An experimental investigation of the Fe-Ni-Sb ternary phase diagram

The ternary system Fe-Ni-Sb has been investigated in the region between 42 and 100 at.% Sb using conventional methods including DTA, X-ray techniques, metallography, and electron probe microanalysis (EPMA). A continuous solid solution was found to exist between the NiAs(B8)-type phases Fe1+xSb and Ni1+/-xSb, whereas the marcasite-type phase FexNi1-xSb2 is only stable in the ranges 0.50 less than or equal to x less than or equal to 1.00 and 0.00 less than or equal to x less than or equal to 0.03, respectively, A skutterudite-type compound FeNiSb6-isotypic with CoSb3-was found to decompose peritectically at 642 degrees C, An isothermal section of the phase diagram was studied at 600 degrees C by X-ray powder diffraction using the Guinier technique, and the lattice parameters of FexNi1-xSb2 and (FeyNi1-y)(1+/-x)Sb were determined as a function of composition, Several samples were investigated by microprobe analysis to fix the phase boundaries of the (FeyNi1-y)(1+/-x)Sb-phase. Four invariant ternary reactions were found in the Sb-rich part of the phase diagram, all of them within the narrow temperature range between 615 and 642 degrees C, The results of the DTA measurements were also used to construct the liquidus surface in the entire composition range investigated, All experimental information was combined with literature data to yield a complete ternary phase diagram in the composition range between 42 and 100 at.% Sb.