Development and application of inverse heat transfer model between liquid metal and shot sleeve in high pressure die casting process under non-shooting condition

摘要

To predict the heat transfer behavior of A380 alloy in a shot sleeve, a numerical approach (inverse method) is used and validated by high pressure die casting (HPDC) experiment under non-shooting condition. The maximum difference between the measured and calculated temperature profiles is smaller than 3 ℃ , which suggests that the inverse method can be used to predict the heat transfer behavior of alloys in a shot sleeve. Furthermore, the results indicate an increase in maximum interfacial heat flux density (qmax) and heat transfer coefficient (hmax) with an increase in sleeve filling ratio, especially at the pouring zone (S2 zone). In addition, the values of initial temperature (TIDS) and maximum shot sleeve surface temperature (Tsimax) at the two end zones (S2 and S10) are higher than those at the middle zone (S5). Moreover, in comparison with fluctuations in heat transfer coefficient (h) with time at the two end zones (S2 and S10), 2.4-6.5 kW ·m -2 ·K -1, 3.5-12.5 kW ·m -2 ·K -1, respectively, more fluctuations are found at S5 zone, 2.1-14.7 kW ·m -2 ·K -1. These differences could theoretically explain the formation of the three zones: smooth pouring zone, un-smooth middle zone and smooth zone, with different morphologies in the metal log under the non-shot casting condition. Finally, our calculations also reveal that the values of qmax and hmax cast at 680 ℃ are smaller than those cast at 660 ℃ and at 700 ℃ .