| 摘要: | 針對含鎵（Ga）之Al-0.5Mg-0.08Sn合金經退火後，分析其電化學腐蝕之變化，及觀察對微結構(腐蝕型態、第二相等)的影響，旨在了解鎵對鋁負極合金活化機制的作用。結果顯示，隨著鎵含量的增加，分散於晶界的第二相含量增加，這些第二相有助於抑制晶粒粗化的效果，因此導致腐蝕形貌較為均勻。合金中的顆粒狀富Mg相、與鋁基地之間會產生微電偶腐蝕效應。藉由極化曲線（LSV）、和析氫腐蝕測試（HER），觀察到鋁負極合金的活化機制。
此外，此外，當此含鎵(Ga)鋁合金應用於空氣電池負極進行電化學測試時，相較於未添加鎵的合金，Al-0.5Ga-0.5Mg-0.08Sn合金的腐蝕電位（Ecorr）顯得更負值，腐蝕電流（icorr）也較高，但其析氫量也隨之增加，從而影響陽極效率。在3.5wt% NaCl（中性）電解質中，陽極極化曲線顯示出明顯的鈍化區；而在4M KOH（鹼性）電解質中，陽極鈍化區則顯著消失。對於含0.5Ga合金，腐蝕電位從3.5wt% NaCl中的-1.492V降為4M KOH中的-1.946V。隨著鎵含量的增加，溶解過程中的阻抗降低，從而加快了溶解速率並增強了陽極的活化效果。
;The electrochemical corrosion behavior of Ga-containing Al-0.5Mg-0.08Sn alloys after annealing was analyzed, along with the impact on the microstructure (corrosion morphology, secondary phases, etc.), aiming to understand the role of gallium in the activation mechanism of aluminum anode alloys. The results show that with increasing Ga content, the amount of secondary phases dispersed along the grain boundaries increases. These secondary phases help suppress grain coarsening, leading to a more uniform corrosion morphology. A galvanic corrosion effect occurs between the particulate Mg-rich phases and the aluminum matrix. Through polarization curves (LSV), and hydrogen evolution corrosion tests (HER), the activation mechanism of the aluminum anode alloy was observed.
Furthermore, when this Ga-containing aluminum alloy was applied to the anode of an air battery for electrochemical testing, compared to the alloy without Ga, the Al-0.5Mg-0.08Sn-0.5Ga alloy exhibited a more negative corrosion potential (Ecorr) and higher corrosion current (icorr), but the hydrogen evolution rate also increased, which affected the anode efficiency. In a 3.5wt% NaCl (neutral) electrolyte, the anode polarization curve showed a distinct passive zone; however, in a 4M KOH (alkaline) electrolyte, the anode passive zone significantly disappeared. For the 0.5Ga-containing alloy, the corrosion potential dropped from -1.492V in the 3.5wt% NaCl to -1.946V in the 4M KOH. As the Ga content increased, the impedance during the dissolution process decreased, thereby accelerating the dissolution rate and enhancing the activation effect of the anode. |
