Experimental Investigation And Thermodynamic Calculation Of Phase Equilibria In The Cu-(Co, Cr) Based Ternary Alloys

With the rapid development of the micro-electronics industry,the demand for the high performance copper alloy is much more exigent.Cu-Co and Cu-Cr based alloys with high intensity and conductivity are considered as the potential high performance copper alloy.In order to improve the alloy properties and optimize alloy compositions, it is necessary to obtain the phase diagrams and other basic theory information in the Cu-Co and Cu-Cr based alloys.In this paper,experimental determination and thermodynamic assessments on the phase equilibria of the Cu-Co-X(X:Cr,Mo,Nb,Si,V,W) and Cu-Cr-X(X:Nb,Si, Ta,V) ternary systems were carried out.Major research contents are listed as follows:(1) The phase equilibria on the Cu-Co side in the Cu-Co-X(X:Cr,Mo,Nb,Si,V, W) ternary systems at 800℃,900℃,1000℃and 1100℃have been experimentally determined.(2) The phase equilibria on the Cu-Cr side in the Cu-Cr-X(X:Nb,Si,Ta,V) temary systems at 800℃,900℃,1000℃and 1100℃have been experimentally determined,and the phase equilibria in the Cu-Cr-Nb ternary system at 1100℃, 1200℃and 1300℃have been experimentally determined.(3) On the basis of experimental data obtained by this work and previous reports, the phase equilibria of the Cu-Co-Cr and Cu-Cr-Nb ternary systems have been calculated and optimized.The calculated results are in good agreements with the experimental data.(4) The effects of alloying elements and addition quantity on the miscibility gap of the liquid phase and solidified morphology in the Cu-Co and Cu-Cr based alloys are investigated,and the reason for the difference of the solidified morphology is explained by thermodynamic calculation.The obtained results of each system in this work can be applied to establish the thermodynamic database of Cu based alloys.In addition,the results in this work can provide important theoretical guidance on designing high performance Cu based alloys.