在濕砂模鑄造過程之熱傳模式分析中，砂模與金屬界面熱傳情形是一關鍵性的問題，若無法妥善地處理此界面條件，會直接影響分析的結果。由於濕砂模與鑄件間非為緊密接觸，在模與金屬界面之熱傳方析中，需要一界面熱傳係數h來估算金屬的界面熱束，但是界面熱傳係數是一個未知值，無法單純以實驗或理論的方法獲得，目前的研究都是使用逆運算法算出界面熱傳係數。不過在金屬凝固時之潛熱釋放與濕砂模中之水份的汽化和水蒸氣之凝結會造成溫度計算的困難，如果在凝固時有過冷產生，其計算的困難度就更高，因此本文提出總容量法、外插法、修正總容量法和銅塊法，以簡易之方式估算出砂模與金屬界面熱通量及界面熱傳係數，以利於鑄造凝固過程的熱傳分析。並利用FIDAP軟體模擬分析整個鑄件鑄造過程，在凝固熱傳分析方面可以驗證修正總容量法、總容量法和外插法的可行性。另外，也運用FIDAP模擬分析鑄件在澆注時的流場和充填情形，可作為澆鑄溫度和速度與排氣設計的參考，因而可避免產生充填不足或孔洞等缺陷。

In the heat-transfer analysis of a green sand mold casting process, how to grasp the heat-transfer condition at the sand-mold/metal interface is a key problem. Not manipulated properly, it will directly affect the final result of the analysis. Because it is not perfect contact at the interface, the analysis needs an interfacial heat transfer coefficient to compute the heat fluxes from the metal to the sand mold at the interface. The heat transfer coefficient for a given casting process is unknown. No general formulas or easy ways can be applied to obtain the heat transfer coefficient for any kinds of mold/metal interface. In the literature, inverse methods were generally applied to estimate the interfacial heat transfer coefficient. However, the latent-heat release of metal solidification and the evaporation heat of moisture and the condensation of vapor in the sand mold make the calculations of inverse methods difficult to compute interfacial heat transfer coefficients, especially for those solidification processes having a significant undercooling and recalescence phenomena. To overcome this difficulty, the lump capacitance and extrapolation and modified lump capacitance and copper chunk methods are proposed in this study to calculate the interfacial heat transfer coefficient for the casting process in a green sand mold. Moreover, the resulting interfacial heat transfer coefficients were put into the FIDAP software to compute the temperature fields of casting during the solidification processes. The computed complete solidification time and cooling curves are quite similar to the experimental ones. Besides, the FIDAP simulation of a filling process can help us to understand the flow field during the process, which can assist the mold design and the quality control of a casting process.

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