Modeling of thermal explosion in constrained dies for B₄C-Ti and BN-Ti powder blends

The process of reactive in-situ synthesis of dense particulate reinforced TiB₂/TiC and TiB₂/TiN ceramic matrix composites from B₄C-Ti and BN-Ti powder blends with and without the addition of Ni has been modeled. The objective of modeling was the determination of optimal thermal conditions preferable for production of fully dense ceramic matrix composites. Towards this goal heat transfer and combustion in dense and porous ceramic blends were investigated during heating at a constant rate. This process was modeled using a heat transfer-combustion model with kinetic parameters determined from the differential thermal analysis of the experimental data. The kinetic burning parameters and the model developed were further used to describe the process of combustion synthesis in a constrained die under pressure. It has been shown that heat removal from the reaction zone affects the ignition temperature of thermal explosion.