Dispersion hardened metal sheet and process

Claim 1

IN A PROCESS FOR PRODUCING A SHEET OF FACE-CENTEREDCUBIC METAL, HAVING A MELTING TEMPERATURE OF FROM 1000 TO 1540*C., SAID SHEET HAVING A PARTICULATE REFRACTORY OXIDE DISPERSED THEREIN AND HAVING HIGH STRENGTH AT ELEVATED TEMPERATURES, THE STEPS COMPRISING (1) CONSOLIDATING TO A SOLID BODY HAVING A DENSITY ABOVE ABOUT 30% OF THEORETICAL DENSITY A POWDER OF SAID METAL IN WHICH THERE IS SUBSTANTIALLY UNIFORMLY DISPERSED ABOUT FROM 0.01 TO 5.0% BY VOLUME OF REFRACTORY METAL OXID PARTICLES HAVING AN AVERAGE SIZE OF FROM 5 TO 250 MILLIMICRONS, SAID OXIDE HAVING A FREE ENERGY OF FORMATION AT 1000*C. ABOVE 60 KILOCALORIES PER GRAM ATOM OF OXYGEN AND A MELTING POINT ABOVE 1000*C., (2) EXTRUDING SAID SOLID BODY AT FROM 1200 TO 2400*F. TO A FORMED BODY HAVING A LENGTH SUBSTANTIALLY GREATER THAN ITS WIDTH OR THICKNESS, (3) ROLLING SAID FORMED BODY, AT A TEMPERATURE NOT SUBSTANTIALLY HIGHER THAN ABOUT 50% OF ITS ABSOLUTE MELTING POINT TO EFFECT A REDUCTION OF AT LEAST 30% IN ITS THICKNESS AND FORM A SHEET, (4) HEAT-TREATING SAID SHEET AT ABOVE ITS RECRYSTALLIZATION TEMPERATURE BUT BELOW ITS MELTING POINT FOR A TIME SUFFICIENT TO EFFECT RECRYSTALLIZATION OF THE METAL THEREIN IN A PREFERRED (321)<121> CRYSTALLOGRAPHIC ORIENTATION, SAID ORIENTATION BEING SO PERFECT AS TO HAVE AN ANGULAR DEVIATION OF NO MORE THAN ABOUT 30* FROM EACH POLE OF THE IDEALIZED ORIENTATION AS MEASURED ON A STEREOGRAPHIC PROJECTION AT ONE HALF THE MAXINUM INTENSITY VALUE, AND (5) ROLLING SAID RECRYSTALLIZED SHEET AT A TEMPERATURE BEOW ITS RECRYSTALLIZATION TEMPERATURE IN A DIRECTION PERPENDICULAR TO THE DIRECTION OF THE INITIAL ROLLING OF SAID FORMED BODY, TO FFECT A FURTHER REDUCTION OF ITS THICKNESS.