A kinetic model for reaction bonding process of silicon powder compact

In order to obtain detailed information about the kinetics and the reaction nature of a complex reaction process like reaction bonding of silicon 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 nitride without taking into account the multiple reaction mechanisms. In the present study, a comprehensive kinetic model, which is based on analysis of the multiple mechanisms in a silicon powder compact reacting with nitrogen gas and forming silicon nitride, is constructed for a solid-gas reaction bonding process with specific application to the reaction-bonding of silicon nitride. The model will incorporate the rate equation for each mechanism into a constitutive equation from which more complete information of process kinetics can be predicted. The results predicted by the present model have been compared with previous experimental results and satisfactory agreement obtained. (C) 1997 Elsevier Science Limited.