Noncontact density measurements of tantalum and rhenium in the liquid and undercooled states

Abstract

Electrostatic levitation together with multibeam heating and ultraviolet imaging overcame contamination, imaging, and sample position stability problems associated with handling of liquid tantalum and rhenium. Here, the density [ρ(T)] of these metals is reported in the superheated and undercooled states. Over the 2760–3580 K interval, the density of tantalum was measured as ρ(T)=1.50×104−0.41(T−Tm) kg m−3, where the melting temperature Tm, was 3290 K. For rhenium, the density was determined (2700–3810 K) as ρ(T)=1.84×104−0.91(T−Tm), with Tm=3453 K. From these data, respective volume expansion coefficients of 2.7×10−5 and 4.9×10−5 K−1 were calculated. At Tm, the data agree well with the literature values.

Electrostatic Levitation Research and Development at JAXA: Past and Present Activities in Thermophysics

“…1a and 2a) [27]. Three focused beams (50 W each) of CO 2 lasers (10.6 µm emission) in a same plane, separated by 120 degrees, hit the specimen.…”

“…Here is presented a summary of the thermophysical property measurements (density, vapor pressure, surface tension, viscosity) of refractory materials above as well as below their melting points. [27,[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] The density was determined by simultaneously recording the temperature and images of a non-rotating spherical sample illuminated from behind with a UV source. Upon closing the shutters of all lasers, the sample was cooled and the data could be obtained over a large temperature range.…”

Density Measurements of Mould Flux Slags by Electrostatic Levitation Method

“…[2][3][4][5][6][7] To the knowledge of the present authors, very little work has been reported on ESL measurements of oxide materials 8,9) and levitation of multicomponent oxide systems has never been reported yet. In the present study, the measurements of the density a complex slag by the ESL method and similar measurements by the sessile drop method have been carried out and the results are compared.…”

Minimizing convection effects to measure diffusion in liquid droplets during high-temperature electrostatic levitation

“…The levitation mechanism is conceptually simple, despite the experimental complications of an active control system required to maintain a stationary sample position. 1,2 Although limited to noncontact methods, a wide variety of thermophysical properties have been measured in ESL experiments, including heat capacity and hemispherical emissivity, [3][4][5] phase transition temperatures, 4,6,7 density and thermal expansion, 5,8,9 viscosity and surface tension, 5,10 electrical conductivity, 11 and x-ray or neutron scattering structure factors. 12,13 To further expand the electrostatic levitation technique and enable the measurement of transport properties of liquids, the contribution from convective transport must be either negligible or precisely known.…”