钇和锶的添加对Mg-14Li-1Al合金的电化学性能的影响(英文)

Effects of Yttrium and Strontium Addition on Electrochemical Behavior of Mg-14Li-1Al Alloys

制备了Mg-14Li-1Al(LA141),LA141-0.3Y,LA141-0.3Sr和LA141-0.3Y-0.3Sr合金,采用动电势极化曲线,恒电势电流-时间曲线,交流阻抗技术以及扫描电子显微镜等手段测试了这些合金在0.7 mol/L氯化钠溶液中的电化学性能。研究了氧化镓作为电解液添加剂对镁合金恒电势放电性能的影响。结果表明:在有与无氧化镓的情况下,合金的电化学活性和利用效率都按照以下顺序递增:LA141<LA141-0.3Sr<LA141-0.3Y<LA141-0.3Y-0.3Sr,电解液中添加氧化镓分别将放电电流密度和利用效率提高了至少4%和13%。交流阻抗测试结果表明合金的极化阻抗按照以下顺序递减:LA141>LA14-0.3Sr>LA141-0.3Y>LA141-0.3Y-0.3Sr。扫描电子显微镜观察发现,镁中添加Y和Sr可以阻止合金表面浓密氧化物的生成并且可以加快其在电解液中的脱落。在提高镁合金电化学性能方面,Y的作用比Sr的作用强,当Y和Sr同时添加进镁合金中,效果都将比单独添加Y和Sr的任何一种更好。LA141-0.3Y-0.3Sr表现出了最好的电化学活性和利用效率,而且合金表面的放电产物也最疏松。

Mg-14Li-1Al （LA141）,LA141-0.3Y,LA141-0.3Sr and LA141-0.3Y-0.3Sr alloys were prepared and their electrochemical behavior in 0.7 mol/L NaCl solutions was investigated by means of potentiodynamic polarization,potentiostatic current-time and electrochemical impedance spectroscopy measurements as well as by scanning electron microscope examination.The effects of gallium oxide as an electrolyte additive on the potentiostatic discharge performances of these magnesium alloys were studied.The discharge activities and utilization efficiencies of these alloys increase in the order：LA141＜LA141-0.3Sr＜LA141-0.3Y＜LA141-0.3Y-0.3Sr,both in the absence and the presence of Ga2O3.The addition of Ga2O3 into NaCl electrolyte solution improves the discharging current of the alloys by more than 4％ and enhanced the utilization efficiencies of the alloys by more than 13％.Electrochemical impedance spectroscopy measurements show that the polarization resistances of the alloys decrease in the following order：LA141＞LA141-0.3Sr＞LA141-0.3Y＞LA141-0.3Y-0.3Sr.Scanning electron microscopy indicates that the alloy elements Y and Sr can prevent the formation of dense oxide film on the alloy surface and accelerate the peeling off the oxide products.In the respect of improving the electrochemical performance Y is more obvious than Sr and it is the most significant when Y and Sr are alloyed in magnesium at the same time.LA141-0.3Y-0.3Sr exhibits the best performance in terms of activity and utilization efficiency and the most loose oxide products on alloy surface.