Clarke D Davis

US Patent:

50630210, Nov 5, 1991

Filed:

May 23, 1990

Appl. No.:

7/527456

Inventors:

Vidhu Anand - Sayre PA
Sanjay Sampath - Sayre PA
Clarke D. Davis - Wyalusing PA
David L. Houck - Towanda PA

Assignee:

GTE Products Corporation - Stamford CT

International Classification:

G22F 100

US Classification:

419 12

Abstract:

A method is disclosed for preparing an intimate mixture of powders of nickel-boron-silicon alloy and molybdenum metal powder suitable for thermal spray coatings which comprises milling a starting mixture of the alloy and molybdenum powder to produce a milled mixture wherein the average particle size is less than about 10 micrometers in diameter, forming an aqueous slurry of the resulting milled mixture and a binder which can be an ammoniacal molybdate compound or polyvinyl alcohol, and agglomerating the milled mixture and binder. The intimate mixture and binder are preferably sintered in a reducing atmosphere at a temperature of about 800. degree. C. to about 950. degree. C. for a sufficient time to form a sintered partially alloyed mixture wherein the bulk density is greater than about 1. 2 g/cc. The resulting sintered mixture is preferably entrained in an inert carrier gas, passed into a plasma flame wherein the plasma gas can be argon or a mixture of argon and hydrogen, and maintained in the plasma flame for a sufficient time to melt essentially all of the powder particles of the sintered mixture to form spherical particles of the melted portion, and to further alloy the sintered mixture, and cooled.