| 摘要 |
<p>995,231. Casting processes. PRECISION METALSMITHS Inc. May 15, 1964, No. 20354/64. Heading B3F. A process of investment casting comprises the steps of forming a refractory mould which has a pattern cavity, externally coating the mould with a combustible deoxidizing agent, the surfaces of the mould cavity being free of the deoxidizing agent, and firing the mould in a reducing atmosphere ready for the casting operation. When the casting takes place the deoxidizing agent on the mould surface burns and produces a reducing atmosphere which protects the metal in the mould as it solidifies. The deoxidizing agent is graphite.</p> |
