This paper reports the physical properties of PFC(Perfluorocarbon. equi-mass mixture of C8H18 and C8F16O here). The PFC is a good candidate for liquid-liquid direct contact heat exchange beccause it is inert chemically and insoluble to water. ln the present study, five thermal properties of PFC(density, kinematic viscosity, interfacial tension with water, specific heat, and thermal conductivity) were measured by using various measuring methods in the temperature range from 273.15K to 323.15K. From the data obtained, the thermal properties for PFC were regressed as a function of temperature. ln addition, thermal diffusivity and Prandtl number of PFC were expressed as a function of temperature.
The linear thermal expansion of Cu-Mo composites is measured in the temperature range of 30 to 850°C with the push-rod dilatometer method. The thermal diffusivity and the specific heat are measured by the laser flash method in the range from 20 to 600°C with stepping up every 50°C, and the thermal conductivity is calculated from the relation of λ=a⋅cp⋅ρ, where ρ is the density of the composites. The composition of the Cu-Mo composites is varied from 10 to 90 mass% in Cu and the residue is Mo. The temperature dependence on these thermal properties and the anisotropy of the the linear thermal expansion are investigated.
lt is a common practice to coat specimen surfaces with black thin films when thermal diffusivities of low emissive solid materials are measured with the laser flash method. Thin films coated on the specimen surfaces increase uncertainty of the measured thermal diffusivity values because of their thermal resistance. The laser flash method was improved by introducing two hemispherical mirrors facing both sides of the specimen surfaces in order to measure low emissive solid materials without coating. Thermal diffusivities of a gold specimen and an electrolytic iron specimen (NIST RM8421) roughened with GC#600 grinding paper were measured by this method with reproducibility better than 0.5% in standard deviation.
The solid solubility of Li in Al under pressure is studied using the microscopic electronic theory. An increase of the solubility exceeding 20 at % Li in Al is predicted under a pressure of 10 GPa. The obtained results for the lattice constant, the heat of solution, the pressure-volume relation, and elastic moduli in the α-Al-Li system are presented theoretically.