Abstract
This work investigates the effects of additive elements on the microstructural evolution, thermal transformation, morphological, and magnetic properties of Ni-Si-rich (Ni₈₀Si₂₀)₉₅M₅ (M = Al, Cu, Zr) ternary alloys. The alloys were manufactured by conventional solidification using an arc-melting system under a vacuum atmosphere. Systematic characterizations were carried out through a combined study of X-ray diffraction (XRD), differential thermal analysis (DTA), differential scanning calorimetry (DSC), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), Vickers micro-hardness tester, and vibrating sample magnetometry (VSM). XRD analysis detected the presence of β₁-Ni₃Si and γ-Ni₃₁Si₁₂ phases, revealing variations in peak intensities and crystallite sizes among the alloys, influenced by the third alloying element. Both the XRD and SEM-EDX results confirm that the alloys consist of the intermetallic phases and exhibit compositional homogeneity, with measured values closely matching the nominal compositions. DSC indicated thermal stability between 60–680 °C for all alloys, while DTA traces displayed single or double endothermic peaks between 1074 and 1197 °C. Vickers micro-hardness measurements revealed distinct differences among the Ni₈₀Si₂₀)₉₅M₅ alloys, with values of 613.4, 823, and 882.4 HV for M = Al, Cu, and Zr, respectively, highlighting the strengthening effect of the alloying elements. Magnetic properties such as the remanent magnetization (M_r) and the coercive field (H_c) were calculated from the hysteresis loops, and the results are thoroughly discussed. This work provides meaningful insights for designing, improving, and controlling the parameters of the new Ni-Si-rich ternary alloys with desired properties.

Key words
arc melting, Ni-Si based alloys, ternary alloys, microstructure, magnetic properties, minor alloying

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