Electrical-resistivity Measurements of Liquid Fe–C Alloys Using the Four-terminal Method

抄録

Electrical-resistivity measurements of liquid Fe–C alloys were attempted using a new probe developed on the basis of the four-terminal method. The four graphite electrodes (except their ends) were covered with alumina tubing and were combined together with an outer alumina tube such that the sample diameter was determined by the outer tubing. The as-prepared probe was dipped into the liquid samples for measuring their resistivity. With the aim to confirm the reliability of the technique, the probes were firstly used to measure the electrical resistivity of liquid Ga and Sn samples. Subsequently, electrical-resistivity measurements were conducted for Fe-4.31mass%C and Fe-4.57%C samples at ca. 1585 K; these measurements yielded values of 1.48×10⁻⁶ and 1.58×10⁻⁶ Ω·m, respectively. A comparison with the reported data suggests that the electrical resistivity of liquid iron progressively increased with the carbon concentration up to 3 mass%, beyond which it showed a drastic increase. This resistivity change might have occured because of the structure of the liquid Fe–C alloy.