Abstract: A method of combustion synthesis is provided wherein a relatively low field or voltage is applied to a precursor material prior to ignition. The field is at a voltage level effective to energize the material such that a combustion wave is propagated in a controlled manner through the material and without substantial Joule heating prior to ignition of the material, but below voltage levels necessary to initiate combustion. The precursor material, typically comprising a mixture of components which contain stoichiometric amounts of the elements in the desired final product in powder form, is compressed to form a compact having a desired relative density. This compact is subjected to an electric field or voltage at a suitable energy level to achieve the desired energizing of the material. The thus-treated compact is then ignited at a suitable location by, e.g., radiative energy applied from an ignition means.

Abstract: Transition metal carbonitrides (in particular, titanium carbonitride, TiC.sub.0.5 N.sub.0.5) are synthesized by a self-propagating reaction between the metal (e.g., titanium) and carbon in a nitrogen atmosphere. Complete conversion to the carbonitride phase is achieved with the addition of TiN as diluent and with a nitrogen pressure .gtoreq.0.6 MPa. Thermodynamic phase-stability calculations and experimental characterizations of quenched samples provided revealed that the mechanism of formation of the carbonitride is a two-step process. The first step involves the formation of the nonstoichiometric carbide, TiC.sub.0.5, and is followed by the formation of the product by the incorporation of nitrogen in the defect-structure carbide.