsfläche mit dem Gips. Das hat ungleichmäßiges Schwinden zur Folge, so daß Risse entstehen; auch Ungleichmäßigkeiten in, der Korngröße, die beim Mahlen unvermeidlich sind, können Anlaß zu ungleichmäßigem Schwinden und infolgedessen Rissen geben. Dies trifft auch für Körper zu, die durch Pressen geformt werden. Die Risse sind vielfach erst nach dem Brände feststellbar.Process for producing electrically insulating and gas-tight Bodies made of aluminum oxide Bodies made of aluminum oxide are often formed by casting in plaster molds. In doing so, however, the bodies often lack cracks. this is evidently due to the fact that the mass inside the body among others Conditions solidified than at the contact surface with the plaster of paris. There is something uneven about it Shrinkage resulting in cracks; also irregularities in, the grain size, which are inevitable during grinding can give rise to uneven shrinkage and as a result, there will be cracks. This also applies to bodies that are formed by pressing will. The cracks are often only noticeable after the fire.
Zur Behebung dieser Mängel hat man als Sinterungsmittel der Tonerde Erdalkalienverbindungen zugesetzt. So hat man beispielsweise Berylliumoxyd, Magnesiumoxyd und Calciumfluorid verwendet mit einem Metall-Behalt von einigen Prozenten. Wenn sich durch den Zusatz der genannten Stoffe auch die Ausschußzahlen bei der Fertigung verringerten, so waren die Erfolge doch nicht voll befriedigend.To remedy these deficiencies one has the alumina as a sintering agent Alkaline earth compounds added. For example, one has beryllium oxide, magnesium oxide and calcium fluoride used with a metal content of a few percent. if The number of rejects in production is also increased by adding the substances mentioned decreased, the results were not entirely satisfactory.
Genlöß der Erfindung wird bei einem Verfahren zum Hersellen elektrisch isolierender und gasdichter Körper durch Sintern von Formlingen aus Gemengen aus Aluminiumoxyd und Verbindungen der Erdalkalien als Erdalkälienverbindung Mägnesiumfluorid in solchen Mengen zugegeben, daß ihr Gehalt, berechnet auf Magnesium, I %o des Gesamtgewichtes nlicht übersteigt.In accordance with the invention, a method of manufacturing is electrical insulating and gas-tight body made by sintering moldings from batches Aluminum oxide and compounds of alkaline earths as alkaline earth compounds, magnesium fluoride added in amounts such that their content, calculated on magnesium, is 1% o of the total weight nlight exceeds.
Das Magnesiumfluorid wirkt anscheinend ätzend auf die Aluminiumoxydkristalle und findet leicht Angriffsteilen. Infolgedessen braucht man nur wenig, Magnesiumfuorid und kommt mit Mengen aus unter I%: Magnesiumgehalt. Es hat sich gezeigt, däß mit Zusattem'-in, dieser geringen Menge die Rißgefahr beseitigt ist und einwandfreie dichte Erzeugnisse erhalten werden, ohne daß sich die guten Eigenschaften des Aluminiumoxyds ändern.The magnesium fluoride appears to be corrosive to the aluminum oxide crystals and easily finds attack parts. As a result, you only need a little, magnesium fluoride and comes from quantities below I%: Magnesium content. It has been shown that with Zusattem'-in, this small amount the risk of cracking is eliminated and perfectly sealed products can be obtained without impairing the good properties change of alumina.
Ein Zusatz von beispielsweise o,8%o Magnesiumfiuorid entspricht einem Magnesiunmgehalt von etwa o,3%.An addition of, for example, 0.8% magnesium fluoride corresponds to one Magnesium content of about 0.3%.
Das Verfahren eignet sich insbesondere zum Herstellen von Isolierkörpern für Zündkerzen und, von gasdichten Rohren, z. B. Schutzrohren für Pyrometer und Heizelemente.The method is particularly suitable for producing insulating bodies for spark plugs and, of gas-tight pipes, e.g. B. Thermowells for pyrometers and Heating elements.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DES124860D DE715926C (en) | 1936-11-05 | 1936-11-05 | Process for the production of electrically insulating and gas-tight bodies from aluminum oxide |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DES124860D DE715926C (en) | 1936-11-05 | 1936-11-05 | Process for the production of electrically insulating and gas-tight bodies from aluminum oxide |
Publications (1)
Publication Number | Publication Date |
---|---|
DE715926C true DE715926C (en) | 1942-01-09 |
Family
ID=7536708
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DES124860D Expired DE715926C (en) | 1936-11-05 | 1936-11-05 | Process for the production of electrically insulating and gas-tight bodies from aluminum oxide |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE715926C (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1215569B (en) * | 1961-07-28 | 1966-04-28 | Corhart Refractories Co | Process for the production of refractory cast materials |
DE1232053B (en) * | 1963-05-06 | 1967-01-05 | Corhart Refractories Co | Refractory materials and furnace linings |
DE1261436B (en) * | 1961-12-01 | 1968-02-15 | Feldmuehle Ag | Sintered body made of aluminum oxide |
DE1275936B (en) * | 1964-04-14 | 1968-08-22 | Babcock & Wilcox Co | Ceramic insulating material resistant to hydrogen at high temperatures |
-
1936
- 1936-11-05 DE DES124860D patent/DE715926C/en not_active Expired
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1215569B (en) * | 1961-07-28 | 1966-04-28 | Corhart Refractories Co | Process for the production of refractory cast materials |
DE1261436B (en) * | 1961-12-01 | 1968-02-15 | Feldmuehle Ag | Sintered body made of aluminum oxide |
DE1261436C2 (en) * | 1961-12-01 | 1973-07-26 | Feldmuehle Ag | Sintered body made of aluminum oxide |
DE1232053B (en) * | 1963-05-06 | 1967-01-05 | Corhart Refractories Co | Refractory materials and furnace linings |
DE1275936B (en) * | 1964-04-14 | 1968-08-22 | Babcock & Wilcox Co | Ceramic insulating material resistant to hydrogen at high temperatures |
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