A PROCESS MODEL FOR ACTIVE BRAZING OF CERAMICS .1. GROWTH OF REACTIONLAYERS

In the present investigation process modelling techniques have been ap plied to describe reaction layer growth during active brazing of ceram ics. As a starting point, the classical solution for parabolic growth of transformation products is considered. Specific computational featu res are then explicitly built into the model to allow for transient ef fects during heating and cooling as well as changes in the growth kine tics due to depletion of the active element during brazing. This appro ach gives considerable scope for optimization of both process and join t properties through adjustment of the filler metal composition and th e temperature-time programme under which brazing takes place. The aptn ess of the process model is illustrated in an accompanying paper (Part II).