The density of twelve ternary liquid lithium–potassium–lead alloys with Li contents from 5 at.

An experimental study of the volumetric properties of the ternary system Li–K–Pb in the liquid state was carried out. The density (ρ) and volumetric thermal expansion coefficient (β) were measured for alloys of the following stoichiometric compositions: Li3KPb4, LiKPb2, LiK3Pb4, LiKPb, Li4K3Pb4, Li4KPb2, Li16K3Pb7 and Li5KPb3. The experiments employed a contactless method of irradiating samples with a narrow beam of gamma quanta in the range from the liquidus temperatures of the alloys to 1000 K with an uncertainty of ρ and β values of 0.6–0.9 % and 4–7 % respectively. Based on the obtained results, recommended temperature dependences of the studied properties were compiled and the relative excess molar volume was calculated. The latter was found to be negative for all alloys and anomalously large in absolute value, about 20–30 %. According to experimental studies of binary Li–Pb and K–Pb alloys, such significant volumetric compression may indicate the presence of short-range chemical order in the form of ionic complexes in the liquid Li–K–Pb system.

An experimental study of the relative elongation and the thermal expansion of a number of the magnesium–lithium alloys containing 5, 10, 17, 21, 25, and 30 at

A homogeneous eutectic alloy of the magnesium-lithium-calcium ternary system containing 72.5 at.

In the present study, the isobaric heat capacity of ultralight magnesium-lithium alloys with composition of 21, 25 and 30 at. pct Li were measured in the temperature range 185–775 K, most measurements were made for the first time. Measurements were performed by the method of differential scanning calorimetry using a DSC 404 F1 setup. The estimated uncertainty of the obtained results was 2–3 pct. The temperature dependences and the tables of recommended data on their basis were developed for scientific and practical application. For all studied Mg-Li alloys an abrupt change in the heat capacity was observed at the temperatures of about 220–260 K, which is apparently caused by the martensitic phase transformation. It was found that the specific molar heat capacity values of Mg-Li alloys containing 21–30 at. pct Li in the temperature interval of 250–685 K practically coincide with each other and can be estimated within the limits of DSC measurement uncertainties using the heat capacity temperature dependence of solid magnesium. It is possible to estimate the heat capacity of the studied alloys (with an accuracy not exceeding the measurement uncertainty) using the Neumann-Kopp rule, but in a much narrower temperature range of 250–456 K.

Using a laser flash method, the thermal conductivity (lambda) of Pb and eutectic alloy Bi-Pb (55.2 wt% Bi) melts is measured in the temperature range from the melting point to 1300 K with 3.2-6.0 % uncertainty. The results are compared with the data of other authors. Based on the measurements, the thermal diffusivity (a) and the Lorenz number of melts are calculated. Tables of recommended data for a and lambda along with estimated errors are drawn up.

An experimental investigation of the heat capacity of corrosion-resistant refractory nickel base alloy ChS88U-VI used as a material of the turbine blades for marine engines, blades of converted aircraft gas turbine engines and industrial gas turbine was carried out for the first time. The heat capacity of the alloy has been measured by the method of differential scanning calorimetry in the temperature range 300–1270 K of the solid state, including the phase transition region. The estimated error of the data obtained was 2–4

Using the method of differential scanning calorimetry, the heat capacity of Mg-Ca alloys containing 10.50, 33.34, and 73.00 at.

An experimental study of the heat transfer coefficients of Mg–Ca eutectic alloys with a calcium content of 10.5 and 73.0 at λ ) and thermal diffusivity ( a ) are obtained in the temperature range 300– 571… 695 K of the solid state. The estimated errors of the obtained data are 3.0–3.4 λ and a , respectively. Reference tables and recommended temperature dependences of the studied properties are developed, which can be used for various scientific and practical applications.

Experimental studies of the thermal expansion, heat capacity and thermal conductivity of the eutectic magnesium–lithium alloy (with composition of 23.0 at.% lithium) were performed in the temperature range of 80 K to 400 K. The relative elongation and thermal expansion coefficient of this ultralight magnesium–lithium alloy were measured by the dilatometric method using a DIL-402C setup. Measurements of the heat capacity were carried out by the differential scanning calorimetry using a DSC 404 F1 setup. Investigation of the thermal conductivity was performed by the hot-disk technique using a Hot-Disk TPS 2500S setup. The temperature dependences were constructed and tables of recommended values of the investigated properties were presented. It was found that in Mg77Li23 alloy a phase transition occurs in the range of 223 K to 253 K, where the heat capacity and the linear thermal expansion coefficient change abruptly. This transition is presumably related to the martensitic transformation of the lithium-rich bcc magnesium–lithium alloys to the hcp structure.

