| 摘要 |
The preformed body is provided with a casing (13) of glass which is made gas-impenetrable by heating before carrying out the isostatic pressing. Inside the glass casing there is arranged on the preformed body an intermediate layer (12) which counteracts the penetration of molten glass from the casing into the preformed body. The intermediate layer comprises a layer of one or more intermediate phases in the system Al2O3 - SiO2, for example mullite 3 Al2O3.2 SiO2, or a layer containing one or more such intermediate phases as main constituent. In a preferred embodiment a layer of boron nitride is arranged inside the intermediate layer. The powdered material from which object is manufactured consists preferably of aluminium oxide or an aluminium oxide-based ceramic. |
