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Mechanical alloying (MA) is a process that has proven to be a versatile tool to produce nanostructured composites and alloys from normally immiscible materials. The process parameters can be varied to control the degree of alloying and the microstructure characteristics, so it is possible to produce magnetic materials with novel properties. The phase diagrams of Ni–Ag and Fe–Ag show that mutual solubility is very low in both solid and liquid states. However, partial solid solution has been found in these systems prepared by sputtering [N. Kataoka, K. Sumiyama, Y. Nakamura, J. Phys. F: Metal. Phys. 15 (1985) 1405–1411] and also by mechanical alloying [S. Nasu, S. Morimoto, H. Tanimoto, B. Huang, T. Tanaka, J. Kuyama, K.N. Ishihara, P.H. Shingu, Hyperfine Interact. 67 (1991) 681–686]. The ball milling process as a non-equilibrium technique can force the mixing of immiscible systems. We report a study on the Fe–Ni–Ag system by mechanically alloying the individual powders in different compositions Fex–Nix–Ag100−2x (x = 20, 40, 60) and also by preparing the solid solution (Fe, Ni) compound by mechanical alloying the powders for 50 h and then this pre-alloyed powder is further mechanically alloyed with Ag in different proportion to obtain the alloy (FeNi)xAg100−x. The system prepared by the alloying of the three elements show inmiscibility with Ag, but in the pre-alloyed FeNi further addition of silver seems to diffuse into the FeNi lattice indicating a partial solubility of Ag into the FeNi. |
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