Thermal and mechanical properties of Mg–Al–Si–O–N glasses with up to 6.2 at.% nitrogen

Abstract

This study investigates the structural, thermal, and mechanical properties of Mg–Al–Si–O–N glasses. Six compositions with increasing nitrogen content from 1.7 to 6.2 at.% were synthesized by melting mixtures of high-purity oxide and nitride precursors, followed by quenching and annealing. Structural analysis via X-ray diffraction and Raman spectroscopy confirms the amorphous nature of the glasses and highlights distinct spectral features based on the Mg/Al ratios, providing insight into the changes of the Si-O and Al-O bond concentration with the nitrogen content. The effects of nitrogen incorporation on density, molar volume, atomic packing density, glass transition temperature, and thermal expansion were systematically examined, revealing strong correlations. Measurements of elastic moduli, hardness, and fracture toughness underscore the role of nitrogen and the Mg/Al ratio in enhancing the mechanical properties. The findings demonstrate that by increasing the nitrogen content, the glass becomes stiffer and denser, and the mechanical properties are improved.