The influence of mechanochemical activation on combustion synthesis of Si3N4

This study addresses itself in the performance of Si3N4 combustion synthesis, occurred in the presence of Si3N4 and NH4Cl powders in N2 atmosphere of 6 MPa. Mechanochemical activation of Si powder, achieved via high-energy attrition milling up to 24 h, increases the intensity and the efficiency of the reactions between Si and N2 as well as combustion temperature. Benign processing conditions, anticipated with lower mechanochemical activation of Si powder, low N2 pressures, and low combustion temperatures, favor formation of α-Si3N4.