FCC 結構之高熵合金近年被廣泛的研究並發現其優秀之抗輻射性能，但在進行輻照研究時，為了時間成本以及研究人員的輻射安全考量，研究團隊多以離子輻照取代中子輻照，並以 Displacement Per Atom （DPA）作為損傷程度的參考指標。然而，在相同的DPA下，使用不同的離子種類輻照會對材料的性質變化產生影響。
在本研究中，分別使用300 keV，劑量 5x1015 cm-2 的金屬鎳離子，以及190 keV，劑量 8.5x1015 cm-2 的鈍氣氬離子輻照各種不同成分的鎳基合金，產生約 20 DPA 的損傷。結果顯示，鎳離子輻照後之晶格常數有增加的趨勢，但氬離子輻照後則有樣品晶格常數下降；機械性質的部分，氬離子輻照相較鎳離子輻照造成了更嚴重的材料腫脹，並在硬化率的部分也出現不同的趨勢。此外，本研究亦使用氙離子進行極高損傷（~90 DPA）之研究，並發現機械性質的變化並非隨著損傷程度提升而有全然的正相關。NiCoFeCrMn 高熵合金則在面對各種不同的離子輻照，皆展現了良好的微結構與機械性質之穩定性。

FCC structured high entropy alloys have been widely studied in recent years and have been evidenced to have excellent radiation resistance. Yet, in consideration of time and cost of irradiation experiments and the radiation safety of researchers, ion irradiation is often used to simulate the radiation damage caused by neutron irradiation, and Displacements Per Atom (DPA) is used as a reference indicator for damage. However, different ion species could induce diverse impact on the material properties of high entropy alloys even under an approximate DPA. .
In this study, Ni-based alloys of different compositions were irradiated with 300 keV, 5x1015 cm-2 of nickel ions and 190 keV, 8.5x1015 cm-2 of argon ions, resulting in approximately 20 DPA of damage. The results showed that the lattice constant tended to increase after nickel ion irradiation, while the lattice constant decreased after argon ion irradiation in some samples. In addition, xenon ions were also used in this study to investigate the effects of high radiation damage (~90 DPA). The results indicated that the mechanical properties didn’t entirely correlate with the damage level. The NiCoFeCrMn high-entropy alloy exhibited excellent stability in microstructural and mechanical properties under irradiations with various ion species.

摘要 i
Abstract ii
目錄 iii
表目錄 v
圖目錄 vi
1 第一章 緒論 1
2 第二章 文獻回顧 3
2.1 高熵合金 3
2.1.1 高熵合金簡介 3
2.1.2 高熵合金四大效應 4
2.2 輻射損傷 9
2.2.1 輻射引發之孔洞和氣泡 12
2.2.2 輻射造成之差排環 13
2.2.3 輻射誘發偏析（Radiation Induced Segregation，RIS） 15
2.3 輻射引發之機械性質變化 16
2.3.1 硬化效應 16
2.3.2 膨脹效應 18
2.4 高熵合金的輻射損傷 19
2.4.1 抗輻照能力 19
3 第三章 實驗方法與原理 22
3.1 樣品準備 23
3.1.1 熔煉 23
3.1.2 冷加工與退火 23
3.1.3 樣品切割 24
3.1.4 研磨與拋光 24
3.2 離子佈植 25
3.2.1 Stopping and Range of Ions in Matter（SRIM） 25
3.2.2 輻照實驗 26
3.3 材料檢測 26
3.3.1 成分分析 26
3.3.2 硬度試驗 27
3.3.3 表面高低分析 28
3.3.4 晶體結構分析 28
3.3.5 缺陷分析 29
4 第四章 結果與討論 30
4.1 實驗結果 30
4.1.1 成分分析 30
4.1.2 SRIM 模擬結果 31
4.1.3 材料體積膨脹 34
4.1.4 材料硬化 43
4.1.5 結晶性與晶格常數 49
4.1.6 微結構影像 56
4.2 討論 64
4.2.1 試片成分複雜度之影響 64
4.2.2 不同離子源的影響 66
5 第五章 結論與未來工作 68
5.1 結論 68
5.2 未來工作 69

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