Aluminum oxynitride at pressures up to 180 GPa

Abstract

Hugoniot equation-of-state data of shock compressed aluminum oxynitride (AlON), consisting of 64.1 mol% Al2O3⋅35.9 mol% AlN with a density of ∼3.68 g/cm3, have been determined to 180 GPa. The relationship between shock velocity (Us) and particle velocity (Up) is expressed by a straight line: Us(km/s)=8.08+0.761Up(km/s). Although there is no evidence of phase transition in the data, the determined Hugoniot of AlON has been compared with those of oxide spinels such as MgAl2O4 and Fe3O4. We discuss the systematics of high pressure phase transitions of spinels that indicate a phase transition to CaTi2O4-type phases. The phase transition to CaTi2O4-type structures implies that the recently discovered Si3N4 spinel also may be transformed into a CaTi2O4-type phase with increasing pressure.

Recent Advances in New Hard High‐Pressure Nitrides

“…[ [74] However, it has not yet been possible to recover the post-spinel phase. There are also several reports regarding the shock-wave synthesis of ternary (BN)C x with a diamondlike structure.…”

Elastic constants of oxynitride aluminum spinel phases

“…Again we remove another Al atom from Al 23 N 5 O 27 (see Fig. 1 27 . This is as a result of the two defect sites (Al(1) and Al (2)) in the unit cell.…”

Nanoindentation characterization of deformation and failure of aluminum oxynitride

“…Since a pressure-induced solid-state phase transformation of AlON from a spinel-type structure to a CaTi 2 O 4 -type structure has been reported [8], the pop-in behavior in the load-depth profile of nanoindentation experiments may result from the first-order phase transitions that can cause significant volume changes [27]. To characterize the possible phase transition induced by nanoindentation, Raman microscopy was employed to characterize the microstructure of the indented regions.…”

“…There is considerable interest in the use of AlON as a transparent armor ceramic against high impact pressures [4]. Shock loading and Kolsky-bar experiments suggest that the mechanical response of AlON under dynamic loading and high pressures involves detectable inelastic deformation that may result from dislocation plasticity, twinning or pressured-induced solid-state phase transitions [5][6][7][8]. Nevertheless, the underlying micro-mechanisms responsible for the nonlinear phenomenon have not been fully understood to date.…”