碳纳米管对AZ31镁合金抗腐蚀性能影响与机制研究

Effects of Carbon Nanotubes on the Corrosion Resistance of AZ31 Magnesium Alloy and Its Mechanism

摘要:

研究碳纳米管对镁合金抗腐蚀性能的影响，在氩气保护下，采用搅拌铸造法制备碳纳米管增强AZ31镁基复合材料，观察并分析其显微组织，并进行盐水静态浸渍试验，研究碳纳米管的加入量对复合材料在3.5%NaCl(质量分数, 下同)溶液中腐蚀行为的影响，测试浸泡过程中3.5%NaCl介质的pH值变化；利用扫描电子显微镜对复合材料腐蚀形貌进行观察和分析；并对复合材料的抗腐蚀机制进行分析。结果表明：碳纳米管的加入能有效地提高复合材料的抗腐蚀性能，当碳纳米管加入量为1.5% (质量分数)时，平均腐蚀速率由AZ31基体3.2068 mg/(m2·s)降为1.1069 mg/(m2·s)

Abstract:

Carbon nanotubes (CNTs)-enforced AZ31 magnesium-based composites were fabricated by stirring-casting under the protection of Ar. Their microstructure was observed and the effect of CNTs addition on the corrosion resistance of AZ31 magnesium alloy was studied by immersing all the samples in 3.5wt% NaCl solution. The change of pH value was tested during the immersing progress. The fractographs were observed and analyzed via scanning electron microscope. Corrosion resistance mechanism of CNTs/magnesium composites was researched. The results show that CNTs addition can increase the corrosion resistance of the composites effectively. Corrosion rate changes from 3.2068 mg/(m2·s) to 1.1069 mg/(m2·s) with 1.5wt% CNTs addition