Experimental and computational study of diffusion mobilities for fcc Ni-Cu-Mn alloys

Based on the available thermodynamic description and experimental diffusivities, the diffusion mobilities of Ni, Cu and Mn for fcc Ni-Cu-Mn ternary alloys have been investigated in the present work. Interdiffusion coefficients for fcc Ni-Mn binary alloys with Mn content up to 60 at% and for Ni-rich fcc Ni-Cu-Mn ternary alloys were measured using diffusion couple method combined with Electron Probe Micro-Analyzer (EPMA) technique. During the assessment of diffusion mobilities by means of the CALPHAD method, experimental interdiffusivities for Cu-rich fcc Cu-Mn-Ni alloys were also taken into account. Comparisons between the results calculated using the diffusion mobilities assessed in the present work and the experimental data show that a good agreement has been obtained for the diffusion data such as the diffusion coefficients, concentration profiles and diffusion paths. Thus it is believed that the diffusion mobilities for fcc Ni-Cu-Mn alloys obtained in the present work can be applied for a wide composition range.