Titanium metallization of Si3N4 ceramics by molten salt reaction: Mechanism and interfacial structure

Abstract

In the present work, a new method of molten salt reaction fortitanium metallization of Si₃N₄ has been developed. It was foundthat the decomposition of the titanium divalent compound led to theformation of a titanium coating. The thickness or weight gain persurface area of the coated sample increased with treating time andtemperature. When the treating temperature was below 1123 K, thedeposition process was controlled by the combination of interfacialreaction and the diffusion of N, Ti or Si in the coating layer, butwhen the temperature was above 1123 K, the process was only controlledby the diffusion of these elements. Field emission SEM observationrevealed the multi-layer structure of TiN and Ti₅Si₃ at theinterface. Based on the thermodynamic calculations and otheranalysis, the possible reactions were determined.