UPGRADING TITANIUM, ZIRCONIUM AND HAFNIUM POWDERS BY PLASMA PROCESSING

摘要

13 A method for upgrading commercially available titanium, zirconium or hafnium powder typically containing chloride contaminant characterized by the step of contacting the metal powder with an inert gaseous plasma (such as the arc heated stream of an arc heater) for a sufficient time to effect physical separation of metal and contaminant salt. By operating the arc heater at temperatures in excess of the boiling point of the contaminant salt (e.g. above 1686.degree.K for NaC1) the purification can be assisted by vaporization of the salt. After quenching and cooling the upgraded metal powder, any residual contaminant salt on the surface of the metal can be removed by water washing. The upgraded metal powder produced is useful in fabricating high density metal alloy parts by the blended elemental powdered metallurgical process.