Processes for producing dispersions of refractory metal oxides in matrix metals

Claim 1

IN A PROCESS FOR PRODUCING A DISPERSION OF A REFRACTORY METAL OXIDE, IN THE FORM OF PARTICLES IN THE 10 TO 1000 MILLIMICRON SIZE RANGE, IN A MATRIX METAL WHICH DISPERSION CAN BE HOT WORKED BY EXTRUSION THROUGH A DIE UNDER EXTREME PRESSURE AT TEMPERATURES APPROCHING THE MELTING POINT OF THE METAL, THE STEPS COMPRISING FUSING (A) AN OXYGEN-CONTAINING COMPOUND OF A MATRIX METAL, SAID METAL HAVING AN OXIDE WITH A FREE ENERGY OF FORMATION AT 27* C. OF UP TO 75 KILOCALORIES PER GRAM ATOM OF OXYGEN IN THE OXIDE, AND (B) AN OXYGEN-CONTAINING COMPOUND OF ANOTHER METAL, SAID METAL HAVING AN OXIDE WITH A FREE ENERGY OF FORMATION AT 1000*C. GREATER THAN 60 KILOCALORIES PER GRAM ATOM OF OXYGEN IN THE OXIDE, HEATING THE FUSED MIXTURE TO A TEMPERATURE AT WHICH NONOXIDE CONSTITUENTS ARE DECOMPOSED RTO OXIDES, QUENCHING THE FUSED MELT TO OBTAIN A SOLID-STATE MASS COMPRISING COMBINED OXIDES OF THE MATRIX METAL AND THE OTHER METAL, FINELY DIVIDING THE MASS, REDUCING THE OXIDE OF THE MATRIX METAL TO THE METAL AT A TEMPERATURE BELOW THE MELTING POINT OF THE METAL, THE REDUCTION BEING CONTINUED UNTIL THE OXYGEN CONTENT OF THE PRODUCT, EXCLUSIVE OF THE OXYGEN ORIGINALLY INTRODUCED IN CHEMICLALLY COMBINED FORM IN THE FILLER, IS IN THE RANGE OF 0TO 2% BY WEIGHT, WHEREBY A DISPERSION, IN THE MATRIX METAL, OF PARTICLES OF A REFRACTORY OXIDE OF THE OTHER METAL IS OBTAINED, AND THEREAFTER SINTERING THE REDUCED PRODUCT, BEFORE EXPOSING IT TO AN OXIDIZING ATMOSPHERE, UNTIL ITS SURFACE AREA IS LESS THAN ONE SQUARE METER PER GRAM.