| 摘要 |
The present invention involves a method and apparatus for making an intermetallic casting (e.g. a titanium, nickel, iron, etc. aluminide casting) wherein a charge of a solid first metal protected from air as required is disposed in a vessel, and a charge of a second metal that reacts exothermically with the first metal is melted in another vessel. The molten second metal is introduced to the vessel containing the charge of the first metal so as to contact the first metal. The first and second metals are heated in the vessel to exothermically react them and form a melt for gravity or countergravity casting into a mold. The exothermic reaction between the first and second metals releases substantial heat that reduces the time needed to obtain a melt ready for casting into a mold. In particular, the exothermic reaction between the first and second metals, in effect, reduces the residence time of the intermetallic melt in the vessel. This reduced residence time, in turn, reduces potential contamination of the melt by reaction with the vessel material. Moreover, the energy requirements needed to heat and melt the metals in the vessel are considerably reduced. Low cost forms of the first and second metals can be used in practicing the invention. As a result, overall casting costs are reduced. The method and apparatus of the invention can be used to produce large numbers of low cost, low contamination intermetallic castings as needed by the automobile, aerospace, and other industries.
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