本研究係以能量集中打在金屬鐵上，並且加入表面活性元素硫，使得金屬表面受一集中熱源加熱達到熔融狀態，進而產生鎖孔的暫態熱流行為。
此研究為二維暫態模型，使用相位場法(phase-field method)來模擬金屬鐵表面。在研究中考量了質量方程式、動量方程式、能量方程式，以及相位場函數，不考慮濃度擴散所造成的影響。最後可得到因溫度變化而產生熱毛細力造成之熔區流動，以及鎖孔之現象。

This study focuses on transient heat flow behavior in which centralizing energy on the metal Fe and adding active element S makes metal surface come to a heat molten state and produce a keyhole with centralized heat source.
This flow field is based on two-dimensional transient model, using Phase-field method to simulate metal surface. This study is under considerations of the mass conservation equation, momentum equation, energy equation and the phase-field function, regardless of the impact due to the concentration diffusion. At last it will show the flow of the molten zone caused by temperature, the phenomenon of drilling a keyhole, and the flows in molten zone forced by thermocapillary which is caused by variation of temperature.

論文審定書 .................................................................................................... i
誌謝 ............................................................................................................... ii
中文摘要 ...................................................................................................... iii
Abstract ....................................................................................................... iv
目錄 ............................................................................................................... v
符號說明 ..................................................................................................... vii
圖目錄 ........................................................................................................... x
第一章 緒論 .............................................................................................. 1
1.1 文獻回顧 ........................................................................................ 1
1.2 研究目的 ........................................................................................ 1
1.3 論文簡介 ........................................................................................ 2
1.4 相位場法 (phase-field method) .................................................... 2
第二章數學模型之假設與統御方程式 ..................................................... 4
2.1 基本假設與物理模型 .................................................................... 4
(2.1-1) 基本假設 .......................................................................... 4
(2.1-2)物理模型 ............................................................................ 5
2.2 數學模型與統御方程式 ................................................................ 5
(2.2-1) 相位場函數 ...................................................................... 5
(2.2-2) 連續方程式 ...................................................................... 7
(2.2-3) 動量方程式 ...................................................................... 7
(2.2-4) 能量方程式 .................................................................... 11
(2.2-5) 表面張力方程式 ............................................................ 12
2.3 模型架構與邊界條件 .................................................................. 13
(2.3-1) 模型架構 ........................................................................ 13
(2.3-2) 網格設定 ........................................................................ 14
(2.3-3) 初始值設定和邊界條件 ................................................ 15
(2.3-4) 流程圖 ............................................................................ 16
第三章模擬結果與討論 ........................................................................... 17
3.1 模擬條件 .............................................................................. 17
(3.1-1) 各種材料之基本性質 .................................................... 17
(3.1-2) 基本性質的模擬圖 ........................................................ 18
(3.1-3) 模擬說明 ................................................................................ 21
3.2 結果討論 ...................................................................................... 30
第四章結論與未來展望 ........................................................................... 31
4.1 結論 .............................................................................................. 31
4.2 未來展望 ....................................................................................... 31
参考文獻 ..................................................................................................... 32

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