Effect of Shock Compression Conditions on the Production of Cubic Si3N4

Abstract

The yield of cubic γ-Si3N4 phase depending on the shock compression pressure and temperature and on the type of starting modification (α or β) is studied. Pressure and temperature depend on the explosive power, shock-wave loading pattern, KCl content of the charge, and charge density. The yield of the γ-phase was determined by quantitative X-ray diffraction using calculated intensities of lines for each phase. The optimum conditions of shock compression to reach the maximum yield of the cubic phase were found (for specific explosives). It is concluded that the cubic phase forms from hexagonal modifications by the diffusion-controlled mechanism and that the α-phase is metastable.