硼酸铝晶须增强铝复合材料的电化学腐蚀行为

The electrochemical corrosion behavior of alumina borate whisker reinforced aluminum composite

通过对不同扫描速率下电化学极化曲线的测试,研究了3种晶须体积分数的硼酸铝晶须增强纯铝基复合材料在3.5%NaCl溶液中的电化学腐蚀行为,并利用扫描电子显微镜观察了经极化处理后,复合材料表面的微观组织形貌.研究结果表明,随晶须体积分数的增加,复合材料阳极钝化区域逐渐减小,且相应复合材料表面被腐蚀程度也显著增加,即随体积分数的增加,复合材料发生腐蚀的敏感性逐渐增加.对同种晶须体积分数的复合材料而言,随扫描速率的提高,复合材料阳极极化曲线中钝化区域明显增大,从而表明在较高的腐蚀速率下,复合材料更易于钝化.

Potentiodynamic polarizations were performed to examine the electrochemical corrosion behavior of the Al_(18)B_4O_(33)w/Al composites with various whisker volumes fraction in 3.5%NaCl solution. The surface morphology of the composite after corrosion tests was observed by scanning electronic microscopy (SEM). The results of electrochemical measurement indicates that the anodic passive region reduces with the increase in the volume fraction of Al_(18)B_4O_(33) whisker in the composites, which indicates that the sensibility to pitting for the composite increases with the increase in whisker volume fraction. The anodic passive region reduces with the decrease in the scan rate of potentiodynamic technique (in the same volume fraction of whisker), which shows that the composite can be passivated easily at higher scan rate.