Spherical precious metal based powder particles and process for producing same
AssigneeGTE Products Corporation
InventorsPreston B. Kemp, Jr., Walter A. Johnson
Life of this patent
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Abstract
A powdered material and a process for producing the material are disclosed. The powdered material consists essentially of precious metal based spherical particles which are essentially free of elliptical shaped material and elongated particles having rounded ends. The material has a particle size of less than about 20 micrometers. The process for making the spherical particles involves mechanically reducing the size of a starting material to produce a finer powder which is then entrained in a carrier gas and passed through a high temperature zone above the melting point of the finer powder to melt at least about 50% by weight of the powder and form spherical particles of the melted portion. The powder is directly solidified.
Claims28
A process comprising:
- (a) mechanically reducing the size of a precious metal based material to produce a finer powder, the major portion of which has a particle size of less than about 20 micrometers;
- (b) entraining said finer powder in a carrier gas and passing said powder through a high temperature zone at a temperature above the melting point of said finer powder, said temperature being from about 5500.degree. C. to about 17,000.degree. C., said temperature being created by a plasma jet, to melt at least about 50% by weight of said finer powder to form essentially fine spherical particles of said melted portion;
- (c) rapidly and directly solidifying the resulting high temperature treated material while in flight to form fine spherical particles having a particle size of less than about 20 micrometers in diameter, said particles being essentially free of elliptical shaped material and essentially free of elongated particles having rounded ends.
A powdered material consisting essentially of spherical particles of a precious metal based material, said powdered material being essentially free of elliptical shaped material and essentially free of elongated particles having rounded ends, said powdered material having a particle size of less than about 20 micrometers.
A powdered material consisting essentially of spherical particles of a precious metal based material, said powdered material being directly solidified from high temperature treated material, said powdered material having a particle size of less than about 20 micrometers.
Dependencies are inferred from the claim text.