本研究探討鐵鈷鎳鉻基高熵合金於液態鋁湯及空氣中之高溫腐蝕行為以評估其用作盛鋁用容器材料之可行性。本研究中所使用之高熵合金為含鐵、鈷、鎳及鉻四種元素，且具有等莫耳之合金 (代號為H)選擇性添加1~1.5莫耳之錳和(或)鋁元素，形成代號為H-xMn-yAl之合金，其中x和y分別代表合金中錳和鋁元素之原子百分比濃度。
液態鋁腐蝕之結果顯示，純鐵、鐵鈷鎳鉻等莫耳合金與四種鐵鈷鎳鉻基高熵合金於鋁湯中之腐蝕行為皆呈現線性關係，其腐蝕速率分別為: 純鐵 > H > H-17Al > H-19Mn > H-17Mn-14Al > H-16Mn-21Al，顯示鐵鈷鎳鉻基合金接觸鋁湯後，介面所形成之腐蝕產物無法有效地阻隔鋁液之侵蝕，並且鋁及錳元素的添加對合金抗液態鋁腐蝕性質造成了有害的影響。其中錳元素的添加顯著地促進合金元素擴散進入鋁湯的速率以及增加介面層溶解於鋁湯的速率是合金耐鋁液腐蝕性質降低的主要原因。
高溫氧化之結果顯示，四種鐵鈷鎳鉻基高熵合金的氧化動力學皆遵守拋物線性定律，其中H-17Al為四種合金中抗氧化能力最佳者、H-16Mn-21Al第二、H-17Mn-14Al第三，而H-19Mn最差，顯示錳元素的添加對合金抗高溫氧化性質造成了有害的影響。而H-17Al及H-16Mn-21Al合金表面能夠在高溫空氣中形成連續且附著性良好的富氧化鋁層是合金抗高溫氧化性質顯著提升的主要原因。
從液態鋁腐蝕防護之結果可知，預氧化處理可以有效地提升H-17Al及H-17Mn-14Al合金之耐鋁液腐蝕性質，而合金表面之預氧化層與液態鋁反應形成富鋁之氧化物是合金耐鋁液腐蝕的主要原因。

The object of this study is to investigate the orrosion behavior of FeCoNiCr-based high entropy alloys in molten aluminum bath and in high temperature air and to evaluate feasibility of high entopy alloys for use as the crucible materials for aluminum melts. Alloy design for an experimental FeCoNiCr-based high entropy alloys in this study is based on FeCoNiCr equal-molar alloy (designated as H) by adding Mn and/or Al in 1 to 1.5 molar amounts. Designation for the studied alloys is called H-xMn-yAl with the x and y to indicate the atomic percentage of Mn and Al.
The results of liquid Al corrosion indicated that the corrosion behaviors of all alloys followed the linear law, and the pure Fe exhibited the best corrosion resistance, whereas H the second, H-17Al the third, H-19Mn the fourth, H-17Mn-14Al the fifth, and H-16Mn-21Al alloy the worst, showing the corrosion product layers formed on the FeCoNiCr-based alloys in molten Al provide less protection than that formed on pure Fe and a detrimental effect of Al and Mn in the FeCoNiCr-based high entropy alloys. The doping of Mn in the reaction product layer might either assist the diffusion of the substrate alloying elements through these phases, or enhance their dissolution in molten Al.
The results of high temperature oxidation indicated that the oxidation kinetics of all alloys followed the parabolic law, and the H-19Mn alloy exhibited the worst oxidation resistance, whereas H-17Mn-14Al the third, H-16Mn-21Al the second, and H-17Al alloy the best, showing a detrimental effect of Mn in the present alloys. The H-17Al and H-16Mn-21Al alloy outperformed other Mn-containing alloys owing to its ability to form Al-rich oxides and maintain a continuous, slow-growing, and adherent scale.
In the results of corrosion protection to liquid Al, both pre-oxidized H-17Al and H-17Mn-14Al alloys can effectively improve the resistance to molten Al attack. The microstructure of the oxide scale on the alloy surface changes after immersing in Al melt at 700 oC for 120 minutes and the modified Al-rich scales can cause a increasing of the corrosion resistance of H-17Al and H-17Mn-14Al alloys in molten Al.

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