本研究主要探討FeCoNiCrCu0.5塊狀高熵合金時效熱處理製程條件之不同環境腐蝕行為。研究結果顯示鑄造狀態的高熵合金經均質化處理，再以時效熱處理製程(350℃, 500℃, 650℃, 800℃及950℃)處理試片，在3.5 wt% NaCl、1N NaOH 和 1N H2SO4水溶液下，而與304L不銹鋼於3.5 wt% NaCl、1N NaOH 和 1N H2SO4水溶液極化曲線比較；於3.5 wt% NaCl水溶液之極化數據比較中，304L不銹鋼得到最低之腐蝕速率、FeCoNiCrCu0.5高熵合金具有最高之腐蝕速率；1N NaOH水溶液之極化數據比較中，304L不銹鋼得到最低之腐蝕速率、FeCoNiCrCu0.5高熵合金具有最高之腐蝕速率；於1N H2SO4水溶液之極化數據比較中，304L不銹鋼得到最低之腐蝕速率、FeCoNiCrCu0.5高熵合金得到最高之腐蝕速率，其中又以FeCoNiCrCu0.5高熵合金經由650℃時效熱處理製程之FeCoNiCrCu0.5塊狀高熵合金具有較高之腐蝕速率，亦即為具有較差之抗蝕性，研判為FeCoNiCrCu0.5高熵合金中富含銅相，而造成偏析的現象，反而造成腐蝕速率加快，抗蝕性變差。

The corrosion behavior of FeCoNiCrCu0.5 high-entropy alloys under various heat-treatment processes and corrosion environments was studied. The heat treatment of the as-cast alloy specimens was carried out at 1050℃ with 1 hour holding time. After water quenching serial heat-treatments at 350℃, 500℃, 650℃, 800℃ and 950℃ with 24 hours holding time were carried out. The corrosion resistance of the specimens has been evaluated by potentiodynamic polarization of immersion tests. The specimen treated at 950℃ exhibits serious corrosion in NaOH and H2SO4 solution due to significant segregation of Cu-riched phase. Because of the active sensitivity zone of appreciable potential difference, the high-entropy alloy was preferentially attacked along the Cu-riched phase.

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