多元高熵合金由於沒有任何一種含量特別多的主要元素,所以其性質不像一般傳統合金,而是具有相當奇特的性質,且其性質隨著元素種類及其莫耳含量之多寡而變異甚大。本計劃即是依照此合金配置觀念,以電弧熔煉法熔配CrFeCoNiVx合金並進行各項性質的分析,其中x為0.5及1,以研究釩變量對CrFeCoNiVx合金微結構、硬度及腐蝕性質的影響。本計畫將研究從軟質FCC晶粒狀組織的CrFeCoNi轉變成較硬的CrFeCoNiVx的合金的變化過程,包括硬度的變化情形,以及對腐蝕行為的影響;以明瞭釩元素在此系列合金中的作用。其中,腐蝕性質的研究會包括極化曲線、以及利用交流阻抗頻譜分析奈奎斯特圖(Nyquist plot)及波德圖(Bode plot),以進一步瞭解腐蝕機制;再根據ASTM規範量測這些合金的臨界孔蝕溫度。本計畫的研究中會以SEM及XRD進行微結構的分析,以硬度試驗機及萬能試驗機進行機械性質的測試,再以恆電流/恆電位儀進行電化學分析,以尋求具有機械性質及耐腐蝕性質最佳組成的合金。
The behaviors of multi-element high entropy alloys are not similar to traditional alloys because they have no special major element. Their unique properties vary with the elements and the mole fraction. The CrFeCoNiVx alloys (x = 0.5 and 1) will be prepared to study the microstructures, hardness, and corrosion behaviors. This project will investigate the microstructures transformation of CrFeCoNiVx alloys, the mechanical properties and corrosion behaviors of these alloys will be also included. The microstructures of the alloys will be examined by SEM and XRD. Also, this project will investigate the polarization behaviors of CrFeCoNiVx alloys. The Nyquist plots and Bode plots of these alloys will be studied by electrochemical impedance spectroscopy (EIS) method. The critical pitting temperatures (CPT) of CrFeCoNiVx alloys will be studied based on the standard of ASTM G150-99.