Application Of A Modified Molecular Interaction Volume Model (M-MIVM) To Partially Liquid Alloys Containing Silver, Gold, Gallium, Copper Or Indium

Activity is of great significance to the quantitative calculation and analysis of thermodynamics in metallurgical processes.Experimental measurement of activity has many difficulties such as high equipment requirements and high difficulty.Using a physical-based thermodynamic model to predict and analyze activity not only greatly simplifies the workload,but also helps to understand and elucidate the mechanism of chemical reactions,and at the same time helps to discover the internal relationships between different physical and chemical phenomena.Therefore,the study of activity is one of the important directions of metallurgical thermodynamics.(1)Alloys-containing silver,gold,and gallium are extensively used in solders,semiconductors,and catalysts.Thus,the further exploration on its thermodynamic properties is necessary.The modified molecular interaction volume model(M-MIVM)was applied in thermodynamic calculations of the liquid alloys containing silver,gold,or gallium,meanwhile its calculating results were compared with that of Redlich-Kister polynomial,the sub-regular solution model(SRSM),Chou's model,as well as the molecular interaction volume model(MIVM).The results show that M-MIVM manifested superiority in activity fitting of binary systems and the activity prediction of the ternary system,such as the mean standard deviations of M-MIVM in asymmetric binary systems were 0.0138,whereas the values for Redlich-Kister polynomial were found as 0.0139.Moreover,the average relative errors for M-MIVM and Redlich-Kister polynomial in 10 ternary alloys were calculated as 20.04% and 32.97%,respectively.The former advantage comes from the introduction of Scatchard-Hildebrand theory in its derivation process,while the latter comes from the essential attributes of local composition model.Finally,the iso-activity curves of all components of the liquid AgCd-In alloy system were predicted by M-MIVM.(2)The M-MIVM was compared with Wilson?NRTL(Non-Random-Two-Liquid)as well as the MIVM in copper,indium binary and multi-component liquid alloys.MMIVM manifested superiority in activity fitting of the 8 symmetric binary systems,the order of the fitting effects of these four models are as follows: M-MIVM(0.0089)>NRTL(0.0246)>Wilson(0.0247)>MIVM(0.0377).Moreover,in the 9 multi-component systems,M-MIVM shows certain accuracy,stability and reliability.Finally,the activity of all components of the liquid Ag-Cu-In-Sn alloy system were predicted by M-MIVM.