A new noncontact calorimetric method has been developed based on inductive heating of a metallic spherical bulk sample by a power-modulated radio-frequency field under ultrahigh vacuum conditions. From the pyrometrically measured temperature response the specimen’s external (due to radiative heat loss) and internal relaxation time (due to thermal conductivity) are found to differ by more than two orders of magnitude allowing the specific heat as well as thermal conductivity of the sample to be determined as a function of temperature. The agreement between the measured and predicted temperature response for solid Nb demonstrates the applicability and accuracy of the method which is particularly useful for metastable or chemically reactive samples at high temperature.

The surface tension and viscosity of the Ni-based superalloys LEK94 and CMSX-10 were measured by the oscillating drop method in a containerless electromagnetic processing device on board a parabolic flight airplane. Surface oscillations were recorded by 150 and 200 Hz frame rate digital cameras positioned in two perpendicular directions and by the inductive coupling between the oscillating sample surface and the oscillating circuit of the radio frequency heating and positioning generator. The surface tension as a function of temperature of LEK94 and CMSX-10 was obtained asσ(T) = 1.73 − 4.51 × 10⁻⁴[T—1656 K (1383 °C)] Nm⁻¹andσ(T) = 1.71 − 5.80 × 10⁻⁴[(T—1683 K (1410 °C)] Nm⁻¹, respectively. The viscosity at the liquidus temperatures as 9.8 and 7.8 mPa.s, respectively. In addition, some basic thermophysical properties such as solidus and liquidus temperatures, densities at room temperature, and thermal expansion in the solid phase are reported.

The effect of severe plastic deformation by high-pressure torsion (HPT) on the structure and plastic tensile properties of two Zr-based bulk metallic glasses, Zr_55.7Ni₁₀Al₇Cu₁₉Co_8.3 and Zr₆₄Ni₁₀Al₇Cu₁₉, was investigated. The compositions were chosen because, in TEM investigation, Zr_55.7Ni₁₀Al₇Cu₁₉Co_8.3 exhibited nanoscale inhomogeneity, while Zr₆₄Ni₁₀Al₇Cu₁₉ appeared homogeneous on that length scale. The nanoscale inhomogeneity was expected to result in an increased plastic strain limit, as compared to the homogeneous material, which may be further increased by severe mechanical work. The as-cast materials exhibited 0.1% tensile plasticity for Zr₆₄Ni₁₀Al₇Cu₁₉ and Zr_55.7Ni₁₀Al₇Cu₁₉Co_8.3. Following two rotations of HPT treatment, the tensile plastic strain was increased to 0.5% and 0.9%, respectively. Further testing was performed by X-ray diffraction and by differential scanning calorimetry. Following two rotations of HPT treatment, the initially fully amorphous Zr_55.7Ni₁₀Al₇Cu₁₉Co_8.3 exhibited significantly increased free volume and a small volume fraction of nanocrystallites. A further increase in HPT rotation number did not result in an increase in plastic ductility of both alloys. Possible reasons for the different mechanical behavior of nanoscale heterogeneous Zr_55.7Ni₁₀Al₇Cu₁₉Co_8.3 and homogeneous Zr₆₄Ni₁₀Al₇Cu₁₉ are presented.