Computer Simulation of Spinodal Decomposition in Fe–Cr–Ni Ternary Alloys and Fe–Cr–Mo–Ni Quaternary Alloys

Abstract

Numerical simulations of phase separation in Fe-Cr-Ni ternary alloys and Fe-Cr-Mo-Ni quaternary alloys similar to ferrite phases in duplex stainless steels were performed with using of the Cahn-Hilliard equations. A new numerical model based on the Gauss-Seidel and Newton-Raphson methods were utilized to obtain efficient and accurate solution.We obtained that small addition of Ni retard phase separation of Cr in Fe-Cr-Ni ternary alloys. The simulation results on behavior of Mo and Ni in Fe-Cr-Mo-Ni ternary alloys were quite similar to Mo in Fe-CrMo and Ni in Fe-Cr-Ni ternary alloys. It is known that behavior of Mo or Ni along the trajectory of the peak tops of Cr concentration is determined by the sign of second derivative of Cr and Mo or which of Cr and Ni. The effect of Ni on the peak height of Cr in Fe-Cr-Mo-Ni quaternary alloys is similar to which in FeCr-Ni alloys.Numerical simulation results on the variation of peak height of Cr are qualitatively in good agreement with those obtained by the Atom-Probe-FIM.

Electrolyte pH dependence of composition, roughness parameters, particle diameter and magnetic features of nanostructured Fe‐Co‐Ni/ITO deposits prepared by electrochemical deposition method

“…These results are consistent with the results reported in previous and recent studies. 27,28,30 However, different compositional reports according to the electrolyte pH were also documented in the literature. 26,31 In this research, we also examined whether abnormal codeposition occurs during the ECD process of the deposits.…”

“…In addition, the deposit fabricated at low electrolyte pH of 2.5 had slightly higher Fe and Co contents, but lower Ni content compared to the deposit electrochemically manufactured at the electrolyte pH of 4.0 and electrolyte temperature of 25 • C. 28 Previous studies investigated the influence of the electrolyte pH on the composition and current efficiency of the ternary ferromagnetic alloy films electrochemically fabricated from chloride-sulphate-tartaric acid electrolyte on Si/Ti/Cu substrates 27 and from sulphate electrolyte on titanium substrates. 30 These studies showed that the Fe and Co contents increased, but the Ni content decreased in electrochemically deposited Fe-Co-Ni deposits as the electrolyte pH decreased from 3.5 to 2 27 and from 5.2 to 3.2. 30 The composition, structure, magnetic features, and surface morphology using a SEM were also examined in Ni-Co-Fe films electrochemically produced from sulphate based electrolytes on titanium substrates at high (3.6) and low (3.0) electrolyte pH values.…”

“…30 These studies showed that the Fe and Co contents increased, but the Ni content decreased in electrochemically deposited Fe-Co-Ni deposits as the electrolyte pH decreased from 3.5 to 2 27 and from 5.2 to 3.2. 30 The composition, structure, magnetic features, and surface morphology using a SEM were also examined in Ni-Co-Fe films electrochemically produced from sulphate based electrolytes on titanium substrates at high (3.6) and low (3.0) electrolyte pH values. 26 An increase in the Fe and Co contents, but a decrease in the Ni content of the Ni-Co-Fe films was reported as the electrolyte pH was increased.…”

“…Apart from these effective coating parameters, the pH of the electrolyte significantly affects the properties of electrochemically produced magnetic materials. [24][25][26][27][28][29][30][31] A decrease in the pH of the electrolyte induces an increase in the hydrogen evolution. This causes a change in the electrochemical conditions near the cathode surface, resulting in a change in the surface structure.…”