本研究是探討無探針摩擦攪拌點銲過程中材料流動與溫度之行為，利用有限差分法來模擬分析銲接過程中之材料流動與溫度變化，並與實驗所量測之溫度及塑性流動現象相互比較。使用圓柱座標來建立三維穩態摩擦攪拌焊接製程之模型。理論模擬則使用流體力學基之模型，同時求解連續方程式，動量守衡及能量守衡方程式。

過去之研究有關工件緊鄰工具之表面速度大部分均假設為已知，本研究分成兩部分，其中純滑動部分，所假設材料之表面速度為零，純黏滯與部份黏滯的則假設表面速度為未知，工件表面速度計算則使用施加剪應力(τ )與黏性剪應力相等。黏滯與部份黏滯之施加剪應力則使用(1.3)式表示。最後探討施加壓力或擠壓力(plunge force)與工具轉速對工件溫昇及黏滯比之影響。研究中發現工件材料開始產生流動時並不一定是由溫度高的點開始發生，而是與摩擦係數、壓力皆有關係。另外亦發現黏滯發生的方向是由工件中心往肩部邊緣，並且在肩部邊緣要達到全滯狀態，在實驗上幾乎是不可能發生的。

The present study was to investigate the friction stir spot welding (FSSW) process, material flow and temperature behavior without probe,using Finite Difference Method to simulate and analyze the material flow and temperature changes and compare with experiment in the welding process. Use cylindrical coordinates to create a three-dimensional steady-state friction stir welding process model. The theoretical simulation of fluid dynamics based model, while solving the continuity equation, momentum conservation, and energy balance equations.
The speed of surface close to the workpiece are assumed to be known in past studies. This study is divided into two parts, Where in pure sliding portion, assuming that the surface speed of the material is zero, partial sticking is assumed that the surface speed is unknown,
The calculation of surface speed on workpiece let the shear stress of the tool equal to viscous shear stress of material. Finally, we discuss the temperature rise and the effect of sticking ratio by pressure or plunge force on the workpiece.
The study found that start generating the material flow of the workpiece is not always occur by high temperature point, but with the friction coefficient and pressure. The study also found that the sticking occurs in the direction from the center of the workpiece to the shoulder edge. In the experiment ,the state to achieve full sticking in the shoulder edge, is almost impossible happen.

中文摘要 ii
英文摘要 iii
總目錄 iv
圖目錄 vi
表目錄 viii
符號說明 ix
第一章　緒論 1
　　1.1摩擦攪拌點銲概述 1
　　1.2 文獻回顧 3
　　1.3 研究目的 8
　　1.4 論文架構 9
第二章　理論模型 10
　　2.1材料流動方程式 11
　　2.2 熱傳方程式 16
　　2.3工件上表面速度與溫度之計算 21
　　2.4 數值方法 22
第三章　結果與討論 27
　　3.1不同壓力下低碳鋼之溫度與速度分佈 28
　　3.2不同壓力下鋁合金之溫度與速度分佈 36
　　3.3不同轉速下鋁合金溫度與速度分佈 39
　　3.4壓力變化下之工件溫度、扭矩及功率關係 42
　　3.5鋁合金材料流動之理論分析與實驗觀察比較 44
第四章　結論 48
參考文獻 50

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