Thermodynamic Calculation Of Phase Equilibria In Some Co-based Ternary Alloys

At present,the γ’ precpitate alloy and Heusler alloy is one of the important research fields of Cobalt-based alloys.Due to lack of theoretical guidance,most of the research have Costly research and development cycle.CALPHAD(CALculation of PHAse Diagram)is an useful method to predict material organization based on the thermodynamic database.In recent years,our research group has carried out a large number of experimental studies on the phase diagram of the above Cobalt-based alloys.In this paper,the thermodynamics optimization and calculation of the Co-based systems are carried out by CALPHAD method.In order to improve the thermodynamics database of Co-based alloys.The main research results are as follows:(1)Based on the relevant experimental information of Co-W binary system,a set of thermodynamic parameters for recalculating Co-W system was modified by using the Calphad method.Thus,the thermodynamic model of Co7X6 Compound in the Co-based system was unified.(2)Based on the relevant experimental information of present work and literatures,the Co-V-X(X:Mn,Nb,Sn)ternary system has been performed by using CALPHAD method.The calculated results are in good agreement with the experimental data.The phase boundary of fcc phase separation(miscibility gaps)in the Co-V-Mn ternary system has been performed.(3)Based on the relevant experimental information of present work and literatures,the Co-W-X(X:Nb,Ni)ternary system has been performed by using CALPHAD method.The calculated results are in good agreement with the experimental data.The phase boundary lines of fcc phase separation in the Co-W-Ni ternary system has been performed.(4)Based on the relevant experimental information of previous literatures,the Nb-Si-V ternary system,the important Component of the Co-based alloys,has been performed by using CALPHAD method.The calculated results are in good agreement with the experimental data.