Thermal expansion behavior of iron carbide FeC

Harjo, S.   ; Shiota, Yoshinori*; Yonemura, Masao*; Tomota, Yo*; Kamiyama, Takashi*; Umemoto, Minoru*

Iron Carbide FeC (called "cementite") is an important phase for engineering steels. The amount and shape of cementite determine mechanical and thermal properties of the steels. Cementite is also suggested as the major phase in the inner core of the centre of the earth. However, since the cementite single-phase specimen was so difficult to prepare, its physical properties have not been examined well. Recently, the preparation of cementite bulky specimen has been performed by using plasma-sintering with mechanical milling. The lattice parameters of the prepared bulky pure cementite and Mn-alloyed cementite were measured at VEGA-KENS (Time-of-Flight neutron powder diffractometer) in a temperature range from room temperature to 673 K, to determine their thermal expansion coefficients. Results of the measurements will be presented.