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Tham khảo tài liệu 'casting (1998) part 14', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Temperalure C FJ Fig. 11 Calculated and theoretical enthalpy versus temperature curves for cast iron of eutectic composition. Source Ref 18 Fig. 12 Calculated and experimental cooling curves for eutectic gray iron poured in a 50 mm 2 in. diam bar molded in resin bonded sand. Thermocouples were inserted in the middle of the casting. Source Ref 34 Figure 13 gives theoretical predictions of the width of the mushy zone for the cast iron sample shown in Fig. 12. The data are in good agreement with the experimental values for the beginning and end of solidification for the thermocouple in the center of the sample. Time s Fig. 13 Calculated beginning and end of solidification wave fronts for a 50 mm 2 in. diam bar and experimental points for a thermocouple placed at the center of the bar. Source Ref 34 A macro-micro modeling approach can have many structure-related applications. For example macro-micro modeling has been used to attempt to predict the gray white structural transition in cast irons Ref 35 36 . As previously discussed applications of this method can also be extended to the primary phase. Typical calculated and experimental cooling curves for a hypoeutectic Al-8.5Si alloy are given in Fig. 14. Fig. 14 Experimental and simulated cooling curves and calculated fraction of solid for an Al-8.5Si alloy. Source Ref 37 The microenthalpy scheme Fig. 10b has been incorporated into the 3-MOS program an FEM code developed in Switzerland from the library Modulef Ref 19 38 39 . It is essentially based on an enthalpy method. Because the variation of enthalpy is independent of the solidification path once the heat flow is known the macro- and microscopic calculations can be somehow decoupled. At the macro level one can still solve the heat flow equation as mentioned in the section Macroscopic Modeling in this article. Once the variations of enthalpy A H at all nodes are known the solidification path can be computed. As shown in Fig. 10 b the macroscopic time-step Ar can be .