Abstract
For the precise measurement of the electrical resistivity of molten metals at high temperature, the fourprobe method has been improved by use of a newly designed cell in which the four electrodes made of the same material as the specimen were installed.
The results of the preliminary experiment on molten tin and copper were in excellent agreement with those of the previous studies by other investigators, and it was proved that “the improved four-probe method” was quite suitable for the measurement of the electrical resistivity of molten metals at high temperature.
The electrical resistivity of molten iron, cobalt and nickel, obtained in the temperature range from melting point to about 1 660°C (iron) and 1 620°C (cobalt and nickel), showed a linear dependency on temperature as represented by the following equations.
Fe: ρ (μΩ·cm) =0.0154t (°C) +112.3
Co: ρ (μΩ·cm) =0.0192t (°C) +91.8
Ni: ρ (μΩ·cm) =0.0116t (°C) +70.2
Probable error in the measurement was estimated to be about ±0.2%. The ratio of the resistivity of the liquid metal (ρl) to the solid metal (ρs) at melting point was evaluated to be 1.06, 1.14 and 1.40 for Fe, Co and Ni respectively.
