Studies of Etching Microstructures on Metals

这项研究调查了发生在金属和非金属中的局域腐蚀现象。该计划探索决定蚀坑在哪里开始以及它们是如何生长的因素。例如，在铝和其他一些金属中，蚀刻凹坑的侧壁可能会出现氧化物钝化；这会导致蚀刻具有恒定侧壁宽度的深微米大小的空腔。点蚀位置与扫描电子显微镜所确定的表面成分分布相关联。通过系统处理控制的重要变量包括位错亚结构、杂质偏析和空位浓度。为这些研究选择的模型体系是铝在氯化物溶液中的蚀刻。最终目的是利用从这项研究中获得的有关蚀坑起始的信息来预先编程金属表面上的蚀坑的特定图案。

This research investigates localized etching phenomena which occur in metals and nonmetals. The program explores the factors that determine where etch pits initiate and how they grow. For instance, in aluminum and some other metals etch pits can exhibit oxide passivation at their sidewalls; this leads to etching of deep micron-sized cavities with constant sidewall widths. Sites of pitting are correlated with surface composition profiles determined by scanning transmission electron microscopy. Important variables that are controlled through systematic processing include dislocation substructure, impurity segregation, and vacancy concentration. The model system selected for these studies is aluminum etched in chloride solutions. The ultimate goal is to use the information on etch pit initiation gained from this research to preprogram specific patterns of etch pitting on metal surfaces.