Method of producing oxide-dispersion-strengthened alloys

Abstract

Abstract A METHOD IS DISCLOSED FOR PRODUCING AN ALLOY HAVING A FINE UNIFORMLY DISPERSED HARD REFRACTORY OXIDE MATERIAL IN A DUCTILE MATRIX METAL. THE ALLOY IS MADE FROM AN ALLOY POWDER, THE INDIVIDUAL PARTICLES OF WHICH EACH CONTAIN THE METAL OF WHICH THE REFRACTORY OXIDE IS FORMED AND THE MATRIX METAL, THE OXIDE-PRODUCING REACTIVE METAL BEING ONE THAT HAS A MUCH GREATER AFFINITY FOR OXYGEN THAN THE MATRIX METAL AND IS SOLUBLE IN THE MATRIX METAL. THE POWDER PARTICLES ARE FORMED PREFERABLY INTO THIN FLAKES, OF THE ORDER OF 5 MICRONS OR LESS THICK, IN A CONTOLLED OXYGEN CONTAINING ENVIRONMENT TO OXIDIZE THE SURFACES OF BOTH THE REACTIVE METAL AND THE MATRIX METAL IN A THIN FILM. THE ALLOY POWDER FLAKES PRODUCED ARE THIN ENOUGH TO ALLOW OXIDATION OF A SUBSTANTIAL PORTION OF THE REACTIVE METAL AND A PORTION OF THE MATRIX METAL TO SOME PREDETERMINED DEGREE. THE OXIDIZED FLAKES ARE THEN PLACED IN A NETUTRAL OR INERT ENVIRONMENT AT AN ELEVATED TEMPERATURE TO REMAIN A SUFFICIENT TIME TO ALLOW THE MATRIX OXIDES TO REACT WITH THE MATRIX AND THEREBY TO SUPPLY OXYGEN TO THE REACTIVE METAL TO OXIDIZED THE REACTIVE METAL WITHIN THE INTERIOR OF THE FLAKES. THE FLAKE POWDERS, NOW FREE OF MATRIX OXIDE OR OXYGEN IN SOLUTION, ARE COMPACTED, HEAT IS APPLIED TO BRING THE TEMPERATURE OF THE COMPACT TO A HOT WORKING TEMPERATURE WHILE MAINTAINING THE INERT ENVIRONMENT, AND THE COMPACT IS EXTRUDED OR OTHERWISE HOT WORKED TO A WROUGHT ALLOY FORM. FAVORABLE RESULTS FOR SOME PURPOSE HAVE BEEN OBTAINED BY REDUCING THE SURFACE MATRIX METAL OXIDES WITHOUT THE INTERNAL OXIDATION STEP, AND THEN FOLLOWING THE FURTHER STEPS MENTIONED TO PROVIDE THE WROUGHT ALLOY.

Inventors

• 👤 Nicholas J Grant
• 👤 William F Schilling

Bibliographic Details