Grain boundary analysis of silicon nitrides by 400kV analytical electron microscope

The microstructure and the chemical composition of the grain boundary phase of silicon nitrides containing 9 wt % Y.O3 additive are studied by a 400 kV high resolution analytical electron microscope, fitted with an energy dispersive X-ray spectrometer (EDS) and an electron energy loss spectrometer (EELS). The chemical composition of the matrix grain and the grain boundary phase are determined from the quantitative analysis of the EDS spectra. It is shown that the bending stress and the Weibull modulus at high temperature are explained in terms of the difference of the chemical composi-tion of the grain boundary. Key words = silicon nitride: grain boundary analysis: energy dispersive spectroscopy (EDS): electron energy loss spectroscopy (EELS): 400 kV analytical electron microscop