Tailoring the thermal, magnetic and electrochemical performance of 60Fe-40Ni alloys: The pivotal role of Y2O3 dispersoids

The development of high-performance soft magnetic composites is essential for electromagnetic applications operating in corrosive and thermally fluctuating environments. This study aims to investigate the synergistic effect of yttrium oxide((Y 2 O3) 3 ) particles as reinforcement material by 2, 4, 6, and 8 wt% ratios on the structural, magnetic, thermal, and electrochemical properties of a 60Fe-40Ni matrix. Mechanically milled powders were cold pressed under 700 MPa and then sintered at 1100 °C for 1 h under argon flow in a horizontal tube furnace. Y 2 O 3 additions gradually decreased the density, while maintaining a relative density above 90%. X-ray diffraction (XRD) patterns confirmed the stabilization of the face-centered cubic (FCC) γ-(Fe, Ni) structural matrix. Vibrating sample magnetometry (VSM) analysis of the soft ferromagnetic behavior of the base alloy; this behavior is characterized by a saturation magnetization (Ms) of 156 emu/g, attributed to the highly symmetric γ-phase. Electrochemical results identified the 6 wt% Y 2 O 3 composites as the optimum threshold, exhibiting the lowest corrosion rate of 9.39 x 10 −6 mm/year. Bode plots and equivalent circuit models showed that yttria dispersoids increase the diffusion path tortuosity of chloride ions, thus stabilizing the passive film. Higher concentrations above 6% caused localized agglomeration, slightly increasing electrochemical impedance. The (60Fe-40Ni) 0.94 /(Y 2 O 3 ) 0.06 composite exhibits superior magnetic flux, dimensional stability, and corrosion resistance, making it a candidate material for advanced electromagnetic components and sensor cores requiring simultaneous magnetic and electrochemical stability.