The enthalpy and heat capacity of solid and liquid Mg2Ca intermetallic alloy were measured by massive high-temperature isothermal drop calorimeter over the temperature range of 298.15–1177 K. The estimated errors in the data on enthalpy and heat capacity were 0.2

The presented research investigated the thermal diffusivity (a) and the thermal conductivity (λ) of one of the most promising heat-resistant nickel alloys, Inconel 617. The measurements were carried out in the temperature range from 300 to 1475 K using the laser flash method on the LFA-427 setup. The estimated errors of the obtained data depending on temperature were 2–4

Thermophysical properties of solid and liquid calcium (99.75 wt % pure) were experimentally studied with high accuracy in the temperature range 720–1290 K using dilatometer measurements, gamma-ray attenuation measurements (the gamma-ray method), high-temperature drop calorimetry, and the laser flash method. The behaviors of the density, enthalpy, and thermal conductivity of calcium in the fusion–crystallization region were studied. The enthalpy of fusion was measured as 8075 J/mol, the relative density change upon fusion as 3.3%, and the relative change in thermal conductivity upon fusion as 26%. The results were compared to the respective values in the related literature. The measurements at temperatures above 720 K either significantly amend the available literature data, or are currently unique. The constancy of the heat capacity of liquid calcium in the temperature range 1115–1290 K was verified. Fitting equations were derived, and recommended values of the investigated properties of calcium were tabulated for 720–1290 K, the temperature range where calcium is in the condensed state.

Thermal conductivity of liquid alloys of the caesium-lead system with a Pb content of 40, 50, 60, and 66.7 at. % is measured by the laser flash method in the temperature range from the liquidus line to 1173 K with an error of 4-6%. It is found that the thermal conductivity of the investigated alloys, obtained by mixing liquid metals Cs and Pb, drops by an order of magnitude to values: 0.5-4.0 W/(m K), characteristic of molten salts. It is shown that the thermal conductivity concentration dependence of the Cs-Pb system liquid alloys has a broad minimum near the equiatomic composition. An analysis of the obtained experimental data indicates the formation of a chemical short-range order in the liquid Cs-Pb system in the vicinity of the equiatomic composition, which indirectly confirms the existing ideas about the presence of Zintl complexes Cs4Pb4 in these melts.

The laser flash method was used to measure the thermal diffusivity ( a ) of carbonyl iron in the temperature range of 300–1700 K with a detailed study of the critical region of 980–1170 K. The initial experimental data in the field of the magnetic phase transformation are processed by the scaling power law. The values of the critical indexes (γ′, γ) for the thermal diffusivity are obtained below and above the Curie temperature T С = 1048 ± 5 K; these values are γ 1pt ' = 0.51 and γ = 0.35, which significantly exceed in magnitude the value of the characteristic critical index for the heat capacity (γ ≈ –0.1). The thermal conductivity (λ) is calculated from the measured data on the thermal diffusivity. The results are compared with the known literature data, and special attention is paid to the behavior of the curves a ( T ) and λ( T ) in the region of the magnetic phase transformation. A table of the recommended temperature dependences for a and λ along with estimated errors has been developed.

Experimental studies of the volumetric properties of the Mg2Ca intermetallic compound and eutectic magnesium–calcium alloys (with compositions of 10.5 and 73 at.% calcium) in the temperature range of 100 K to 1230 K of the solid and liquid states were carried out using the gamma-ray attenuation technique and the dilatometric method. Measurements of the density and volumetric thermal expansion coefficient of Mg–Ca melts, as well as the density change during melting-crystallization, were performed for the first time. The concentration dependences of the volumetric properties of the Mg–Ca system and approaches for calculating density and thermal expansion coefficients of promising magnesium–calcium alloys are proposed.

The thermal conductivity of liquid alloys of the cesium–bismuth system with 20–66 at

Thermophysical properties of solid and liquid calcium (99.75 wt

Экспериментально исследована теплопроводность жидких сплавов системы цезий–висмут с содержанием Bi 20–66 ат. % в интервале температур от линии ликвидуса до 1173 К с погрешностью 4–6%. Обнаружено, что величина теплопроводности жидких висмутидов цезия для указанных составов и температур принимает низкие, типичные для жидких солей, значения от 0.7 до 4.5 Вт/(м К). По результатам измерения теплопроводности рассчитаны температуропроводность и число Лоренцо. Анализ температурных и концентрационных зависимостей изученных свойств косвенно подтверждает существующие в литературе взгляды о наличии в расплавах висмутидов щелочных металлов упорядоченных структур, называемых ионными комплексами, оказывающими существенное влияние на теплофизические свойства расплавов и разрушающимися с ростом температуры.