INFLUENCE OF DISLOCATION STRESS ON THE CORROSION BEHAVIOR OF (111)AND (123) SURFACE PLANE OF ALUMINUM SINGLE CRYSTAL

摘要

The corrosion behaviors of (111) and (123) surface plane of high purity aluminumsingle-crystal were observed after chemical etching. The amount of etching pits on (111) planewas higher than that on (123) plane, and the average distance of the etching pits were 29.13μmand 37.37μm on (111) and (123) plane respectively which should be larger than the averagedistance between dislocation ends where they emerged at the surface. The tensile stresses on (111)and (123) plane were calculated according to the stress fields of different edge and screwdislocations. It is deduced that the etching pits nucleate at the sites where the dislocations meet thesurface, which is promoted by the tensile stresses around the dislocations. The tensile stressfluctuation induced by dislocation stress fields is stronger on (111) plane than that on (123), whichinduces higher nucleation rate on (111) surface plane.