Ultra-precision surface finishing and feature generation on metal additive manufactured components with controlled tool path design

Abstract

Metal additive manufacturing (AM) is a rapidly emerging technology gaining significant attention in industries. The intrinsic advantages of design freedom and mass customization establishes the dominance of AM over conventional methods. In the present scenario, nanofinished metallic surfaces with micro-features forms major requirement in industries for controlling reflectivity, fluid retention capacity and frictional performance of surfaces. However, the existing metal AM technology is incapable to produce high resolution microfeatures over the part surfaces due to restriction in laser spot diameter. Moreover, the fabricated metal AM parts are far different from nominal CAD design model due to form deviations and the presence of excessive surface irregularities. The aforementioned challenges lower the efficacy of metal AM surfaces in optical and tribological applications. Thus, a secondary surface post-treatment method is inevitable to overcome aforementioned limitations. Therefore, the present study proposes a hybrid method combining metal AM with ultra-precision surface finishing to achieve nanofinished features on customized metal AM components. The unmelted powder particles and other surface irregularities were eliminated through multiple finishing passes which ultimately yielded a surface finish of ∼ 49 nm. Based on designed tool path, micro-feature generation was successfully accomplished on metal AM surface with minimal deviations in the geometric profile of the feature.