ECAP变形对MWCNTs/AZ31复合材料抗腐蚀性能的影响

Effects of ECAP on the Corrosion Resistance of MWCNTs/AZ31 Composite

摘要:

采用碳纳米管孕育块铸造法制备多壁碳纳米管/AZ31镁基复合材料，经等径角挤压(ECAP)变形后对复合材料在3.5%NaCl (质量分数) 的腐蚀介质中进行静态浸渍试验和电化学极化曲线测定，研究等径角挤压变形工艺对复合材料抗腐蚀性能的影响；利用数码相机、扫描电子显微镜对复合材料腐蚀前后的表面形貌进行观察和分析；并对复合材料的抗腐蚀机理进行分析。结果表明：等径角挤压变形工艺能有效的提高多壁碳纳米管(CNTs)/AZ31复合材料的抗腐蚀性能，经等径角挤压变形4道次后，复合材料的平均腐蚀速率由挤压态的0.6035 mg/(m2·s)降为0.2963 mg/(m2·s)。腐蚀电流密度Icorr由ECAP变形前的3.363 μA/cm2减小到2.269 μA/cm2

Abstract:

Multi-Walled Carbon Nonotubes (MWCNTs)/AZ31 composites were fabricated by joining preform of MWCNTs during melting. The corrosion behaviors of the composites with equal channel angular pressing (ECAP) for different passes were studied by immersion and electrochemical corrosion experiments in 3.5%NaCl (mass fraction) corrosion medium. The effects of ECAP on corrosion resistance of MWCNTs/AZ31 composite were investigated. The surface morphologies of the composites before and after the corrosion testing were observed and analyzed by digital camera and scanning electron microscope (SEM). The results show that ECAP effectively improves the corrosion resistance of MWCNTs/AZ31 composites. After 4 passes-ECAP, the average corrosion rate of MWCNTs/AZ31 composites immersed in 3.5%NaCl corrosion medium for 24 h changes from 0.6035 mg/(m2·s) to 0.2963 mg/(m2·s) and the corrosion current density (Icorr) is decreases from 3.363 μA/cm2 to 2.269 μA/cm2