| 摘要 |
<p>In order to prevent the embrittlement of the outer surfaces of titanium dental castings caused by alpha case formation, the invention proposes a process and a ceramic mould in which the surfaces of the mould, including those of the casting hopper and casting channels which come into contact with the molten titanium are coated with a gas-permeable ceramic shell inert with respect to the molten titanium which is embedded in a gas-permeable, ceramic or ceramisable supporting compound of such a composition that the ceramic shell embedded n the supporting compound is under compressive stress during it sintering process and the casting operation.</p> |
