在本研究中開發出一項創新且較經濟的擴散接合製程技術，以液膜保護法(Liquid Film Protection, LFP) 取代傳統昂貴的真空設備來保護擴散接合表面，達到鋁合金擴散接合的目的。試片經化學腐蝕後及擴散接合前，均浸在無水酒精(dehydrated alcohol)中保護，防止再度氧化，以夾具夾持二鋁合金板片放置於鹽浴內，當溫度瞬間升高時，無水酒精受熱蒸發，可由界面完全揮發消失，在兩接合面間形成暫態的真空，產生二清潔的表面，以利擴散接合的進行。實驗首先針對高強度AA7475、AA8090、AA5083超塑性鋁合金及AA7075傳統鋁合金的擴散接合製程，進行同質材料的研究與分析。主要係探討擴散接合製程參數：接合溫度、加壓變形量、接合時間、擴散接合材質及LFP方法對擴散接合之影響。實驗結果顯示，材料兩邊之晶粒已穿越原始接合界面而形成新的結晶結構。加壓變形量、溫度及時間的增加均會明顯提升接合強度與接觸比值(contact ratio)，而以變形量的影響較大。為進一步探討液膜保護法對鋁合金擴散接合製程的有效性及可應用性，因此本研究另以異質鋁合金材料進行擴散接合製程，以驗證不同材料的合金成分於液膜保護法的製程中，在接合界面是否確有相互擴散的事實。金相觀察顯示，異質鋁合金擴散接合試片接合界面兩邊均有明顯的擴散層，且不論是異質或同質鋁合金，其晶粒已明顯貫穿接合界面。最後配合SEM觀察分析發現異質鋁合金的合金原子確實是有穿透接合界面，並相互產生擴散作用。實驗結果證明，液膜保護(LFP)法為一有效且經濟的方法來從事鋁合金之擴散接合製程。

The solid-state diffusion bonding process is performed using a economic liquid film protection (LFP) method for AA8090, AA5083 AA7475 and AA7075 aluminum alloys in contrast to the more costly vacuum environment. Diffusion bonding couples made from those aluminum alloys was utilized in this study to elucidate the effectiveness of this LFP method. Both monolithic diffusion bonding systems and bi-alloy diffusion bonding systems were used to verify the presence of inter-atomic diffusion mechanism during the diffusion bonding process.
After chemical etching and prior to bonding, aluminum sheets were immersed in dehydrated alcohol to isolate surface from air. Two sheets were then joined with a special clamp to form a specimen that was pressed and heated in a salt bath. Protecting liquid film completely volatilizes on heating to bonding temperature thus keeping bonding surface free from oxidation. Effectiveness of the LFP method is studied for various combinations of process parameters, the bonding temperature, the amount of press deformation, and the holding time. The contact ratio, contact length on the bonding interface divided by the total length of bonding interface, is identified as an important index for bonding strength.
Metallographic observations reveal that the bonding interface disappears and looks like a wiggled line with scattered discontinuous porous structure for both monolithic and bi-alloy diffusion bonding systems. In the bi-alloy diffusion bonding systems, diffusion layers of the width of 50μm to 80μm are observed along the bonding interface showing an evidence for a complete solid-state bonding. Further scanning electron microscope (SEM) observations and analyses reveal that the alloying atoms in aluminum alloys of the bi-alloy diffusion bonding system do penetrate the bonding interfaces and diffuse into the other side. Results reveal that the LFP is an effective method for the diffusion bonding diffusion process of aluminum alloys.

目 錄
中文摘要 ----------------------------------------------------------- i
英文摘要 ----------------------------------------------------------- iii
誌謝 --------------------------------------------------------------- v
目錄 --------------------------------------------------------------- vi
圖索引 ------------------------------------------------------------- vii
表索引 ------------------------------------------------------------- x
第一章 緒 論 ---------------------------------------------- 1
第二章 文獻回顧 ---------------------------------------------- 7
2.1 超塑性的基本原理 -------------------------------------- 7
2.2 擴散接合的基本原理 ------------------------------------ 10
2.2.1 液相接合 ---------------------------------------------- 14
2.2.2 固相接合 ---------------------------------------------- 15
2.3 擴散鍵結機構 ------------------------------------------ 17
2.4 製程參數的影響 ---------------------------------------- 20
2.4.1 溫度的影響 -------------------------------------------- 20
2.4.2 時間的影響 -------------------------------------------- 21
2.4.3 壓力的影響 -------------------------------------------- 22
2.5 接合材料的表面前處理 ---------------------------------- 23
第三章　　 實驗方法 ---------------------------------------------- 31
3.1 實驗材料 ---------------------------------------------- 31
3.2 實驗設備 ---------------------------------------------- 32
3.3 實驗之製程參數 ---------------------------------------- 32
3.4 擴散接合實驗步驟 -------------------------------------- 36
3.5 金相試片製作與顯微鏡結構觀察 -------------------------- 38
3.6 接觸比值之計算 ---------------------------------------- 38
3.7 晶粒尺寸之計算 ---------------------------------------- 39
3.8 剪力強度測試 ------------------------------------------ 39
3.9 SEM/EDS觀察與分析 ----------------------------------- 40
第四章 　　 結果與討論
4.1 表面處理與液膜保護法 ---------------------------------- 43
4.2 AA7475, AA8090及AA5083三種超塑性鋁合金使用LFP方法進行同
質材料的擴散接合 -------------------------------------- 48
4.2.1 AA7475超塑性鋁合金同質材料的擴散接合 ----------------- 48
4.2.2 AA8090超塑性鋁合金同質材料的擴散接合 ----------------- 61
4.2.3 AA5083超塑性鋁合金同質材料的擴散接合 ----------------- 71
4.3 同質鋁合金接觸比值與剪力強度的關係(線性迴歸) ----------- 80
4.4 　　AA7475, AA8090, AA5083及 AA7075四種鋁合金使用LFP方法進行異質材料的擴散接合 --------------------------------------- 85
4.4.1 金相觀察 ------------------------------------------------ 85
4.4.2 SEM/EDS定性分析-合金分佈曲線 --------------------------- 86
4.4.3 合金原子在不同鋁合金中的擴散係數 ------------------------ 88
4.4.4 機械性質 ------------------------------------------------ 106
4.5 傳統非超塑性鋁合金使用LFP方法進行同質材料的擴散接合 --- 110
第五章 　　　結 論 ------------------------------------------------ 119
第六章 　　　未來尚需進行的工作-------------------------------------- 121
參考文獻 ------------------------------------------------------------ 123
附 錄 ------------------------------------------------------------ 129
(A). 拉伸實驗之等值應力 -------------------------------------- 129
(B). 表面鋅置換法-液相接合 ----------------------------------- 132
(C). 擴散接合機構分析 ---------------------------------------- 137
(D). SEM量測之異質鋁合金合金分佈曲線 ----------------------- 148
(E). SEM/EDS分別針對母材與擴散層進行合金成分測試 ----------- 149
(F). 接合剪力強度與接觸比值之實驗數據 ------------------------ 153
作者簡介 ------------------------------------------------------------ 157
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