| Abstract: | 本研究主要是針對新開發之高熵合金AlxCo1.5CrFeNi1.5Ti0.5Moy 孔蝕行為及其電化學特性之研究。並分別改變Al 及Mo 含量以探討這兩種金屬元素在高熵合金腐蝕中所扮演的角色，並與316 不鏽鋼作比較分析。結果顯示高熵合金較316 不鏽鋼在氯鹽環境中有較好的抗一班腐蝕的效果，而高熵合金本身已高Mo 低Al 為優，其排列順序為Al0.1-Mo0.2＞Al0.1-Mo0.1＞Al0.2-Mo0.1。而高熵合金Al0.1-Mo0.1 之臨界孔蝕溫度隨著氯鹽濃度的升高而下降。由金相顯示，本高熵合金可看出合金呈現樹枝狀之微觀結構，在到達臨界孔蝕溫度後其腐蝕鑄造狀態之位址發生在樹枝間。由此說明樹枝與樹枝間合金成份的差異促使臨界孔蝕溫度的下降，高熵合金孔蝕情形亦趨嚴重，並擴大，加深。
This study mainly focused on the electrochemical pitting corrosion behavior of the newly developed high entropy alloy
Al0.1Co1.5CrFeNi1.5Ti0.5Mo0.1. In the experiment, the roles of the Al and Mo content in the high entropy alloy on the corrosion were evaluated and
compared with type 316 stainless steel.The result shows that high entropy Al0.1-Mo0.1 has a better corrosion resistance than type 316 stainless steel in chloride salt solution. As comparing for the high entropy alloy itself.Al and high Mo content has better pitting corrosion resirtain and can be arranged in the following: Al0.1-Mo0.2>Al0.1-Mo0.1>Al0.2-Mo0.1.The critical pitting temperature (CPT) of the Al0.1-Mo0.1 in NH4Cl solution decreases as the chloride salt concentration increases.The metallography of the sample alloy exhibits a typical dendritic cast structure where
pitting occurs effen the specimen reaches the CPT. Once the CPT being surpassed, the pitting situation of the high entropy alloy tends to be serious, accounting for the varing alloy composition in the dencritic regions. |
