Reactive phase formation in the diffusion zone between Si3N4 and Ni-Cr alloys

The interaction between dense Si3N4 and Ni-Cr-alloys at 1398K was investigated. Reactive phase formation can be explained by assuming a N2-pressure at the interface. To understand the thermodn. and diffusion kinetics in this system direct nitriding of Ni,Cr(Si)-alloys from the N2-gas atm. was performed and a thermodn. description of the nitrogen behavior was attempted by using the Thermo-calc databank system. The \"up hill\" diffusion of nitrogen towards the front of nitride ppts. can be predicted. [on SciFinder (R)