LOW FLOW RATE NOZZLE AND SPRAY FORMING PROCESS

摘要

RD-19,940 An improved nozzle which allows molten metals to be sprayed at low metal flow rates. This is useful for the Plasma Arc Melting process which used a hearth to prevent ceramic inclusions in the end product. The new nozzle design avoids metal freeze-off at the nozzle tip because a bore insert is positioned into a standard nozzle. The bore insert is a conduction heater, e.g., it is fabricated from boron nitride or the like. In use, molten metal is in contact with the insert so it maintains the insert at about the temperature of the molten metal; this then maintains the nozzle tip at a higher temperature than that of a standard nozzle. Freeze-off in the nozzle is non-occurring as long a molten metal is in the crucible.