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

Sergey V Ushakov,Robert Prieler,Alexandra Navrotsky,Jonas Niessen,Dante G Quirinale,Rainer Telle

doi:10.3390/ma14040822

Sergey V Ushakov, Robert Prieler + Show 4 more

Open Access

https://doi.org/10.3390/ma14040822

Copy DOI

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.

Highlights

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
Refractory oxide ceramics are usually produced by sintering, and applicationdriven incentives to study high temperature oxide melts have been largely limited to metallurgical slugs and glasses
Electromagnetic [14] and electrostatic [15] levitation have been successfully used for contactless high temperature studies on metal alloys for decades [16,17,18,19,20,21,22]

Summary

Introduction

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. 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 situation has changed with the application of additive manufacturing techniques to ceramic materials [2,3,4,5,6,7] These techniques often involve laser melting, and their advance is hampered by a lack of data on oxide melts. The “exploding wire” technique [8,9] has been in development for more than 300 years and has been adapted for electrically conductive carbides and nitrides [10,11,12,13] In this method, pulse discharge through a metallic wire or conducting ceramic coating provides instantaneous heating and excludes any contamination from the container.

Methods

Results

Conclusion