Method for producing solid or hollow spherical particles of chosen chemical composition and of uniform size

Patent · Fri Jan 01 00:00:00 EST 1988

OSTI ID:866727

Hendricks, Charles D ^[1]

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1. Livermore, CA

A method is provided for producing commercially large quantities of high melting temperature solid or hollow spherical particles of a predetermined chemical composition and having a uniform and controlled size distribution. An end (18, 50, 90) of a solid or hollow rod (20, 48, 88) of the material is rendered molten by a laser beam (14, 44, 82). Because of this, there is no possibility of the molten rod material becoming contaminated with extraneous material. In various aspects of the invention, an electric field is applied to the molten rod end (18, 90), and/or the molten rod end (50, 90) is vibrated. In a further aspect of the invention, a high-frequency component is added to the electric field applied to the molten end of the rod (90). By controlling the internal pressure of the rod, the rate at which the rod is introduced into the laser beam, the environment of the process, the vibration amplitude and frequency of the molten rod end, the electric field intensity applied to the molten rod end, and the frequency and intensity of the component added to the electric field, the uniformity and size distribution of the solid or hollow spherical particles (122) produced by the inventive method is controlled. The polarity of the electric field applied to the molten rod end can be chosen to eliminate backstreaming electrons, which tend to produce run-away heating in the rod, from the process.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4774037
• OSTI ID: 866727
• Country of Publication: United States
• Language: English

Related Subjects

method
producing
solid
hollow
spherical
particles
chosen
chemical
composition
uniform
size
provided
commercially
quantities
melting
temperature
predetermined
controlled
distribution
18
50
90
rod
20
48
88
material
rendered
molten
laser
beam
14
44
82
possibility
becoming
contaminated
extraneous
various
aspects
electric
field
applied
vibrated
aspect
high-frequency
component
added
controlling
internal
pressure
rate
introduced
environment
process
vibration
amplitude
frequency
intensity
uniformity
122
produced
inventive
polarity
eliminate
backstreaming
electrons
tend
produce
run-away
heating
various aspects
chemical composition
spherical particles
melting temperature
size distribution
temperature solid
electric field
laser beam
hollow spherical
field intensity
inventive method
uniform size
field applied
internal pressure
frequency component
producing solid
spherical particle
producing commercial
controlled size
/264/65/75/376/