合金凝固路徑的預(yù)測
(State Key Laboratory for Solidification Process,
Northwestern Polytechnic University, Xi＇an 710072, China)
摘 要: 使用DTA和LMC定向凝固淬火技術(shù)分別確定了Al-Cu-Zn合金富鋁角的液相面和固/液界面溶質(zhì)分凝因數(shù)。 基于一維平板模型的枝晶幾何形狀描述，使用數(shù)值模型計(jì)算了Al-1.5Cu-3Zn合金凝固過程中的液相濃度和平衡溫度。發(fā)現(xiàn)在平衡凝固條件下， 液相在α相區(qū)內(nèi)結(jié)束凝固， Scheil非平衡凝固條件下的凝固過程在單變量線上結(jié)束，樣品中初生晶相的含量為97.4％，非平衡共晶含量為2.6％； 同時(shí)分析了液相混合條件對凝固路徑的影響。
關(guān)鍵字: Al-Cu-Zn合金； 凝固路徑； 相圖； 數(shù)值模型
Al-1.5Cu-3Zn fromexperimental phase
diagram and numerical model
（State Key Laboratory for Solidification Process,
Northwestern Polytechnic University, Xi＇an 710072, China）
Abstract:The liquidus surface and solute partition coefficience in the Al-rich corner of the Al-Cu-Zn alloy were determined by differential thermal analysis (DTA) and LMC directional solidification and quenching technology.A numerical model for the calculation of solidification path was developed on the basis of the platelike dendrite geometry. The equilibrium solute concentration and liquidus temperature were calculated in the Al-1.5Cu-3Zn alloy.The solidification path ended in the α(Al) phase domain in the case of equilibrium solidification, and the path ended in the liquidus valley for the case of the Scheil non-equilibrium solidification. The volume fraction of the primary phase was 97.4% and that of eutectic was 2.6%.The effect of incomplete mixing of the rejected solute on the solidification path was also discussed.
Key words: Al-Cu-Zn alloy; solidification path; phase diagram; numerical
