Process for forming 312 phase materials and process for sintering the same

Abstract

A process is provided for forming a material comprising an M X Z phase comprising the steps of: (a) providing a mixture of (i) at least one transition metal species, (ii) at least one co-metal species selected from the group consisting of aluminum species, germanium species and silicon species, and (iii) at least one non-metal species selected from the group consisting of boron species, carbon species and nitrogen species; (b) heating said mixture to a temperature of about 1000° C. to about 1800° C., in an atmosphere within a substantially enclosed heating zone, for a time sufficient to form said M X Z phase; wherein the atmosphere has an O partial pressure of no greater than about 1×10 atm. The process provides a substantially single phase material comprising very little MZ -phase. A process for preparing a dense, substantially single-phase M X Z phase workpiece includes providing a highly-pure M X Z -phase powder pre-form and sintering said pre-form at a temperature of about 1000° C. to about 1800° C., in an atmosphere within a substantially enclosed heating zone, for a time sufficient to form a dense, substantially single-phase, M X Z -phase workpiece; wherein the atmosphere has an O partial pressure of no greater than about 1×10 atm.