Patent Number: 7,753,989

Title: Direct passivation of metal powder

Abstract: A method of producing passivated Ti or Ti alloy particles with oxygen concentrations of less than about 900 parts per million (ppm), which includes introducing a halide vapor of Ti or the metal constituents of the alloy at sonic velocity or greater into a stream of liquid alkali or liquid alkaline earth metal or mixtures thereof forming a reaction zone in which the halide is reduced by the liquid metal present in sufficient excess of stoichiometric such that Ti or Ti alloy powder from the reduction of the halide by the liquid metal is friable. After filtration and distillation excess liquid metal is removed from the Ti or Ti alloy powder that is then maintained at elevated temperature for a time sufficient to grow the particles to average diameters calculated from BET surface area measurement greater than about one micron. After cooling the Ti or Ti alloy powder to temperature of about C. or less, the cooled Ti or Ti alloy powder is contacted with air and/or water to passivate the particles to produce friable metal powder and to remove other reaction products. A system for accomplishing the method is also shown.

Inventors: Ernst; William (Frankfort, IL), Jacobsen; Lance (Minooka, IL)

Assignee: Cristal US, Inc.

International Classification: B22F 9/28 (20060101)

Expiration Date: 2022-07-13 0:00:00