FORFARANDE OCH ANORDNING FOR FRAMSTELLNING AV HOGRENT METALLPULVER GENOM ELEKTRONSTRALEUPPHETTNING

摘要

High-purity metal powder is made by the electron beam melting of a starting material in rod form in a vacuum wherein the molten metal is momentarily caught on a spinning plate rotating at high speed and flung therefrom and thereafter solidified by cooling. The metal on the spinning plate is bombarded with an electron beam that is so focused and periodically deflected that its focal spot is many times smaller than the diameter of the spinning plate. The beam deflection between the rotational center of the spinning plate and its marginal area is performed such that the spinning plate is scanned in a zone that extends radially of the axis of rotation of the spinning plate and is small in relation to its diameter. Cooling of the metal particles to the point of solidification is accomplished by radiation loss.