Study Of Atomic Diffusion Mobilities In Fcc Co-Cu-Cr, Fe-Cu-Cr,Ni-Cu-Si Alloys

With the development of material science and technology, the study of material foundation has become a great part of today’s material research. In order to explore and develop new high-performance materials for meeting the high requirement of high property material, the researchers have already combined the study of material foundation with the study of physics, chemistry, mathematics and computer technology using the way of experiment, calculation and simulation tools.This work is aimed to study the atomic mobility of Co based, Fe based and Ni based ternary alloys which have a great value in the industry. The system in the study was: Co-Cu-Cr, Fe-Cu-Cr, Ni-Cu-Si ternary system. Based on the application of engineering, this work is significant for completing the data base of thermodynamics and kinetics for Co based, Fe based and Ni based ternary alloys, it’s also of great importance for design high-performance material. Based on the experimental data and the theory of diffusion, the study get the atomic mobility of fcc Co-Cu-Cr, Fe-Cu-Cr, Ni-Cu-Si ternary alloys with DICTRA calculation, these values will complete the data base of Co based, Fe based and Ni based systems.The main solution for the study of this work is making the diffusion couple which consists by different ingredient elements. After heat treatment, cutting and making metallographic, the experimental date which including the concentration profiles for all diffusion couple will be obtained by detecting the diffusion couple with EPMA. During the data preparation stage, the kinetic and thermodynamic data of relevant element which have been reported such as atom mobility, diffusion coefficient have to be summarized and assessed which will be used for the calculation of atomic mobilities and inter-diffusivites in next step.The calculation solution of DICTRA is introduced in chapter one, the experimental solution and procedure are described as well in chapter two. Based on the experimental data and measured concentration profiles in diffusion couples, the atom mobility and diffusion coefficient in Co-Cr-Ni、 Cu-Co-Fe、 Cu-Co-Ni alloy was calculated and assessed by using DICTRA within CALPHAD framework, which are studied in chapter three, chapter four and chapter five of this work. The comparisons of concentration profiles and diffusion paths for all diffusion couples are presented which shows a good agreement between experiment data and calculated values.