THE TENSILE STRENGTH OF SOME REFRACTORY METALS AT HIGH TEMPERATURES
The tensile strengths of the refractory metals niobium, tantalum, tungsten, and molybdenum were measured in the range 0 to 2300 deg C. Up to 800 C a standard Hounsfield tensometer was used, but from 800 to 2200 deg C the measurements were made in a carbon-tube vacuum furnace. The behavior of these metals was comparable in every respect, at equivalent homologous temperatures, with that of the lower-melting-point metals. The upper temperature limit was imposed by a reaction between carbon vapor from the furnace tube and the specimen. Above 2000 deg C a carbide was formed on the surface and diffused into the specimen, thereby affecting the mechanical properties appreciably. (auth)
We study the basic properties of tensor random fields (TRFs) of the wide-sense homogeneous and isotropic kind with generally anisotropic realizations. Working within the constraints of small strains, attention is given to antiplane elasticity, thermal conductivity, classical elasticity and micropolar elasticity, all in quasi-static settings albeit without making any specific statements about the Fourier and Hooke laws. The field equations (such as linear and angular momentum balances and strain–displacement relations) lead to consequences for the respective dependent fields involved. In effect, these consequences are restrictions on the admissible forms of the correlation functions describing the TRFs.