Measurements of Density of Liquid Oxides with an Aero-Acoustic Levitator

Abstract

Densities of liquid oxide melts with melting temperatures above 2000 °C are required to establish mixing models in the liquid state for thermodynamic modeling and advanced additive manufacturing and laser welding of ceramics. Accurate measurements of molten rare earth oxide density were recently reported from experiments with an electrostatic levitator on board the International Space Station. In this work, we present an approach to terrestrial measurements of density and thermal expansion of liquid oxides from high-speed videography using an aero-acoustic levitator with laser heating and machine vision algorithms. The following density values for liquid oxides at melting temperature were obtained: Y2O3 4.6 ± 0.15; Yb2O3 8.4 ± 0.2; Zr0.9Y0.1O1.95 4.7 ± 0.2; Zr0.95Y0.05O1.975 4.9 ± 0.2; HfO2 8.2 ± 0.3 g/cm3. The accuracy of density and thermal expansion measurements can be improved by employing backlight illumination, spectropyrometry and a multi-emitter acoustic levitator.

Densities of Liquid Tm2O3, Yb2O3, and Lu2O3 Measured by an Electrostatic Levitation Furnace Onboard the International Space Station

“…Our density value for Yb 2 O 3 at its melting temperature showed a good agreement with the value reported by Ushakov et al using an AAL [2]. The density data obtained by Granier and Heurtault with an ADL [3] were about 6% lower than our results.…”

“…The sample position is monitored, and the acoustic pressures are adjusted using a feedback control algorithm. The densities of Ln 2 O 3 s obtained by this method are reported by Ushakov et al [2].…”

“…As the additive manufacturing (3D printing) techniques progress with ceramics materials [1], demands for the measurement of the thermophysical properties of oxide melts are increasing [2]. However, due to their high melting temperatures and the risk of contamination from walls, thermophysical property measurements of molten oxides with conventional techniques such as crucibles are difficult.…”

“…Densities of Ln 2 O 3 were measured by direct [2,3] and indirect methods [4]. As for the indirect methods, Courtial and Dingwell measured the density of Na-disilicates, which contained 0 to 6% of Ln 2 O 3 and had melting temperatures below 1300 • C, using the double-bob Archimedean method.…”

Special Issue: Thermal Analysis of Materials

“…Another set of papers deals with the development of new or application-specific approaches, namely laser interferometry techniques for high precision measurements on non-standard samples, such as composite truss structures [ 5 ]; measurements of high temperature compressive creep in spark plasma sintering apparatuses [ 6 ]; measurements of the density of liquid oxides with aero-acoustic levitators [ 7 ]; and the simultaneous estimation of thermal conductivity and heat capacity in metal alloys [ 8 ].The range of materials covered includes polymers [ 9 , 10 ]; natural complex inorganic materials, such as natural sorbents [ 1 ] and industrial-grade thermal insulation [ 4 ]; single phase ceramic materials, such as spinel MgAl 2 O 4 [ 11 ], rare earth sesquioxides [ 12 ], and double perovskite cobaltites [ 13 ]; metals, alloys, and intermetallic compounds [ 8 , 14 , 15 , 16 ].…”