Evaluation System of Soundness of Vacuum Arc Melted Ingots of Ti Alloys

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Vacuum Arc Remelting is most popular for the secondary Ti alloy melting. Quality of Ti alloy ingots is determined during solidification process from a high temperature melt heated by the arc discharge.Prediction of solidification behavior in VAR of Ti alloys is very important to produce sound ingots, because the arc discharge phenomenon and fluid flow are very complex and the basic processes are not fully understood. This research is to numerically calculate the temperature and fluid flow rate distributions and the metal-pool shape, and to provide basic understandings to control the optimum conditions of VAR ingots. In accordance with the magnitude of melting current, there are two regions of occurence of fluid flow dominated by the natural convection and the electromagnetic force. The optimum condition to produce sound ingots exists in the condition that no solid shell forms in the meniscus, fluid flow rate is large and also influenced by the electromagnetic force and the cooling rate is comparatively large.Predicted and observed values of current and Voltage are very good.