Properties of Co-doped N-type FeSi2 processed by mechanical alloying

Abstract

Iron-silicide was produced with a mechanical alloying process and consolidated through vacuum hot pressing. The as-milled powders were of metastable state and fully transformed into the β-FeSi 2 phase through subsequent isothermal annealing. The as-consolidated iron silicides consisted of an untransformed mixture of α-Fe 2 Si 5 and ε-FeSi phases and a partially transformed β-FeSi 2 phase was found in the low density compact. Isothermal annealing was carried out to induce transformation into a thermoelectric semiconducting β-FeSi 2 phase. The transformation behavior of the β-FeSi 2 was investigated utilizing DTA, SEM, and XRD analyses. Isothermal annealing at 830 o C in vacuum led to a thermoelectric semiconducting β-FeSi 2 phase transformation, but some residual metallic α and ε phases were unavoidable even after 96 hours of annealing. The iron silicide microstructures were investigated using SEM and TEM. The mechanical and thermoelectric properties of the β-FeSi 2 materials before and after isothermal annealing are characterized in this study.

Friction and wear properties of Fe–Si intermetallic compounds in ethyl alcohol

“…5. Therefore, it is considered that the bFeSi 2 phase have higher microvickers hardness than aFeSi 2 phase as reported by Ur et al [11]. ball specimens, the Fe-70.5at% Si disk specimens exhibited the lowest friction coefficients 5 min after starting the friction and wear tests.…”

Environmental-friendly thermoelectric materials

“…Iron silicide is considered to have great potential as thermoelectric conversion devices for mid temperature range (230 -630 o C) without any driving mechanism [109]. Among several phases of iron silicide, semiconducting β-FeSi2 has been widely known and well received as TE material for power generators, thermal sensor and optoelectronic applications since 1964 [110].…”