Rheological properties of Y-Si-Al-O-N glasses — elastic moduli, viscosity and creep

Abstract

Three oxynitride glasses from the Y-Si-AI-O-N system and differing in their N/O ratio were studied in the 800-1000 ~ temperature range. Their viscosities were measured using a threepoint bending test through the glass transition domain. For a given temperature, 4.8 wt% N 2 enhances the viscosity by three orders of magnitude in comparison with the corresponding oxide glass. Nitrogen also improves creep resistance. The activation enthalpy for creep, above Tg, is of the same order as those measured for silicon nitride ceramic (--~900 kJ mol -~). The elastic moduli were determined by ultrasonic techniques, from room temperature up to 1200 ~ which allowed calculation of the free activation enthalpy for viscous flow. Owing to the sharp decrease of shear modulus in the glass transition domain, the free activation enthalpy (~500 kJ mo1-1 ) greatly differs from the activation enthalpy usually measured in creep studies.

Mechanical Spectroscopy of a YSiAlON Glass

“…b = 530 KJlmol) is similar to the activation energy determined by Rouxel from creep test on ~~i A l 0 f f glasses, 400-600 KJ/mol [16].…”

Indentation-induced stress distribution and pressure effect on the resistivity of YSZ

“…The value of V for 10 mol% Y2O3-doped zirconia (YSZ) was estimated to be around 3.9 cm 3 /mol [21]. V increases with increasing temperature, and a similar behavior was reported for typical electrolytes [11,12,27], as well as for creep viscosity measurements in glasses and polymers [28,29].…”

Boson Peak, Elastic Properties, and Rigidification Induced by the Substitution of Nitrogen for Oxygen in Oxynitride Glasses

“…We have chosen three grades of oxynitride glass for which the extensive physical property data are available 3,7,8 . Their compositions are listed in Table I along with their molar mass and number atoms per formula units.…”