Dispersion strengthening of platinumbase alloys

Claim 1

A METHOD FOR PRODUCING A PRECIOUS METAL POWDER PRODUCT SELECTED FROM THE GROUP CONSISTING OF PT, PD, RH, IR, RU AND RE AND ALLOYS OF AT LEAST TWO OF THESE METALS WITH EACH OTHER FOR USE IN FORMING BY POWDER METALLURGY A HIGH STRENGTH PRECIOUS METAL CHARACTERIZED BY HIGH CREEP RESISTANCE AT ELEVATED TEMPERATURES WHICH COMPRISES, PROVIDING UNDER SUBSTANTIALLY INERT CONDITIONS FINELY DIVIDED POWDER OF SAID PRECIOUS METAL OF AVERAGE SIZE WHICH UNDER NORMAL CONDITIONS WOULD BE PYROPHORIC, PROVIDING A SOLUTION OF A REFRACTORY OXIDE-FORMING SALT IN A NON-RESIDUE LEAVING SOLVENT, SAID SALT BEING ONE CAPABLE OF DECOMPOSING ON HEATING TO A REFRACTORY OXIDE WHOSE NEGATIVE FREE ENERGY OF FORMATION IS AT LEAST ABOUT 100,000 CALORIES PER GRAM ATOM OF OXYGEN AT ABOUT 25* C., SLOWLY ADDING SAID METAL POWDER IN SAID SOLUTION UNDER SUBSTANTIALLY INERT CONDITIONS WHILE RAPIDLY STIRRING THE SOLUTION TO FORM A THICK SLURRY, EVPORATING SAID SOLVENT UNDER SAID SUBSTANTIALLY INERT CONDITIONS UNTIL A SUBSTANTIALLY DRY RESIDUE IS OBTAINED IN WHICH THE SALT IS ASSOCIATED AT LEAST WITH THE SURFACE OF THE POWDER, AND UNIFORMLY SPREADING SAID DRY RESIDUE IN A DECOMPOSITION CHAMBER AND SUBJECTING IT TO HEATING AT AN ELEVATED TEMPERATURE AT LEAST SUFFICIENT TO DECOMPOSE THE CONTAINED SALT TO A REFRACTORY OXIDE DISPERSION, WHEREBY A PRECIOUS METAL POWDER PRODUCT IS OBTAINED HAVING A SUBSTANTIALLY UNIFORM DISPERSION OF REFRACTORY OXIDE THROUGHOUT.

Claim 2

A METHOD FOR PRODUCING A PRECIOUS METAL POWDER PRODUCT SELECTED FROM THE GROUP CONSISTING OF PT, PD, RH, IR, RU AND RE AND ALLOYS OF AT LEAST TWO OF THESE METALS WITH EACH OTHER FOR USE IN FORMING BY POWDER METALLURGY A HIGH STRENGTH PRECIOUS METAL CHARACTERIZED BY HIGH CREEP RESISTANCE AT ELEVATED TEMPERATURES WHICH COMPRISES, PROVIDING UNDER SUBSTANTIALLY INERT CONDITIONS FINELY DIVIDED POWDER OF SAID PRECIOUS METAL OF AVERAGE SIZE WHICH UNDER NORMAL CONDITIONS WOULD BE PYROPHORIC, PROVIDING A SOLUTION OF A REFRACTORY OXIDE-FORMING SALT IN A NON-RESIDUE LEAVING SOLVENT, SAID SALT BEING ONE CAPABLE OF DECOMPOSING ON HEATING TO A REFRACTORY OXIDE WHOSE NEGATIVE FREE ENERGY OF FORMATION IS AT LEAST ABOUT 100,000 CALORIES PER GRAM ATOM OF OXYGEN AT ABOUT 25* C., SLOWLY ADDING SAID METAL POWDER IN SAID SOLUTION UNDER SUBSTANTIALLY INERT CONDITIONS WHILE RAPIDLY STIRRING THE SOLUTION TO FORM A THICK SLURRY, EVPORATING SAID SOLVENT UNDER SAID SUBSTANTIALLY INERT CONDITIONS UNTIL A SUBSTANTIALLY DRY RESIDUE IS OBTAINED IN WHICH THE SALT IS ASSOCIATED AT LEAST WITH THE SURFACE OF THE POWDER, AND UNIFORMLY SPREADING SAID DRY RESIDUE IN A DECOMPOSITION CHAMBER AND SUBJECTING IT TO HEATING AT AN ELEVATED TEMPERATURE AT LEAST SUFFICIENT TO DECOMPOSE THE CONTAINED SALT TO A REFRACTORY OXIDE DISPERSION, WHEREBY A PRECIOUS METAL POWDER PRODUCT IS OBTAINED HAVING A SUBSTANTIALLY UNIFORM DISPERSION OF REFRACTORY OXIDE THROUGHOUT.