Experimental Investigation And Thermodynamic Optimization Of The Al-Ni-Sc Ternary System

With its superior comprehensive properties,high strength aluminum alloy has been mainly used in the aerospace field.And with its development,aerospace and military instruments have put forward higher requirements for high-strength aluminum alloy,and the study of dual-phase nano-structure aluminum alloy has become an effective solution.At present,the research on the thermal stability of dual-phase nanostructured aluminum alloy is still in the initial stage,and the related phase diagram thermodynamic database is urgently needed to provide research support.In this work,the isothermal cross sections of Al-Ni-Sc ternary system were determined,and the related thermodynamic optimization calculation was carried out by combining the experiment,First-Principles with CALPHAD.The results of this work are as follows:（1）Using the equilibrium alloy method,the isothermal sections of the Al-Ni-Sc ternary system at 873 K and 673 K were established.The 14three-phase equilibriums at 873 K and 12 three-phase equilibriums at 673K were determined respectively.A total of 7 ternary compounds were found in this system,among whichτ1,τ2,τ3,τ5,τ6,τ7 andτ8 were consistent with related reports.In addition,the low temperature phase Al₄Ni₃ was proved to be stable at 873 K,which complemented the previous work.（2）With the help of the first-principles calculation,the Al-Ni-Sc ternary thermodynamics database was optimized and established based on the binary system thermodynamic parameters in related references.