Measurement Of CeAlCu Ternary Alloy Melt Inter Diffusion Coefficient And Its Temperature Dependence

Diffusion is a characterization of the mass transfer process of matter on the atomic scale.It plays a key role in many important processes such as the distribution of solute elements during the solidification process.At present,the research on the diffusion behavior of alloy melts is mainly concentrated in the binary system,and the research on the diffusion behavior of the ternary and above alloy systems is quite rare.Therefore,this paper selects Ce Al Cu alloy,a typical amorphous alloy system,to study the diffusion behavior.In this paper,combining the predecessor's long capillary technology,sliding shear technology and the multi-layer translational shearing technology in the early stage of this research group,a device for measuring the diffusion of metal melt by the screw-propelled shear unit method is designed and built.It can effectively prevent the alloy melt from diffusing during the heating and cooling process,and at the same time,it can ensure that the diffusion couple is fully connected,which effectively improves the accuracy of the experimental data.The inter-diffusion coefficients of the pseudo-binary diffusion couples Ce₇₅Al₁₀Cu₁₅-Ce₆₅Al₁₀Cu₂₅ are measured by the screw-pushing shear element method,and the inter-diffusion coefficients of the binary alloy melt inter-diffusion coefficients are solved by the method of solving the inter-diffusion coefficients of the binary alloy melt.It is found that the inter-diffusion coefficient is about 70%smaller than that of Ce-Cu binary alloy melt,and its diffusion behavior is significantly slower.It shows that the addition of Al element has a great influence on the diffusion coefficient of Ce-Cu system.Diffusion experiments of Ce₇₀Al₁₀Cu₂₀ ternary alloy melt at different temperatures were carried out,and the inter-diffusion coefficient was calculated by global optimization algorithm.Combining thermodynamic factors to analyze and discuss its diffusion behavior.The results show that the main diffusion coefficient has a greater impact on the diffusion behavior,and the cross-diffusion coefficient term has a smaller impact on the diffusion behavior at high temperatures.The analysis may be caused by the weakening of the interaction between heterogeneous atoms at high temperatures.Comparing the inter-diffusion coefficients of Ce₇₀Al₁₀Cu₂₀ pseudo-binary and ternary alloy melts with those of Ce₈₀Al₂₀ and Ce₈₀Cu₂₀ binary alloy melts,it is found that the inter-diffusion coefficient of ternary alloy melts is significantly lower than that of binary alloy melts.The coefficient indicates that the addition of the third component slows down the diffusion behavior of Ce-based alloy melt.At the same time,it can be found that as the diffusion coefficient decreases,its ability to form amorphous is enhanced.The research results are helpful to explore the relationship between the diffusion coefficient and the ability to form amorphous.Using computer simulation Ce₇₀Al₁₀Cu₂₀ ternary alloy melt self-diffusion coefficient and experimentally measured mutual diffusion coefficient to analyze and discuss the ternary Darken formula.It is found that the Darken formula cannot accurately describe the relationship between self-diffusion and mutual diffusion,and the role of kinetic factors in the diffusion process of the system cannot be ignored.