Control of scale effects in the localized anodic oxidation of aluminium based materials – lokO

阳极氧化层被广泛用于铝产品的磨损和腐蚀保护以及其部件的装饰目的。这些弹性层是通过电化学方法制造的。到目前为止，整个阳极氧化过程要么是大规模实现的，要么是局部实现的，在这种情况下，需要在电解浸泡槽中进行广泛的掩蔽。对于金属和塑料等多种材料的复杂部件或组件，不应为改变所有子区域的表面特性(如磨损、摩擦和硬度)而进行阳极氧化，因为这可能会导致不希望看到的破坏效果。只有在阳极氧化区域的尺寸灵活变化的情况下，才能排除由此造成的塑料损坏。由于缺乏资源和能源效率高的工艺，还不可能在部件上生成局部氧化层。此外，众所周知，多相铝基基板材料存在与工艺相关的挑战，需要定制的阳极氧化策略。由于自由电解射流的应用，局部阳极氧化层的制造是可行的。自由电解射流电化学加工是一种将电化学过程本地化的技术，到目前为止一直被用于电化学材料去除，即所谓的Jet-ECM。第二个项目阶段的总体目标是研究和实验实现各种工业铝合金的均匀、几何形状尖锐的表面结构，并具有高抗摩擦学载荷的能力。通过增加喷射基阳极氧化的本地化程度，可以产生局部多孔的阳极氧化层。至少5微米的局部氧化点的层厚度应超过精细分割、亚微米和微米尺度的金相成分的尺寸。此外，还应通过模拟辅助控制组织成分的转变行为，在非均匀变形合金上实现均匀氧化物的形成。

Anodic oxide layers are widely established for the wear and corrosion protection of aluminum products as well as for decoration purposes of their components. These resilient layers are manufactured electrochemically. So far, the whole anodizing process has either been realized on a large scale or locally, in which case extensive masking was required, in an electrolytic immersion bath. Regarding complex components or assemblies of several materials such as metal and plastic, anodizing should not be performed for the modification of the surface properties (e.g. wear, friction, and hardness) of all subareas, since it might induce undesired damaging effects. The resulting damage of the plastic can only be excluded if the dimensions of the areas which are to be anodized are flexibly variable. Due to the lack of resource- and energy-efficient processes, the generation of local oxide layers was not yet possible on components. Furthermore, it is well-known that multi-phase aluminum-based substrate materials entail process-related challenges and require customized anodizing strategies. The manufacture of local anodic oxide layers is feasible due to the application of the electrolytic free jet. Electrochemical machining using the electrolytic free jet represents a technology for the localization of electrochemical processes, which has thus far been used for electrochemical material removal, the so-called Jet-ECM.The overall goal of the second project period is the investigation and experimental realization of homogeneous, geometrically sharp-contoured surface structures with high resistance against tribological load for a wide range of technical aluminum alloys. By increasing the localization of jet-based anodizing, locally porous, anodic oxide layers are to be produced. A layer thickness of the local oxide spots of at least 5 µm shall be realized to exceed the dimensions of finely divided, sub-microscaled and microscaled, metallographic constituents. In addition, the homogeneous oxide formation on inhomogeneous wrought alloys shall be realized through simulation-assisted control of the transformation behavior of the structural constituents.