发明名称 |
VERFAHREN ZUR HERSTELLUNG VON FORMKOERPERN AUS REAKTIONSGEBUNDENEM SILICIUMNITRID DURCH NITRIDIERUNG UNTER HOHEM STICKSTOFFGASDRUCK. |
摘要 |
The invention is a process for the manufacture of shaped articles of reaction-bonded silicon nitride in which pre-shaped articles of silicon powder are heated in a first stage under a nitrogen gas pressure of at least 6 MPa at a heating rate of not more than 50 DEG C. per hour to a reaction temperature below the melting point of silicon, the article is maintained at the reaction temperature for at least 0.5 hours and subsequently, in a second stage, heating the article at a heating rate of at least 500 DEG C. per hour to a temperature above the melting point of silicon and maintaining the article at that temperature for from 1 to 7 hours. The process can nitridate both pre-shaped articles consisting of silicon powder and, optionally, up to 15% by weight Si3N4 powder and those containing up to 10% by weight of a sintering aid such as Y2O3. In the former case, porous shaped articles having a density of from 87 to 91% TD and, in the latter case, dense shaped articles having a density of more than 98% TD, are obtained. In all cases, in a total nitridation time of less than 15 hours, a conversion of at least 95% of the silicon originally present into silicon nitride is achieved, which, in the finished shaped article, is substantially in the beta -modification. |
申请公布号 |
AT67751(T) |
申请公布日期 |
1991.10.15 |
申请号 |
AT19860105361T |
申请日期 |
1986.04.17 |
申请人 |
ELEKTROSCHMELZWERK KEMPTEN GMBH |
发明人 |
HUNOLD, KLAUS, DR. DIPL.-ING.;LIPP, ALFRED, DR. DIPL.-CHEM.;REINMUTH, KLAUS, DR. DIPL.-CHEM.;ARNOLD, PETER;NAPHOLCZ, JOHANNES |
分类号 |
C04B35/58;C04B35/584;C04B35/591;C04B35/593;(IPC1-7):C04B35/58 |
主分类号 |
C04B35/58 |
代理机构 |
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