Thermodynamic interactions of niobium and molybdenum on titanium in liquid iron were studied in the temperature range of 1873$1973 K by measuring the effects of niobium and molybdenum on the solubility product for TiN formation in liquid iron using the metalnitride-gas equilibration technique. The experimental results were thermodynamically analyzed using Wagner's interaction parameter formalism to determine the first-order interaction parameters of niobium and molybdenum on titanium in liquid iron as 0:0495 AE 0:0049 and 0:01 AE 0:0026, respectively, at 1873 K. Temperature dependence of these parameters was also determined as follows.

Two Molar ratios 1 : 1 and 1 : 2 of AR grade nickel oxide and iron oxide powder was mixed and compacted. The fired compacts were isothermally reduced in pure hydrogen at 500, 550, 600 and 650 C. Based on thermogravimetric analysis, the reduction behavior and kinetics reaction mechanism were studied comparatively for the different mixed oxides ratios. The initial fired powder and the various reduction products were characterized by XRD, SEM, TEM and reflected light microscope to reveal the effect of hydrogen reduction on composition and microstructure of produced Ferronickel alloy. Synthesis of nanocrystalline Fe 1Àx Ni x alloy with 33 and 20 at% Ni for reduction of 1 : 1 and 1 : 2 NiO/Fe 2 O 3 ratios was detected respectively. The activation energy values were calculated from Arrhenius equation and the approved mathematical formulations for the gas solid reaction were applied. It was found that for NiO/Fe 2 O 3 of both 1 : 1 and 1 : 2 ratios, the initial reduction stages is controlled by the combined gaseous diffusion and interfacial chemical reaction mechanisms while at the final reduction stages the reaction is controlled by the interfacial chemical reaction mechanism.