发明名称 |
Process for the preparation of powder for optically transparent ceramic made of gamma-aluminium oxynitride and the powder obtained therefrom. |
摘要 |
The process consists in reacting aluminium nitride with alpha -alumina and with an alumina with a high specific surface or a precursor which generates an alumina with a high specific surface. More precisely, the process consists in mixing the aluminium nitride, the alpha -alumina and the alumina with a high specific surface or the precursor of such an alumina, in drying the said mixture, in heating the said mixture at a temperature sufficient to obtain a gamma -aluminium oxynitride powder and then in grinding the powder thus obtained. The agglomerated gamma -aluminium oxynitride powder is characterised in that the porosity of the agglomerate is greater than 75%. The ground gamma -aluminium oxynitride powder is characterised in that 100% of the particles have a size of less than 10 mu m and in that it has a transmittance of at least 8% measured at 2500 cm<-1> on a KBr disc with a thickness of 0.9 mm containing 3.33% of gamma -aluminium oxynitride. |
申请公布号 |
EP0619269(A2) |
申请公布日期 |
1994.10.12 |
申请号 |
EP19940400569 |
申请日期 |
1994.03.16 |
申请人 |
ELF ATOCHEM S.A. |
发明人 |
BACHELARD, ROLAND;DISSON, JEAN-PIERRE;MORLHON, BRUNO |
分类号 |
C01B21/072;C01B21/082;C01F7/00;C04B35/58 |
主分类号 |
C01B21/072 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|