鑄造技術發展已有數千年的歷史，隨著時代進步與環境的變遷，對於材料的特性及強度需求增加，而在金屬凝固過程中，溫度與濃度場的變化則是會影響材料的顯微結構，其中微結構的控制更是改善機械性質及物理特性的關鍵所在。一般的鑄造過程是不易控制其凝固結構之形態，最多只能改變其晶粒大小，而方向性凝固之方法可使得鑄件的微結構沿著某一固定方向成長。
本文以錫鉛合金為測試材料，採三種實驗模式來探討不同冷激銅盒入口水溫、載台下降速率與加熱器溫度，對於方向性凝固之影響。並透過巨、微觀金相組織觀察、冷卻曲線、溫度梯度、鑄件各位置離開加熱區時間與凝固時間的分析，來了解鑄件晶粒尺寸與對晶體成長之束縛控制的情形，以及溫度場的分佈。
本研究進一步以有限差分法與Beck逆運算法為基礎，藉由此方法來逆運算錫鉛合金在方向性凝固實驗中，在軸向底部、頂部與徑向的界面熱傳係數，再以此界面熱傳係數計算鑄件凝固時之溫度場的變化，並與實驗溫測值作比較分析。

The casting skill has been developed for several thousands years. With the time progress and the environmental change, the material application becomes more severe and hence the promotion requirement of material properties and strength increases. In a solidification process of metal, the temperature and concentration fields will affect the microstructures of materials and the influence is the key point of improving the mechanical and physical properties. In a general casting process, it is not easy to control the morphology of solidifying microstructures, in which only the grain size can be easily changed. The scheme of directional solidification can make the microstructures grow along a fixed direction.
In this study, Sn-Pb alloy is used as the testing material and three experimental models of different water temperatures of copper chill, descending speeds of platform and heater temperatures are designed to study their effects on the directional solidification. After the solidification, the macro and micro structures are observed. The effects of these three models on cooling curve, temperature gradient, growth rate, grain size, the constraint of dendrite growth, and temperature distributions are also investigated.
Further, the finite difference method and the Beck inverse scheme are utilized to analyze the temperature variation during the process of directional solidification. At first, the metal/mold interfacial heat transfer coefficients along the axial direction at the bottom and the top of the casting and those along the radial direction on the peripheral surface are estimated inversely based on the measured temperatures during the solidification experiments. With the interfacial coefficients, the temperature field of the casting in the process is calculated numerically and the computed temperatures are compared with the experimentally measured ones.

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