PHASE-EQUILIBRIA IN FE-IR-S SYSTEM

The sections Ir-Fe1-xS and Fe1-xS-Ir2S3 in the ternary system Ir-Fe-S are studied by differential thermal, microscopic, and X-ray spectral a nalysis and by measuring the microhardness of individual phases. The s olubility of iridium in iron sulfide depends significantly on the sulf ur content in the sulfide: in the monosulfide (36.5 mass % S), the sol ubility is no more than 0.4 mass %; in the sulfide Fe1-xS, where x = 0 .15, it is similar to 10 mass %. In the section Ir-Fe1-xS, there is a eutectic equilibrium L reversible arrow (Ir, Fe) + FeS at 990 degrees C; in the section Fe1-xS-Zr2S3, a sulfide solid solution is formed and undergoes solid-phase eutectoidal breakdown with increase in the irid ium-sulfide content; iron and iridium sulfides are deposited.