Process to increase yield of fines in gas atomized metal powder

摘要

A method for producing ultrafine powder from a metal or metal alloy, including such high surface tension metals and alloys as copper, Cu-Al-Fe alloys and Ni-Cr-Fe-B-Si alloys. A stream of molten metal is atomized under aspiration conditions by a cone of impinging gas streams, the apex of the gas cone being 10-21 mm from the melt outlet and 11-24 mm from the gas orifices. The gas velocity is greater than Mach 1, and the mass flow ratio of melt to gas is less than 0.10.