晶须增强纯铝基复合材料表面腐蚀形貌的原子力显微术观察

利用原子力显微镜观察了纯铝基复合材料早期腐蚀过程中表面形貌的变化特征，研究了SiCw/Al和Al18B4O32w/Al两种复合材料的腐蚀行为，结果表明，两种复合材料在3.5%NaCl溶液中具有明显的点蚀倾向，且随腐蚀时间的增加，点蚀抗的尺寸显著增大，观察发现晶须与基体的界面是腐蚀易于发生的地方，点蚀首先在晶须的端部产生，随后沿着晶须与基体的界面扩展，SiCw/Al和Al18B4O33w/Al复合材料的界面腐蚀机制存在较大的差别，这主要是由于二者界面结合状态不同造成的。

ATOMIC FORCE MICROSCOPY OBSERVATION OF CORRODED SURFACE OF WHISKER REINFORCED PURE ALUMINUM MATRIX COMPOSITE

The characters of surface morphology of pure aluminum matrix composites were observed by atomic force microscope (AFM) during the early stages of corrosion. The corrosion behavior of the interface between whisker and matrix was studied, and the corrosion features and behavior of the matrix far away the whisker was also investigated by AFM for both of SiCw/pure Al and Al18B4O33w/pure Al composites. The results indicated that two composites could occur pitting in 3.5%NaCl solution, and the size of the pit increased with increasing corrosion time. The investigation of AFM revealed that corrosion occurred preferentially at the interface between the whisker and matrix, and pits formed at the end of the whisker and propagated along the interface easily. The corrosion mechanism of interface is different for both of SiCw/pure Al and Al18B4O33w/pure Al composites because the interface bond states of two composites are different.