A KINETIC-MODEL FOR REACTION BONDING PROCESS OF SILICON POWDER COMPACT

In order to obtain detailed information about the kinetics and the rea ction nature of a complex reaction process like reaction bonding of si licon nitride mathematical modelling of the process is necessary. The previous quantitative models for this process have been based only on the mechanism that the nitrogen diffuses through the solid silicon nit ride without taking into account the multiple reaction mechanisms. In the present study, a comprehensive kinetic model, which is based on an alysis of the multiple mechanisms in a silicon powder compact reacting with nitrogen gas and forming silicon nitride, is constructed for a s olid-gas reaction bonding process with specific application to the rea ction-bonding of silicon nitride. The model will incorporate the rate equation for each mechanism into a constitutive equation from which mo re complete information of process kinetics can be predicted. The resu lts predicted by the present model have been compared with previous ex perimental results and satisfactory agreement obtained. (C) 1997 Elsev ier Science Limited.