METAL CASTING

摘要

A method of casting metal in a mould, the mould comprising a mould cavity and a gas expansion chamber in communication with the mould cavity, the gas expansion chamber containing an exothermic composition comprising a metal and an oxidising agent, the method comprising filling the mould cavity with hot molten metal such that a portion of the molten metal overflows into the gas expansion chamber, the heat emitted by the hot molten metal in the gas expansion chamber causing the metal and the oxidising agent of the exothermic composition to react exothermically and thereby to generate gas and/or to cause gas already present in the gas expansion chamber to expand, thereby increasing the gas pressure above the molten metal.