Thermal conductivity measurement of molten copper using an electromagnetic levitator superimposed with a static magnetic field

Abstract

The thermal conductivity of molten copper was measured by the periodic laser-heating method, in which a static magnetic field was superimposed to suppress convection in an electromagnetically levitated droplet, to extend the measurement range of the method up to a relatively high thermal conductivity. Before measuring the thermal conductivity, the optimum conditions for static magnetic field, the laser frequency of periodic heating and sample diameter were investigated by numerical simulation both for the flow and thermal fields in an electromagnetically levitated droplet and for the periodic laser heating of the droplet in the presence of melt convection. As a result, the temperature dependence of the thermal conductivity of molten copper was proposed in the temperature range between 1383 and 1665 K. In addition, by comparing our results with those of previous studies, it was demonstrated that the present method of measuring thermal conductivity is also available for molten materials with a relatively high thermal conductivity, such as molten copper.

Dynamics of double-pulse laser printing of copper microstructures

“…At fixed QCW power, when the second femtosecond pulse irradiates the heated donor film with different delays Δt, the donor film exhibits different temperatures below or above melting. For copper, as shown in Table 1, some of the physical properties of the film are significantly temperature-dependent [22][23][24][25]. One can expect different behaviors depending on the hydrody In column 1, we present the ejection images corresponding to each condition.…”

Reference Correlations for the Thermal Conductivity of Liquid Bismuth, Cobalt, Germanium, and Silicon

“…Employing values for the heat capacity 14 and the density, 5 the thermal conductivity can easily be obtained. Previous measurements by the group of Fukuyama of the thermal conductivity of liquid copper, 42 nickel, 43 and iron, 44 and by Nishi of the thermal conductivity of liquid nickel, 28 have already been employed in our recent reference correlation for the thermal conductivity of these metals. 7 Thus these two sets formed the primary data sets.…”

Normal spectral emissivity measurement of molten copper using an electromagnetic levitator superimposed with a static magnetic field

“…To solve the above problems related to both container and melt convection, Kobatake et al [1][2][3] and Fukuyama et al [4] have developed a novel method of measuring the thermophysical properties of molten materials by the containerless electromagnetic levitation (EML) technique together with the use of a static magnetic field to suppress melt convection in materials. Using this technique, they have measured the specific heat or thermal conductivity of molten silicon [3], molten stainless steel [4], molten nickel [5], molten iron [6,7] and molten copper [8]. In addition, Tsukada et al [9], Sugioka et al [10] and Baba et al [11] have carried out numerical simulations of melt convection in an electromagnetically levitated droplet of silicon, iron and nickel in a static magnetic field, and demonstrated that the EML technique together with the application of a static magnetic field is effective for precisely measuring the thermal conductivity of molten materials, by comparing the numerical results with experimental ones.…”