挤压后硼酸铝晶须增强铝复合材料表面的腐蚀特征

CHARACTERISTICS OF CORRODED SURFACE OF EXTRUDED ALUMINUM BORATE WHISKER REINFORCED PURE ALUMINUM COMPOSITE

利用原子力显微镜观察了挤压态Al18B4 O3 3 w/ pureAl复合材料早期腐蚀过程中表面形貌的变化特征 .研究了沿与挤压方向成不同角度截取的Al18B4 O3 3 w/pureAl复合材料在 3 5 %NaCl溶液中的腐蚀规律 .结果表明 :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 .挤压后沿与挤压方向成不同角度截取的Al18B4 O3 3 w/ pureAl复合材料表面腐蚀坑的深度存在差别 .

The changes of the surface morphology of an extruded composite of Al 18B 4O 33 w/pure Al during the early stages of corrosion by 3.5%NaCl solution were observed by atomic force microscopy.The features of corrosion of the composite samples with different normal angles to the extrusion orientation in 3.5%NaCl solution were studied.The results indicated that corrosion occurred preferentially at the interface between whisker and matrix.Pitting occurred frequently at the end of whisker firstly and propagated along the interface between whisker and matrix.The number and size of pits on the surfaces of the extruded Al 18B 4O 33 w/pure Al composite samples are different due to the sample surfaces with various angles to the extrusion orientation of the bulk composite.