Thermal expansion of molybdenum in the range 1500–2800 K by a transient interferometric technique

Abstract

The linear thermal expansion of molybdenum has been measured in the temperature range 1500–2800 K by means of a transient (subsecond) interferometric technique. The molybdenum selected for these measurements was the Standard Reference Material SRM 781 (a high-temperature enthalpy and heat capacity standard). The results are expressed by the relation $\begin{gathered} (l - l_0 )/l_0 = 6.0373 \times {\text{10}}^{ - {\text{3}}} - 1.1175 \times {\text{10}}^{ - {\text{5}}} T + 1.3557 \times {\text{10}}^{ - {\text{8}}} T^2 \hfill \\ {\text{ }} - 4.6688 \times 10^{12} T^3 {\text{ + 6}}{\text{.9032}} \times {\text{10}}^{ - {\text{16}}} T^4 \hfill \\ \end{gathered}$ where T is in K and l ₀ is the specimen length at 20°C. The maximum error in the reported values of thermal expansion is estimated to be about 1% at 2000 K and not more than 2% at 2800 K.