Transparent oxynitride glasses: Synthesis, microstructure, optical transmittance and ballistic resistance

Oxynitride glasses with five different compositions were prepared by melting batches at 1600 °C for 2 h under N2 atmosphere in a Si–Mo-heated resistance furnace. The amorphous nature of these samples was verified by an X-ray diffractometer with Cu/Kα radiation. UV/visible wavelength region light transmission spectra of samples showed that the transmittance of the obtained glasses (1 mm, 2 mm and 3 mm thickness) can reach up to 80% in the visible region (above 400 nm). The Vickers indentations were analyzed by the scanning electron microscopy (SEM). The ballistic resistance represented by Drel value was assessed by physical and mechanical properties including density, hardness, elastic modulus and fracture toughness. It was found that the Drel value of oxynitride glasses can reach up to 2.56 and is higher than that of sapphire, which is 2.4.