本論文旨在探討含鉭等莫爾比例合金對氦離子輻射損傷的影響，並加入不銹鋼 420 做為對照。本研究採用氦離子輻照模擬反應器中核能結構材料受中子輻照（n, α）核反應產生的氦累積，使用蒙地卡羅模擬粒子遷移的計算程式 SRIM（Stopping and Range of Ions in Matter）預測氦離子照射的縱深及損傷分佈。經由機械性質分析與微結構觀察，藉此釐清氦離子照射誘發的輻照腫脹和輻照硬化的機制。
當前的結果表明，合金元數與輻照溫度共同影響輻照腫脹和輻照硬化。合金元數、輻照溫度增加會導致輻照腫脹程度降低，高熵合金具有比純金屬、簡單合金更好的抗輻照腫脹能力。一至四元含 Ta 合金在室溫下輻照後硬化程度隨合金元數增加而降低，當輻照溫度增加到某一個臨界值，硬化程度開始下降，且合金元數高的合金具有更高的臨界溫度。五元高熵合金 HfNbTaTiZr 具有特殊的硬化現象，經 673 K 輻照後硬化程度是所有含 Ta 合金中最低的，然而，經 923 K 輻照後，硬度甚至低於未佈植前的原始硬度，稱為輻照軟化。

This study aims to investigate the influence of He ion irradiation on Ta-containing equimolar alloys and compare with stainless steel 420. He ion irradiation was used in this study to simulate the He accumulation of nuclear energy structure materials in reactors through neutron irradiation (n, α) nuclear reaction. The Monte Carlo calculation code SRIM (Stopping and Range of Ions in Matter) was also used in this study to predict the depth and damage distributions of He ion irradiation. Through mechanical property analysis and microstructure observation, the mechanisms of radiation swelling and radiation hardening induced by He ion irradiation can be clarified.
The results show that the irradiation temperature and the elemental number of alloys are correlative to the swelling and hardening induced by irradiation. The increase in elemental number of alloys or the irradiation temperature will decrease the radiation swelling. High entropy alloys have better resistance to radiation swelling than pure metals and binary alloys. For Ta-containing alloys consisting of one to four elements, the hardening induced by irradiation decreases with the increase in constituent elements of alloys and irradiation temperature. As the irradiation temperature increases to a critical value, the radiation hardening begins to decrease, and the alloys composed of greater elements corresponds to a higher critical temperature. The five-element high-entropy alloy HfNbTaTiZr has a special hardening phenomenon. The radiation hardening of HfNbTaTiZr at 673 K is the lowest one among all Ta-containing alloys, and the hardness after 923 K irradiation is even lower than the pristine hardness, and this is the so-called radiation softening.

摘要...............ii
Abstract...............iii
致謝...............iv
目錄...............v
表目錄...............viii
圖目錄...............ix
第一章 序論...............1
第二章 文獻回顧...............3
2.1 高熵合金（High entropy alloys）...............3
2.1.1高熵效應（High entropy effect）...............4
2.1.2 嚴重晶格扭曲效應（Severe lattice distortion effect）..........5
2.1.3 遲緩擴散效應（Sluggish diffusion effect）..........10
2.1.4 雞尾酒效應（Cocktail effect）..........14
2.1.5 耐火高熵合金（Refractory high entropy alloys）HfNbTaTiZr.......15
2.2 輻射損傷..........19
2.2.1 氦氣泡的擴散..............21
2.2.2 輻照效應..........23
2.3 高熵合金的輻射損傷...........26
2.3.1高熵合金的重離子輻射損傷..........26
2.3.2 高熵合金的氦離子輻照..................31
2.4 高熵合金的輻射損傷 MD 模擬..................33
第三章 實驗製程與原理................36
3.1 試片製備.................37
3.2 氦離子照射..................37
3.3 SRIM 電腦模擬計算程式..................38
3.4 微結構觀察............38
3.4.1 掃描式電子顯微鏡 SEM.............39
3.4.2 低掠角 X 光繞射儀 GIXRD................39
3.4.3 電子顯微鏡 TEM...............39
3.4.4 原子力顯微鏡 AFM...............40
3.5 機械性質量測..................41
3.5.1 硬度量測..................41
第四章 結果與討論...................43
4.1 SRIM 模擬..................43
4.2 SEM 分析....................47
4.3 GIXRD 分析.................52
4.3.1 GIXRD 圖譜................52
4.3.2 計算晶格常數..................54
4.4 硬度縱深分佈與 NIX AND GAO 模型.....................58
4.4.1 硬度縱深分布....................58
4.4.2 Nix and Gao Model 修正硬度 H0.....................60
4.5 300 K 氦離子輻照的輻射損傷...................63
4.5.1 輻照腫脹分析.....................63
4.5.2 硬化率分析..................65
4.6 673 K 氦離子輻照的輻射損傷.....................67
4.6.1 氦氣泡分析.................67
4.6.2 輻照腫脹分析....................71
4.6.3 硬化率分析........................72
4.7 923 K 氦離子輻照的輻射損傷........................74
4.7.1 輻照腫脹分析......................74
4.7.2 硬化率分析.....................75
4.8 氦離子輻照溫度對輻射損傷的影響...................77
4.8.1 輻照腫脹分析....................77
4.8.2 硬化率分析..................79
4.8.3 晶格常數分析....................81
第五章 結論與未來工作......................83
5.1 結論...................83
5.2 未來建議....................85

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