Ternary Phase Equilibria in Transition Metal-Boron-Carbon-Silicon Systems. Part III. Special Experimental Techniques. Volume II. A Pirani-Furnace for the Precision Determination of the Melting Temperature of Refractory Metallic Substances.

摘要

An advanced design of a Pirani furnace is presented which allows the precision determination of the melting temperatures of refractory metallic alloys. The method uses resistance heating of a specimen held between two water-cooled electrodes. The temperature of the phase change is determined optically with a disappearing-filament type micropyrometer at a small hole located in the center of the sample. Temperature calibration procedures, as well as methods and tools for the specimen preparation, are discussed. Measurements of the melting points of refractory metals and alloys, as well as of isothermal reaction temperatures in binary metal-carbon and metal-boron systems, are presented and compared with earlier data. (Author).