臺灣博碩士論文加值系統

本研究探討時效溫度與時間對多元合金微結構(兩種析出物的特徵)、機械性質(硬度、強度、延性)與變形微結構的影響。合金在時效之後可比固溶處理態最多硬化三倍左右。時效溫度越高越快達到尖峰硬度，但尖峰硬度值越低。時效溫度較低者，直到本研究最大時效時間仍未達尖峰硬度。透過時效條件的最佳化，可達到相當優異的降伏強度、抗拉強度與伸長量總體表現。本研究並定量分析合金析出物體積分率、直徑與密度在不同時效溫度隨時效時間之變化，並依此建立模型，可描述析出物粗化過程的微結構變化。基於此模型搭配相關析出強化理論，可成功預測出合金降伏強度的整體變化趨勢，對於降伏強度絕對值的預測也有相當的準確度，而有效建立微結構及機械性質間的關聯。

In this research, we study the effects of aging temperature and time on the microstructure of multicomponent alloys, mechanical properties and deformed microstructures. After aging treatment, alloys harden about three times than the solution treatment. The higher the aging temperature, the sooner reaching the peak hardness, but the lower the value of peak hardness. By optimizing the aging conditions, we can obtain highly excellent behavior of yield strength, ultimate tensile strength and elongation. Also, this work quantitative analysis the volume fraction, diameter and density of precipitates as the varies of aging time and modeling. Based on this model with the theory of precipitation hardening, we succeed forecast the whole change tendency of yield strength, the absolute values of the prediction are quite accurate. Finally, we associate the microstructure and mechanical properties effectively.

誌謝 i
摘要 ii
Abstract iii
目錄 iv
圖目錄 vi
表目錄 x
壹、 前言 1
貳、 文獻回顧 2
2.1 多元合金 2
2.2 多元合金中的獨特效應 3
2.3 多晶材料的強化機制 8
2.4 析出強化機制 13
2.5 析出硬化型多元合金之機械性質及微結構 15
2.6 研究動機 19
第二章參考文獻 20
參、 實驗步驟 22
3.1 實驗設計與流程 22
3.2 合金製備 24
3.3 熱處理 24
3.4 金相製備 24
3.5 拉伸試片製備 25
3.6 TEM試片製備 26
3.7 硬度量測 26
3.8 拉伸試驗 26
3.9 合金晶體結構分析 27
3.10 合金微結構分析 27
3.11 析出相定量分析 28
第三章參考文獻 30
肆、 結果與討論 31
4.1 短時間時效硬化曲線 31
4.2 時效一小時與一天之機械性質及微結構 34
4.3 調整製程使合金機械性質最佳化 46
4.4 長時間時效硬化曲線及析出物成長行為 56
4.5 析出硬化的定量描述與預測 67
4.6 層狀結構對機械性質之影響 74
4.7 變形微結構 78
第四章參考文獻 85
伍、 結論 88

第二章文獻回顧
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